A 1.alpha.-hydroxy-vitamin D derivative represented by formula (I): ##STR1## wherein R.sub.1 represents a hydrogen atom or a hydroxyl group; and R.sub.2 represents a straight-chain or branched lower alkyl, lower alkenyl or lower alkynyl group, which is substituted with a hydroxyl group, a halogen atom, a cyano group, a lower alkoxy group, an amino group or an acylamino group, is disclosed. The compound exhibits calcium metabolism regulating activity and differentiation stimulating activity on tumor cells, etc. and is useful as a treating agent for diseases caused by abnormal calcium metabolism, such as osteoporosis and osteomalacia, or as an antitumor agent.
一种由公式(I)表示的α-羟基
维生素D衍
生物:##STR1##其中R.sub.1代表氢原子或羟基基团;R.sub.2代表直链或支链低级烷基,低级烯基或低级炔基,其被羟基基团,卤素原子,
氰基,低级烷氧基,
氨基或酰胺基取代,该化合物表现出调节
钙代谢和刺激肿瘤细胞分化等活性,并可用作治疗因异常
钙代谢引起的疾病,如骨质疏松和软骨病,或作为抗肿瘤剂。