Sesquiterpenes from Stems of Syringa pinnatifolia var. alashanensis

Objective To study the chemical constituents of the volatile oil from the stems of Syringa pinnatifolia var. alashanensis. Methods The volatile oil from the stems of S. pinnatifolia var. alashanensis was obtained by steam distillation. They were isolated by chromatography on silica gel, Sephadex LH-20 columns and TLC, etc. The structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Results Five sesquiterpenes were isolated from the volatile oil. Conclusion Compound 1 is a new sesquiterpene.