1 40H (1r,4s,5s,6s)-4-aminospiro[bicyclo[3.1.0]hexane-2,1'-cyclopropane]-4,6-dicarboxylic acid 1.000 2 40F (1s,2s,5r,6s)-2-aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid 0.867 3 JIX (1s,4r,5r,6s)-4-amino-2-oxabicyclo[3.1.0]hexane-4,6-dicarboxylic acid 0.750 4 W92 (1r,4r,5s,6r)-4-azanyl-2-oxabicyclo[3.1.0]hexane-4,6-dicarboxylic acid 0.750