ABSTRACT
The ethanolic extract of the stems of Viburnum fordiae Hance showed insecticidal and α-glucosidase inhibitory activities and then was fractionated by bioactivity-guided fractionation to obtain a rare C13-norisoprenoid (1), together with a new phenolic glycoside (2), and seven known compounds, alangionoside C (3), pisumionoside (4), koaburaside (5), 3,5-dimethoxy-benzyl alcohol 4-O-ß-d-glucopyranoside (6), 3,4,5-trimethoxybenzyl-ß-d-glucopyranoside (7), arbutin (8), and salidroside (9). The previously undescribed compounds were elucidated as (3R,9R)-3-hydroxy-7,8-didehydro-ß-ionyl 9-O-α-d-arabinopyranosyl-(1â6)-ß-d-glucopyranoside (1) and 2-(4-O-ß-d-glucopyranosyl)syringylpropane-1,3-diol (2) by spectroscopic data (1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, HSQC-TOCSY, HRESIMS, IR and ORD) and chemical methods. Compound 1 showed potent insecticidal effect against Mythimna separata with LD50 value of 140 µg g-1. Compounds 2, 5, 6, 8 and 9 showed varying α-glucosidase inhibitory activity with IC50 values ranging from 148.2 to 230.9 µM.
Subject(s)
Glycoside Hydrolase Inhibitors/chemistry , Glycoside Hydrolase Inhibitors/pharmacology , Insecticides/chemistry , Insecticides/pharmacology , Viburnum/chemistry , Animals , Drug Evaluation, Preclinical/methods , Glucosides/chemistry , Glucosides/pharmacology , Glycosides/chemistry , Glycosides/pharmacology , Magnetic Resonance Spectroscopy , Molecular Structure , Moths/drug effects , Phenols/chemistry , Phenols/pharmacology , Plant Extracts/chemistry , Spectrometry, Mass, Electrospray Ionization , Structure-Activity RelationshipABSTRACT
Two new phenolic glycoside compounds (1, 2) and ten known analogues (3-12) have been isolated from the ethanolic extract of Brassica rapa flowers and identified as 2-O-ß-d-glucopyranosyl-(1S)-(4-methoxyphenyl)ethylene glycol (1), 2-(4-O-ß-d-allopyranosyl)phenyl-ethanol (2), 2-O-ß-d-glucopyranosyl-(1S)-phenylethylene glycol (3), 2-O-ß-d-glucopyranosyl-(1R)-phenylethylene glycol (4), (Z)-p-coumaryl-O-ß-d-glucopyranoside (5), phenyl-O-ß-d-glucopyranoside (6), 2-phenylethyl-O-ß-d-glucopyranoside (7), salidroside (8), 2-(2-hydroxyphenyl)ethanol-O-ß-d-glucopyranoside (9), 4-methoxybenzyl-O-ß-d-glucopyranoside (10), 2,4,6-trimethoxyphenyl-1-O-ß-d-glucopyranoside (11) and sachaliside 1 (12). The structures of 1 and 2, including absolute configurations, were determined by spectroscopic data (1H NMR, 13C NMR, HSQC, HMBC and ORD) and chemical methods. In addition, most of them exhibited inhibitory activity with IC50 values ranging from 14.43 to 50.20 µM in comparison to the positive control acarbose (IC50 = 15.76 µM) in intestinal α-glucosidase inhibitory activity tests.
