Structures of Sesquiterpenes of Curcuma aromatica SALISB. II. : Studies on Minor Sesquiterpenes

Abstract

Further study on the sesquiterpenes from Curcuma aromatica (Zngiberaceae) has resulted in the isolation of eleven minor sesquiterpenes, 1-11 having guaiane, seco-guaiane and germacrane skeletons, and their structures were elucidated by proton nuclear magnetic resonance (¹H-NMR) and ¹³C-nuclear magnetic resonance (¹³C-NMR) spectroscopy, as well as chemical investigation. The stereochemistry of these sesquiterpenes was elucidated by 2D NMR techniques such as ¹H-^H correlation (COSY) and nuclear Overhauser effect correlation (NOESY), and circular dichroism (CD) spectroscopy.