The structures of four new diterpene alkaloids, spiramines A, B, C, and D.

The structures of four new diterpene alkaloids, spiramines A, B, C, and D. Spiromines A, B, C, and D New Diterpene Alkaloids from Spiraea japonica var. acuminata Franch The structures of four new diterpene alkaloids, spiramines A, B, C, and D. Diterpene alkaloids from roots of Spiraea japonica Spiromines A, B, C, and D New Diterpene Alkaloids from Spiraea japonica var. acuminata Franch Four New C20-Diterpene Alkaloids, Spirasine I, Spirasine II, Spirasine VII and Spirasine VIII from Spiraea japonica New Diterpene Alkaloids from the Roots of Spiraea japonica New Diterpene Alkaloids from the Roots of <i>Spiraea </i><i>japonica</i> New Spiramines from Spiraea japonica var. ovalifolia Three New Diterpene Alkaloids from Spiraea japonica