A New Flavonol Glycoside from Tristemma hirtum (Melastomataceae)

Chemical investigation of the plant Tristemma hirtum P. Beauv (Melastomataceae) resulted to the isolation of a new flavonol glycoside named quercetin-7-O-α-D-arabinofuranoside (1), together with nine known compounds including 3′-hexadecanoyl-2′-(9aZ)-tetradecanoyl-glycerol 1′-O-[β-D-galactopyranosyl-(1″ → 6″)-α-D-galactopyranoside] (2), arjunolic acid (3), β-sitosterol-3-O-β-D-glucopyranoside (4), terminolic acid (5), quercetin (6), asiatic acid (7), maslinic acid (8), 1β-O-galloylpedunculagin (9) and 6-hydroxyapigenin 7-O-β-D-glucopyranoside (10) from the methanol extract using normal and reversed phase column chromatography. The structures of these compounds were determined by comprehensive interpretation of their spectral data mainly including 1D- 2D-NMR (¹H-¹H COSY, HSQC, and HMBC) spectroscopic and ESI-TOF-MS mass spectrometric analysis.

Integracide K: A New Tetracyclic Triterpenoid from Desmodium uncinatum (Jacq.) DC. (Fabaceae)

A new tetracyclic triterpenoid [4,4,24-trimethylcholesta-Δ(8,9;14,15;24,28)-trien-3β,11β,12α-triol-12-acetate, 3-sulfate] sodium salt (1), together with eight known compounds including ergosterol 5α,8α-endoperoxide (2), 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (3), 3-O-β-D-2-acetyl-amino-2-deoxyglucopyranoxyloleanoic acid (4), hydnocarpin (5), derrone (6), isovitexin (7), erythrinin C (8), and 5,4'-dihydroxy-2''-hydroxyisopropyldihydrofurano [4,5:7,8]-isoflavone (9), were isolated from the EtOAc soluble fraction of the methanol extract of aerial part of Desmodium uncinatum collected in the western highland of Cameroon. The structures of these compounds were established by comprehensive interpretation of their spectral data mainly including 1D- (¹H and ¹³C), 2D-NMR (¹H-¹H COSY, HMQC, HMBC) spectroscopic and ESI-TOF-MS mass spectrometric analysis. The isolation of an integracide-like compound from plant origin is a very unusual finding.