**14. Angiotensin I-converting enzyme inhibitory peptides**

Two non-competitive ACE inhibitors, Ile-Phe-Leu (IC50, 44.8 M) and Trp-Leu (IC50, 29.9 M), were isolated from the tofuyo (fermented soybean food) extract. The first sequence is con‐ tained in the alpha- and beta-subunits of beta-conglycinin, while the second sequence exists in the B-, B1A- and BX-subunits of soybean glycinin. The inhibitory activity of Trp-Leu was unaffected by the gastrointestinal proteases pepsin, chymotrypsin and trypsin. About 30% of the activity remained after successive digestion by these proteases [17].
