| abstract |
The present invention provides hydroxamic acid derivatives represented by the following formula (I), having anti-aging efficacy and a method for preparation thereof: wherein, R1 is or, herein, R5 and R6 each independently represents a hydrogen atom, a C1-C10 alkyl group or a C3-C6 cyclic alkyl group; R2 is CONH, NHCO, CONR7 or NR7CO, herein, R7 represents a C1-C10 alkyl group; R3 is (CH)n-, herein, n=0 or 1; and R4 is a hydrogen atom or a C1-C10 alkyl group. Further, the present invention provides skin-care external compositions for preventing skin aging, containing said hydroxamic acid derivatives represented by the formula (I) as an active ingredient. |