Le thiosemicarbazide et le 4-méthylthiosemicarbazide réagissent par condensation avec des dérivés benzaldéhyde pour donner des produits de type thiosemicarbazone pouvant jouer le rôle de ligands.Ces derniers peuvent conduire en milieu éthanolique à la formation de divers complexes en réagissant avec des sels métalliques comme les chlorures et/ou bromures de cuivre(II), de nickel(II), de zinc(II), de cobalt(II) et de cadmium(II). La structure de ces ligands et de leurs complexes a été déterminée par spectroscopie infrarouge, par des analyses élémentaires et par cristallographie. Les ligands se présentent tous sous forme thione à l’état solide tandis que les complexes obtenus peuvent revêtir différents états : soit monodentés, mononucléaire ou polynucléaire à deux atomes de soufre provenant du groupement thiosemicarbazone, comme l’étude cristallographique a pu le démontrer, soit bidentés avec des sites decoordination dont l’azote provenant du groupement imine et le soufre du groupement thiol. Les propriétés antifongiques de ces divers composés ont été testées vis-à-vis de champignons pathogènes de l’homme comme Aspergillus fumigatus, Candida albicans, C. glabrata, C. tropicalis, C. krusei, C. parapsilosis et Exophiala dermatitidis. Seuls les complexes avec le cadmium ont montré des activités antifongiques significatives et le ligand de pdiméthylaminobenzaldéhyde thiosemicarbazone a inhibé presque totalement la croissance d’E. dermatitidis / Thiosemicarbazide and 4-methylthiosemicarbazide react with benzaldehyde derivatives by condensation to give different thiosemicarbazone ligands. The latter conduct in ethanolic medium to various complexes by reacting with chlorides and / or bromidesof copper (II), nickel (II), zinc (II), cobalt (II) and cadmium (II). The structures of the ligands and their complexes have been determined mainly by crystallography and by infrared spectroscopy, as well as by elementary analyzes. The ligands are in thion form in solid form.The complexes obtained are either monodentate, mononuclear or polynuclear complexes with two sulfur atoms of the thiosemicarbazone group, such as the determination of the crystal structure has shown either bidentate complexes with coordination sites, imine nitrogen and sulfur of the thio group. Their antifungal properties have been tested against human pathogenic strains: Aspergillus fumigatus, Candida albicans, C. glabrata, C. tropicalis, C. krusei, C. parapsilosis and Exophiala dermatitidis. Only thecomplexes with cadmium exhibited significant activities against the fungal species studied and the thiosemicarbazone of p-dimethylaminobenzaldehyde ligand almost completely inhibited the growth of E. dermatitidis

Thesis (M. Sc. (Botany)) -- University of Limpopo, 2018 / The aim of the study was to investigate medicinal plants used for the treatment of various ailments by the traditional healers and local people and to determine antifungal activities against animal fungal pathogens. Ethnobotanical survey was conducted to identify medicinal plants used by local people and traditional healers to treat various ailments in Makhado Local Municipality, Vhembe District, Limpopo, South Africa. A questionnaire was designed to gather information on the local name of plants, plant parts used and the methods of preparation and administration by the traditional healers. In our findings, sixty-three medicinal plants belonging to thirty-three families were identified to be used for treatment of various diseases such as chest complaint, sexual transmitted infections, headache, swollen legs, hypertension, blood purification, asthma, and infertility. Specific parts of the plant used for medicinal purposes vary from species to species and from one traditional healer to another. The dominant families were Fabaceae, Celastraceae and Euphorbiaceae. Of the sixty-three plants species identified, trees were the most predominant plant form (53%), followed by shrubs (23%), herbs (14%), and climbers (10%). Root, fruit, bark, leaves, seeds and in some instances the whole plant are used for the preparation of medicine while decoction and infusion were the general methods of preparation. The mode of administration of medicine was mainly oral. The most frequently used plant species were Warbugia salutaris (Bertol.f.) Chiov, Sclerocarya birrea (A.Rich) Hochst and Eleondron transvaalense (Burtt Davy) R.H. Archer. Eight plant species (Asparagus buchananii Bak., Albuca seineri (Engl. & K.Krause) J.C Manning & Goldblatt, Elephantorrhiza elephantina (Burch.) Skeels, Indigofera circinnata Benth, Maerua juncea Pax, Pentarrhinum insipidum E. Mey., Senna italica Mill. and Schinus molle L.) were selected based on the information given by the local people and the traditional healers for further phytochemical analysis and microbiological assays. Antifungal activities of the selected plant species were determined against three fungal pathogens namely, Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. Of the tested plant species, hexane leaf extracts of M. juncea, ethyl acetate leaf extracts of S. italica, A. buchananii and E. elephantina were the most active against Candida albicans, Cryptococcus v neoformans and Aspergillus fumigatus with Minimum inhibitory concentration (MIC) values ranging between 0.02 mg/ml and 0.08 mg/ml. Bioautography assay was used to determine the number of active compounds in the plant extracts. No active compounds were observed in some plant extracts against the tested animal fungal pathogens indicating possible synergism. The most promising plant species were: A. buchananii, A. seineri and M. juncea, all had shown good activity with 4 compounds against A. fumigatus. Acetone and methanol extracts had the same active compounds visible on bioautograms. Most of the active compounds were observed in TLC chromatograms developed Benzene: ethanol: ammonia hydroxide (BEA) eluent solvent system. Based on excellent antifungal activity against the tested microorganisms, leaf extracts of A. buchananii, A. seineri M. juncea, P. insipidum and root extracts of I. circinnata were also tested for cytotoxicity against the Vero kidney cells. All plant extracts investigated were relatively not toxic against the cells with LC50 ranging between 0.131 mg/ml and  1 mg/ml. Water extracts of A. buchananii, A. seineri and M. juncea had LC50  1 mg/ml. The leaf aqueous extracts of P. insipidum were less toxic than root aqueous extracts of I. circinnata with LC50 of 0.65 mg/ml and 0.49 mg/ml against the Vero kidney cells respectively. The results indicate that the local people and traditional healers in Makhado Local Municipality use medicinal plants and their indigenous knowledge on the treatment of fungal infections and related ailments. / University of Limpopo and National Research Foundation (NRF)

L'étude des plantes utilisées en médecine traditionnelle au Togo est compliquée à cause de l’absence de matériel de pointe. L'identification assistée par ordinateur de produits basés sur des utilisations en médecine traditionnelle (CAPITURE) a été évaluée dans le cadre d'une enquête ethnobotanique sur le traitement traditionnel des maladies fongiques dans la Préfecture de Tchamba (Togo). Cette méthode a prédit et identifié les plantes les plus biologiquement actives parmi les 43 espèces recensées au cours de l’enquête : Pterocarpus erinaceus prédit être plus actif contre les champignons, et Daniellia oliveri contre les bactéries. Les plantes ont ensuite été testées contre les champignons, les bactéries et les cellules cancéreuses. Comme prédit par CAPITURE, P. erinaceus était plus actif contre les champignons et D. oliveri contre les bactéries. Fait intéressant, les deux plantes ont présenté une activité sur les cellules cancéreuses sans être toxique pour les cellules humaines normales. Dans une troisième étape, en utilisant la chimie analytique, les composés responsables des activités biologiques ont été identifiés. La plupart de ces composés n'ont jamais été signalés dans les espèces végétales ou dans la nature, avec une activité biologique dans la gamme micro-molaire. Enfin, en réduisant la poudre des organes végétaux à la taille de nano-particules, une meilleure activité biologique a été observée par rapport à celle de l'extrait organique. En conclusion, cette recherche a mené à la découverte de nouvelles molécules avec une activité biologique intéressante, molécules qui nécessiteront une étude approfondie et détaillée / The investigation of plants used for traditional medicine in Togo is complicated as modern techniques are not available. Computer-aided product identification from traditional usage records (CAPITURE) was evaluated in the context of an ethnobotanical survey on the traditional treatment of fungal diseases in Tchamba District (Togo). This method predicted and identified the most biologically active plants out of the 43 species survey-recorded: Pterocarpus erinaceus predicted to be more active against fungi and Daniellia oliveri against bacteria. The plants were then tested against fungi, bacteria and cancer cells. As predicted with CAPITURE, P. erinaceus was more active against fungi and D. oliveri against bacteria. Interestingly, both plants presented activity on cancer cells without being toxic to normal human cells. In a third step, using analytical chemistry, the compounds responsible for the biological activities were identified. Most of those compounds have never been reported in the plant species or in nature at all, with biological activity in the micromolar range. Finally, pharmaceutical technology was used: by nanosizing the powder of the plant organs, a better biological activity was observed in comparison to that of the organic extract. In conclusion, this research led to the discovery of new molecules with an interesting biological activity that will need further and more detailed investigation

Made available in DSpace on 2015-05-14T12:59:56Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 8420094 bytes, checksum: e38d9fce0fc67703d2f3e878474b7c32 (MD5) Previous issue date: 2013-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Piper L. genus is the largest one among the Piperaceae. Containing at least 1000 species, they are located mainly on the neotropical region of Earth and it draws our attention due to its medical, economical, chemical and cultural properties, such as anti-inflamatory, antibacterial and fungicide actions. Piper genus species have been becoming research sources for specific classes of secondary metabolites which play an important role concerning biological activities, including alkaloids, amides, chalcones, chromenes, flavonoids, lignans, terpenes, cyclopentanediones, steroids, porphyrin derivatives and benzoic acid derivatives. Piper caldense C. DC., which is commonly known as Pimenta D arda , is used in Paraíba as sedative, snake venom antidote, anti-toothache agent, and as active in located pain treatments through the use of compresses. This research reports the phytochemical study of P. caldense C. DC. leaves and fruits. Through usual chromatographic methods and spectroscopic techniques such as IR and one and two-dimensional ¹H and ³CNMR techniques and comparison with literature data it was possible to isolate and identify an mixture of the β-sitosterol and sitgmasterol steroids, besides porphyrin substances: 15-hydroxy-A-pophyrinlactone and a phaeophytin. Those fractions were obtained from crude ethanolic extract of P. caldense C. DC. leaves. Three benzoic acid derivatives were isolated from the hexane extract of P. caldense C. DC. fruits. From its leaves and fruits it was possible to obtain seven compunds commonly found it many vegetal species, but for the first time stated from P. caldense C. DC. The hexane and dichloromethane fruit extracts and isolated substances were submitted to microbiological assay and antifungal activites were detected concerning Candida genus yeast. This test is being done for the first time in the fruits of the studied species. / O gênero Piper L. é o maior da família Piperaceae, compreendendo pelo menos 1000 espécies, que se encontram distribuídas especialmente na região neotropical do globo terrestre e se destaca por suas propriedades medicinais, econômicas, químicas e culturais (anti-inflamatória, antibacteriana, anestésia e fungicida, dentre outros). Espécies do gênero Piper têm-se tornado fontes de pesquisa de classes específicas de metabólitos secundários com marcantes atividades biológicas, incluindo alcaloides, amidas, chalconas, cromenos, flavonoides, lignanas, terpenos e ciclopentanodionas, esteroides, derivados porfirínicos e derivados do ácido benzoico. Piper caldense C. DC., conhecida popularmente como pimenta d arda , é utilizada na Paraíba como sedativa, antídoto para picadas de cobras, para dores de dente, bem como na forma de compressa no local afetado para alívio da dor. Este trabalho reporta o estudo fitoquímico das folhas e frutos de P.caldense C. DC. Utilizando-se métodos cromatográficos usuais e técnicas espectroscópicas de IV e RMN de 1H e 13C uni e bidimensionais e a comparação dos dados com a literatura foi possível isolar e identificar do extrato etanólico bruto das folhas de Piper caldense C.DC., uma mistura de esteroides, o β-sitosterol e o estigmasterol, e duas substâncias porfirínicas, a 15-hidroxi-porfirionolactona A e a feofitina a, e, do extrato hexânico dos frutos, três derivados do ácido benzoico, compreendendo ao total sete substâncias, descritas pela primeira vez em Piper caldense C. DC. Os extratos hexânico e diclorometânico dos frutos e suas substâncias isoladas foram submetidos a ensaios microbiológicos, apresentando atividade antifúngica frente a leveduras do gênero Candida. Este ensaio está sendo feito pela primeira vez nos frutos da espécie estudada.