Structural Elucidation and Antimicrobial Activities of a New Acyclic Monoterpenoid from the Volatile Oil of Artemisia mongolica

new acyclic monoterpenoid, namely mongolin A ( 1 ), was isolated from the volatile oil of Artemisia mongolica (Fisch. ex Besser) Fisch. ex Nakai. The structure of 1 was elucidated by spectroscopic methods, including UV, IR, HR-ESI-MS, and extensive 1D and 2D NMR techniques. The antimicrobial activity of 1 was evaluated by the agar plate diffusion method. Mongolin A exhibited an obvious inhibitory effect against Propionibacterium acnes .