Patent ID: 7282522

Claim:
A hydroxamic acid derivative represented by the following formula(I): wherein, R 1 is wherein, R 5 and R 6 each independently represents a hydrogen atom, an alkyl group having from 1 to 10 carbon atoms or a cyclic alkyl group having from 3 to 6 carbon atoms; R 2 is CONH, NHCO, CONR 7 or NR 7 CO, herein, R 7 represents an alkyl group having from 1 to 10 carbon atoms; R 3 is —(CH 2 ) n —, herein, n=0 or 1; and R 4 is a hydrogen atom or an alkyl group having from 1 to 10 carbon atoms; on the proviso that compounds in which R 1 is wherein R 5 and R 6 each are H, R 2 is CONH, and n=0, and compounds in which R 1 is wherein R 5 is H and R 6 is CH 3 , R 2 is CONH and n=0 or 1 are excluded.