of the cation, a is 1 or 2, and b and c are the smallest integers that result in a neutral compound, preferably such that the compound is not a salt of alanosine or dopastin, as described in U.S. Pat. No. 5,212,204; ##STR6## wherein R1 and R2 are independently selected from the group consisting of a straight chain or branched chain C1 -C12 alkyl group and a benzyl group, with the proviso that no