A new monodesmosidic triterpenoid saponin from the leaves of Pometia pinnata.

Phytochemical investigation of the leaves of Pometia pinnata resulted in the isolation of a new triterpenoid saponin (1), together with a known compound, kaemferol 3-O-alpha-L-rhamnopyranoside (2). The structure of 1 was established as 3-O-[alpha-L-arabinofuranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl]-hederagenin. The structure elucidation of the isolated compounds was based primarily on 1D- and 2D-NMR techniques, including 1H and 13C NMR spectra, DEPT, and by 2D COSY, HMQC, HMBC and TOCSY experiments.

A new triterpenoid saponin from the stem bark of Pometia pinnata.

Phytochemical investigation of the stem bark of Pometia pinnata resulted in the isolation of a new triterpenoidal saponin. The structure of the new compound, pometin (1), was established as 3-O-[beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 3)-beta-D-glucopyranosyl]-oleanolic acid based on 1D and 2D-NMR analysis including COSY, 2D J-resolved, HMQC, HMBC correlations and chemical transformations.

Saponins from the seeds of Achras sapota.

A new pentacyclic triterpenoid saponin (2) along with one known was isolated from the cotyledons of Achras sapota. Their structures were determined with the help of (1)H NMR, (13)C NMR and MS spectral data. The isolated compounds were named as 3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl protobassic acid (1) and 3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-16alpha-hydroxy protobassic acid (2). Compound 2 showed antibacterial activity against Gram positive and negative bacteria.