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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo etnofarmacol?gico e fitoqu?mico das esp?cies medicinais Cleome spinosa Jacq, Pavonia varians Moric e Croton cajucara Benth

Leal, Ros?lia de Sousa 02 September 2008 (has links)
Made available in DSpace on 2014-12-17T15:42:04Z (GMT). No. of bitstreams: 1 RoseliaSL.pdf: 2427942 bytes, checksum: 72c973dd87b5433d7d0b592195af336a (MD5) Previous issue date: 2008-09-02 / In this present work an ethnographic research was performed with 84 native medicinal specimens from the Litoral Norte Riograndense, from which two plants Cleome spinosa Jacq e Pavonia varians Moric were submitted to ethnobotanic, phytochemistry and pharmacologic investigations. Additionally, a phytopharmacological research of the medicinal specimen Croton cajucara Benth ( native plant of the Amazon region of Brazil) was improved. The obtained phytochemical results of the C. spinosa and P. varians showed the presence of flavonoids constituents, among other components. The two flavonoids (2S)-5-hydroxy-7,4 -dimethoxy-flavanone and 5,4 -dihydroxy-3,7,3 -trimethoxy-flavone were isolated from C. spinosa. The antioxidant activity of the hydroalcoholic extracts of C. spinosa and P. varians solubilized in the microemulsion systems SME-1 and SME-4, was evaluated in the DPPHmethod. The used SME systems [obtained with Tween 80: Span 20 (3:1) and isopropyl myristate (IPM)] improved the dissolution of those tested polar extracts, with higher efficacy to the SME-1 system (in which ethanol was included as cosurfactant). The CE50 values evidenced for P. varians were 114 [g/mL (SME-1) and 246 [g/mL (SME-4); for C. spinosa it was 224 [g/mL (SME-1) and 248 [g/mL (SME-4), being the system SME-1 more effective for both tested extracts. The hydroalcoholic extracts of P. varians (HAE-PV) was also submitted to pharmacological screening for antinociceptive activity in animal models. The oral administration of this extract (100, 300 and 1000 mg/kg) inhibited the acetic acid-induced writhing in mice. The higher inhibition (74%) was evidenced to the 1000 mg/kg administered dose. Its effect on the central nervous system (CNS) was investigated by tail flick and formalin-method and reveled that it has negligible antinociceptive action on the CNS. After taking consideration of HAE-PV interaction, Pavonia varians Moric could be used as a potent analgesic agent in case of peripheral algesia, without affecting the CNS. The phytochemical study of the stem bark of Croton cajucara Benth lead to the isolation of 19-nor-clerodanetype diterpenes, as well as to the separation of its fixed oil FO-CC. This non polar oil material reveled to be rich in sesquiterpenes and 19-nor-clerodanes components. The biologic effect of OF-CC was evaluated in the development in vitro of the fungis phytopatogens such as Fusarium oxysporum, Rhizoctonia solani and Sclerotium rolfsii. Significant inhibitory effect of the tested fungis (at 0,2 mg.mL-1 dosage) were comproved. A Mass Spectrometry study of clerodane-type diterpenes was developed in order to identify characteristic fragments on mass spectrometra of both clerodane and 19-nor-clerodane presenting an α,β-insaturated carbonyl moiety at ring A of the decalin-system. For that study, mass spectroscopy data were analysed for 19-nor-clerodanes [trans-dehydrocrotonin (DCTN), trans-crotonin (CTN), cis-cajucarin B (c-CJC-B), and cajucarinolide (CJCR)] and for clerodanes [isosacacarin (ISCR) and transcajucarin A (t-CJC-A)] obtained from the stem bark of C. cajucara, and also clerodane-type from other species. The trans-junction of the enone-system clerodanes was clear correlated with the presence of the characteristic ions at m/z 95, 121 e 205. Meanwhile, the characteristics ions at m/z 122 e 124 were correlated to cis-junction. The trans-junction of the enone-system 19-nor-clerodanes showed characteristics ions at m/z 161, 134 e 121. This study could be successful employed for identification of clerodane constituents from other specimens without any additional spectroscopic analyses, as well as a previously phytochemical analyzes in clerodane project search / Neste trabalho realizou-se uma pesquisa etnogr?fica envolvendo oitenta e quatro esp?cimes vegetais nativas do Litoral Norte Riograndense. Duas destas esp?cies Cleome spinosa Jacq e Pavonia varians Moric foram alvo de estudos etnobot?nico, fitoqu?mico e farmacol?gico. Em adi??o, ampliou-se os estudos fitofarmacol?gicos de Croton cajucara Benth, uma esp?cie medicinal nativa da regi?o Amaz?nica. Os resultados fitoqu?micos de Cleome spinosa e Pavonia varians indicaram dentre outros metab?litos especiais, a presen?a de flavon?ides. Os flavon?ides (2S)-5-hidroxi-7,4 -dimetoxi-flavanona e 5,4 -diidroxi-3,7,3 -trimetoxi-flavona foram isolados de Cleome spinosa. A atividade antioxidante dos extratos hidroalco?licos de P. varians e C. spinosa solubilizados em sistemas microemulsionados (SME), foi avaliada frente ao radical livre DPPH. Os sistemas SME-1 e SME-4 [contendo Tween 80: Span 20 (3:1) e miristato de isopropila (IPM)] mostraram-se eficazes na solubiliza??o dos extratos avaliados, tendo sido observado melhor efic?cia para o sistema SME-1 [EC50 = 113,84 μg/mL (SME-1) and 246,00 μg/mL (SME-4) para P. varians e EC50: 223,97 μg/mL (SME-1) e 248,37 μg/mL (SME-4) para C. spinosa (sistema SME-1contendo etanol como cotensoativo e SME-4, isento de cotensoativo]. A a??o antinociceptiva de Pavonia varians foi confirmada atrav?s do teste das contor??es abdominais, tendo sido observado rela??o dose/efeito inibit?rio dependente do extrato hidroalco?lico desta esp?cie. Os testes do tipo tail flick e da formalina afastaram a possibilidade da participa??o de mecanismos antinociceptivos no sistema nervoso central. No entanto, no teste da formalina evidenciou-se a participa??o de mecanismos antiinflamat?rios na produ??o do efeito antinociceptivo deste extrato. O estudo fitoqu?mico das cascas do caule de Croton cajucara Benth conduziu ao isolamento de diterpenos do tipo 19-nor-clerodano, bem como ? obten??o do ?leo fixo OF-CC, rico em sesquiterpenos e 19-nor-clerodano bioativos. O efeito de OF-CC foi avaliado no desenvolvimento in vitro dos fungos fitopatog?nicos Fusarium oxysporum, Rhizoctonia solani e Sclerotium rolfsii propagados em meio de cultura Batata-dextrose-agar. A resposta fisiol?gica, variou de acordo com o tipo de fungo testado, tendo sido observado que o OF-CC apresentou efeito fungist?tico significativo, com efeito inibit?rio mais est?vel para o g?nero de fungo Fusarium oxysporum. Realizou-se ainda, um estudo de espectrometria de massas objetivando-se a identifica??o de fragmentos caracter?sticos de diterpenos do tipo clerodano (com dados obtidos na literatura) e 19-nor-clerodano (isolados das cascas do caule de C. cajucara), tendo sido evidenciado que a jun??o trans de clerodanos est? correlacionada com a presen?a dos ?ons caracter?stico de m/z 95, 121 e 205. Os sistemas de jun??o cis de clerodanos apresentaram ?ons caracter?sticos de m/z 122 e 124. A jun??o trans de 19-nor-clerodanos foi correlacionada com a presen?a dos ?ons caracter?stico de m/z 161, 134 e 121. Este estudo pode ser utilizado na identifica??o de diterpenos do tipo clerodano e 19-nor-clerodano, contendo carbonila α,β-insaturada no anel A do sistema decal?nico, evitando desta forma, a brigatoriedade de isolamento e caracteriza??o via RMN

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