The goal of this PhD research was directed to the isolation and structural elucidation of the secondary metabolites from four species of Durio plants, especially from those growing in the island of Borneo; This island contains most Durio species. The structures of isolated compounds were deduced using state-of-the-art approaches, including 1D and 2D nuclear magnetic resonance (NMR), mass spectrometric (MS) and circular dichroism (CD) analyses. From the bark of the woody species Durio zibethinus Murr. (Bombacaceae), that was collected in Pontianak, a chemically diverse group of oxygenated compounds was obtained. These included caffeoyl triterpenes, lignans and phenylpropanoid derivatives. During this research, one new compound 27-O-cis-caffeoylcylicodiscate was obtained which resulted from a trans to cis isomerization; this process might be caused by acid and light. Two presumed fungal metabolites were also isolated during this study, these possibly arising from fungal (unknown species) contamination of the bark. The relative stereochemistry of 4-hydroxymellein were also established by conversion to it diacetate and measurement of the coupling constant between H-3 and H-4. The absolute configuration was determined by comparison of []D values with those from the literature. Assignment of the 13C NMR spectrum for (+)-(R)-de-O-methyllasiodiplodin was completed using HSQC-TOCSY data. The methanol extract of the bark of Durio kutejensis (Hassk.) Becc. was fractionated and purified by C18-HPLC. Two new caffeoyl pentacyclic triterpenes 3-O-trans-caffeoyl-2-hydroxyolean-12-en-28-oic acid and 3-O-trans-caffeoyl-2-hydroxyurs-12-en-28-oic acid, together with five known compounds were isolated. The known compound fraxidin had previously been obtained from D. zibethinus Murr. The bark of Durio carinatus Mast., a plant species which has non edible fruit was collected in Sambas district, West Kalimantan. Three new lignans, boehmenan X, (-)-(7S,8S)-threo-carolignan X and (-)-(7R,8S)-erythro-carolignan X, and a new caffeoyl triterpene 3-O-cis-caffeoyl betulinic acid, together with three known lignans and one known caffeoyl triterpene, were obtained from the crude MeOH extract. The relative configurations and conformational models of the diastereomers threo- and erythro-carolignan X were determined by the coupling constant data for H-7′ and H-8′ and supported by 2D NMR spectroscopic analysis including NOESY and HSQC-HECADE in CDCl3. However, the magnitude of the coupling constants for both compounds in MeOH-d4 was similar. The stability of the individual conformers was solvent dependent and must be considered for their contribution to the overall conformational equilibria. This stability was determined by steric interactions, dipole repulsion effects and intramolecular hydrogen bonding. The absolute configuration of the two new diastereomers was established by application of circular dichroism (CD) and optical rotation []D measurements. Another Durio plant studied and collected in Bengkayang region, West Kalimantan, was Durio oxleyanus Griff. From the MeOH extract of its bark, two new lignans, (-)-(7S,8S)-threo-carolignan Y and (-)-(7R,8S)-erythro-carolignan Y were isolated using C18-HPLC. The relative stereochemistry of the carolignan Y diastereomers could not be deduced from the coupling constants for H-7′ and H-8′ either in CDCl3 and MeOH-d4, because of the presence of multiple conformers. The conformational model for the diastereomers of carolignan Y was similar to that of threo- and erythro-carolignan X in MeOH-d4. Using 2D NMR spectroscopic methods, including NOESY and HSQC-HECADE, the relative stereochemistry of the threo and erythro isomers of carolignan Y was confirmed. Further, the absolute configuration of threo- and erythro-carolignan Y was explored via analysis of CD spectra and by comparison of experimentally obtained []D values with literature values.

The plant kingdom contributes significantly to the natural products that are used for the treatment of a large number of ailments and disease across the globe. Included in these species is the Helichrysum genus (Asteraceae), which comprises of more then 600 species across Africa of which 244 species are found in South Africa. Helichrysum species are used in many cases for the treatment of coughs, colds, fever, infection, headaches, menstrual pain and are also very popular for wound dressing due to their potential antibacterial properties. The most common Helichrysum species used in traditional medicine and for several medicinal purposes are H. cymosum, H. odoratissimum, H. petiolare and H. nudifolium. Previously published research has shown that several of the Helichrysum species do have antimicrobial activity with the most relevant to this study being the discovery of antiviral activity of H. aureonitens against herpes simplex virus type 1 (HSV-1) as well as the reports of anti-HIV (human immunodeficiency virus) activity of several Helichrysum species. With this knowledge, a more in-depth study was initiated to identify the possible active constituents in South African Helichrysum species against HIV. Due to the need to speed up drug discovery especially against epidemic diseases like HIV, this study investigated a new tool (nuclear magnetic resonance (NMR) – based metabolomics) to speed up drug discovery form natural products especially when anti-viral constituents are investigated. odoratissimum, H. petiolare and H. nudifolium. Previously published research has shown that several of the Helichrysum species do have antimicrobial activity with the most relevant to this study being the discovery of antiviral activity of H. aureonitens against herpes simplex virus type 1 (HSV-1) as well as the reports of anti-HIV (human immunodeficiency virus) activity of several Helichrysum species. With this knowledge, a more in-depth study was initiated to identify the possible active constituents in South African Helichrysum species against HIV. Due to the need to speed up drug discovery especially against epidemic diseases like HIV, this study investigated a new tool (nuclear magnetic resonance (NMR) – based metabolomics) to speed up drug discovery form natural products especially when anti-viral constituents are investigated. In this study very promising anti-HIV results were obtained from several aqueous extracts (1:1 methanol/water) using a full virus model i.e. Helichrysum populifolium (IC50 12 μg/ml), H. appendiculatum (IC50 17 μg/ml), H. cymosum ssp. clavum (IC50 19 μg/ml), H. oxyphyllum (IC50 19 μg/ml) and H. cymosum ssp. cymosum (IC50 21 μg/ml). With the use of NMR-based metabolomics and multivariate data analysis (MVA) the specific characteristic that differentiated the active extracts from the non-active extracts was identified by making use of Orthogonal Projections to Latent Structures – Discriminant Analysis (OPLS-DA). This characteristic was then used as a “blue print” or “fingerprint” to guide the process of fractionation and purification. H. populifolium showed the highest anti-HIV activity and thus was selected as the candidate extract for further analysis. After a very quick and simple chromatographic fractionation process, seven fractions were compared against the activity profile by making use of their NMR profiles, which then visually indicated which of the fractions had the highest similarity. Fraction 6 had the most similar “fingerprint”. The compounds of this active fraction were then identified with the use of liquid chromatography – ion trap – time of flight (LC-IT-TOF) for quick identification. The analysis revealed the presence of five chlorogenic type compounds, 3,4-dicaffeoyl quinic acid (DCQA), 3,5-DCQA, 4,5-DCQA, 1,3,5- tricaffeoyl quinic acid (TCQA) and 5-malonyl-1,3,4-TCQA of which several are well known to have anti-HIV activity ranging from 0.85μM to 12μM. We were thus able to show with this study the possibility of using NMR-based metabolomics guided fractionation to guide the process of fractionation and identification from an active characteristic profile to the active constituents within the active H. populifolium extract. / Thesis (PhD)--University of Pretoria, 2013. / gm2014 / Plant Science / unrestricted

Le syndrome métabolique comme le diabète de type 2 sont des pathologies chroniques souvent étroitement liées. Le syndrome métabolique via des dysfonctionnements physiologiques qui s'auto-entretiennent et s'amplifient conduira au diabète de type 2. Les dysfonctionnement majeurs sont l'obésité abdominale, l'inflammation et le stress oxydant tissulaire et enfin l'insulino-résistance des tissus sensibles à l'insuline. Il convient donc de lutter efficacement contre ces dysfonctionnements afin de lutter contre ces pathologies chroniques. Les travaux de l'équipe dans laquelle j'ai effectué ma thèse ont permis de mettre en évidence les effets pléiotropes de substances de la famille des dérivés caffeoyls. Ces dérivés largement reconnus comme substances antioxydantes ont des effets insulino-sensibilisants (augmentent le captage de glucose sous stimulus insulinique) et aussi insulino-stimulants (augmentent la capacité sécrétrice de la cellule -pancréatique). Les plantes qui produisent ces dérivés caffoyls sont donc des sources intéressantes de nouveaux aliments santé, d'allégations ou encore de boissons infusées aptes à lutter contre le syndrome métabolique. Les Astéracées semblent disposer de ces substances bénéfiques.Durant ma thèse, j'ai pu montré l'effet antidiabétique d'un extrait de racine de chicorée sauvage (NCRAE), riche en acide chicorique (CRA) et en dérivés caffeoyl-quinic acides (CQAs). L'analyse de l'extrait par LC-MS a permis de déterminer le ratio CRA/CQAs de 70/30. Nous avons montré qu'un mélange d'acide chicorique et d'acide chlorogénique (70/30) mime l' effet antidiabétique de NCRAE. Nous démontrons pour la première fois le bénéfice antidiabétique d'un mélange de dérivés caffeoylsDe nombreuses Astéracées produisent des mélanges divers de dérivés caffeoyls. Afin de mieux comprendre les effets de mélanges caffeoyls nous avons décidé de réaliser une évaluation des effets biologiques in vitro d'extraits riches en caffeoyls issus de dix Astéracées. Nous voulons ensuite réaliser une analyse corrélative entre leurs contenus et leurs effets. L'analyse LC-MS est en cours actuellement.Enfin, deux plantes exotiques (du Congo Kinshasa) bien connues pour leur vertu antidiabétique par les tradipraticiens ont été étudiées. Bien que faisant parties d'autres familles botaniques, celles-ci contiennent également des dérivés caffeoyls. Il était donc intéressant d'appliquer nos critères d'évaluation in vitro du potentiel antidiabétique d'une plante afin d'envisager ou non l'implication des dérivés caffeoyls.Mon travail soutien l'usage en mélanges des dérivés caffoyls afin de lutter contre le syndrome métabolique et le diabète de type 2. / Metabolic syndrome and type 2 diabetes are considered as chronic pathologies. The metabolic syndrome via physiological dysfunctions that self-sustain and expand will lead to type 2 diabetes. The major dysfunctions are abdominal obesity, inflammation and tissue oxidative stress and finally tissue insulin resistance. insulin sensitive. It is therefore necessary to fight effectively against these dysfunctions in order to fight against these chronic pathologies. The work of the team in which I carried out my thesis made it possible to highlight the pleiotropic effects of substances of the family of caffeoyls derivatives. These derivatives widely recognized as antioxidant substances have insulin-sensitizing effects (increase glucose uptake insulin stimulus) and also insulin-stimulating (increase the insulin secretion capacity of the -pancreatic cell). The plants that produce these caffoyl derivatives are therefore interesting sources of new health foods, claims or beverages infused to oppose the metabolic syndrome. Asteraceae seem to have these beneficial substances.During my thesis, I was able to show the antidiabetic effect of wild chicory root extract (NCRAE), rich in chicoric acid (CRA) and caffeoyl-quinic acid derivatives (CQAs). Analysis of the extract by LC-MS determined the CRA / CQAs ratio of 70/30. We have shown that a mixture of chicoric acid and chlorogenic acid (70/30) mimics the antidiabetic effect of NCRAE. We demonstrate for the first time the antidiabetic benefit of a mixture of caffeoyl derivativesMany Asteraceae produce various mixtures of caffeoyl derivatives. In order to better understand the effects of caffeoyl mixtures, we decided to carry out an evaluation of the in vitro biological effects of caffeoyl rich extracts from ten Asteraceae. We then want to carry out a correlative analysis between their contents and their effects. LC-MS analysis is ongoing.Finally, two exotic plants (Congo Kinshasa) well known for their antidiabetic properties by traditional "healers" were studied. Although belonging to other botanical families, these also contain caffeoyl derivatives. It was therefore interesting to apply our criteria of in vitro evaluation of the antidiabetic potential of a plant in order to envisage or not the implication of the caffeoyls derivatives.My work supports the use in mixtures of caffoyl derivatives to fight against metabolic syndrome and type 2 diabetes.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-05T14:14:07Z No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T13:40:18Z (GMT) No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) / Made available in DSpace on 2017-05-17T13:40:18Z (GMT). No. of bitstreams: 1 celsodeoliveirarezendejunior.pdf: 1703037 bytes, checksum: 06b6ddaff72097b07ba5ec7185f315b5 (MD5) Previous issue date: 2010-07-30 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / Este trabalho trata da síntese de cicloexanopoliois derivados do ácido quínico, esterificados com os ácidos cafeico e gálico. Esses compostos são candidatos novos agentes antivirais, principalmente como inibidores da enzima HIV-integrase, devido à semelhança estrutural com os derivados dicafeoíl-cicloexanodiois e ácidos dicafeoíl-quínicos, potentes inibidores dessa enzima. A partir de reações de esterificação, proteção e desproteção de compostos fenólicos e cicloexanopoliois foram sintetizados 41 compostos, sendo 26 inéditos, com rendimentos que variaram de 20 a 100%. As reações de proteção e desproteção seletivas das hidroxilas foram realizadas com sucesso. Na benzilação dos compostos (1R,2S,3R,5S)-1,2-Ocicloexilideno-1,2,3,5-tetraidroxicicloexano e (1R,2S,3R,5R)-1,2-O-cicloexilideno- 1,2,3,5-tetraidroxicicloexano a metodologia por transferência de fase se mostrou mais eficiente do que a metodologia convencional. Na tentativa de clivagem seletiva dos grupos benzila dos compostos (1R,2S,3R,5S)-1,2-di-O-(3’,4’-di-O-acetil)-cafeoíl-3,5-di-O-benzil-1,2,3,5-tetraidroxicicloexano e (1R,2S,3R,5R)-1,2-di-O-(3’,4’-di-Oacetil)-cafeoíl-3,5-di-O-benzil-1,2,3,5-tetraidroxicicloexano foram utilizadas quatro metodologias diferentes obtendo-se, para cada uma, a clivagem de grupos protetores diferentes. As estruturas dos compostos obtidos foram elucidadas por espectroscopia na região do infravermelho, RMN de 1H e de 13C, além da caracterização por ponto de fusão e poder rotatório específico. Alguns compostos finais foram encaminhados para testes anti-herpes (HSV-1 e HSV-2) e para avaliação das propriedades antioxidantes e antiparasitárias e serão encaminhados para testes anti- HIV-integrase. / This work describes the synthesis of cyclohexanepoliols derived from quinic acid, esterified with caffeic and gallic acids. These compounds are candidates as new antiviral agents, particularly as inhibitors of HIV integrase, due to their structural similarity to dicaffeoyl cyclohexanediols and dicaffeoyl quinic acid derivatives, potent inhibitors of this enzyme. We synthesized 41 compounds using reactions of esterification, protection and deprotection of phenolic and cyclohexanepoliol derivatives. The reactions of protection and selective deprotection of the hydroxyl groups were performed successfully. In the benzylation of compounds (1R, 2S, 3R, 5S)-1,2-O-cyclohexylidene-1,2,3,5-tetrahydroxycyclohexane and (1R, 2S, 3R, 5R)-1,2-O-cyclohexylidene-1,2,3,5-tetrahydroxycyclohexane the methodology employing phase transfer was more efficient than the conventional method. In an attempt to cleave selectively the benzyl groups of compounds (1R, 2S, 3R, 5S)-1,2-di-O-(3',4'-di-O-acetyl)-caffeoyl-3,5-di-O-benzyl-1,2,3,5-tetrahydroxycyclohexane and (1R,2S,3R,5R)-1,2-di-O-(3',4'-di-O-acetyl)-caffeoyl-3,5-di-O-benzyl-1,2,3,5- tetrahydroxycyclo-hexane four different methodologies were used. Each procedure led to cleavage of different protecting groups. The structures of the compounds were characterized by infrared spectroscopy, 1H and 13C NMR, melting point and specific optical rotation. Final compounds were sent for testing against herpes (HSV-1 and HSV-2) and biological evaluation of their antiparasitic and antioxidant properties and will be referred for testing against HIV integrase.