Les paysans stockent entre 60 et 80% de la production des grains qui est régulièrement infestée par les insectes ravageurs. Les plantes insecticides méritent dêtre valorisées à travers notamment leur huile essentielle afin de limiter la dépendance des paysans aux insecticides chimiques, largement utilisés au Nord du Cameroun et dont les dangers sont bien connus. Lanalyse chromatographique de quelques huiles essentielles locales, révèle que Cymbopogon citratus (DC.) Stapf. (Poacée), Ocimum gratissimum L. (Lamiacée) et Ocimum suave Willd (Lamiacée) sont constituées respectivement du citral, du thymol et de leugénol à plus de 50%. Les huiles essentielles de Annona senegalensis Pers. (Annonacée), Hyptis spicigera Lam. (Lamiacée), et Xylopia aethiopica (Dunal) A. Rich. (Annonacée), contiennent majoritairement des monoterpènes hydrocarbonés dont lα-phellandrène, lα-pinène, le sabinène et le β-pinène. H. spicigera et X. aethiopica, dont la composition varie suivant lorigine de la plante, sont les plus efficaces contre Callosobruchus maculatus (F.) et Sitophilus zeamais (Motsch.), principaux ravageurs primaires des greniers au Nord du Cameroun. Lactivité insecticide de H. spicigera est marquée par sa teneur en α-pinène (39,0%) tandis que celle de X. aethiopica est due à leffet synergique de ses composés. La volatilité des huiles essentielles nécessite des supports aptes à réguler le relarguage des molécules volatiles. Avec plus de 90% de molécules volatiles libérées en 7 jours, la poudre des infrutescences de X. aethiopica, qui contiennent plus de 5% dhuile essentielle, bien que toxique contre C. maculatus, ne permet pas de réguler et de prolonger la libération des molécules volatiles. Le kaolin testé dégrade lhuile essentielle X. aethiopica tandis que lincorporation de lamidon à la gomme arabique permet de libérer en 7 jours, 40,5 à 55,9% des molécules volatiles suivant la proportion damidon. Cette combinaison est un système qui autorégule le relarguage en deux phases. La première phase a un taux de relarguage élevé qui entraîne un effet « Knock down » sur C. maculatus, et la seconde phase présente un relarguage lent et prolongé qui pourrait, par un effet répulsif, éviter linfestation des grains stockés. Cette étude est une contribution du projet « STOREPROTECT PIC-2003 » à la protection des denrées stockées par lutilisation des ressources locales au Nord du Cameroun.

The construction of diverse molecular architecture conceived and created by Nature, continues to be the most exiting and challenging task to the practitioners of organic synthesis. As a result of refinement in isolation and purification techniques, recent advances in the spectroscopic methods particularly two-dimensional NMR spectroscopy and routine use of single crystal X-ray crystallography, the isolation and structural elucidation of the complex natural products has become a routine exercise. Even those natural products which are present in minute quantity, are being unraveled from the newer and exotic sources such as marine flora and fauna, microbial organisms and insect world. This has been a big boon for the synthetic organic chemists, providing them with increasing number of exciting objectives. The recent advances in the field of natural product synthesis testify to the organic chemists endeavors to meet these emerging challenges. Nature's expertise and virtuosity in creating a phenomenal array of carbocyclic frameworks is most notably highlighted in the terpenoid group of natural products. Indeed, the number and type of carbocyclic skeleta among terpenes continues to grow unabated as more and more natural products are being routinely isolated from the various sources. Thus, various polycyclic natural products bearing new and novel fused assemblies of five, six, seven and eight membered rings and replete with dense functionalization and stereogenic centers are being regularly encountered. The present investigation represents synthetic efforts towards some novel and recently isolated terpenoid natural products. Two main themes have been pursued. The first involves the construction of a functionalized hydroazulene framework employing RCM as the key step and its further elaboration to the 5,7,6-tricyclic framework present in diterpene guanacastepene-A and 5,11-fused bicyclic system present in neodolabellane diterpenes. The second theme explores the synthetic versatility of the well-established photo-thermal metathetic approach to linear triquinanes through its application to the total synthesis of novel and recently isolated natural product cucumin E. It further explores the utility of 5-5-5 fused ring system to access 5-8 system. This strategy has led to the stereoselective total synthesis of natural product asterisca-3(15),6~diene belonging to the rare asteriscane family. The present thesis entitled "Towards the Total Synthesis of Terpenoid Natural Products" describes our endeavors towards the synthesis of 5-7-6, 5-11, 5-5-5 and 5-8 fused natural products and has been organized under four chapters. Chapter I. Studies toward the total synthesis of novel diterpene antibiotic guanacastepene A. Chapter EL Synthesis of the novel 5,11-fused bicyclic framework of neodollabellane diterpenoids. Chapter HI. A Stereoselective total synthesis of the novel triquinane sesquiterpene cucumin E. Chapter IV. Total synthesis of 5-8 ring fused sesquiterpene hydrocarbon asterisca-3(15),6-diene. The Chapter I describes a stereoselective approach towards the construction of the novel 5,7,6-rig fused framework present in the diterpene antibiotic guanacastepene A 1, recently isolated from an unidentified fungus growing on the tree Daphnopsis americana by Clardy et al. Besides its structural novelty, guanacastepene A exhibits impressive activity towards methicilline-resistant Staphylococcus aureus and vancomycine-resistant Entereococcusfaecium. Thus, 1 has evoked an unprecedented attention from the synthetic community and we too were enticed to enter this arena. Scheme 1 (structural formula) The synthetic approach towards guanacastepene A 1, envisage in this study, was revealed through a retrosynthetic analysis which identified hydroazulenic core 2 (AB rings) with requisite level of functionalities as an advanced precursor to which a six membered ring could be annulated through appropriate protocols. The hydroazulene core 2 was to be accessed from the substituted cyclopentenone 4 through the intermediacy of 3 and the former in turn could be prepared from the readily available endo tricyclo[5.2.1.026]deca-3,8-diene-5-one 6, Scheme 1. In this approach to the AB ring hydroazulenic core 2 of 1, some essential requirements were recognized at the outset. These were the setting up the key cis relationship of the angular methyl group at C11 and the neighboring bulky-isopropyl group at C12, installation of a desirable level of functionalization in the five membered ring and a functional group handle in seven-membered ring to Scheme 2 (structural formula) append the six membered ring with requisite functionality. Keeping these considerations in mind, readily available endo-tricyclo[5.2.1.02-6]deca-3,8-diene-5-one 6 with well-established propensity toward reactivity on exro-face was identified to be starting point, Scheme 1. Copper(I)mediated stereoselective 1,4-addition of isopropylmagnesium iodide on 6, followed by sequential a-alkylation with allyl bromide and methyl iodide led to 7 as a single diastereomer and correctly installed the methyl and isopropyl groups in the required cis-relationship, Scheme 2* Retro-Diels-^Ider reaction in 7 under flash vacuum pyrolysis (FVP) liberated the cyclopentenone 8. For the annulation of a seven-membered ring to cyclopentenone 8, recourse was taken to a ring closing metathesis-(RCM) based protocol. Barbier-type addition of 4-bromo-1-butene to 8 in the presence of lithium metal and oxidative transposition of the resulting allylic alcohol with PCC furnished enone 9 in good yield. On exposure to Grubbs' catalyst, enone 9 underwent smooth RCM reaction to deliver the desired hydroazulenic framework 10, Scheme 2. The bicyclic hydroazulenic enone 10 was now poised for the elaboration of functionalities in the context of evolution to the natural product 1. Thus, 10 was elaborated to epoxy alcohol 11 in a three step sequence, Scheme 2. TMSOTf mediated opening of epoxide ring to yield cis-enediol, protection of the resultant diol as an acetonide and allylic oxidation furnished the key enone 12, Scheme 2. Attempts to alkylate the enone 12 to install the C16 methyl group and the precursor side chain for six membered ring annulation failed consistently. Recourse was then taken to a-carboethoxylation in 12 using Mander's reagent proved to be quite effective and further alkylation with methyl iodide furnished 13 as a single stereoisomer with the correct stereochemical positioning of the quaternary methyl group at C8. Intermediate 13 was elaborated to tricyclic framework 14 of guanacastepane A in five steps, by setting up NaOEt mediated intramolecular aldol reaction as key step, for the construction of six membered ring, Scheme 2. In tricyclic cross-conjugated dienone 14, complete carbon framework of the natural product guanacastepene A 1, with a copious disposition of functionalities was realized. Further efforts to transform 14 to 1 were not very encouraging. However a variant of ring C annulation on 12 is being investigated by a colleague in the group to achieve the total synthesis of the natural product. In travails towards 1 and 14, several deviations from the expected course, leading to the new tricyclic structural variants of the biologically promising guanacastepene A 1 were encountered and these findings will also be detailed in this chapter of the thesis. In the Chapter n of the thesis, synthetic studies directed towards the bicyclic framework present in novel neodolabellane type diterpenes like a-and (3-neodolabellenol 17a and 17b isolated from an unknown species of Australian soft coral by Coll et al will be delineated. The readily accessible bicyclic hydroazulenic enone 13, also served as an advanced intermediate for the construction of the 5-11 fused bicyclic skeleton 16 of neodollabellane diterpenoids via an oxy-Cope rearrangement. Elaboration of 13 to the divinyl carbinol 15 and its [3.3] sigmatropic rearrangement (oxy-Cope rearrangement) to 16 and related reactions will be described, Scheme 3. Scheme 3(Structral formula) Chapter III describes the first total synthesis of the sesquiterpenoid natural product cucumin E 26 bearing a novel triquinane framework, and reported recently from the mycelial cultures of agaric Macrocystidia cucumis (Pers ex Fr.) by the groups of Steglich and Anke. Synthesis of 26 was accomplished following an interesting variant of the photo-thermal metathetic approach to linear triquinanes delineated by us sometime ago, Scheme 4. Cucumin E 26 attracted our attention as this sesquiterpene [Scheme 4 (Structural formula)] bears an Interesting biogenetic relationship to the related hirsutane group of linear triquinanes from which it can be derived through the migration of a methyl group. Towards the synthesis of 26, the readily available pentacyclic dione 18 was identified as the key starting material and was elaborated to 19 using FVP (flash vacuum pyrolysis) conditions under which 18 underwent [2+2]-cycloreversion of the cyclobutane ring to furnish the cis, syn, cis-triquinane, Scheme 5. On exposure to base, 19 could be equilibrated through back and forth double bond isomerization to furnish the cis,antecis-isorner 20 in reasonable yield. Attention was now turned towards the installation of the network of four methyl groups present in 26 and relevant functional group adjustments. Catalytic hydrogenation of 20, selective mono-Wittig olefination and subsequent gem-dimethylation furnished olefinic ketone 21. At this stage, the carbonyl group in 21 was sought to be removed and recourse was taken to the Barton deoxygenation protocol to furnish 22, Scheme 5. The next task en-route to the cucumin skeleton was the introduction of the angular methyl group at C7 to generate the complete Cis carbon framework. For this purpose, the ketal group in 22 was deprotected to furnish the ketone 23. Angular methylation in 23 exhibited fair regioselectivity to yield 24 as the major product. The enone moiety in 24 was established through allylic oxidation following the Sharpless catalytic selenium dioxide oxidation followed by PDC oxidation to afford 25. Rh(III)-mediated isomerization of the exocyclic double bond in 25 delivered cucumin E 26, whose spectral characteristics were exactly identical to the natural product as established through direct comparison, Scheme 5. In Chapter IV, the total synthesis of the bicyclo[6.3.0]undecane-based sesquiterpene hydrocarbon asterisca-3(15),6-diene 38, isolated from Lippia integrifolia (Griseb) by Konig et al. and representing the simplest member of the asteriscane family, is described. Our approach to the bicyclo[6.3.0]undecane system was based on the 'carbocyclic ring equivalency' concept. Thus, bicyclo[3.3.0]octane ring system is an eight-membered ring equivalent and tricyclo[6.3.0.02'6]undecane (linear triquinane system) is the latent form of the bicyclo[6.3-0]undecane system through the scission of the central bond as shown in Scheme 6. Following this concept a synthesis of 38 was envisaged from the cfe,syn, cis-triquinane bis-enone 28, readily and quantitatively available from the pentacyclic-caged dione 27, through flash-vacuum pyrolysis (FVP), as described earlier. More stable bis-enone 29 was obtained from 28 by relocation of one of the enone moieties in 28 through thermal activation under static conditions. The two double bonds in 29 could be now easily differentiated and hence it served as an appropriate substrate for further elaboration. Thus, bis-enone 29 on selective catalytic hydrogenation and regioselective gem-dimethylation afforded 30, Scheme 7. At this stage, the two-carbonyl functionalities in 30 were sought to be removed and this was achieved in a stepwise manner. The sequence involved chemoselective thioketalisation of the enone carbonyl followed by reductive desulfurization in metal-ammonia milieu and led to a diastereomeric mixture of alcohols (resulting from the concurrent reduction of the saturated ketone under metal-ammonia conditions). The diastereomeric mixture of alcohols was deoxygenated following the Barton protocol to yield tricyclic hydrocarbon 31, Scheme 7. Catalytic ruthenium mediated oxidative fragmentation of the tetrasubstituted olefinic bond in 31 afforded the 5,8-fused os-bicyclic dione 32. Wittig olefination of cis-bicyclic dione 32 proceeded regioselectively at the carbonyl group distant from the ring junction and furnished keto-olefin 33. However, the isomerization of exocyclic double bond in 33 to the desired endo position (corresponding to C6-C7 in the natural product) to yield 34 proved to be difficult due to unwanted transannular cyclization. Consequently, the transformation of 33 to the desired 34 was carried out through a five-step sequence. The sequence involved the reduction of the carbonyl group in 33 to yield alcohol, protection of the resultant alcohol as IMS-ether and RhCb mediated isomerization of the exo-double bond to the desired endo position. Further deprotection of the TMS ether and oxidation led to the acquisition of the expected enone 34, Scheme 7. Finally, the exo- methylene unit present in the natural product was installed by Wittig olefination in 34 to furnish 35, corresponding to the 'assigned structure' of the natural product. However the spectral data of synthetic 35 was distinctly different from that reported for the natural product and a revision of the natural product structure was warranted. A careful analysis of the spectral data led us to the surmise that the natural product could be the trans-isomer and we embarked on its synthesis. Consequently, cis-bicyclic diketone 32 on exposure to base could be readily equilibrated to the more stable trans-isomer 36 in which the later was the major product (1:4). Bicyclic trans-dione 36, like its cis sibling 32 underwent a facile regioselective Wittig olefination to yield keto-olefin 37, Scheme 8. RhCk-mediated double-bond isomerization in 37 proceeded without any complications and gave a readily separable mixture of regiomeric olefinic ketones 38 and 39 in the ratio 2:3, respectively. Wittig olefination on the required keto olefin 39 proceeded smoothly to furnish the bicyclic hydrocarbon 40 whose spectral characteristics [lH NMR, 13C NMR) exactly matched those reported for the natural product, Scheme 8. A total synthesis of the natural product asterisca-3(15),6-diene has been accomplished. These synthetic efforts necessitate the revision of the earlier assigned structure of the natural product from cis-35 to trans-38. (For structural formula pl see the original document)

Les résines végétales sont des sécrétions de végétaux qui ont été utilisées par l’homme de l’Antiquité à nos jours dans de nombreuses applications (pharmaceutique, cosmétique et artistique). Ces exsudats sont composés majoritairement de terpènes. L'identification et la quantification de l'ensemble de ces composés dans les extraits végétaux reste un défi du fait de leur très grande diversité structurale. L’objectif de ce travail a été de développer de nouvelles approches analytiques pour identifier et quantifier les composés terpéniques présents dans ce matériel végétal afin d’en assurer le contrôle qualité et la certification. Deux méthodes séparatives ont été sélectionnées: la TLC et la GC. Pour ces deux techniques on s’est intéressé à toutes les potentialités de leur couplage avec la spectrométrie de masse. Le développement en TLC-1D et TLC-2D a permis le « screening » rapide des résines végétales et la faisabilité du couplage avec le MALDI-TOF-MS a été mise en évidence pour l’identification des marqueurs majoritaires (acides triterpéniques). La GC a permis une caractérisation plus aboutie des résines en mettant en place une méthode d’analyse exhaustive des terpènes des plus volatils au non-volatils. L’optimisation des différentes étapes de la méthodologie GC-MS s’est effectuée en se basant sur la méthode des plans d’expérience ainsi que sur des analyses statistiques tels que l’ACP et la CAH. Dans un souci d’apporter des éléments plus précis pour distinguer les résines les plus proches, la quantification de leurs marqueurs majoritaires a été établie après une validation complète de la méthode GC. L’ensemble de ce travail a permis de développer des outils pour une caractérisation rapide des extraits de résines permettant de différencier les espèces même les plus proches. / Resins are hydrocarbon secretions of many plants and well known for their protective benefits. They have been used as raw materials for a wide range of applications (pharmaceutic, cosmetic and artistic). Plant resins are complex mixtures of organic substances mainly terpenoid compounds which constitute the most abundant and structurally diverse group of plant secondary metabolites. The chemical characterization of this material results in long and difficult separation due to the wide range of polarity and volatility of its constituents. The aim of this work was to develop new analytical approaches to improve the identification of resins certifying their origin and ensuring the quality control. For that purpose two analytical methods were selected: TLC and GC approaches hyphenated to mass spectrometry. TLC-1D and TLC-2D allow a rapid screening and first visual differences of resins. The innovating TLC coupling to MALDI-TOF-MS gives a clear identification of major markers (triterpenic acids). In order to have complementary information about the composition of resins, a gas chromatography-mass spectrometry (GC-MS) method was developed to analyze volatile to non-volatile compounds. The various stages of optimization were based on experimental design and statistical (PCA and HAC) approaches. For closely related resins, a quantitative approach was investigated based on a complete validation for major markers. This work allows the development of two complementary techniques that give a powerful approach for fast and reliable differentiation of various resins even the closest ones.

The increasing expansion of aquaculture, the stress on the animals in farming systems and the adverse effects caused by conventional anesthetics has encouraged the search for natural anesthetics, safer, more effective, with lower side effects and less residual waste. In this context, this work aimed to evaluate the anesthetic potential of the essential oil (EO) from leaves of Nectandra megapotamica in fat snook (Centropomus parallelus) and its chemical composition. For extraction of the EO, the leaves were separated in young (EO-Y) or old (EO-O) and chemical composition analysis was performed by GC/MS. The major constituents of the Y and O-EOs were: bicyclogermacrene (46.5/34.6%), α-pinene (26.8/26.2%), β-pinene (7.9/12.3%), and germacrene D (9.6/9.1%). In the first experiment, four different concentrations of each EO were tested in fat snook acclimated to two salinities (zero and 33 ppt) to evaluate anesthesia induction and recovery time. In the second experiment, two concentrations of EO-O were tested in fish acclimated to both salinities for the evaluation of stress parameters (glucose, lactate, Na+ and K+ plasma levels) caused by handling. In the third experiment, the fish were transported in plastic bags, supplied with both water salinities and two concentrations of EO-O for evaluation of water quality and mortality after transport. Mild sedation was achieved at 30 μL L-1 and deep anesthesia at 150 μL L-1 with both EO. The EO-O was not able to avoid the stress of handling, as evidenced by elevated glucose and lactate plasma levels observed in all treatments and controls. The treatments did not change significantly the plasma Na+ and K+ levels in the fish kept at both salinities. During transportation, the use of EO-O did not improve the water quality and post-transport mortality. On the contrary, the fish transported with the highest concentration of EO-O in seawater had significantly higher mortality than the other groups. In conclusion, the EO of N. megapotamica at the tested concentrations was efficient to induce sedation and anesthesia in fat snook, but was not effective in preventing the stress generated by handling and transport of this species. / A crescente expansão da aquicultura, o estresse imposto aos animais nos sistemas de cultivo e os efeitos adversos causados pelos anestésicos de uso convencional têm levado ao incentivo da pesquisa por anestésicos de origem natural, eficazes e mais seguros, com menos efeitos colaterais e menores efeitos residuais. Neste contexto, esta dissertação objetivou a avaliação do potencial anestésico do óleo essencial (OE) das folhas de Nectandra megapotamica em robalos-peva (Centropomus parallelus) e sua caracterização química. Para a extração do OE, as folhas foram classificadas em jovens (OE-J) e velhas (OE-V) e a análise de sua composição química foi realizada por CG/EM. Os constituintes majoritários foram: biciclogermacreno (46.5/34.6%), α-pineno (26.8/26.2%), β-pineno (7.9/12.3%) e germacreno D (9.6/9.1%). O potencial anestésico do OE foi avaliado através dos tempos de indução e recuperação da anestesia e as respostas bioquímicas geradas pelo manuseio e transporte dos peixes. No primeiro experimento, quatro concentrações de cada OE foram testadas em robalos-peva aclimatados a duas salinidades (0 e 33 ) para avaliar os tempos de indução e recuperação da anestesia. No segundo experimento, duas concentrações do OE-V foram testadas em robalos-peva aclimatados às duas salinidades para avaliar os parâmetros bioquímicos relacionados ao estresse (níveis plasmáticos de glicose, lactato, Na+ e K+) causado pelo manuseio. No terceiro experimento, os peixes foram transportados em sacos plásticos nos dois tipos de água e com duas concentrações do OE-V, com a finalidade de avaliar a qualidade da água e a mortalidade pós-transporte. Ambos OEs produziram sedação leve na concentração de 30 μL L-1 e anestesia profunda com 150 μL L-1. O OE-V não foi eficaz em evitar o estresse do manuseio, pois os elevados níveis plasmáticos de glicose e lactato observados nos controles também foram detectados nos grupos tratados. Os tratamentos não modificaram significativamente os níveis séricos de Na+ e K+ nos peixes em ambas as salinidades. Durante o experimento de transporte, o uso do OE-V não preveniu a deterioração da qualidade da água nem a mortalidade pós-transporte. Ao contrário, o grupo transportado com a concentração mais elevada do OE-V em água salgada apresentou uma mortalidade significativamente maior em relação aos demais grupos. Concluindo, o OE de N. megapotamica mostrou-se eficiente para indução de sedação e anestesia em robalos-peva nas concentrações testadas, mas não foi eficaz em prevenir o estresse gerado pelo manuseio e transporte nessa espécie.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nectandra megapotamica (Lauraceae) is abundant in the Deciduos Forest in Santa Maria-RS. Its essential oil (EO) has been studied for biological activities due to its anti-inflammatory, antifungal, antimicrobial, and cytotoxic effects against tumor cells, among others. The presence of phenylpropanoids as well as sedative and anesthetic activities in R. quelen were observed in the prospect of EO of Nectandra megapotamica. As a hypothesis, we considered the seasonal variability and the occurrence of chemical phenotypes for the individuals in the same population of the species with different biological activities for the EO. The objectives of this study were to define the potential of N. megapotamica in a population in Santa Maria-RS for the production of EO; to determine the yield (Y), chemical composition and the seasonal variation of EO; to evaluate the possible occurrence of chemical phenotypes (differentiated chemical composition); to isolate compounds of interest; and to perform tests of biological activities for the EO and for the isolated compound. The EO samples were obtained from fresh leaves, which were initially separated in young (YL) and old leaves (OL) by hydrodistillation in triplicate for three hours. The collections occurred in function of the seasons in two locations in Santa Maria-RS (Morro do Elefante, and in the proximity of the 318 km of BR 158). The respective Y values were determined, and EO samples were analyzed by GC/MS. Some samples were also analyzed by GC-FID, in triplicate. The chemical composition of the EO was analyzed and grouped by multivariate techniques, main components and hierarchical grouping. The EO was also fractionated by CC, for the isolation of a compound, whose identification happened by NMR. The discrepant groups (CG2 and CG5) were tested for allelopathic, insecticide and anesthetic activities in fish. The compound obtained from CG5 was identified as isoelemicin (phenylpropanoid) and also tested for the anesthetic activity. The largest Y for the EO was observed in spring (YL 0.24% and OL 0.14%) during flowering, fruiting and foliation, and the lowest in autumn (YL 0.13% and OL 0.11%) in the rustification and at rest. The major constituents were α-pinene with greater Y in spring and summer (YL 30.81% and OL 35.86%), and bicyclogermacrene with greater Y in autumn and winter (YL 24.19% and OL 21.73%), which formed two large CG. In the CG of bicyclogermacrene, the presence of phenylpropanoids was observed and therefore it constituted a specific group (CG5). However, CG2 presented higher concentration of monoterpenoids. In the biological tests, the allelopathic activity (lower seed germination and seedling development) for L. sativa var. regina, B. subalternans, G. max, A. strigosa, L. multiflorum and O. sativa was observed when the seeds were submitted to the EO. Moreover, the insecticidal activity was observed in N. viridula, and also sedation in R. quelen. The CG5 was superior than CG2, concerning allelopathy in O. sativa; however, both groups were active at the concentration of 15% EO for the other species, which inhibits 100% germination of B. subalternans (QG5) and A. strigosa (both groups). Regarding the insecticidal action of EO at 5%, the CG5 promoted 46.67% mortality of N. viridula, and CG2 only 14.44%. Concering R. quelen, we observed toxicity associated with sedation, both by the EO similar to CG5 and by isoelimicin. The stage of anesthesia was observed at the concentracion of 500 mg L-1 EO; however, the effect was lower than that observed for eugenol (positive control). In conclusion, the species in the population assessed has the potential to produce EO as a source of new bioactive molecules and biological action mechanisms that should consider the toxicity component, which requires further studies. / Nectandra megapotamica (Lauraceae) é abundante na Floresta Estacional Decidual em Santa Maria-RS. O seu óleo essencial (OE) vêm sendo estudado quanto às atividades biológicas, devido a sua ação anti-inflamatória, antifúngica, antimicrobiana, citotóxica contra células tumorais, dentre outras. Na prospecção do OE foram encontrados fenilpropanoides, além de atividades sedativas e anestesicas em Rhamdia quelen. Como hipótese, considerou-se que haja variabilidade sazonal e ocorrência de fenótipos químicos para os indivíduos na mesma população da espécie, com atividade biológica diferenciada para o OE. Os objetivos deste trabalho foram pesquisar o potencial de N. megapotamica, em uma população em Santa Maria, para a produção de OE; determinar o rendimento (R), a composição química e sua variação sazonal; avaliar a possível ocorrência de fenótipos químicos (composição química diferenciada); isolar constituintes de interesse; e por fim, realizar testes de atividades biológicas, para o OE e para o isolado. Os OE foram obtidos de folhas frescas, inicialmente separadas em jovens (FJ) e velhas (FV), por hidrodestilação em triplicata por três horas. As coletas ocorreramem função das estações do ano, em dois locais em Santa Maria-RS (Morro do Elefante e, na proximidade do km 318 da BR 158). Foram determinados os respectivos R, e os OE foram analisados por CG-EM. Algumas amostras também foram analisadas por CG-DIC, em triplicata. A composição química do OE dos indivíduos coletados foi analisada e agrupada por técnicas multivariadas, componentes principais e agrupamento hierárquico. Foi também realizado fracionamento do OE por CC, para o isolamento de uma substância, cuja identificação se deu por RMN. Determinados os grupos químicos (GQ) e o constituinte isolado, os grupos mais discrepantes (GQ2 e GQ5) foram testados quanto a atividade alelopática, inseticida e anestésica em peixes. A isoelemicina foi avaliada para esta última. O maior R do OE foi observado na primavera (FJ 0,24% e FV 0,14%), durante a floração, frutificação e foliação, e o menor no outono (FJ 0,13% e FV 0,11%), na rustificação e repouso. Os constituintes majoritários foram α-pineno, com maior R na primavera e verão (FJ 30,81% e FV 35,86%), e biciclogermacreno, com maior R no outono e inverno (FJ 24,19 e FV 21,73%). Estes formaram dois grandes GQ. No GQ do biciclogermacreno foi observada a presença de fenilpropanoides, que constituíram um grupo específico (GQ5). Já o GQ2 apresentou maiores teores de monoterpenoides. Do OE do GQ5 foi isolada a isoelemicina (fenilpropanoide). Nos testes biológicos realizados foram observadas atividade alelopática (menor germinação de sementes e desenvolvimento de plântulas) para Lactuca sativa cv. regina, Bidens subalternans, Glicine max, Avena strigosa, Lolium multiflorum e Oryza sativa; atividade inseticida em Nezara viridula e sedação em R. quelen. O GQ5 foi superior ao GQ2, nos testes de alelopatia em O. sativa, mas ambos os grupos foram ativos na concentração de 15% de OE para as demais espécies, inibindo100% da germinação de B. subalternans (GQ5) e de A. strigosa (ambos os grupos). Na ação inseticida com 5% do OE, o GQ5 promoveu 46,67% de mortalidade de N. viridula, e o GQ2 apenas 14,44%. Em R. quelen foi observada sedação associada à toxicidade, tanto pelo OE similar ao GQ5 (obtido do segundo local de coleta) como pela isoelemicina. O estágio de anestesia foi observado na concentração de 500 mg L-1 de OE, mas o efeito foi inferior ao observado para o eugenol com 50 mg L-1 (controle positivo). Conclui-se que a espécie, na população avaliada, possui potencial para produzir OE, como fonte de novas moléculas bioativas e mecanismos de ação biológica, que devem considerar a componente de toxicidade, o que exigirá novas pesquisas.

Terpenos são compostos que fazem parte da constituição de óleos essenciais. Estes compostos são formados pela condensação de unidades de isopreno e quando contêm oxigênio são denominados terpenoides. O presente trabalho teve como objetivo avaliar a atividade antimicrobiana e antioxidante dos terpenoides citral, citronelal, citronelol, 1,8-cineol, geraniol, α-terpineol e do sesquiterpeno β-cariofileno. Para tanto, as concentrações inibitórias mínimas (CIM) e as doses inibitórias 50% (DI50) foram determinadas através do método de diluição seriada (0 a 10 μL/mL v/v) em microplacas. A viabilidade celular, na concentração inibitória mínima, foi avaliada por plaqueamento e contagem. Foi avaliado também o efeito dos terpenoides sobre a respiração de bactérias e leveduras. Além disso, testes específicos envolvendo citral, citronelal, citronelol e geraniol foram realizados com as leveduras Saccharomyces cerevisiae e Candida albicans, sendo eles: avaliação da sobrevivência, lise celular e perda de componentes celulares. A atividade antioxidante in vitro dos terpenoides foi determinada pelo método DPPH(1,1-difenil 2-picrilhidrazil)A atividade antioxidante in vivo de citral e citronelal foi realizada utilizando S. cerevisiae como organismo modelo. Os resultados mostraram que os seis terpenoides e sesquiterpeno têm atividade antimicrobiana, com variação entre as concentrações destes isolados e o tipo de microrganismo avaliado. De um modo geral, o citral foi o terpenoide que exibiu ação antimicrobiana mais expressiva, enquanto o β-cariofileno afetou um número restrito de microganismos. A presença de citral e citronelal, nas concentrações inibitórias mínimas correspondentes, reduziu a respiração de Salmonella typhinmurium e Staphylococcus aureus. C. albicans e S. cerevisiae, quando tratadas com CIM de citral, citronelal, citronelol e geraniol, tiveram a respiração inibida. Geraniol foi o terpenoide com maior atividade microcida sobre C. albicans. Citral, citronelol, citronelal e geraniol induziram a perda de componentes celulares tanto em C. albicans quanto em S. cerevisiae. Todos os compostos mostraram atividade antioxidante in vitro, particularmente o citral. Por outro lado, citronelal foi o único terpenoide que apresentou atividade antioxidante in vivo, sobre células eucarióticas. De uma maneira geral, o presente trabalho mostrou que o citral apresenta importante atividade antioxidante e antimicrobiana, induzindo a perda de componentes celulares e inibindo a respiração. Estas informações são importantes para aplicações farmacológicas deste composto ou óleos essenciais com elevada concentração de citral. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-03T18:58:15Z No. of bitstreams: 1 Dissertacao Cristiane Menegotto Toscan.pdf: 1090361 bytes, checksum: 9966c4bc0984b31ac43b1694565a97b7 (MD5) / Made available in DSpace on 2014-06-03T18:58:15Z (GMT). No. of bitstreams: 1 Dissertacao Cristiane Menegotto Toscan.pdf: 1090361 bytes, checksum: 9966c4bc0984b31ac43b1694565a97b7 (MD5) / Terpenes are the main constituents of plant essential oils. These compounds are formed by the condensation of isoprene units, and when contain oxygen are named terpenoids. The present work aimed to evaluate the antimicrobial and antioxidant activity of terpenoids citral, citronellal, citronellol, 1,8-cineole, geraniol, α- terpineole and sesquiterpene β-caryophyllene. Thus for, the minimal inhibitory concentrations (MIC), and the inhibitory dosage 50% (ID50) were determined using the microplate serial dilution method (0 to 10 μL/mL v/v). Cell viability at the MIC concentration was evaluated by plating and counting. The effect of terpenoids on bacterial and yeast respiration was evaluated. Moreover, the following specific tests were developed on Saccharomyces cerevisiae and Candida albicans using citral, citronellal, citronellol and geraniol: cell viability, cellular lysis, and loss of cellular components. The in vitro antioxidant activity of the terpenoids was determined by the DPPH (1,1-difenil 2-picrilhidrazil)essay. In vivo antioxidant activity of citral and citronellal was evaluated using S. cerevisiae as model organism. The results showed that all the six terpenoids and one sesquiterpene have antimicrobial activity, with variation among terpenoids and microrganisms. In general, citral exhibited the highest antimicrobial activity, where β-cariophyllene affects a restricted number of organisms. The presence of citral and citronellal at their MICs reduced respiration of Salmonella typhimurium and Staphylococcus aureus. Respiration inhibitory activity of citral, citronellol, citronellal and geraniol was also evidenced on C. albicans and S. cerevisiae. Geraniol was the terpenoid with the highest microcide activity on C. albicans and S. cerevisiae, as determined by the methylene blue staining method. Citronellal and citronellol exhibited low lytic activity on S. cerevisiae, but not on C. albicans. Citral, citronellol, citronellal and geraniol induced the loss of cellular components in both C. albicans and S. cerevisiae. All the compounds showed in vitro antioxidant activity, particularly citral. Conversely, citronellal was the only terpenoid with in vivo antioxidant activity on eukaryotic cells. In general, the present work showed that citral has an important antioxidant and antimicrobial activity, inducing the loss of cellular components and inhibiting cell respiration. These informations are important for the pharmacological application of this compound or essential oils with high concentration of citral.

Terpenos são compostos que fazem parte da constituição de óleos essenciais. Estes compostos são formados pela condensação de unidades de isopreno e quando contêm oxigênio são denominados terpenoides. O presente trabalho teve como objetivo avaliar a atividade antimicrobiana e antioxidante dos terpenoides citral, citronelal, citronelol, 1,8-cineol, geraniol, α-terpineol e do sesquiterpeno β-cariofileno. Para tanto, as concentrações inibitórias mínimas (CIM) e as doses inibitórias 50% (DI50) foram determinadas através do método de diluição seriada (0 a 10 μL/mL v/v) em microplacas. A viabilidade celular, na concentração inibitória mínima, foi avaliada por plaqueamento e contagem. Foi avaliado também o efeito dos terpenoides sobre a respiração de bactérias e leveduras. Além disso, testes específicos envolvendo citral, citronelal, citronelol e geraniol foram realizados com as leveduras Saccharomyces cerevisiae e Candida albicans, sendo eles: avaliação da sobrevivência, lise celular e perda de componentes celulares. A atividade antioxidante in vitro dos terpenoides foi determinada pelo método DPPH(1,1-difenil 2-picrilhidrazil)A atividade antioxidante in vivo de citral e citronelal foi realizada utilizando S. cerevisiae como organismo modelo. Os resultados mostraram que os seis terpenoides e sesquiterpeno têm atividade antimicrobiana, com variação entre as concentrações destes isolados e o tipo de microrganismo avaliado. De um modo geral, o citral foi o terpenoide que exibiu ação antimicrobiana mais expressiva, enquanto o β-cariofileno afetou um número restrito de microganismos. A presença de citral e citronelal, nas concentrações inibitórias mínimas correspondentes, reduziu a respiração de Salmonella typhinmurium e Staphylococcus aureus. C. albicans e S. cerevisiae, quando tratadas com CIM de citral, citronelal, citronelol e geraniol, tiveram a respiração inibida. Geraniol foi o terpenoide com maior atividade microcida sobre C. albicans. Citral, citronelol, citronelal e geraniol induziram a perda de componentes celulares tanto em C. albicans quanto em S. cerevisiae. Todos os compostos mostraram atividade antioxidante in vitro, particularmente o citral. Por outro lado, citronelal foi o único terpenoide que apresentou atividade antioxidante in vivo, sobre células eucarióticas. De uma maneira geral, o presente trabalho mostrou que o citral apresenta importante atividade antioxidante e antimicrobiana, induzindo a perda de componentes celulares e inibindo a respiração. Estas informações são importantes para aplicações farmacológicas deste composto ou óleos essenciais com elevada concentração de citral. / Terpenes are the main constituents of plant essential oils. These compounds are formed by the condensation of isoprene units, and when contain oxygen are named terpenoids. The present work aimed to evaluate the antimicrobial and antioxidant activity of terpenoids citral, citronellal, citronellol, 1,8-cineole, geraniol, α- terpineole and sesquiterpene β-caryophyllene. Thus for, the minimal inhibitory concentrations (MIC), and the inhibitory dosage 50% (ID50) were determined using the microplate serial dilution method (0 to 10 μL/mL v/v). Cell viability at the MIC concentration was evaluated by plating and counting. The effect of terpenoids on bacterial and yeast respiration was evaluated. Moreover, the following specific tests were developed on Saccharomyces cerevisiae and Candida albicans using citral, citronellal, citronellol and geraniol: cell viability, cellular lysis, and loss of cellular components. The in vitro antioxidant activity of the terpenoids was determined by the DPPH (1,1-difenil 2-picrilhidrazil)essay. In vivo antioxidant activity of citral and citronellal was evaluated using S. cerevisiae as model organism. The results showed that all the six terpenoids and one sesquiterpene have antimicrobial activity, with variation among terpenoids and microrganisms. In general, citral exhibited the highest antimicrobial activity, where β-cariophyllene affects a restricted number of organisms. The presence of citral and citronellal at their MICs reduced respiration of Salmonella typhimurium and Staphylococcus aureus. Respiration inhibitory activity of citral, citronellol, citronellal and geraniol was also evidenced on C. albicans and S. cerevisiae. Geraniol was the terpenoid with the highest microcide activity on C. albicans and S. cerevisiae, as determined by the methylene blue staining method. Citronellal and citronellol exhibited low lytic activity on S. cerevisiae, but not on C. albicans. Citral, citronellol, citronellal and geraniol induced the loss of cellular components in both C. albicans and S. cerevisiae. All the compounds showed in vitro antioxidant activity, particularly citral. Conversely, citronellal was the only terpenoid with in vivo antioxidant activity on eukaryotic cells. In general, the present work showed that citral has an important antioxidant and antimicrobial activity, inducing the loss of cellular components and inhibiting cell respiration. These informations are important for the pharmacological application of this compound or essential oils with high concentration of citral.

Made available in DSpace on 2014-08-20T13:59:06Z (GMT). No. of bitstreams: 1 tese_milene_conceicao_lima.pdf: 1117046 bytes, checksum: 61412e1bba4614df5d623d5245902770 (MD5) Previous issue date: 2013-04-05 / Several abiotic factors can coordinate or alter metabolic processes of growth and development plants such light, temperature, water availability, climate, soil nutrition and inorganic compounds. The objective of this study was to evaluate performance of A. millefolium L. (yarrow) against abiotic factors. To achieve this objective were have conducted two experiments in which the first was observed antimicrobial activity in vitro and essential oil yield of yarrow grown with nitrogen levels (0, 75 and 150 kg urea ha-1) and subjected different levels of shading 0% (full light) and 70% (70% shading). The second experiment were observed growth characteristics, production photosynthetic pigments, antioxidant enzymes activity, concentrations hydrogen peroxide, malondialdehyde, ascorbate and deidroascorbato, antioxidant activity by method DPPH and secondary metabolites synthesis in yarrow cultivated under light conditions (full light and blue, red and black shade net) and subjected different collection periods (eight weeks shading, two and four weeks after shading). The results show that oil yield extracted from flowers was stimulated by medium nitrogen level and full light increased the oil yield extracted from leaves. The highest essential oil yield was observed in reproductive structures. Antimicrobial activity of oil was confirmed against microorganisms species. Yeast strains were inhibited by the lowest concentration. The dry mass of leaves and flowers was favored in plants grown under full light. The content of chlorophyll a and b were higher in plants cultivated under blue net, total chlorophyll content was lower in plants under full light and plants two weeks after shading was increase of chlorophyll a, b and total, equivalent did not shaded plants. Catalase activity increased plants acclimated to high light intensity and low light did not stimulate ascorbate peroxidase, but increased superoxide dismutase and content of hydrogen peroxide. Lipid peroxidation was reduced presence of the spectrum blue and red light and low light intensity generated by nets black and blue, reduced accumulation of ascorbate. Content of deidroascorbato increased acclimation process to sunlight and antioxidant activity was more pronounced extracts of flowers. Levels total phenols and flavonoids were stimulated by full light. Oil yield extracted from flowers was higher than leaves. Major metabolite oil extracted from leaves was farnesol and flowers were farnesol and chamazulene. Results for medicinal species A. millefolium L. indicated that light intensity, light quality, collection periods and nitrogen fertilization influence growth, photosynthetic pigments production, secondary metabolites and antioxidant response. / Diversos fatores abióticos podem coordenar ou alterar os processos metabólicos de crescimento e desenvolvimento em plantas como a luz, temperatura, disponibilidade hídrica, clima, nutrição do solo e compostos inorgânicos. O objetivo deste estudo foi avaliar o comportamento de A. millefolium L. (mil-folhas) frente aos fatores abióticos. Para atingir este objetivo foram realizados dois experimentos, na qual no primeiro foi verificada a atividade antimicrobiana in vitro e rendimento do óleo essencial de mil-folhas cultivada com concentrações de nitrogênio (0, 75 e 150 Kg ureia ha-1) e submetida a diferentes níveis de sombreamento 0% (luz plena) e 70% (sombreamento 70%). No segundo experimento foram avaliadas características de crescimento, produção de pigmentos fotossintéticos, atividade de enzimas antioxidantes, teores de peróxido de hidrogênio, malondialdeído, ascorbato e deidroascorbato, atividade antioxidante pelo método DPPH e síntese de metabólitos secundários em mil-folhas cultivada sob condições de luminosidade (luz plena e sombreamento com malha azul, vermelha e preta) e submetida a diferentes períodos de coleta (oito semanas de sombreamento, duas e quatro semanas após o sombreamento). Os principais resultados mostram que o rendimento do óleo extraído de flores foi estimulado pela concentração nitrogenada intermediária e o extraído de folhas foi favorecido pela luz plena, sendo maior nas estruturas reprodutivas. A atividade antimicrobiana do óleo foi confirmada frente aos microrganismos, sendo as cepas fúngicas inibidas pela menor concentração. A massa seca das folhas e flores foi favorecida nas plantas cultivadas com luz plena. Os teores de clorofila a e b foram maiores nas plantas cultivadas com a malha azul, o conteúdo de clorofila total foi menor nas plantas sob luz plena e em plantas com duas semanas após o sombreamento ocorreu um incremento de clorofila a, b e total, equivalendo-se às plantas não sombreadas. A atividade da catalase aumentou em plantas aclimatadas em alta intensidade de luz e a baixa luminosidade não estimulou a ascorbato peroxidase, mas incrementou a superóxido dismutase e o teor de peróxido de hidrogênio. A peroxidação lipídica foi reduzida na presença dos espectros de luz azul e vermelha e a baixa intensidade de luz, gerada pelas malhas preta e azul, reduziu o acúmulo de ascorbato. O conteúdo de deidroascorbato aumentou em processo de aclimatação à luz solar e a atividade antioxidante foi mais acentuada em extratos de flores. Os teores de fenois e flavonoides totais foram estimulados pela luz plena. O rendimento do óleo extraído de flores foi maior em relação ao de folhas. O metabólito majoritário do óleo extraído de folhas foi o farnesol e os extraídos de flores foram o farnesol e camazuleno. Os resultados encontrados para a espécie medicinal A. millefolium L. indicaram que a intensidade luminosa, qualidade de luz, períodos de coleta e fertilização nitrogenada influenciam no crescimento, produção de pigmentos fotossintéticos, de metabólitos secundários e resposta antioxidante.

De nombreuses biomolécules qui constituent les plantes vasculaires ne sont synthétisées que par certains taxons de plantes et ont donc une spécificité chimiotaxonomique. Certaines d'entre elles, tels que les bioterpénoïdes, sont particulièrement résistantes et sont préservées dans les sédiments où elles se transforment en géoterpénoïdes lors de la diagenèse. Ces géoterpénoïdes conservent, partiellement ou totalement, leur spécificité initiale (spécifité paléochimiotaxonomique). Cependant, nos connaissances actuelles en paléochimiotaxonomie botanique, qui permettent d'associer ces biomarqueurs moléculaires à des taxons végétaux, restent encore lacunaires. L'objectif de cette étude est de déterminer la signature moléculaire des familles de conifères fossiles. 68 représentants appartenant aux 7 familles actuelles de conifères ont été artificiellement maturés par pyrolyse en milieu confiné afin de reproduire en laboratoire la transformation des bioterpénoïdes en géopterpénoïdes. Les résultats montrent que les Pinaceae, les Araucariaceae, les Cupressaceae, les Sciadopityaceae, les Podocarpaceae, les Taxodiaceae et les Taxaceae "fossilisés" peuvent se distinguer par la nature et la proportion relative de ces terpénoïdes. De plus, la comparaison des signatures moléculaires ont permis de réaliser des regroupements intergénériques pour chaque famille. Ces regroupements sont comparables avec ceux de la classification phylogénétique. À terme, ces résultats pourront être utilisés dans le cadre d’études paléobotaniques, paléoenvironnementales, environnementales et archéologiques / Many biomolecules that constitute terrestrial vascular plants are only synthesized by a restricted number of plant taxa and have thus a chemotaxonomic specificity. Some of these biomolecules, like the terpenoids, are particularly resistant and can be preserved within sediments where they are transformed into geomolecules during diagenesis. Geoterpenoids keep, partially or totally, their initial specificity (palaeochemotaxonomic specificity). However, our current knowledge in botanical palaeochemotaxonomy, allowing to link these plant biomarkers to plant taxa, remains incomplete. The aim of this study is to determine the molecular signature of fossil conifers. In this objective, 68 species belonging to the 7 extant conifer families were subjected to artificial maturation by confined pyrolysis. This process converts the bioterpenoids included within the plant material into geoterpenoids. The results show that the "fossilized" Pinaceae, Araucariaceae, Cupressaceae, Sciadopityaceae, Podocarpaceae, Taxodiaceae and Taxaceae can distinguished from each other by the nature and the relative proportion of these geoterpenoids. The comparison of these molecular signatures allows to achieve intergeneric groups for each family. These groups are comparable to those of the phylogenetic classification. In the future, these results could be used for palaeobotanical, palaeoenvironmental, environmental and archaeological assessments

Cette thèse porte sur la dégradation photochimique des résines naturelles utilisées dans la fabrication de vernis à tableaux. Différentes résines ont été choisies pour notre étude : la sandaraque, le copal de Manille, la colophane, le mastic et la dammar. Des vernis à tableaux ont été fabriqués à partir de ces résines dissoutes dans de l’alcool, de l’huile ou de l’essence de térébenthine selon d’anciennes recettes. Ils ont par la suite été vieillis artificiellement en enceinte d’irradiation. L’étude en spectrométrie infrarouge a permis de montrer qu’une identification du type de résine était possible par cette technique. De nombreuses bandes d’absorption spécifiques ont été mises en évidence mais tendent à disparaître tout au long du photovieillissement. Néanmoins, la bande des CH (2850-3050 cm-1) permet de séparer les résines diterpéniques et triterpéniques, et l’analyse en composante principale des données permet d’affiner les identifications. Les analyses en CPG-SM nous ont permis d’identifier la plupart des molécules présentes au sein de nos vernis grâce à l’étude des fragmentations en spectrométrie de masse. Dans ce cadre, une étude poussée du comportement des molécules a été effectuée, notamment par des expériences en SM/SM. Quatre phénomènes de photodégradation ont été observés : l’isomérisation, la scission, l’hydroxylation et l’oxydation de type Norrish I des terpènes présents. Le choix du solvant utilisé dans la fabrication du vernis influence fortement la composition du vernis et sa cinétique de dégradation, en particulier dans le cas d’un vernis à l’huile. La présence d’une vitre devant le vernis a également une influence, plus ou moins importante, sur les mécanismes photochimiques. Des vernis anciens récupérés auprès de conservateurs-restaurateurs ont été identifiés grâce à la base de données effectuée à partir de nos expérimentations, validant notre méthodologie. Les premiers essais de polymères à empreinte moléculaire ont également été effectués donnant des résultats encourageants pour l’étude de mélanges de terpènes / This thesis presents a study on the photochemical degradation of natural resins used in the manufacture of painting varnishes. Following the literature, five resins were chosen for our experiments: sandarac, Manila copal, colophony, mastic and dammar. Varnishes were made from those resins dissolved in alcohol, oil or turpentine spirit, as found in old recipes. They were then photo-aged by irradiation under artificial light. The study by infrared spectrometry enabled the identification of the type of resin. Although various specific absorption bands were highlighted, they tend to disappear all along the photoageing process. Nevertheless, the C-H band situated between 2850 and 3050 cm-1 allows to separate diterpenic and triterpenic resins and the analysis by principal components can help the identification. Thanks to the study by GC-MS we could identify most of the molecules present in our varnishes by developing the fragmentation study in mass spectrometry. An advanced study of the molecules behaviour was done, especially by MS/MS experiments. Four photo-degradation reactions were observed: isomerisation, cleavage, hydroxylation and Norrish I oxidation of the terpenoids. The choice of the solvent used in the varnish can affect its composition and degradation kinetic, mostly for oil varnishes. Besides, a window pane placed before the varnish will influence the photochemical mechanisms. Ancient varnishes collected by conservator-restorers were analysed and identified thanks to the database elaborated from our results, validating our methodology. The first experiments of molecularly imprinted polymers were carried out with some encouraging results for the analysis of mixed terpenoids