1 042 N-{[(2s,3s)-3-(ethoxycarbonyl)oxiran-2-yl]carbonyl}-L-threonyl-L-isoleucine 1.000 2 76V N-{[(2s,3s)-3-(ethoxycarbonyl)oxiran-2-yl]carbonyl}-L-isoleucyl-L-isoleucine 0.893 3 75V N-{[(2s,3s)-3-(ethoxycarbonyl)oxiran-2-yl]carbonyl}-L-isoleucyl-L-alanine 0.786