Khaya ivorensis is the most important tree species providing African mahogany. Like the other members of its genus, the species can grow to be large - 30 to 35 meters with trucks over 1 m in diameter. Khaya A. Juss. (Meliaceae) is mainly distributed in Africa and Madagascar, it is also cultivated in Southern China. Its IUCN Red List status is “vulnerable.” Xishuangbanna Tropical Botanical Garden (XTBG) is home to some trees of African mahogany.

Assoc. Prof. XU Youkai and his colleagues of XTBG previously conducted chemical investigation of K. ivorensis and their investigation indicated that this plant was a good source of limonoids. As a continuation of their studies of this medicinal plant in search of biologically significant secondary metabolites, the fruits of K. ivorensis were investigated.

Three mexicanolide-type limonoids, 14,15-didehydroruageanin A (1), 3-O-methylbutyrylseneganolide A (2), and seneganolide A (3), along with five known d-seco limonoids, 1,3-dideacetylkhivorin (4), 7-deacetylkhivorin (5), 3-deacetylkhivorin (6), 1-deacetylkhivorin (7) and 3-deacetyl-7-oxokhivorin (8), were isolated from the fruits of Khaya ivorensis. Among these compounds, 1 and 2 were new compounds; and compounds 3, 4, 7, and 8 were obtained from this plant for the first time. The cytotoxicity evaluation showed that only compounds 2, 3, and 4 exhibited cytotoxicity against certain tumor cell lines.

The study was supported by NSFC-U1302222, CAS 135 program (XTBG-F02), and Ethnobotanical Investigation of Plants for Industrialization in Southwest China (2012FY110300).

The study entitled “Limonoids from the Fruits of Khaya ivorensis” has been published online in Molecules.