Cyclic triterpenoid Saponins from Campanula lactiflora

Abstract

Two cyclic natural compounds, 3 beta-O-[alpha-L-rhamnopyransoyl-(1 -> 2)-beta-D-glucopyranosyl]-13 alpha,14 alpha-epoxy-8 alpha,12 beta,15-trihydroxy-(17E,21E)-17,21-campanuldien-6'(30)-olide, called lactifloroside A, 1, and 3 beta-O-[beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranosyl]-13 alpha,14 alpha-epoxy-8 alpha,12 beta-dihydroxy-(17E,21E)-17,21-campanuldien-6'(30)-olide, called lactifloroside B, 2, were isolated for the first time from Campanula lactiflora and their structures deduced by high field 1D and 2D 400 MHz NMR, FT-IR, HPLC, CC-MS, (+/-) LC-MS/MS and (+) FAB-MS spectra. The aglycones of the 2 saponins were named 13 alpha,14 alpha-epoxy-3 beta,8 alpha,12 beta,15-tetrahydroxy-(17E,21E)-17,21-campanuldien-30-oic acid and 13 alpha,14 alpha-epoxy-3 beta,8 alpha,12 beta-trihydroxy-(17E,21E)-17,21-campanuldien-30-oic acid, and designated as campanuloic acid and 15-deoxycampanuloic acid, respectively.