Evolvosides C-E, flavonol-4-O-triglycosides from Evolvulus alsinoides and their anti-stress activity

Phytochemical investigation of the n-butanol fraction of Evolvulus alsinoides (Linn.) led to the isolation of three new phenolic glycosides, evolvosides C, D and E (1-3) along with six known compounds (4-9). The structures of the compounds were elucidated on the basis of spectroscopic analysis, viz. 1D and 2D NMR experiments, chemical study, and comparison with literature data. Evolvoside C (1) was characterized as kaempferol 4'-O-beta-D-glucopyranosyl-(1 -> 2)-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranoside, whereas evolvosides D and E (2-3) were found to be mono and di-O-methyl derivatives of 1. The new compounds (1-3) represent rare triglycoside derivatives of flavonol at C-4'. The isolated compounds (1-6) were screened for acute stress-induced biochemical changes in male Sprague-Dawley rats at a dose of 40 mg/kg body weight. Compounds 1 and 2 displayed anti-stress effects by normalizing hyperglycemia, plasma corticosterone, plasma creatine kinase, and adrenal hypertrophy. Compounds 3 and 6 were also found to be effective in normalizing most of these stress parameters, whereas compounds 4 and 5 were ineffective in normalizing most of these effects. (C) 2013 Elsevier Ltd. All rights reserved.