1,2,5-Trihydroxyxanthone

Phytochemistry, 1994, 36(2):501-506.

Antioxidant xanthones from Garcinia subelliptica.[Reference: WebLink]

METHODS AND RESULTS:
From the woods of Garcinia subelliptica four new xanthones, garciniaxanthone C, 1,2,5-Trihydroxyxanthone, 2,6-dihydroxy-1,5-dimethoxyxanthone and 1,2-dihydroxy-5,6-dimethoxyxanthone have been isolated along with a new benzophenone derivative, 4′,6-dihydroxy-2,3′4-trimethoxybenzophenone. Their structures have been determined on the basis of mainly spectroscopic data and some chemical reactions.
CONCLUSIONS:
Antioxidative properties of all the isolated xanthones have been evaluated in vitro using three assay systems to measure antilipidperoxidation, free radical and superoxide anion scavenging activity.

Phytochemistry. 1998 Nov;49(5):1395-402.

Xanthones from Hypericum japonicum and H. henryi.[Pubmed: 9842731]

METHODS AND RESULTS:
From the aerial part of Hypericum japonicum, one new xanthone glycoside, 1,5-dihydroxyxanthone-6-O-beta-D-glucoside, one novel dimer xanthone, bijaponicaxanthone, and the first natural prenylated xanthone, 1,3,5,6-tetrahydroxy-4-prenylxanthone, were isolated together with the four known xanthones, 1,5,6-trihydroxyxanthone, isojacereubin, 6-deoxyisojacareubin and 4',5'-dihydro-1,5,6-trihydroxy-4',4',5'-trimethylfurano (2',3':4,5) xanthone. five previously known xanthones, kielcorin, cadensin, 1,7,-dihydroxyxanthone, 1,5-dihydroxy-4-methoxyxanthone and 1,2,5-Trihydroxyxanthone were also found in the dichoromethane extract of the stems and leaves of H. henryi. Their structures were elucidated by spectroscopic and chemical methods.
CONCLUSIONS:
Some of the compounds from H. japonicum were found to exert an interesting coagulant activity in an in vitro test. The chemotaxonomic value of xanthones is discussed briefly.