Chemical investigation of ceylonese plants. Part VII. Extractives of Calophyllum thwaitesii Planch and Triana and Calophyllum walkeri Wight (Guttiferae)

Abstract

The bark and timber extractives of C. thwaitesii Planch and Triana and C. walkeri Wight have been studied. The former contained taraxerol and friedelin in the bark whilst the latter had taraxerol and β-simiarenol. In addition a new di-isoprenylated xanthone, named thwaitesixanthone, has been isolated from the former and shown to be 13-hydroxy-3,3,10,10-tetramethyl-3H,10H-dipyrano[3,2-a:2′,3′-i]xanthen-14-one (IV) while calabaxanthone, 5-hydroxy-8-methoxy-2,2-dimethyl-7-(3-methylbut-2-enyl)-2H-pyrano[3,2-b]xanthen-6-one (I) was isolated from the latter. The timber extractives of both species gave 1,5-dihydroxyxanthone, 1,7-dihydroxyxanthone, jacareubin (IIa), and β-sitosterol. The latter species also contained guanandin (VIII), 1,3,5-trihydroxy-2-(3-methylbut-2-enyl)xanthone (X), and the new metabolite 1,5-dihydroxy-2,3-dimethoxyxanthone (IX).