16-HYDROXYLATED WITHANOLIDES FROM EXODECONUS-MARITIMUS

In addition to the known compounds withanolide A (4), withanone (5), a nd NIC-3 (6), three 16-hydroxylated withanolides were isolated from Ex odeconus maritimus. The new withanolides were identified as 6 alpha,7 alpha-epoxy-5 alpha,16 beta-dihydroxy-1-oxowitha-2,17(20),24-trienolid e (exodeconolide A, 1), 6 alpha,7 alpha-epoxy-5 alpha,16 alpha-dihydro xy-1-oxowitha-2,17(20),24-trienolide (exodeconolide B, 2), and 6 alpha ,7 alpha-epoxy-5 alpha,16 alpha,17 alpha-trihydroxy-1-oxowitha-2,24-di enolide (exodeconolide C, 3), by a combination of spectroscopic (1D an d 2D NMR, MS) and chemical methods with the aid of molecular modeling.