Determination of the absolute stereochemistry of two new aristophyllene sesquiterpenes: a combined theoretical and experimental investigation.

Aristoyunnolins G (1) and H (2), two new diastereoisomeric sesquiterpenes featuring a rare aristophyllene skeleton, were isolated from the traditional Chinese medicine Aristolochia yunnanensis. Their absolute stereochemistry involving three chiral centers was determined by combined chemical, spectral, and Density Functional Theory (DFT) calculation methods.