• 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.

• Natural Product Sciences
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• v.11 no.4
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• pp.220-224
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• 2005

Extensive chemical studies on the stem bark extracts of two Guttifereous plants namely Mesua daphnifolia and Garcinia nitida have led to the isolation of eight xanthones. Mesua daphnifolia gave cudraxanthone G (1), ananixanthone (2), 1,3,5-trihydroxy-4-methoxyxanthone (3) and euxanthone (4) while Garcinia nitida gave inophyllin B (5), 1,3,7-trihydroxy-2,4-bis (3-methylbut-2-enyl)xanthone (6), 3-isomangostin (7) and rubraxanthone (8). All these compounds were assayed against the MDA-MB-231 (human estrogen receptor negative breast cancer) cells. A structure-activity relationship study showed that structurally, all the 1, 3-oxygenated xanthones which carried unsaturated prenyl side chains (either 3-methylbut-2-enyl or 1,1-dimethyl-2-propenyl) at carbones C-2 and C-4 in the xanthone ring A are essential for the outstanding activities in the assay.

• Natural Product Sciences
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• v.12 no.3
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• pp.138-143
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• 2006

Our continuing interest on Garcinia and Mesua species has led us to carry out a detail study on the chemistry of the root bark of Garcinia mangostana (Guttiferae) since this part of the plant has not been investigated before, and the strm bark of Mesua corneri (Guttiferae) an uninvestigated species. This study has yielded six xanthones, ${\alpha}-mangostin$ (1), ${\beta}-mangostin$ (2), ${\gamma}-mangostin$ (3), garcinone-D (4), mangostanol (5) and gartanin (6) from Garcinia mangostana and two xanthones rubraxanthone (7) and inophyllin B (8) from Mesua corneri. Structural elucidations were achieved using $^1H,\;^{13}C$ NMR and MS data. The crude hexane and chloroform extracts of the root bark of Garcinia mangostana and the hexane extract of the stem bark of Mesua corneri were found to be active against CEM-SS cell lines with $IC_{50}$ values less than $30\;{mu}g/ml$. Moreover, ${\gamma}-mangostin$ gave a very low $LC_{50}$ value of $4.7\;{mu}g/ml$ while rubraxanthone gave an $LC_{50}$ value of $5.0\;{mu}g/ml$ indicating these two compounds to be potential lead compounds for anti-cancer activity against the CEM-SS cell line. This paper reports the isolation and identification of these compounds as well as bioassay data for the crude extracts, ${\gamma}-mangostin$ and rubraxanthone.