2 PRENYLATED ANTHRONES IN HARUNGANA-MADAGASCARIENSIS

Two new anthrones were isolated from Harungana madagascariensis in add ition to a known anthrone, two xanthones, four anthraquinones and two flavonoids. The structures of the two anthrones were determined to be 1,3,8-trihydroxy-4,5-diisoprenyl-7-methylanthrone (harunganol A) and 1 ,3,8-trihydroxy-4,5,7-triisoprenyl-7-methyl- anthrone (harunganol B) b y spectroscopic analysis. The other anthrone, 8-dihydroxy-2-isoprenyl- 3-methoxy-6-methylanthrone which has been once derived from natural pr oduct, and one xanthone, 1,5,6-trihydroxy-7-methoxyxanthone which has been synthesized earlier were isolated for the first time as genuine n atural products.