To provide a new ultraviolet absorber, the melanin production inhibitor and ultraviolet light protection agents and / or. Of the formula (1) 2-substituted-6-alkyl-5-oxo-5,6-dihydro-(7H) pyrrolo [3,4-d] Salts and a pharmaceutically acceptable expression or pyrimidines compounds, (2) 2-substituted alkyl-7-oxo-5,6-dihydro (7H) pyrrolo or [2,3-d] pyrimidines compounds ultraviolet absorber used as an active ingredient, melanin production inhibitor and ultraviolet light protection agents and / or. Or formula [equation (1) in (2), R8 from R1 is hydrogen or a lower alkyl group independently, -CH2CH2OCH3, -CH2COR9 (R9 = CH3, C2H5, NH2), - the CH2-OCOC2H5 X is -N ( R10) - (R10 = CH3, C2H5, Ph, -CH2Ph, -CH (Ph) 2, -COCH3, -COOCH3, -SO2CH3), - CH2 -, - CH (CH3) -, - CH (C2H5) -, I show the S- - -O -,. However Ph is a phenyl group]新たな紫外線吸収剤、紫外線防護剤及び/又はメラニン産生抑制剤を提供する。式(1)の2-置換-6-アルキル-5-オキソ-5,6-ジヒドロ(7H)ピロロ[3,4-d]ピリミジン類化合物、または式(2)の2-置換-7-アルキル-6-オキソ-5,6-ジヒドロ(7H)ピロロ[2,3-d]ピリミジン類化合物またはその薬学的に許容される塩類を有効成分とする紫外線吸収剤、紫外線防護剤及び/又はメラニン産生抑制剤。〔式(1)または式(2)において、R1からR8は独立に水素または低級アルキル基、-CH2CH2OCH3、-CH2COR9(R9=CH3、C2H5、NH2)、-CH2-OCOC2H5を;Xは-N(R10)-(R10=CH3、C2H5、Ph、-CH2Ph、-CH(Ph)2、-COCH3、-COOCH3、-SO2CH3)、-CH2-、-CH(CH3)-、-CH(C2H5)-、-O-、-S-を;示す。但しPhはフェニル基である〕
