| abstract |
According to the invention there is provided a compound of Formula (I) in which: A is a C2-8 alkylene group; R1, R2, R3 and R4 are independently selected from hydrogen, C1.4 alkyl, C2-4 dihydroxyalkyl in which the carbon atom attached to the nitrogen atom does not carry a hydroxyl group and no carbon atom is substituted by two hydroxyl groups, or R2 and R3 together form a C2 -6 alkylene group which with the nitrogen atom to which R2 and R3 are attached forms a heterocyclic ring; X1, X2 and X3 are independently selected from hydrogen, hydroxyl, NR1-A- NR2R3R4+ (Zm-)1/m, halogeno amino, C1.4 alkoxy or C2-8 alkanoyloxy; and (Zm-)1/m is an anion of charge m; or a derivative in which the group NR1 is quaternarised. c, UU) 4- U)> a) C U) L-U) C - U E ) E c) C: )0 a) ) L- CE C0 Co Coc cu 0 >, 0, CD 0) cm' cm I ofl12 |