abstract |
A compound of Formula 1: ** Formula ** in which: in which R1 is H, ** Formula ** CH2NH2, or CH2NHC (O) (CH2) mCO2H; R2 is H, ** Formula ** CH2NH2, or CH2NHC (O) (CH2) mCO2H; provided that either R1 or R2 are H, and provided that in addition both of R1 and R2 and are not H simultaneously; R3 is H; m is 1, 2, 3, 4, or 5; n is 1, 2, 3, 4, or 5. |