Há muitos agentes terapêuticos comercializados sob forma racêmica. Os enantiômeros podem apresentar diferenças significativas nos perfis farmacocinético e farmacodinâmico. O uso do enantiômero puro em formulações farmacêuticas pode resultar em melhor ajuste de dose e menos efeitos adversos. A atropina, um alcalóide natural da Atropa belladonna, é a mistura racêmica de l-hiosciamina e d-hiosciamina. Este fármaco é principalmente utilizado para dilatar a pupila e como um antiespasmódico. Para quantificar estes enantiômeros, foram desenvolvidos métodos analíticos utilizando a cromatografia líquida de alta eficiência (CLAE) com as fases estacionárias quirais Chiralcel-OD® e Chiral-AGP®. Para quantificar estes enantiômeros em soluções oftálmicas, foi realizada a validação com sucesso de um método por CLAE, empregando uma coluna Chiral-AGP®, a 20°C. A fase móvel foi uma solução tampão fosfato (contendo 10 mM de 1-octanosulfonato de sódio e 7,5 mM de trietilamina, ajustada para pH 7,0 com ácido fosfórico) e acetonitrila (99:1 v/v). A vazão foi de 0,6 mL/min, com detecção ultravioleta em 205 nm. No intervalo de concentração de 14,0 µg/mL a 26,0 µg/mL, o método é linear (r > 0,9999), exato (100,1% - 100,5%) e preciso (RSDsistema ≤ 0,6%; RSDintra-dia ≤ 1,1%; RSDentre-dias ≤ 0,9%). O método é específico e os testes de validação asseguram que as soluções de padrão e amostra são estáveis até 72 horas. O planejamento fatorial assegura a robustez com variação de ±10% nos componentes da fase móvel e 2°C na temperatura da coluna. / There are many therapeutic agents commercialized under racemic form. The enantiomers can show significant differences in the pharmacokinetic and pharmacodynamic profiles. The use of pure enantiomer in pharmaceutical formulations can result in better adjustment of dose and less adverse effects. Atropine, an alkaloid of the Atropa belladonna, is a racemic mixture of l-hyoscyamine and d-hyoscyamine. This drug is mainly used to dilate the pupil and as an antispasmodic agent. To quantify these enantiomers analytical methods were developed, using high performance liquid chromatography (HPLC) with chiral stationary phases Chiralcel OD® and Chiral AGP®. To quantify these enantiomers in ophthalmic solutions the validation of a HPLC method was performed using a Chiral AGP® column at 20°C. The mobile phase consisted of a buffered phosphate solution (containing 10 mM 1-octanesulfonic acid sodium salt and 7.5 mM triethylamine, adjusted to pH 7.0 with ortho-phosphoric acid) and acetonitrile (99:1 v/v). The flow rate was 0.6 mL/min, with ultraviolet detection at 205 nm. In the concentration range from 14.0 mg/mL to 26.0 mg/mL, the method is linear (r > 0.9999), exact (100.1% - 100.5%) and precise (RSDsystem ≤ 0.6%; RSDintra-day ≤ 1.1%; RSDinter day ≤ 0.9%). The method is specific and the validation tests assure that standard and sample solutions are stable for up to 72 hours. The factorial design assures the robustness with variation of ± 10% in the mobile phase components and 2°C of column temperature.

Τα ινδολοκαρβαζόλια είναι αλκαλοειδή και παρουσιάζουν ενα ευρύ φάσμα βιολογικών ιδιοτήτων, όπως αντιβακτηριακές, αντιμυκησιακές, αντιικές, υποτασικές, νευροπροστατευτικές ιδιότητες. Όμως η σημαντικότερη δράση τους είναι η αντικαρκινική. Η εργασία αυτή είναι ένα review των συνθετικών μεθόδων και των βιολογικών ιδιοτήτων των ινδολοκαρβαζολίων. Επίσης σχολιάζονται η βιοσύνθεσή τους, παράγωγες ενώσεις των ινδολοκαρβαζολίων αλλά και υποψήφια φάρμακα με δομή ινδοκαρβαζολίου. / Indolocarbazoles are alkaloids which display a wide range of biological properties including antibacterial, antifungal, hypotensive and neuroprotective properties. Their greatest interest is their antitumour properties. This is a review of the synthetic methods and biological properties of indolocarbazoles. Τheir biosynthesis, their derivatives and possible drugs are also included.

A novel hetero Diels-Alder reaction has been developed to facilitate the synthesis of annelated pyridines as models for pyridoacridine alkaloids. The key reaction is based on an intramolecular Diels-Alder reaction of an aza-1,3-butadiene with an appropriate dienophile, to yield the desired annelated pyridine. An extension of this methodology is to exploit the Eglinton copper (IT) dimerisation of terminal acetylenes. This allows for a unique double intramolecular hetero Diels-Alder reaction, where four new rings are formed in one step. This allows for a facile route to annelated bipyridines. Ultimately this methodology has led to an approach to the total synthesis of the natural product eilatin, a member of the class of compounds known as pyridoacridines.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The phytochemical study of the crude extract hexane, methanol and fractions (acid ether, basic ether and basic acetate) from the stem bark of E. crista-galli (Fabaceae) resulted in the isolation of four compounds: The phytosterol stigmasterol (70), the triterpene lupeol (71) and the alkaloids erysotrine (1) and epierythratidine (50), usual in the genus Erythrina. The structures of the isolated metabolites were elucidated by 1H and 13C NMR uni and bidimensional, and compared with standard sample and data available in the literature. The extracts, fractions and isolated compounds were tested for their antimicrobial and antitumor front cancer cells HT29 (colorectal) activities, as well as regarding the capacity of inhibition of enzymes prolyl oligopeptidase, dipeptidil peptidase-VI and acetylcholinesterase. The crude methanolic extract, all fractions and individual compounds showed high antimicrobial activity mainly against Gram-positive and Gram-negative bacteria. The results were satisfactory in POP inhibition assays, when the crude methanolic extract and its fractions, mainly acid ether fraction, showed great inhibitor potential against this enzyme. For DPP-IV only the crude hexane extract was active. The in vitro antitumoral activity of the crude methanolic extract, basic fractions and the isolate alkaloids was investigated at different concentrations against the human colon cancer cell line HT-29 (PicoGreen dsDNA assay). The results suggest that the anti-proliferative effect of E. crista-galli extract on HT-29 cancer cells may be attributed, at least in part, to the presence of the erythrinian alkaloids 1 and 50. / O estudo fitoquímico do extrato bruto hexânico, metanólico e frações (éter ácida, éter básica e acetato básica) das cascas do caule de E. crista-galli (Fabaceae) resultou no isolamento de quatro compostos: o fitoesterol estigmasterol (70) e o triterpeno lupeol (71) além dos alcaloides erisotrina (1) e epieritratidina (50) usuais do gênero Erythrina. As estruturas dos metabólitos isolados foram elucidadas através de RMN 1H e 13C, uni e bidimensionais, além de comparação com amostra padrão quando existente e dados disponíveis na literatura. Os extratos, as frações e os compostos isolados foram testados quanto à sua atividade antimicrobiana, antitumoral frente a células cancerígenas HT29 (colorretal) e de inibição das enzimas POP, DPP-IV e AChE. Dentre as amostras testadas, o extrato bruto metanólico (EBM), suas frações (FEA, FEB e FAB) e compostos isolados apresentaram grande potencial antimicrobiano principalmente frente as bactérias Gram-positivas e Gram-negativas. Os resultados obtidos nos ensaios enzimáticos foram satisfatórios para a enzima POP, onde o EBM e suas frações, principalmente a fração éterea ácida (FEA), demonstraram grande potencial inibidor desta enzima. Para a DPP-IV apenas o extrato bruto hexânico (EBH) mostrou-se ativo. O efeito antitumoral da planta em questão também foi investigado e os resultados obtidos indicam que o EBM, a combinação das frações FEB e FAB e o alcaloide epieritratidina (50) possuem um grande efeito antiproliferativo frente às células do colorretal (HT29) após 72 horas de exposição.

Espécies de Psychotria encontradas no sul do Brasil produzem alcalóides do tipo monoterpeno indólicos, alguns deles com interessantes atividades biológicas e oriundos de novas rotas biossintéticas. P. leiocarpa Cham. & Schlecht. acumula N, b-D-glicopiranosilvincosamida (GPV), o primeiro alcalóide N-glicosilado desta classe a ser descrito. O extrato contendo GPV apresenta atividade analgésica inespecífica e, na planta, sua biossíntese é regulada pelo desenvolvimento e por luz. P. umbellata Vell., por sua vez, produz psicolatina, que apresenta alto potencial farmacológico, pois apresenta atividade analgésica do tipo opióide, ansiolítica e antipsicótica, interagindo com receptores de diversos sistemas de neurotransmissores no sistema nervoso central. Além disso, psicolatina é um eficiente agente redutor de peróxidos e quencher de oxigênio singlet in vitro. Os objetivos do presente trabalho foram estudar a fotorregulação de GPV em plântulas de P. leiocarpa, assim como avaliar os efeitos antioxidantes e antimutagênicos in vivo do extrato foliar bruto de P. umbellata e de psicolatina purificada, utilizando a levedura Saccharomyces cerevisiae. Essas duas últimas substâncias também foram avaliadas quanto à capacidade antioxidante contra o radical hidroxila in vitro. Em ensaios de transição luz-escuro realizados com plântulas assépticas de P. leiocarpa, o acúmulo de GPV mostrou ser responsivo a alterações na condição luminosa de cultivo. O papel negativo do escuro contínuo na biossíntese de GPV foi comprovado pela redução dos níveis deste alcalóide em plântulas cultivadas na luz e transferidas para o escuro. Por outro lado, quando plântulas cultivadas no escuro foram expostas à luz, os níveis de GPVaumentaram, indicando o caráter promotor da luz na produção de GPV. Os efeitos das transições foram mais evidentes em plântulas cultivadas em meio sem sacarose do que em plântulas cultivadas com suprimento exógeno de carboidratos. A biossíntese de GPV é regulada por diferentes faixas de luz. As regiões do azul e do vermelho-extremo aumentaram os teores de GPV. A luz vermelha não afetou de forma significativa o teor de GPV. Os resultados revelam um padrão típico de VLFRs (Very Low Fluence Responses), possivelmente envolvendo ação de PhyA em conjunto com criptocromo.Tanto o extrato bruto foliar de P. umbellata quanto psicolatina apresentaram efeito antioxidante in vivo, reduzindo a inibição do crescimento de Saccharomyces cerevisiae sob estresse oxidativo induzido por peróxido de hidrogênio e paraquat. O extrato e o alcalóide purificado também apresentaram ótima atividade antioxidante in vitro, protegendo contra o ataque do radical hidroxila. Os índices de mutagênese induzida por peróxido de hidrogêncio foram significativamente reduzidos quando as células de S. cerevisiae foram co-cultivadas na presença tanto do extrato quanto de psicolatina. / Species of Psychotria founded in southern Brazil produce a set of novel monoterpene indole alkaloids (MIAs), several of which have interesting biological activities and originate from new metabolic pathways. P. leiocarpa Cham. & Schlecht. accumulates N, b-D-glucopyranosylvincosamide (GPV), the first N-glycosylated MIA described. Leaf extracts containing GPV display nonspecific analgesic activity and, in planta, its biosynthesis is regulated by development and light. P. umbellata Vell., in turn, produces psychollatine which has significant pharmacological potential, since it yields opioid-like analgesic, anxiolytic and antipsychotic activities, interacting with receptors of different neurotransmitter systems in the central nervous system. In addition, psychollatine is an efficient peroxide reducing agent and a singlet oxygen chemical quencher in vitro. This work aimed at studying the photoregulation of GPV in P. leiocarpa seedlings, as well as at investigating the antimutagenic and antioxidant in vivo effects of the crude foliar extract of P. umbellata and purified psychollatine using the yeast Saccharomyces cerevisiae. These last substances were also evaluated for their in vitro antioxidant properties against hydroxyl radicals.In light-dark transition assays with aseptic P. leiocarpa seedlings, GPV accumulation showed to be responsive to changes in light condition. The negative role of continuous dark on GPV biosynthesis was shown by reduction of the alkaloid contents when light growing seedlings were transferred to dark. On the other hand, dark growing seedlings increased GPV contents after light exposure, suggesting a positive light regulation of GPV production. Theseresults were more evident in seedlings cultivated in media without sucrose than in seedlings cultivated with carbohydrate supplementation. GPV biosynthesys is also regulated by different light qualities. Light in the blue and far-red regions increased GPV accumulation, whereas red ligh had no significant influence on GPV yield. These results are in agreement with the profile of VLFRs (Very Low Fluence Responses), mediated by PhyA with coaction of cryptochrome. Both the crude foliar extract of P. umbellata and psychollatine showed in vivo antioxidant effects by reducing the growth inhibition of Saccharomyces cerevisiae under hydrogen peroxide- and paraquat-induced oxidative stress. The extract and the purified alkaloid also showed strong in vitro antioxidant activity against hydroxyl radicals. The levels of hydrogen peroxide-induced mutagenicity were significantly reduced when S. cerevisiae cells were cocultivated with leaf crude extract or psychollatine.

Les nanoparticules métalliques (MNPs) ont un grand succès dans les dernières décennies dû à la variété d'applications dans différents domaines (microélectronique, matériaux, catalyse). Mis à part les solvants organiques, les liquides ioniques, l'eau, le CO2 supercritique et les polyols, en particulier le glycérol, ont démontré leur capacité à stabiliser et immobiliser les nanoparticules métalliques. Ces milieux évitent l'agglomération des MNPs et facilitent leur recyclage. Des nanoparticules de Pd(0) et Ni(0) dans le glycérol, sphériques, petites en taille et bien dispersées, ont été synthétisées avec succès à partir d'une méthodologie simple sous pression d'hydrogène, en présence de différents stabilisants (alkaloïdes, phosphine, polymer). La caractérisation complète de ces matériaux en solution et à l'état solide, ainsi que la possibilité de faire des synthèses à grande échelle et de stocker les solutions catalytiques longtemps, montrent la grande stabilité de ces solutions colloïdales. Les nanoparticules dans le glycérol ont été impliquées dans une large variété de transformations : hydrogénations, hydrodéhalogénations, couplages de Hiyama, additions conjuguées et hydrosilylations. De plus, nous avons étudié l'effet du stabilisant sur la réactivité catalytique, nous permettant de contrôler l'état de surface des nanoparticules et moduler ainsi leur réactivité. Nous avons montré, de même, la capacité du glycérol pour immobiliser les catalyseurs, ce qui s'est traduit par la possibilité de recycler la phase catalytique entre 4 et 10 fois sans perte de metal. En parallèle, nous avons évalué le comportement du Ni(OAc)2 libre de ligands dans le glycérol, en tant que catalyseur alternatif pour des couplages C-C et C-hétéroélément. Nous présentons aussi une étude en flux continu, en collaboration avec la Maison Européenne des Procédés Innovants (MEPI), pour l'hydrogénation de différents groupes fonctionnels, en utilisant les PdNPs dans le glycérol synthétisées préalablement. / Metal nanoparticles (MNPs) have been largely studied in the last decades due to their interesting properties which found applications in several fields (microelectronics, materials and catalysis, among others). In contrast to common organic solvents, ionic liquids, water, supercritical CO2, polyols such as glycerol, represent innovative solvents for the immobilization of MNPs, avoiding their agglomeration and facilitating their recycling. Small, spherical, and well-dispersed Pd(0) and Ni(0) nanoparticles were synthesized under hydrogen pressure in glycerol, in the presence of different kinds of stabilizers (cinchona-based alkaloids, phosphine, polymer). The high stability of these colloidal solutions permitted the full characterization both in solution and at solid state, large-scale synthesis, and stocking the solutions for months. These colloidal catalysts were applied in a large variety of transformations including hydrogenations, hydrodehalogenations, Hiyama C-C couplings, hydrosilylation reactions, and Michael conjugate additions. Furthermore, we conducted a comparative study exhibiting the differences in catalytic reactivity by effect of the stabilizer, allowing us tuning the surface-state of the nanoparticles. Moreover, we showed the ability of glycerol to immobilize metal nanoparticles permitting the recycle of the catalytic phase between 4 and 10 times, without metal leaching. Additionally, we studied the behavior of ligand-free Ni(OAc)2 in glycerol as an alternative catalyst for C-C and C-heteroatom couplings. Also, we developped a continuous flow study, in collaboration with the Maison Européenne des Procédés Innovants (MEPI), for the hydrogenation of different functional groups, using PdNPs in glycerol

[pt] Métodos baseados na cromatografia líquida micelar (MLC) com detecção fluorimétrica foram desenvolvidos para dois estudos de caso. No primeiro deles, seis B-carbolinas (harmol, harmalol, harmane, norharmane, harmine e harmaline) foram plenamente separadas de modo a se aplicar o método para a determinação dos alcaloides em formulações de Passiflora incarnata L., extrato seco de Passiflora alata Dryander e em urina. A separação foi realizada em coluna cromatográfica C18, utilizando fase móvel tamponada (pH 8,0) contendo 220 mmol L-1 de dodecilsulfato de sódio (SDS)/acetonitrila (97/3 por cento v/v). A detecção fluorimétrica permitiu que se atingissem limites de detecção (LOD) abaixo de 3,6 ng g-1 com repetibilidade e precisão intermediária entre 0,1 e 5 por cento. As incertezas combinadas associadas à concentração das B-carbolinas ficaram entre 1 e 9 por cento. O método proposto foi comparado ao método baseado na cromatografia eletrocinética micelar (MEKC) com detecção absorciométrica e os resultados com MLC se mostraram superiores do ponto de vista da capacidade de detecção (por serem os alcaloides naturalmente muito fluorescentes) e de recuperação. Para as amostras de fitoterápicos, o harmol foi quantificado tanto nas amostras de medicamento de Passiflora incarnata quanto em urina de voluntário após a administração de fitoterápico. O harmine foi detectado apenas na amostra de medicamento. Os alcaloides norharmane, harmine e harmaline foram identificados no chá misto de Maracujá, no qual continha em sua composição extrato seco de Passiflora alata Dryander. Na segunda abordagem, um método por MLC foi desenvolvido para a determinação de galantamina e de seus principais metabólitos (N-desmetil galantamina, O-desmetil galantamina, epigalantamina e N-óxido galantamina). A separação da galantamina e dos metabólitos foi feita utilizando coluna cromatográfica C18 com porosidade de 300 angstroms e fase móvel constituída de tampão (pH 5,0) contendo 25 mmol L-1 de SDS/acetonitrila (97/3 por cento v/v). A detecção fluorimétrica permitiu limites de detecção abaixo de 343 ng g-1, repetibilidade e precisão intermediária entre 2,2 e 4 por cento. As incertezas combinadas associadas à concentração de galantamina e dos metabólitos ficaram entre 0,3 e 11 por cento. Ensaios de recuperação foram realizados em amostra de urina fortificada com padrões da galantamina e metabólitos e os resultados obtidos ficaram entre de 91,4 e 114,8 por cento. A comparação entre o método por MLC e o método por cromatografia líquida de alta eficiência com fase reversa foram feitas com amostras de medicamento cujo princípio ativo era o hidrobrometo de galantamina. Os resultados dos teores de galantamina e as variâncias das medidas obtidas por ambos os métodos foram estatisticamente iguais. A sensibilidade da curva analítica obtida por MLC foi duas vezes maior do que a encontrada por cromatografia por fase reversa. Análises de urina de ratos coletadas após a administração do medicamento foram realizadas com o método proposto, sendo que a galantamina mais os metabólitos N-óxido galantamina e N-desmetil galantamina foram identificados nas amostras. Para melhor avaliar o efeito de amplificação de fluorescência da galantamina pelo ambiente organizado, experimentos foram feitos com a separação cromatográfica de fase reversa e com a adição de solução rica em micelas de SDS após a passagem do analito pela coluna cromatográfica. As condições de separação incluíram o uso de coluna cromatográfica C18, fase móvel constituída por tampão (pH 5,0) contendo 2 por cento de propano-2-ol (v/v)/ acetonitrila (80/20 por cento v/v). A solução micelar de SDS (100 mmol L-1), misturada à fase móvel após a coluna cromatográfica, foi preparada com a mesma composição da fase móvel. A sensibilidade da curva analítica de galantamina foi três vezes maior quando o meio micelar foi usado. O resultado prova que o ambiente micelar favorece a medição fluorimétrica de galantam / [en] Methods based on micellar liquid chromatography (MLC) with fluorimetric detection have been developed for two case studies. In the first, six B-carbolines (harmol, harmalol, harmane, norharmane, harmine and harmaline) were fully separated allowing the application of the method for the determination of these alkaloids in Passiflora incarnata L. formulations, in Passiflora alata Dryander dry extract and in urine. The chromatographic separation was performed on a C18 column using a buffered mobile phase consisting of disodium hydrogen phosphate (pH 8.0) containing 220 mmol L-1 of sodium dodecyl sulfate (SDS)/acetonitrile (97/3 percent v/v). The fluorimetric detection allowed limits of detection (LOD) below than 3.6 ng g-1 to be achieved with intermediary precision and repeatability between 0.1 and 5 percent. The calculated combined uncertainties of the concentration of B-carbolines were between 1 and 9 percent. The proposed method was compared with the method based on micellar electrokinetic chromatography (MEKC) with absortionmetric detection. The MLC results were superior from the viewpoint of the detection power (since they are very fluorescent alkaloids) and also in terms of recovery. The harmol was quantified in Passiflora incarnata phitotherapic samples and in urine collected from a voluntary after of the administration of herbal medicine. The harmine was detected only in the phitotherapic sample. The norharmane, harmine and harmaline alkaloids were identified in Passion Fruit tea, which contained dry extract of Passiflora alata Dryander. In the second approach, a method for MLC was developed for the determination of galantamine and its main metabolites (N-demethyl galantamine, O-demethyl galantamine, epigalantamine and N-oxide galantamine). The separation was performed using a C18 chromatography column with porosity of 300 angstroms and with mobile phase consisting of buffer (pH 5.0) containing SDS (25 mmol L-1)/acetonitrile (97/3 percent v/v). The fluorimetric detection enabled LOD below 343 ng g-1 with intermediate precision and repeatability between 2.2 and 4 percent. Combined uncertainties for concentration of galantamine and metabolites were between 0.3 and 11 percent. Recovery experiments were performed on urine samples fortified with galantamine standards and metabolites with results between 91.4 and 114.8 percent. A comparison between the proposed MLC method and reverse phase high performance liquid chromatography was made using medicine samples containing galantamine hydrobromide as the active principle. Galantamine levels and variances achieved with these methods were statistically equal. The analytical curve sensitivity by MLC was two times higher than that found with reverse phase high performance liquid chromatography. Analysis of rat urine, collected after the administration of the medicine, were performed with the proposed method enabling the identification of galantamine, N-oxide galantamine and N-demethyl galantamine. To better evaluate the fluorescence amplification effect of galantamine in the organized environment, experiments were made with conventional chromatographic separation and post-column addition of the aqueous solution rich in micelles. The separation conditions included the use of C18 chromatographic column, mobile phase consisting of buffer (pH 5.0) containing 2 percent of propan-2-ol (v/v)/acetonitrile (80/20 percent v/v). The micellar solution of SDS (100 mmol L-1), added after the chromatographic column, was prepared with the same composition of the mobile phase. The column temperature was 25 degrees C and the sample volume was 20 uL. The sensitivity of the analytical curve of galantamine was three times higher when the micellar solution was mixed, proving that the organized environment favors the galantamine fluorescence even at flow regime. Recoveries with or without post-column mixing with the micelle rich solution were between 97.5 and 102.2 percent.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Eliška Holinská Supervisor: Prof. MUDr. Radomír Hrdina, CSc. Title of diploma thesis: Pharmacoteraphy of headache in adults Headache is one of the most common health problem that encounters almost everyone during the life. Depending on the cause, headaches can be divided on the primary headaches, which are the subject of the diploma thesis, and secondary headaches, which are caused by other diseases. The primary headaches are migraine, tension-type headache, cluster headache and primary chronic daily headache. Headache is not a life-threating condition but it can significantly reduce the quality of life, particularly the chronic forms of headache. The determination of the right diagnosis is essential for the choice of appropriate therapy. For primary headache are typical negative test results, there are no structural lesions or signs of organic brain damage. Diagnostics is comlicated and it is primarily based on a carefully processed medical history. In the therapy of primary headache are used both pharmacological and non-pharmacological methods, optimaly in combination. Pharmacological treatment consists of preventive and acute therapy. The preventive treatment is given to reduce the...

Ce travail de recherche a pour objectifs d’évaluer les activités antibactériennes, antiprolifératives et antioxydantes des extraits de feuilles de Solanum incanum L., S. schimperianum Hochst, S. nigrum L., Physalis lagascae Roem. & Schult. et Withania somnifera (L) Dunal. Plus précisément, les activités antibactériennes, anti-prolifératives et antioxydantes ont été déterminées à partir des extraits méthanoliques et des fractions de glycoalcaloïdes stéroïdiens (SGAF) de chaque plante. La sensibilité des bactéries, à Gram positif et à Gram négatif, était variable en présence de chacun des extraits (valeurs des IC50 dans la gamme de 15 > 1000 μg / mL). L'extrait méthanolique de la feuille de S. schimperianum a montré une activité anti-proliférative intéressante contre les lignées cellulaires humaines testées avec des valeurs de CI50 variant de 2,69 à 19,83 μg / mL tandis que l'activité la plus élevée des fractions de feuilles (SGAF) de W. somnifera a montré des valeurs IC50 variant de 1,29 à 5,00 μg / mL. Les fractions SGAF de toutes les espèces ont montré une activité antiradicalaire plus élevée que leurs extraits méthanoliques. La fraction SGAF de S. schimperianum a montré l'activité antioxydante la plus forte avec une valeur CI50 3,5 ± 0,2 μg / mL pour le test DPPH et 3,5 ± 0,3 μg / mL pour le test ABTS. L'analyse GC-MS des extraits méthanoliques et des fractions SGAF des espèces étudiées a révélé la présence d'alcaloïdes stéroïdiens, de saponines stéroïdiennes, de stéroïdes et d'autres composés comme des terpènes, des phénols et des alcanes. Leur répartition variait selon les espèces et, ce qui peut fournir des éléments pour évaluer les relations chimiotaxonomiques préliminaires. Douze dérivés de l'acide hydroxycinnamique ont été identifiés dans l'extrait méthanolique de la feuille de S. schimperianum et le composé N-caffeoyl agmatine était majoritaire. La présence d'alcaloïdes stéroïdiques comme la solanopubamine et la solanocapsine, ainsi que des dérivés des alcaloïdes 3-amino stéroïdes a été notée. De plus, trois composés, quercétine, kaempférol glycosylé et le β-sitostérol, ont été isolés et identifiés / This study aimed at the evaluation of in vitro antibacterial, antiproliferative and antioxidant activities of methanolic leaf extracts and steroidal glycoalkaloids fractions (SGAFs) of Solanum incanum L., S. schimperianum Hochst, S. nigrum L., Physalis lagascae Roem. & Schult. and Withania somnifera (L) Dunal. The sensitivity of Gram-positive and Gram-negative bacteria to each extract was variable (IC50 values in the range of 15->1000 µg/mL). The methanolic extract of S. schimperianum leaf demonstrated interesting anti-proliferative activity against the human cell lines tested with IC50 values in the range of 2.69 to 19.83 µg/mL while the highest activity from the SGAFs was obtained from W. somnifera leaf with IC50 values in the range of 1.29 to 5.00 µg/mL. The SGAFs of all species demonstrated higher scavenging activity than their respective methanolic extracts. The SGAF of S. schimperianum displayed the strongest antioxidant activity in both assays with IC50 value 3.5 ± 0.2DPPH and 3.5 ±0.3ABTS µg/mL. GC-MS analysis of methanolic and SGAFs extracts of the studied species revealed the presence of steroidal alkaloids, steroidal saponins, steroids and other compounds like terpenes, phenols and alkanes. Their distribution varied among the species and thus they could provide evidence to assess preliminary chemotaxonomic relationships. Twelve known hydroxycinnamic acid amides were tentatively identified from the methanolic extract of S. schimperianum leaf and N-caffeoyl agmatine appeared with the highest intensity. Moreover, the presence of steroid alkaloids solanopubamine and solanocapsine as well as dehydroderivatives of the 3-amino steroid alkaloids was suggested. Furthermore, three compounds quercetin, kaempferol glycoside and β-sitosterol were isolated and identified. In silico investigation of these three compounds for their potency against cancer revealed that β-sitosterol was found to be the most selective compound against human pregnane X receptor (PXR) and gave the highest binding energy (-11.2 kcal/mol). These results suggested that Solanaceae plants endogenous to Sudan could be a potential source of bioactive agents

Espécies de Psychotria encontradas no sul do Brasil produzem alcalóides do tipo monoterpeno indólicos, alguns deles com interessantes atividades biológicas e oriundos de novas rotas biossintéticas. P. leiocarpa Cham. & Schlecht. acumula N, b-D-glicopiranosilvincosamida (GPV), o primeiro alcalóide N-glicosilado desta classe a ser descrito. O extrato contendo GPV apresenta atividade analgésica inespecífica e, na planta, sua biossíntese é regulada pelo desenvolvimento e por luz. P. umbellata Vell., por sua vez, produz psicolatina, que apresenta alto potencial farmacológico, pois apresenta atividade analgésica do tipo opióide, ansiolítica e antipsicótica, interagindo com receptores de diversos sistemas de neurotransmissores no sistema nervoso central. Além disso, psicolatina é um eficiente agente redutor de peróxidos e quencher de oxigênio singlet in vitro. Os objetivos do presente trabalho foram estudar a fotorregulação de GPV em plântulas de P. leiocarpa, assim como avaliar os efeitos antioxidantes e antimutagênicos in vivo do extrato foliar bruto de P. umbellata e de psicolatina purificada, utilizando a levedura Saccharomyces cerevisiae. Essas duas últimas substâncias também foram avaliadas quanto à capacidade antioxidante contra o radical hidroxila in vitro. Em ensaios de transição luz-escuro realizados com plântulas assépticas de P. leiocarpa, o acúmulo de GPV mostrou ser responsivo a alterações na condição luminosa de cultivo. O papel negativo do escuro contínuo na biossíntese de GPV foi comprovado pela redução dos níveis deste alcalóide em plântulas cultivadas na luz e transferidas para o escuro. Por outro lado, quando plântulas cultivadas no escuro foram expostas à luz, os níveis de GPVaumentaram, indicando o caráter promotor da luz na produção de GPV. Os efeitos das transições foram mais evidentes em plântulas cultivadas em meio sem sacarose do que em plântulas cultivadas com suprimento exógeno de carboidratos. A biossíntese de GPV é regulada por diferentes faixas de luz. As regiões do azul e do vermelho-extremo aumentaram os teores de GPV. A luz vermelha não afetou de forma significativa o teor de GPV. Os resultados revelam um padrão típico de VLFRs (Very Low Fluence Responses), possivelmente envolvendo ação de PhyA em conjunto com criptocromo.Tanto o extrato bruto foliar de P. umbellata quanto psicolatina apresentaram efeito antioxidante in vivo, reduzindo a inibição do crescimento de Saccharomyces cerevisiae sob estresse oxidativo induzido por peróxido de hidrogênio e paraquat. O extrato e o alcalóide purificado também apresentaram ótima atividade antioxidante in vitro, protegendo contra o ataque do radical hidroxila. Os índices de mutagênese induzida por peróxido de hidrogêncio foram significativamente reduzidos quando as células de S. cerevisiae foram co-cultivadas na presença tanto do extrato quanto de psicolatina. / Species of Psychotria founded in southern Brazil produce a set of novel monoterpene indole alkaloids (MIAs), several of which have interesting biological activities and originate from new metabolic pathways. P. leiocarpa Cham. & Schlecht. accumulates N, b-D-glucopyranosylvincosamide (GPV), the first N-glycosylated MIA described. Leaf extracts containing GPV display nonspecific analgesic activity and, in planta, its biosynthesis is regulated by development and light. P. umbellata Vell., in turn, produces psychollatine which has significant pharmacological potential, since it yields opioid-like analgesic, anxiolytic and antipsychotic activities, interacting with receptors of different neurotransmitter systems in the central nervous system. In addition, psychollatine is an efficient peroxide reducing agent and a singlet oxygen chemical quencher in vitro. This work aimed at studying the photoregulation of GPV in P. leiocarpa seedlings, as well as at investigating the antimutagenic and antioxidant in vivo effects of the crude foliar extract of P. umbellata and purified psychollatine using the yeast Saccharomyces cerevisiae. These last substances were also evaluated for their in vitro antioxidant properties against hydroxyl radicals.In light-dark transition assays with aseptic P. leiocarpa seedlings, GPV accumulation showed to be responsive to changes in light condition. The negative role of continuous dark on GPV biosynthesis was shown by reduction of the alkaloid contents when light growing seedlings were transferred to dark. On the other hand, dark growing seedlings increased GPV contents after light exposure, suggesting a positive light regulation of GPV production. Theseresults were more evident in seedlings cultivated in media without sucrose than in seedlings cultivated with carbohydrate supplementation. GPV biosynthesys is also regulated by different light qualities. Light in the blue and far-red regions increased GPV accumulation, whereas red ligh had no significant influence on GPV yield. These results are in agreement with the profile of VLFRs (Very Low Fluence Responses), mediated by PhyA with coaction of cryptochrome. Both the crude foliar extract of P. umbellata and psychollatine showed in vivo antioxidant effects by reducing the growth inhibition of Saccharomyces cerevisiae under hydrogen peroxide- and paraquat-induced oxidative stress. The extract and the purified alkaloid also showed strong in vitro antioxidant activity against hydroxyl radicals. The levels of hydrogen peroxide-induced mutagenicity were significantly reduced when S. cerevisiae cells were cocultivated with leaf crude extract or psychollatine.