Potent Antiplatelet, Anti-Inflammatory and Antiallergic Isoflavanquinones from the Roots of Abrus precatorius

Abstract

Five isoflavanquinones have been isolated from the roots of Abrus precatorius L. (Leguminosae). Three of them are new and designated as abruquinones D, E, and F. The pharmacological activities of the isoflavanquinones have been evaluated. The results indicated that abruquinones A, B, and D exhibited remarkable inhibitory effects on the platelet aggregation. The IC₅₀ of abruquinones A and B for the inhibition of the platelet aggregation induced by arachidonic acid (AA) and collagen were less than 5 µg/ml, and of abruquinone D, was less than 10 µg/ml for that induced by AA. On the other hand, abruquinones A, B, D, and F showed strong anti-inflammatory and antiallergic effects. The IC₅₀ of abruquinones A, B, D, and F for the inhibition of superoxide formation were less than 0.3 µg/ml, for the inhibition of the release of both β-glucuronidase and lysozyme from rat neutrophils and the release of both β-glucuronidase and histamine from mast cells were less than 1 µg/ml.

Key words

Abruquinones - isoflavanquinones - anti-platelet activity - platelet aggregation - anti-inflammatory activity - antiallergic activity - Abrus precatorius L. - Leguminosae