Angiotensin I-converting enzyme inhibitor from Grifola frondosa

To investigate the hypotensive compounds From edible mushroom, extracts fro m 10 fruit bodies of mushrooms were screened for the inhibitory activity ag ainst angiotensin I converting enzyme (ACE). The most potent ACE inhibitory activity (58.7%) was detected in a cold water extract of Grifola frondosn, with an IC50 of 0.95 mg. The ACE inhibitory activities of the cold and hot water extracts increased as the extraction time increased, but decreased s lightly 15 h and 90 min, respectively, after extraction. After the purifica tion of ACE inhibitory peptides with acetone fractionation and column chrom atography, we obtained an active fraction with an IC50 Of 0.13 mg and a yie ld of 0.7%. The purified inhibitor showed competitive inhibition on ACE and this peptide maintained inhibitory activity even after digestion by intest inal proteases. (C) 2001 Elsevier Science Ltd. All rights reserved.