头花杜鹃(Rhododendron capitatumMaxim.)是我国西北地区杜鹃属植物中产量较多的一个品种,主要分布在青海、甘肃和四川等省。临床观察结果表明,其挥发油有较好的祛痰和镇咳作用;药理实验结果表明,其急性毒性低于黄花杜鹃(R.anthopogonoides Ma-xim.)、青海杜鹃(R.tsinghaiense Ching.)和百里香杜鹃(R.thymifolium Maxim.)。该挥发油的烯烃部分具有镇咳、祛痰作用。用硅胶柱层析、分馏和含硝酸银的氧化铝柱层 Rhododendron capitatum Maxim. is one of the most abundant species of rhododendrons in northwest China and is mainly distributed in Qinghai, Gansu and Sichuan provinces. Clinical observations showed that the volatile oil had better expectorant and antitussive effects; pharmacological experiments showed that its acute toxicity was lower than R. anthopogonoides Ma-xim. and R. tsinghaiense Ching. R. thymifolium Maxim. The olefin portion of the volatile oil has antitussive and expectorant effects. Column chromatography on silica gel, fractionation and column chromatography of alumina containing silver nitrate