Piperidine and piperazine compounds of formula (I), their salts, isomers, hydrates, isoforms and prodrugs, are new. G = C (sic) or N； A = phenyl (substituted by COOH, CONH2, COOCH3, CN, NH2 or COCH3), naphthyl, benzofuranyl, quinolyl, or e.g. a group of formula (i) or (iv), (the phenyl ring of each being optionally substituted by 1 or 2 CF3, (CH2)oCF3, halo, CONR7R8, CO2R7, COR7, (CH2)oNR7R8, (CH2)oCH3(CH2)oSOR7, (CH2)oSO2R7 or (CH2)oSO2NR7R8； o = 0-2； R1, R7-R10, R15, R16 = H, 1-6C alkyl, 1-6C alkenyl, -CO(1-6C alkyl), (1-6C alkyl)-B, 3-8C cycloalkyl, 1-2C alkyl-3-6C cycloalkyl, 6-10C aryl or heteroaryl having 5-10 atoms selected from C, S, N and O, the aryl and heteroaryl being optionally substituted by 1 or 2 CH3, (CH2)oCF3, halo, CONR7R8, CO2R7, COR7, (CH2)oNR7R8, (CH2)oCH3(CH2)oSOR7, (CH2)oSO2R7 and (CH2)oSO2NR7R8； R2 = H, CH3, OR1, CO2R 1 or CH2CO2R1； B = optionally substituted aromatic, optionally substituted 5-10C hydroaromatic, heteroaromatic or heterohydroaromatic each having 5-10 atoms selected from C, S, N and O, and each optionally substituted by 1 or 2 CH3, CF3, halo, (CH2)pCONR7R8, (CH2)pNR7R8, (CH2)pCOR7, (CH2)pCO2R7, OR7, (CH2)pSOR7, (CH2)pSO2R7 and (CH2)pSO2NR7R8； p = 0-3； R3-R6 = R7, (CH2)p'CONR7R8, (CH2)p'NR7R8, (CH2)p'CO2R7, (CH2)p'Ph, (CH2)p'(p-OH Ph), (CH2)p'-3-indolyl, (CH2)p'SR7 or (CH2)p'OR7； p' = 0-4； with proviso.
