| abstract |
The present invention provides a compound having an excellent inhibitory action on melanin production and being useful as a whitening agent, and a skin external preparation containing the compound. The whitening agent of the present invention comprises, as an active ingredient, a heterocyclic compound represented by formula (1) or a pharmacologically acceptable salt thereof: n n n n n n n n n n wherein R 1 , R 2 , and R 2 ′ are each independently C 1-3 alkyl; Y is S or O; and p is an integer of 0 to 3, wherein when p is 2 or 3, R 1 may be the same or different. |