Bioactive Natural Products from the Marine Sponge-Derived Nocardiopsis dassonvillei OUCMDZ-4534

Nocardiopsis dassonvillei OUCMDZ-4534 was isolated and identified from the sponge, Dysidea avara, from Xisha Islands of China. Compounds 1 similar to 12 were isolated from the fennenation broth of AT. dassonvillei OUCMDZ-4534. By means of spectroscopic analysis, electronic circular dichroism (ECD) and C-13 NMR calculations, their structures were identified as (3aS,7aS)-3a-hydroxy-3a,7a-dihydrobenzofuran-2(3H)-one (la), (3aR,7aR)-3a-hydroxy-3a,7a-dihydrobenzofuran-2(3H)-one (lb), phenazine (2), 1-hydroxyphenazine (3), 1-methoxyphenazine (4), 1,6-dihydroxyphenazine (5), 1-hydroxy-6-methoxv- phenazine (6), 1,6-dihydroxy phenazin-5-oxide (7), dihydrogeodin (8), 2-acetamidophenol (9), 2-benzamidophenol (10), (E)-7-hydroxy cinnamic acid (11), and (E)-7-hydroxy-6-methoxycinnamic acid (12), respectively. This is the first time to resolve racemic-1 and identify the absolute structures of 1a and 1b. Compounds 1 and 9 displayed selective inhibition on A549 and K562 cell lines with the half maximal inhibitory concentration (IC50) of 0.47 and 0.46 mu mol.L-1, respectively. Compounds 4 similar to 8 showed inhibitory activities against K562, A549 and MCF-7 cell lines with IC50 values ranging from 0.02 to 1.48 mu mol.L-1. Compound 11 was cytotoxic to K562 while compound 12 was active against K562 and MCF-7 cell lines with the IC50 values of 1.14, 0.88 and 0.65 mu mol.L-1, respectively. Compounds 7 and 8 showed antimicrobial activities against Aspergillus fumigatus and Pseudoalteromonas nigrifaciens with the minimum inhibitory concentration (MC) of 25.00 and 2.00 mu g.mL(-1), respectively. Compounds 4 similar to 6 and 9 also exhibited inhibitions against the H1N1 virus with the IC50 values of 0.04, 0.16, 0.06 and 0.30 mmol.L-1, respectively.