Three new glycosides of the oleanene-type triterpenes, rivalosides C-E (1-3), along with three known triterpene saponins, momordin IIb (4) and rivalosides A-B (5-6), and five known iridoid glucosides: monotropein, scandoside, deacetylasperulosidic acid, geniposidic acid and asperulosidic acid, were isolated from aerial parts of Galium rivale. The structures of the new compounds were elucidated by spectral methods and chemical means as 2α-acetoxy-3α,19α-dihydroxy-olean-12-en-28-oic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside, 2α,3α,19α-trihydroxy-olean-12-en-28-oic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside and 3-O-β-D-glucuronopyranosyl-24-hydroxy-olean-12-en-28-oic acid 28-O-β-D-glucopyranoside, for rivalosides C-E, respectively. The taxonomic significance of the rivalosides in G. rivale was discussed.
triterpene saponin, Rubiaceae, iridoid glycoside, Galium rivale, rivalosides C-E
NCBI PubMed ID: 11014260Publication DOI: 10.1016/s0031-9422(00)00149-7Journal NLM ID: 0151434Publisher: Elsevier
Correspondence: sderosa@icmib.na.cnr.it
Institutions: Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria, Institute of Botany, Bulgarian Academy of Sciences, Sofia, Bulgaria, Istituto per la Chimica di Molecole di Interesse Biologico del CNR, Napoli, Italy
Methods: 13C NMR, 1H NMR, NMR-2D, IR, FAB-MS, TLC, acid hydrolysis, GC, alkaline hydrolysis, extraction, optical rotation measurement, acetylation, reduction, melting point determination, LPLC, DCCC
Found