Compound according to the formula: ** Formula ** or characterized in that R3 is an alkenyl or C5-C15 alkyl group, an aryl, heterocycle, alkylenearyl, alkenylenearyl, alkylene heterocycle or alkenylene heterocycle group, wherein said alkylene, alkenylene group, aryl or heterocycle may be substituted or unsubstituted, a thioether or C2-C10 ether group, a COR, CO2R, COSR, (CH2) nCOR, (CH2) nCO2R or (CH2) nCOSR group, in which R is H, a C1-C10 alkenyl or alkyl group, a substituted or unsubstituted aryl, a heterocycle group, an alkylenearyl, alkenylenearyl, alkylene heterocycle or alkenylheterocycle group, wherein said alkylene, alkenylene, aryl or heterocycle group is substituted or unsubstituted, or a thioether group containing from 2 to 8 carbon atoms, a group, in which X is O or S, R7 is a thioether, ether, alkenyl or C1-C10 alkyl group, an aryl or heterocycle group, an alkylenyl group, alkenylenearyl, alkylene heterocycle or alkenylene heterocycle , which may be substituted or unsubstituted, wherein said alkylene or alkenylene group, an amine or alkyleneamine group which may be substituted or unsubstituted in the alkylene or mono or disubstituted or unsubstituted group in the amine group with an alkanol group or C1-C4 alkyl, an amino acid or amino ester residue in which the amine of said amino acid or amino ester residue is chemically bonded to the carbon of the group ** Formula ** or a group, ** Formula ** in which R8 is H , an alkenyl or C1-C10 alkyl group, an aryl, heterocycle, alkylenearyl or alkylene heterocycle group, which may be substituted or unsubstituted or an alkylene ester group ** Formula ** wherein n is 1-4 and said group alkylene of said alkylene ester may be substituted with an R10 group, wherein R9 is a C1-C6 alkyl group and R10 is a thioether, ether, alkenyl or C1-C8 alkyl group, an aryl, heterocycle, alkylenearyl, alkenylenyl group , alkylene-heterocycle or alkenylene-5 heter occycle, wherein said alkylene, alkenylene, aryl or heterocycle may be
