Two novel bis—labdanic diterpenoids named calcaratarin G and calcaratarin H were isolated from the rhizomes of Alpinia calcarata Rosc.Their structures were elucidated to be a pair of stereoiso-mers on the basis of t...Two novel bis—labdanic diterpenoids named calcaratarin G and calcaratarin H were isolated from the rhizomes of Alpinia calcarata Rosc.Their structures were elucidated to be a pair of stereoiso-mers on the basis of the spectral evidence.The 2D NMR techniques including’H-1H COSY,HMQC,HMBC,NOESY and HRFABMS were extensively applied to establish the structures.展开更多
文摘Two novel bis—labdanic diterpenoids named calcaratarin G and calcaratarin H were isolated from the rhizomes of Alpinia calcarata Rosc.Their structures were elucidated to be a pair of stereoiso-mers on the basis of the spectral evidence.The 2D NMR techniques including’H-1H COSY,HMQC,HMBC,NOESY and HRFABMS were extensively applied to establish the structures.