NEW ANTIFUNGAL CHROMENYL KETONES AND THEIR PENTACYCLIC DIMERS FROM HYPERICUM-REVOLUTUM VAHL

Two new 2H-1-benzopyranyl ketones 1 and 2 and three new pyrano[3,2-c:4,5,6-d''e'']di[1]benzopyrandiyl diketones 3, 4a/4b, and 5 have been isolated from the leaves and twigs of Hypericum revolutum Vahl (Guttiferae). The structure of 3 (hyperevoline) was established by X-ray analysis as 1,1''-[1,13,13a,13b-tetrahydro-5,8,10-trihydroxy-2,2,6,9,13,13-hexamethyl-2H,7aH-pyrano[3,2-c:4,5,6-d''e'']di[1]benzopyran-4,11-diyl]bis]2-methyl-1-propanone]. The structures of the isolated compounds were established by spectroscopic (UV, IR, EI-MS, 1H- and 13C-NMR) and chemical (acetylation and acidic dimerization) methods.