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ContribuiÃÃo ao Conhecimento QuÃmico de Esponjas do Litoral Cearense: Monanchora arbuscula / Contribution to Knowledge of Chemical Sponges Coastal CearÃ: Monanchora arbusculaJulieta Rangel de Oliveira 03 October 2008 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Monanchora arbuscula (DUCHASSAING & MICHELOTTI, 1864) (Crambeidae) à uma esponja incrustante, maciÃa ou ramificada com atà 15 cm de altura. Cor, variando de salmÃo a vermelho vivo ou rosa claro, provida de canais esbranquiÃados conspÃcuos. Estudos anteriores de M. arbuscula levaram a obtenÃÃo de alguns alcalÃides guanidÃnicos policÃclicos; ptilocaulina, 8b-hidroxiptilocaulina, dehidrobatzelladina C, crambescidina 800 e isoptilocaulina. Neste trabalho, o extrato hidroalcoÃlico da esponja M. arbuscula, coletada no Parque Estadual Marinho âPedra da Risca do Meioâ, na costa Fortalezense, foi particionado com CH2Cl2/H2O (3:1) fornecendo assim o extrato bruto, o qual foi submetido a uma partiÃÃo lÃquido-lÃquido utilizando os solventes Ãter de petrÃleo, diclorometano, acetato de etila e metanol. Sucessivas cromatografias em gel de sÃlica, SEPHADEX LH-20 e/ou HPLC das fraÃÃes diclorometano, acetato de etila e metanol levaram ao isolamento dos alcalÃides guanidÃnicos mirabilina B, 8b-hidroxiptilocaulina, ptilocaulina, 1,8a;8b,3a-desidro-8βâhidroxiptilocaulina, 1,8a;8b,3a-desidro-8α-hidroxiptilocaulina, 3,3a;8b,8a-desidro-8-hidroxiptilocaulina. Mirabilina B, 1,8a;8b,3aesidro- 8βâhidroxiptilocaulina e 1,8a;8b,3a-desidro-8α-hidroxiptilocaulina estÃo sendo citados pela primeira vez para a espÃcie e 3,3a;8b,8a-desidro-8-hidroxiptilocaulina, no melhor do nosso conhecimento, à inÃdito na literatura. Ensaios para a avaliaÃÃo da atividade citotÃxica frente as linhagens de cÃlulas tumorais cÃlon (HCT-8), melanona (MADMB-435), leucemia (HL-60) e glioblatoma (SF-295), indicaram atividade para o extrato bruto, fraÃÃes e os compostos isolados ptilocaulina e 8b-hidroxiptilocaulina. O alcalÃide 8b-hidroxiptilocaulina mostrou-se ativo aos fungos Microsporum canis e Trichophyton rubrum, enquanto ptilocaulina ao Microsporum canis. Mirabilina B mostrou atividade leishmanicida frente a Leishmania chagasi e amazonesis. As estruturas das substÃncias isoladas foram elucidadas atravÃs de mÃtodos espectroscÃpicos, principalmente RMN, incluindo seqÃÃncias de pulsos uni e bidimensionais e comparaÃÃo com dados da literatura. / Monanchora arbuscula (DUCHASSAING & MICHELOTTI, 1864) (Crambeidae) is an incrustant sponge, massive or branched with 15 cm high. Its color ranges from salmon to bright red or light pink with white conspicuous channels. Previous studies of M. arbuscula led to the isolation of some polycyclic guanidine alkaloids; ptilocaulin, 8bhydroxyptilocaulin, dehydrobatzelladine C, crambescidin 800 and isoptilocaulin. In this work, the hydroethanol extract from M. arbuscula collected at â Pedra da Risca do Meioâ Marine State Park, in Fortaleza coast zone was partitioned with CH2Cl2/H2O (3:1) affording the crude extract which was submitted to liquid-liquid partition using petroleumether, dichloromethane, ethyl acetate and methanol as the solvents. Successive chromatograghy over silica gel, SEPHADEX LH-20 and/or HPLC of all solvent fractions led to the isolation of the guanidine alkaloids: mirabilin B, 8bβ-hydroxyptilocaulin, ptilocaulin, 1,8a;8b,3a-didehydro-8βâhydroxyptilocaulin, 1,8a;8b,3a-didehydro-8α-hydroxyptilocaulin, 3,3a;8b,8a-didehydro-8-hydroxyptilocaulin. Mirabilin B, 1,8a;8b,3adidehydro- 8βâhydroxyptilocaulin, 1,8a;8b,3a-didehydro-8α-hydroxyptilocaulin are reported for the first time for the species while 3,3a;8b,8a-didehydro-8-hydroxyptilocaulin has not being reported in the literature yet. Pharmacological assays revealed weak citotoxic activity against 4 cancer cell lines: HCT-8 (human colon carcinoma), MADMB-435 (melanoma), HL-60 (human leukemia) and SF-295 (glioblastoma). The assays indicated activity for the crude extract, several fractions and the isolated compounds ptilocaulin and 8bβ-hydroxyptilocaulin. The alkaloid 8b-hydroxyptilocaulin indicated antifungal activity against Microsporum canis and Trichophyton rubrum, while ptilocaulin against Microsporum canis, Mirabilin B antiprotozoal activity against Leishmania chagasi and amazonesis. Structure elucidation of the isolated substances was performed through spectroscopic methods, mainly NMR, including uni and bidimensional pulses sequences, and comparison with data from literature.
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