The present invention provides a compound having the structure: wherein X is C1-C12 alkyl, C2-C12 alkenyl, C2-C12 alkynyl, cyano, aryl, heteroaryl, alkylaryl, alkylheteroaryl, alkenylaryl, alkenylheteroaryl, alkynylaryl, alkynylheteroaryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, heteroaryloxy, acyl, alkylhydroxy, alkylamino, alkenylamino, alkynylamino, amido, carboxyl, or carboxyl ester, or forms an unsubstituted or substituted cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, indane or tetralin with Y, Y is H or forms an unsubstituted or substituted cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, indane or tetralin with X, or forms an unsubstituted or substituted monocycle with Z; and Z is H or forms an unsubstituted or substituted monocycle with Y; wherein when X and Y are both H, then X is C2alkenyl or C2 alkynyl, and when Y is H forms a substituted cyclohexyl, cycloheptyl with X, the cyclohexyl is other than a trisubstituted cyclohexyl bearing CH3, i-Pr and (CH2)2CO2CH3 groups or CH3, i-Pr and (CH2)3NH2, or a salt or ester thereof.