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Two new compounds have been isolated from the leaves of Hypericum styphelioides. Their structures have been established on the basis of mass spectrometry and 2D NMR techniques as 1,3,5-trihydroxy-2-(2‘,2‘-dimethyl-4‘-isopropenyl)cyclopentanylxanthone (1) and 3,5-dihydroxybenzophenon-4-β-d-glucoside (2). Known compounds 5-O-demethylpaxanthonin (3) and 3-geranyl-1-(3-methylbutanoyl)phloroglucinol (4) were also isolated and characterized. Compounds 1−4 were evaluated for their antioxidative properties in Trolox equivalent antioxidant activity (TEAC) and chemiluminescence (CL) assays.

A tautomeric pair of new isoprenylated benzophenones, aristophenone A (1a) and B (1b), have been isolated from Garcinia aristata fruits. Their structures has been determined using high-field 2D NMR techniques.