new steroidal alkaloids from an undescribed sponge of the genus corticium.two new steroidal alkaloids, along with a previously reported one of the plakinamine class, were isolated from the sponge corticium sp. collected from guam. the structures of the new compounds were determined by combined spectroscopic methods. these compounds exhibited moderate cytotoxicity and antifungal activity as well as dna- and rna-cleaving activities.200111720539
eudistomins w and x, two new beta-carbolines from the micronesian tunicate eudistoma sp.chemical investigation of the micronesian ascidian eudistoma sp. afforded two new eudistomin congeners, which were designated eudistomins w (1) and x (2). the structures of the new compounds were unambiguously established on the basis of nmr spectroscopic ((1)h, (13)c, cosy, (1)h detected direct, and long-range (13)c-(1)h correlations) and mass spectrometric (ei and esims) data. compound 2 exhibited antibiotic activity toward bacillus subtilis, staphyloccocus aureus, and escherichia coli and was ...200312608864
eurysterols a and b, cytotoxic and antifungal steroidal sulfates from a marine sponge of the genus euryspongia.two new steroidal sulfates, eurysterols a (1) and b (2), were isolated from an undescribed marine sponge of the genus euryspongia collected in palau. the structures of the new compounds were assigned by nmr spectroscopic data interpretation. compounds 1 and 2 showed cytotoxicity against human colon carcinoma (hct-116) cells with ic50 values of 2.9 and 14.3 microg/ml, respectively, and exhibited antifungal activity against amphotericin b-resistant and wild-type strains of candida albicans with mi ...200717378608
mirabamides a-d, depsipeptides from the sponge siliquariaspongia mirabilis that inhibit hiv-1 fusion.four new cyclic depsipeptides termed mirabamides a-d (1-4) have been isolated from the marine sponge siliquariaspongia mirabilis and shown to potently inhibit hiv-1 fusion. their structures were elucidated by nmr and esims, and absolute stereochemistry of the amino acids was determined using advanced marfey's methods and nmr. mirabamides contain two new entities, including 4-chlorohomoproline in 1-3 and an unusual glycosylated amino acid, beta-methoxytyrosine 4'-o-alpha-l-rhamnopyranoside (in 1, ...200717963357
melophlins c-o, thirteen novel tetramic acids from the marine sponge melophlus sarassinorum.thirteen new metabolites, melophlins c-o (1-13), were identified from the marine sponge melophlus sarassinorum. compounds 1-13 represent tetramic acid derivatives that differ with regard to the nature of their alkyl side chains. the structures of the new compounds were elucidated on the basis of comprehensive spectral analysis (1h, 13c, 1h-1h cosy, hmqc, and hmbc nmr, as well as low- and high-resolution esims and eims). the absolute configurations of 1, 8, 10, 11, 12, and 13 were determined by e ...200312542345
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