Puupehenone congeners from an indo-pacific hyrtios sponge.

An investigation of the constituents from an Indonesian Hyrtios sponge has provided new insights about the chemistry and biology of the puupehenones, a unique class of merosesquiterpenes. The parent compound, puupehenone (2), has been repeatedly encountered in sponges from four distinct orders. In this study we characterized three compounds, (+)-(5S,8S,9R,10S)-20-methoxypuupehenone (3), (+)-(5S,8S,10S)-20-methoxy-9,15-ene-puupehenol (4), and (+)-(5S,8S,9R,10S)-15,20-dimethoxypuupehenol (5). Their structures were supported by complete sets of spectroscopic data along with comparisons to literature properties. While 5 was observed in the crude extracts, it was also heat labile and could be converted at 35 degrees C to a mixture of 3 and 4. The possibility that 3, 4, and 5 are formed from 2 by a series of methanol additions is discussed. The bioactivity of these compounds in soft-agar cytotoxicity tests was also explored.

Psammaplins from the sponge Pseudoceratina purpurea: inhibition of both histone deacetylase and DNA methyltransferase.

Four novel bisulfide bromotyrosine derivatives, psammaplins E (9), F (10), G (11), and H (12), and two new bromotyrosine derivatives, psammaplins I (13) and J (14), were isolated from the sponge Pseudoceratina purpurea, along with known psammaplins A (4), B (6), C (7), and D (8) and bisaprasin (5). The structures of psammaplins E (9) and F (10), which each contain an oxalyl group rarely found in marine organisms, were determined by spectroscopic analysis. Compounds 4, 5, and 10 are potent histone deacetylase inhibitors and also show mild cytotoxicity. Furthermore, compounds 4, 5, and 11 are potent DNA methyltransferase inhibitors. The biogenetic pathway previously proposed for the psammaplins class is also revisited.