• Natural Product Sciences
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• v.10 no.5
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• pp.220-222
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• 2004

A new prenylated pyranoxanthone, inophyllin B (1), was isolated from the roots of Calophyllum inophyllum (Guttiferae). Together with this compound was also isolated the known pyranoxanthone brasilixanthone B (2) and two common triterpenes friedelin (3) and sitosterol (4). Structural elucidations of these compounds were achieved through $^1H,\;^{13}C$, DEPT, COSY, HSQC and HMBC experiments. The molecular mass was determined using MS techniques. The crude extract indicated weak toxicity to the larvae of Aedes aegypti. We report here the isolation, structural elucidation and bioassay data for Inophyllin B and brasilixanthone B.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2949-2954
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• 2011

This paper describes a concise and efficient synthetic route for the biologically interesting pyranoxanthones, dihydropyranoxanthones, and their derivatives. The key strategies involve pyranyl ring formation, methylation, catalytic hydrogenation, and catalytic dihydroxylation starting from 1,3-dihydroxyxanthen-9-one.