Modulator

A compound of formula I, or a pharmaceutically acceptable salt thereof,

• wherein
• Z is OR1 or NR1R2 wherein each of R1 and R2 is independently H, or a hydrocarbyl group;
• X is an alkylene, alkenylene, or alkynylene group, each of which may be optionally substituted by one or more substituents selected from alkyl, COOH, CO2-alkyl, alkenyl, CN, NH2, hydroxy, halo, alkoxy, CF3, and nitro;
• Y is a polar functional group selected from OH, NO2, CN, COR.3, COOR3, NR3R4,
• CONR3R4, SO3H, SO2—R3, SO2NR3R4 and CF3, where each of R3 and R4 is independently H or a hydrocarbyl group;
• A is phenyl or pyridyl;
• and
• B is (CH2)n where n is 0;
• with the proviso that:
• (i) when A is phenyl, and Z is OH, X—Y is other than C≡C—(CH2)2OH, C≡C—(CH2)2OH, C≡C—(CH2)2CO2Me, (CH2)4CO2H;
• and
• (ii) when A is phenyl, and Z is OMe, X—Y is other than C≡C—(CH2)4OH;
• —(CH2)4—CHO, cis-CH═CH—(CH2)3OH, trans-CH═CH—(CH2)3OH;
• and wherein the compound is other than 1-(N-octylcarbamoyl)methyl-3-carboxmidopyridinuim chloride, 3-methylcarbamoyl-1-dodecyloxycarbonylmethyl-pyridinium or 6-aminomethylpyridine-2-carboxylic acid ethyl ester.