Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Plant Biology." Includes bibliographical references.

Thèse (Ph. D.)--Uppsala, 1937.

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-04-12T13:48:12Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Renyer A. Costa.pdf: 2722184 bytes, checksum: 3090e022cbc49cff37e2a3bf1e21398d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-04-12T13:49:10Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Renyer A. Costa.pdf: 2722184 bytes, checksum: 3090e022cbc49cff37e2a3bf1e21398d (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-04-12T13:49:28Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Renyer A. Costa.pdf: 2722184 bytes, checksum: 3090e022cbc49cff37e2a3bf1e21398d (MD5) / Made available in DSpace on 2017-04-12T13:49:28Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Renyer A. Costa.pdf: 2722184 bytes, checksum: 3090e022cbc49cff37e2a3bf1e21398d (MD5) Previous issue date: 2014-03-17 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Strychnos genus, the main of the Loganiaceae family, is distributed in tropical regions, principally on Africa, Asia, Central and Sourth America .It is well known for its toxic properties, wich led to the isolation a wide variety of indole alkaloids with diverse biological properties and medicinal application. In addition to the use in the manufacture of curare the Strychnos genus is important in ethnopharmacology due to antimalarial, aphrodisiac, tonic, and anti-anemic effects for American species.However, the most studied biological activities are anticonvulsants and relaxing. In this study, was performed a phytochemical and biological studies on the leaves and stem of the species Strychnos amazonica Krukoff. From the hexane extracts of the leaves and stem were obtained, respectively, as binary mixtures, the pentacyclic tritepenes, friedelin and friedelanol and the steroids, sitosterol and stigmasterol. Conventional methodology for obtaining alkaloids led to isolation of strictosidine from leaves and 17-O-methylakagerine along with its derivative named 4-hidroxi-metileno-17-O-methylakagerine, from core of the stem. However, the presence of impurities evidenced in the NMR spectra indicate further analysis for confirmation of the proposed structure of this derivative.The identification of compounds was done by spectroscopic techniques, especially, 1H NMR, HSQC and HMBC MS, and comparison with the literature data. Theoretical studies were performed on 17-Omethyl- akagerine alkaloids and strictosidine, where optimization geometric data obtained by DFT calculation (bond distances and angles) are presented and compared to experimental data (angles provided by coupling constants and X-ray data for similar molecules). Antimicrobial tests performed with methanol extracts of leaves, bark and heartwood, and the isolated alkaloids, showed significant activity of the samples, especially the alkaloid 17-O-methyl-akagerine against Candida albicans, confirming the great pharmacological potential of this species. / O gênero Strychnos, principal representante da família Loganiaceae, distribui-se em regiões tropicais, principalmente, na África, Ásia, América Central e América do Sul. O estudo deste gênero, muito conhecido por suas propriedades tóxicas, levou ao isolamento de diversos alcaloides com importantes atividades biológicas e aplicabilidade medicinal. Além do emprego na confecção dos curares o gênero Strychnos tem história na etnofarmacologia, registrando-se para as espécies americanas efeitos antimaláricos, afrodisíacos, tônicos, febrífugos e antianêmicos. No entanto, as atividades biológicas mais estudadas são as convulsivantes e relaxantes. No presente trabalho, foi realizado um estudo fitoquimico e biológico sobre a espécie da flora americana, Strychnos amazônica Krukoff. A partir dos extratos hexanicos das folhas e do cerne do caule, foram obtidas, respectivamente, misturas binárias, dos tritepenos pentacíclicos, friedelina e friedelanol e dos esteroides sitosterol e estigmasterol. Marcha química convencional para obtenção de alcaloides levou ao isolamento do alcaloide estrictosidina, das folhas, e 17-O-metil-acagerina e seu derivado inédito, denominado de 4-hidroxi-metileno-17-O-metil-acagerina, do cerne. Contudo, a presença de impurezas evidenciadas nos espectros de RMN, recomendam novas análises para confirmação da estrutura proposta para este derivado. A identificação dos compostos foi feita por técnicas espectroscópicasO gênero Strychnos, principal representante da família Loganiaceae, distribui-se em regiões tropicais, principalmente, na África, Ásia, América Central e América do Sul. O estudo deste gênero, muito conhecido por suas propriedades tóxicas, levou ao isolamento de diversos alcaloides com importantes atividades biológicas e aplicabilidade medicinal. Além do emprego na confecção dos curares o gênero Strychnos tem história na etnofarmacologia, registrando-se para as espécies americanas efeitos antimaláricos, afrodisíacos, tônicos, febrífugos e antianêmicos. No entanto, as atividades biológicas mais estudadas são as convulsivantes e relaxantes. No presente trabalho, foi realizado um estudo fitoquimico e biológico sobre a espécie da flora americana, Strychnos amazônica Krukoff. A partir dos extratos hexanicos das folhas e do cerne do caule, foram obtidas, respectivamente, misturas binárias, dos tritepenos pentacíclicos, friedelina e friedelanol e dos esteroides sitosterol e estigmasterol. Marcha química convencional para obtenção de alcaloides levou ao isolamento do alcaloide estrictosidina, das folhas, e 17-O-metil-acagerina e seu derivado inédito, denominado de 4-hidroxi-metileno-17-O-metil-acagerina, do cerne. Contudo, a presença de impurezas evidenciadas nos espectros de RMN, recomendam novas análises para confirmação da estrutura proposta para este derivado. A identificação dos compostos foi feita por técnicas espectroscópicas principalmente, RMN H1, HSQC HMBC e EM, e comparação com dados da literatura. Foram realizados estudos teóricos sobre os alcaloides 17-O-metilacagerina e estrictosidina, onde dados de otimização geométrica obtidos por cálculos DFT (distancias de ligação e ângulos) são apresentados e confrontados com dados experimentais (ângulos previstos pelas constantes de acomplamento e dados de Raio X de moléculas análogas). Testes antimicrobianos realizados com os extratos metanólicos das folhas, casca e cerne, e com os alcalóides isolados, revelaram significante atividade das amostras, com destaque para o alcaloide 17- O-metil-acagerina frente à Candida albicans, evidenciando o grande potencial farmacológico desta espécie.

This thesis deals with phylogenetic relationships at different taxonomic levels. All the plants studied are or have been included in the order Gentianales, which comprises about 17 200 species. The phylogenies are based on parsimony analyses of nucleotide sequence data (DNA) from different regions in the chloroplast genome, but morphological characteristics have also been studied. Analyses of sequence data from the genes rbcL and ndhF provide the interfamilial structure of the order Gentianales, shown to comprise the families Apocynaceae (incl. Asclepiadaceae), Gelsemiaceae, Gentianaceae, Loganiaceae, and Rubiaceae. Exclusion of certain genera from the Loganiaceae is confirmed and their phylogenetic positions are clarified. Some of these genera remain within the Gentianales, while others belong to other orders. Exclusion of the tribe Buddlejeae from the Loganiaceae is confirmed, and a monophyletic group formed by Buddleja, Emorya, Gomphostigma, and Nicodemia is recognized and placed in the Lamiales. The Loganiaceae s.str. forms, after these exclusions, a strongly supported monophyletic group comprising 13 genera. The tribe Paederieae in the family Rubiaceae is analysed using sequence data from the regions rbcL gene, rps16 intron, and the regions trnT-F, and is shown to be paraphyletic. These results lead to a new circumscription of Paederieae comprising the genera Leptodermis, Paederia, Serissa, and Spermadictyon. The tribe Putorieae is reestablished with the single genus Plocama, including 34 species. Aitchisonia, Choulettia, Crocyllis, Gaillonia, Jaubertia, Pseudogaillonia, Pterogaillonia, and Putoria are reduced to synonyms of Plocama based on the molecular analyses and morphological studies. The Mediterranean species of the re-circumscribed Plocama, previously segregated as the genus Putoria, are revised. Two species, Plocama calabrica and P. brevifolia, are recognized, their synonymics are established, and seven lectotypes are selected.

The apparent reversal of trend from modern drugs to herbal medicine is partly due to the fact that synthetic drugs have always shown adverse reactions and other undesirable side effects. Hence, the use of medicinal plants for the treatment of diseases such as diabetes is very common especially in the rural areas. Majority of these plants are used based on the experience and indigenous knowledge without identification of the therapeutic agents. There is enormous wealth of medicinal plants in the world yet many of them have not been discovered or studied scientifically to substantiate their ethno-medicinal usages. Ethnobotanical study has been the method often used to search for locally important plant species for the discovery of crude drugs with low side effects. An ethnobotanical survey was conducted on the medicinal plants commonly used for the management of diabetes mellitus in Nkonkobe Municipality, Eastern Cape of South Africa. Information was obtained through structured questionnaire administered to traditional healers and herbalists in the region. The study revealed 15 species of plants belonging to 13 families. Strychnos henningsii and Leonotis leonorus among others were repeatedly mentioned by the traditional healers as the two mostly used plants for the management of diabetes mellitus. The infusion and decoction of the roots, leaves and barks of these plants are the methods of preparation. The antioxidant potential of aqueous bark extract of S. henningsii was investigated both in vivo and in vitro using spectroscopic method. The antioxidant activity of the extract against hydrogen peroxide (H2O2), 2,2′-azinobis[3-ethylbenzothiazoline6-sulfonic acid] diammonium salt (ABTS), as well as reducing power was concentration dependent. The extract exhibited lower and average scavenging activities against 1,1diphenyl2picrylhydrazyl (DPPH) and nitric oxide (NO) radicals with IC50 value of 0.739 and 0.49 mg/ml respectively. The administration of the plant extract at 250, 500 and 1000 mg/kg significantly increased the activities of the antioxidant enzymes in the hepatotoxic rats induced with carbon tetrachloride. On the other hand, the stem bark extract had lower effect on lipid peroxidation level except at the dose of 250 mg/kg. The effect of oral administration of S. henningsii extract was evaluated in normal Wistar rats for 28 days. The observed result indicated non- toxic effect of sub-acute administration of plant extract to the animals except at certain doses. This is because, there was no apparent damage to some haematological and biochemical parameters used in assessing organ specific toxicity. However, the alterations observed on platelet, white blood cells and its differentials imply parameter and dose selective toxicity when repeatedly consumed on daily basis at the doses investigated. This study also investigated the antidiabetic activities of the extract at the doses of 125, 250 and 500 mg/kg body weight in diabetic rats induced with streptozotocin -nicotinamide for 15 days. The extract appreciably (P <0.05) reduced the blood glucose level, feed and water intake while the best result was obtained at 250 mg/kg. Similarly, the level of triacylglycerol at the three doses investigated was significantly decreased. In addition, the glucose tolerance was reduced to near normal level after 90 min at certain doses. The clinical significance of the extract on some biochemical and haematological parameters lessen both hepatic and renal damages. Anaemic condition in diabetic animals was also improved after plant extract administration. However, no significant effect was observed in white blood cells and some of its differentials. The extract demonstrated strong glucose utilization in 3T3-L1 cells with a response of 278.63 percent of the control at 12.5μg/ml while that of Chang liver cells was 103.54 percent. The cytotoxicity result revealed non toxic effects of the extract to both cell lines. Treatment of 3T3 L1 cells with the extract did not reduce lipid accumulation. The extract inhibited the activity of α- glucosidase and α- amylase in a concentration dependent manner with IC50 values of 38 μg/ml and 60.9 μg/ml respectively. The percentage protein antiglycation of S. henningsii was 18.4, 38.2 and 61.2 perceent for 0.25, 0.5 and 1 mg/ml respectively while aminoguanidine a known inhibitor of protein glycation was 87.2 percent at 1 mg/ml. The FRAP assay values of the extract was 357.05 μmol Fe (II)/g. The findings from this study support the folkloric usage of this plant for the management of diabetes mellitus in the region.