A compound of formula: and pharmacologically acceptable salts thereof wherein: R 16 is hydrogen; R 2 is hydrogen; R 3, R 4, R 5, R 7, and R 8 are hydrogen; R 6 is a nitro group; L is -CH 2 -; n is 1; Z is -S-; the styryl group is either E or Z, and is preferably E in configuration; R 1 is a pharmacologically acceptable functional group which is a functionalized imine or a functionalized methylene group and pharmacologically acceptable salts thereof; and X is an organic or inorganic leaving group selected from where each R 20 independently is selected from hydrogen, C1-C3 alkyl or two adjacent R 20 together with the atoms to which they are attached form a 5-6 member carbocyclic or heterocyclic ring which may contain one or more double bonds or be aromatic; where each R 21 independently is selected from hydrogen, C1-C3 alkyl, or two R 21 together with the atom to which they are attached form a 5-6 member heterocyclic ring; where R 23 is hydrogen or a C1-C3 alkyl, R 24 is hydrogen, a C1-C3 alkyl, a -N(R 31) 2 group, or a -NH-CO-NHR 31 group and R 25 is hydrogen, a C1-C3 alkyl, a -N(R 31) 2 group, or an -NH-CO-NH-R 31 group, where R 31 is hydrogen, C1-C3 alkyl, or C1-C3 aminoalkyl, or R 24 and R 25 together with the atoms to which they are attached form a 5-6 member carbocyclic ring or heterocyclic ring which optionally contains one or two double bonds or is aromatic; and where R 27 is hydrogen or C1-C3 alkyl, each R 28 is hydrogen or a C1-C3 alkyl group, and R 29 is hydrogen, or a C 1 -C 3 alkyl or R 27 with its adjacent R 28 or R 29 with one of R 28 together with the atoms to which they are attached forms a 5-6 member heterocyclic or carbocyclic ring; optionally wherein R 27 is hydrogen; or a compound of formula: where: X is a halogen or and R 1 is a pharmacologically acceptable functional group which is a functionalized imine or a functionalized methylene group and pharmacologically acceptable salts thereof. R 16 is hydrogen; R 2 is hydrogen; R 3, R 4, R 5, R 7, and R 8 are hydrogen; R 6 is a nitro group; L is -CH 2 -; n is 1; Z is -S-; the styryl group is either E or Z, and is preferably E in configuration; R 1 is a pharmacologically acceptable functional group which is a functionalized imine or a functionalized methylene group and pharmacologically acceptable salts thereof; and X is an organic or inorganic leaving group selected from where each R 20 independently is selected from hydrogen, C1-C3 alkyl or two adjacent R 20 together with the atoms to which they are attached form a 5-6 member carbocyclic or heterocyclic ring which may contain one or more double bonds or be aromatic; where each R 21 independently is selected from hydrogen, C1-C3 alkyl, or two R 21 together with the atom to which they are attached form a 5-6 member heterocyclic ring; where R 23 is hydrogen or a C1-C3 alkyl, R 24 is hydrogen, a C1-C3 alkyl, a -N(R 31) 2 group, or a -NH-CO-NHR 31 group and R 25 is hydrogen, a C1-C3 alkyl, a -N(R 31) 2 group, or an -NH-CO-NH-R 31 group, where R 31 is hydrogen, C1-C3 alkyl, or C1-C3 aminoalkyl, or R 24 and R 25 together with the atoms to which they are attached form a 5-6 member carbocyclic ring or heterocyclic ring which optionally contains one or two double bonds or is aromatic; and where R 27 is hydrogen or C1-C3 alkyl, each R 28 is hydrogen or a C1-C3 alkyl group, and R 29 is hydrogen, or a C 1 -C 3 alkyl or R 27 with its adjacent R 28 or R 29 with one of R 28 together with the atoms to which they are attached forms a 5-6 member heterocyclic or carbocyclic ring; optionally wherein R 27 is hydrogen; or a compound of formula: where: X is a halogen or and R 1 is a pharmacologically acceptable functional group which is a functionalized imine or a functionalized methylene group and pharmacologically acceptable salts thereof. X is a halogen or and R 1 is a pharmacologically acceptable functional group which is a functionalized imine or a functionalized methylene group and pharmacologically acceptable salts thereof.