Four new Sesquiterpenoids from Sphaeranthus indicus

Abstract

Isolation and characterisation of two new eudesmanolides, 5α-hydroperoxy-7α-hydroxy-isosphaerantholide (1) and (11α,13-dihydro-7α-hydroxyfrullanolide-13-yl)-adenine (2) from the flower heads of Sphaeranthus indicus are described. In addition, 5α-hydroxy-isosphaerantholide (3) and 11α,13-dihydro-eudesman-3,5,7-triene-6α-12-olide (4) are reported first time as a metabolite of S. indicus and as a natural product, respectively. The structures of these compounds were established from rigorous analysis of their high-resolution mass, IR, UV, 1H NMR, 13C NMR and 2D NMR spectral data.