Studies on the chemical constituents of Isodon japonica var. glaucocalyx

Objective To study the constituents and provide guidance for further investigation of bioactivity of Isodon japonica var. glaucocalyx. Methods Compounds were separated and purified by silica gel column chromatography and their structures were determined by spectroscopic methods.Results Four known compounds were isolated and identified from the leaves of Isodon japonica var. glaucocalyx. Three of them were ent-kaurane diterpenoids glaucocalyxin A (1), glaucocalyxin B (2), glaucocalyxin C (3) and the other one was flavonoid agastachoside (4). Conclusion The agastachoside is separated from genus Isodon for the first time.