Certain proliferative diseases and conditions, particularly certain lung, breast, brain, ovarian, prostate, colon, characterized by overexpression of one or more CDK enzymes and / or one or more abnormal CDK activities. A novel group of protein kinase inhibitors useful for the treatment of rectal cancer, leukemia and the like. The inhibitors have the general structure (I). (I) [Selection diagram] None細胞増殖性疾患及び状態、特に、1つ以上のCDK酵素の過剰発現及び/または1つ以上の異常なCDK活性を特徴とする、特定の肺癌、乳癌、脳癌、卵巣癌、前立腺癌、結腸直腸癌、及び白血病等の治療に有用な新規なプロテインキナーゼ阻害剤群。該阻害剤は、一般構造(I)を有する。(I)【選択図】なし