Isolation, structural elucidation of new phytoecdysteroids from Ajuga decumbens Thunb

Five new phytoecdysteroids (1, 2, 3, 4, and 5) were isolated from Ajuga decumbens Thunb. planted at Pingtan island of Fujian Province. Their structures were elucidated by NMR(1H NMR, 13C NMR, DEPT, HMBC, HSQC, 1H–1H COSY, ROESY), and HRESIMS. Especially, compound 2 is the epimer of Cyasterone, which was directly confirmed using single crystal X-ray diffraction analysis.