A novel monoterpenoid from leaf exudates of Tarchonanthus camphoratus with anti-leishmanial activities

Abstract

One new monoterpenoid; 2,3,3a,4,5,7a-hexahydro-7a-methyl-4-methylene-1H-inden-5-ol (1) along with five known compounds including; two sesquiterpenes, costic acid derivative (2), (-)-parthenolide (3), and four known methoxylated flavonoids; 5,7,3´,4´-tetrahydroxy-3-methoxyflavone (4), 5,7,4´-trihydroxy-6-methoxyflavone (5), 5,7,3´,4´-tetrahydroxy-6-methoxyflavone (6) and 5-hydroxy-7,8-dimethoxyflavanone (7) were characterized from the leaf exudates of Tarchonanthus camphoratus. The structures of these compounds were determined based on spectroscopic data analyses. The new compound exhibited good anti-fungal activity against Cryptococcus neoformans with an IC50 value of 5.62 µg/mL. Compounds 1 and 2 exhibited moderate anti-leishmanial activities against Leishmania donovani with IC50 values of 14.17 and 12.84 µg/mL, respectively, (vs 0.85 for pentamidine and 0.12 µg/mL for amphotericin B). Compound 6 and 7 also showed anti-leishmanial activities with IC50 values of 26.24 and 23.15 µg/mL, respectively. All compounds tested were not cytotoxic at 5 µg/mL.