Cytotoxic ring A-seco triterpenoids from the stem bark of Dysoxylum lukii

Excelxylin A: a new seco A-ring tirucallane triterpenoid from the stem bark of Dysoxylum excelsum

A new seco-A tirucallane triterpenoid named excelxylin A (1), along with two known seco-A triterpenoids (2-3), were isolated from the n-hexane extract of Dysoxylum excelsum (Spreng.) Blume ex G.Don stem bark. The structure and stereochemistry configuration of compounds 1-3 was established by NMR, IR, and HR-ESI-MS spectroscopic data analyses and comparison of their NMR data with literatures. The compounds exhibited the carbon framework for seco-A ring tirucallane triterpenoid, first reported in the Dysoxylum genus. All compounds were tested for their cytotoxicity against human cervical HeLa cells.

Triterpenoids from Dysoxylum genus and their biological activities

This study aims to analyze the ethnobotanical, chemical, and biological activities of triterpenoid compounds isolated from the Dysoxylum genus of the Meliaceae family between 1974 and 2021. The species are mainly distributed in Africa, Asia, and Australia, and used as a traditional medicine to treat various diseases. Triterpenoid was first isolated in 1976 and as tetranortriterpenoid or limonoid, it was named dysobinin. Several studies were conducted for more than 40 years on the plants' stems, bark, and leaves, where approximately 279 triterpenoid compounds from several groups such as dammarane, nortriterpenoid, oleanane, lupane, tirucallane, cyclolanostane, or cycloartane, glabretal, and cycloapoeuphane-types were isolated with some synthetic products. In addition, the hypothetical route of triterpenes biosynthesis from this genus was identified, and tirucallane-type were reported to be 37.6% of the total compounds. The anti-malarial, anti-feedant, antimicrobial, anti-inflammatory, antioxidant, vasodilative effect, anti-viral, cortisone reductase, and cytotoxic activities of the extract were also evaluated. The results showed the necessity of using the triterpenoid compounds from the Dysoxylum genus in traditional medicine and the discovery of new drugs.