No / Four new polyhydroxylated sterols are isolated from Marine sponge Callyspongia fibrosa collected from the Gulf of Mannar, western Bay of Bengal (India). The structural assignment is based on 1H and 13C NMR spectra. All sterols are based on the known 24S-24-methyl cholesterol 1 which is also isolated, and contain 3b,6b-dihydroxy system and 25-O-acetate as common features (except in the case of sterol 6 that has a D25 in the place of 25-OAc). Additional OH substitution is also present at 5a in 4a and at 8b in 5. A further 12b-OH is present in 6 and 7. The hydroxylation pattern is so far known only in coral sterols but is without a precedent in sponge sterols. The major steroid 4a showed antimalarial activity against Plasmodium falciparum on the chloroquine-resistant stain better than on the chloroquine-sensitive strain.

Made available in DSpace on 2014-12-17T15:42:11Z (GMT). No. of bitstreams: 1 RusceliDA_DISSERT.pdf: 4254928 bytes, checksum: 4fab1232a45d2adb5dcfe7b1b0dac83a (MD5) Previous issue date: 2013-04-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Recently, marine organisms have attracted attention because of the complexity and potent biological activity from your secondary metabolites. Our planet has 80% it surface covered by oceans and seas, therefore, housing a wide number of different forms of life, among them, the sponges. These sessile and filtrating animals, according to numerous researches, come showing like true chemistry factories. The substances from these animals, sometimes show as news targets to therapeutics agents, and some countries has already use them for treatment of some diseases. Further of the secondary metabolites, the polysaccharides of marine origin also have been target of studies, because the presence of the sulfates groups in its molecules. Polysaccharides with differents biological activities have been related in a large number of researches. Actually, many studies show the sponges as source of promising medicine. These studies inspire new researches, because the few number of sponges species studied until now. Because of that, the present work shows the chemistry prospection of the sponge Callyspongia vaginalis. Chromatographic methods in silica gel allowed the isolations of two secondary metabolites: the known β- sitosterol and a ceramide, no reported in the genus Callyspongia, previously. The analysis of the their lipid extracts show different kinds of fatty acids with a variety of chain length (saponifiable fraction), and others metabolites like Lupenone and stigmasterol, also unprecedented in the genus. The Polysaccharide characterization and the elucidation of the secondary metabolites acquired through of chromatography analysis (CC, molecular exclusion) and spectrometric (NMR 1H and 13C, mass, IR), respectively and comparison with literature data / A diversidade estrutural de subst?ncias de origem marinha, associadas as suas atividades biol?gicas, t?m atra?do aten??o de pesquisadores do mundo inteiro. Dentre os organismos estudados atualmente dois grupos de invertebrados marinhos, as asc?dias e as esponjas, merecem destaque. Estes animais s?sseis e filtradores, segundo in?meras pesquisas, v?m se mostrando verdadeiras f?bricas qu?micas , produzindo subst?ncias que por vezes apresentam-se como aspirantes a agentes terap?uticos, com efic?cia cl?nica comprovada. Al?m dos metab?litos secund?rios, os polissacar?deos de origem marinha tamb?m tem sido alvo de estudos, sendo relatados diversos compostos sulfatados e com diferentes atividades biol?gicas associadas a estes. Tendo em vista a pequena quantidade de esp?cies de esponjas estudadas at? o momento, comparado ao potencial qu?mico destes organismos, o presente trabalho apresenta a prospec??o qu?mica da esponja Callyspongia vaginalis. T?cnicas cl?ssicas de cromatografia em gel de s?lica permitiram o isolamento de dois metab?litos secund?rios: o β-sitosterol e uma ceramida, ambos in?ditos no g?nero Callyspongia. A an?lise das fra??es lip?dicas mostraram diferentes tipos de ?cidos graxos com variados tamanhos de cadeia (fra??o saponific?vel), e de outros metab?litos como lupenona e estigmasterol, tamb?m in?ditos no g?nero em quest?o. O polissacar?deo obtido atrav?s do material animal tamb?m foi isolado e, como amplamente relatado na literatura apresentou-se sulfatado, caracter?stica diferencial dos polissacar?deos de origem marinha. A caracteriza??o do polissacar?deos e a elucida??o estrutural dos metab?litos secund?rios foram realizadas atrav?s da an?lise dos dados de espectrometria de massa, Infravermelho e Resson?ncia Magn?tica Nuclear de Hidrog?nio-1 e Carbono-13, atrav?s de sequ?ncias de pulsos uni e bidimensionais e compara??o com dados da literatura