Kenganthranol F, a new anthranol from Psorospermum aurantiacum

A new anthranol, kenganthranol F, was isolated from the ethyl acetate extracts of the seeds and the whole plant of the Cameroonian plant Psorospermum aurantiacum (Hypericaceae), together with fifteen known compounds viz., ferruginin B, vismin, vismion D, haronginanthrone, kenganthraquinone, kenganthranol B and kenganthranol E isolated from the fruits and 3-geranyloxyemodinanthrone, 2-geranylemodin, bianthrone A1, vismione D, 1,8-dihydroxy-3-geranyloxy-6-methylanthraquinone, vismione M, vismiaquinone, vismiaquinone C being isolated from the whole plant. The structure of the new isomer of kenganthranol F was determined to be 1,8,10-trihydroxy-3,4-[2,2-dimethyldihydropyrano]-6-methyl-2,5-bis-(3,3-dimethylallyl)-anthrone.