Polyketides from a marine sponge-derived fungus Mycelia sterilia and proton-proton long-range coupling.

A series of polyketide-originated metabolites (1-5) were isolated from a marine sponge-derived fungus Mycelia sterilia. Of these, 1-3 were new compounds. Their structures were elucidated by spectroscopic methods as (4R*, 5S*, 6S*, 8S*, 13R*)-1-(2,8-dihydroxy-1,2,6-trimethyl-1,2,6,7,8,8a-hexahydro-naphthalen-1-yl)-3-methoxy-propan-1-one (1), 4,8-dihydroxy-7-(2-hydroxy-ethyl)-6-methoxy-3,4-dihydro-2H-naphthalen-1-one (2) and 1-methyl-naphthalene-2,6-dicarboxylic acid (3). In 1, the proton-proton long-range coupling phenomenon claimed attention and was discussed.

Five new bidesmoside triterpenoid saponins from Stauntonia chinensis.

Eleven triterpenoid saponins (1-11) were isolated from Stauntonia chinensis DC. (Lardizabalaceae), including five new compounds, yemuoside YM(21-25) (1-3, 6, 7) structures of which were elucidated by chemical methods and a combination of MS, 1D- and 2D- NMR experiments including DEPT, (1)H--(1)H COSY, HSQC, HMBC, TOCSY, and NOESY as 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonicacid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), 3-O-beta-D-xylopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), 3-O-beta-D-glucopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (3), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (6), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-arabinopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (7).