Three xanthones from Poeciloneuron pauciflorum and Mammea acuminata

From the stem of Poeciloneuron pauciflorum, two new xanthones (1,6-dihydroxy-7-methoxyxanthone and 1,6-dihydroxy-7-methoxyxanthone 6-O-beta-D-glucoside) in addition to 12 known compounds (1,5-dihydroxy-, 1,5-dihydroxy-3-methoxy-, 1,7-dihydroxy-, 1-hydroxy-7-methoxy-, 2-methoxy-, 4-methoxy-, 1,4,5-trihydroxy-, 1,3,5-trihydroxy-, 1,3,6-trihydroxy-7-methoxy-, 1,3,7-trihydroxy-, 3-hydroxy-2-methoxyxanthone and (-)-epicatechin) were isolated. From the aerial parts (stems and bark) of Mammea acuminata, a new xanthone (2,7-dihydroxyxanthone) was isolated in addition to two known xanthones (1,5-dihydroxy- and 5-hydroxy-1-methoxyxanthone) and (-)-epicatechin. The structures were established by spectral analysis and total synthesis in case of 1,6-dihydroxy-7-methoxyxanthone. (C) 1997 Elsevier Science Ltd.