Isolation of an angiotensin converting enzyme inhibitory substance from Chrysanthemum boreale makino

Abstract

Thirty plants of the Compositae family were screened for inhibitory activity of angiotensin converting enzyme (ACE) and Chrysanthemum boreale Makino was selected for further investigation since it had the highest inhibitory activity. Crude water extract of the flowers of Chrysanthemum boreale Makino was prepared by steeping in water at 95°C for 2 h, followed by centrifugation at 8000 × g for 30 min. Crude extract was then filtered using YM-3 and YM-1 membranes. An ACE inhibitor was isolated using consecutive chromatographic methods including: gel permeation chromatography, ion exchange chromatography, normal and reverse phase HPLC. The inhibitor was identified to be guanosine by mass spectrometry and NMR studies.