In one embodiment, the invention includes amino-acid based compounds in accordance with formula (I) above in which Z is a hydrogen atom, R1 is a hydrogen atom and A is ???C(CH2OH)3, wherein Q is is a substituent selected from the group consisting of ???N(R2)2, ???NR2N(R2)2, ???SR2, an alkoxy, a halogenated alkoxy, an O-acyl and an O-halogenated acyl.