| 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 ... | 2003 | 12542345 |
| 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 ... | 2003 | 12608864 |
| 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, ... | 2007 | 17963357 |