Three new antifungal phthalide derivatives from Cajanus cajan

Abstract

Three new phthalide derivatives, denominated Cajanthalides A, B and C (1–3), were identified from the leaves of Cajanus cajan. Their structures were meticulously elucidated through comprehensive analysis utilizing UV, IR, NMR (1D and 2D), HRESIMS, chiral analysis and DP4+ analysis. Notably, these new phthalide derivatives are present in racemic forms, with compounds 2 and 3 sharing identical planar structures. A plausible biogenetic pathway is proposed to account for the biosynthesis of compounds 1–3. Biological evaluation revealed that compound 2 exhibited moderate antifungal activity against C. neoformans, C. albicans and M. furfur with MIC values of 40 μg/mL.