Pharmacologically active components of viticis fructus (Vitex rotundifolia). II. The components having analgesic effects

Abstract

The extract of Viticis Fructus appeared to have an analgesic effect, and was subjected to activity-guided separation using acetic acid-induced writhing in mice. The active fraction gave new compounds, vitexfolin A (1A), B and C, 10-O-vanilloylaucubin (3), dihydrodehydrodiconiferylalcohol-β-D- (2'-O-p-hydroxybenzoyl)glucoside (4), and vanilloyl-β-D-(2'-O-p- hydroxybenzoyl)glucoside, together with agnuside (2) and erythro- and threoguaiacylglycerols. Compounds 1A and 2 - 4 showed significant writhing inhibition following oral administration at doses of 15, 50, 25, and 50 mg/kg, respectively. The effect on pressure pain threshold was tested using compounds 1A and 2 at a dose of 50 mg/kg, and only the former produced the analgesia. The analgesic effect of some related iridoid glucosides is also discussed.