Chemical composition of the essential oils of three Mexican oreganos species

A comparative study of the essential oils of the original Mexican oregano Lippia graveolens HBK (Verbenaceae) with the two most widely commercialized substitutes, namely, Monarda austromontana Epling (Lamiaceae) and Poliomintha longiflora Gray (Lamiaceae) using GC and GC-MS (EI) as analytical methods[1], revealed different fingerprints. While the oil of L. graveolens possesses the highest content of carvacrol (34.0%) and thymol (7.0%), M. austromontana possesses anisole (12.6%) and 2-carene (13.6%) as the major components. On the other hand, the oil of P. longiflora contains important amounts of thymol acetate (10.3%) and o-cymene (20.2%). The antimicrobial properties of the species were screened against five bacteria selected for their health significance. The results indicated that the three species display similar antibacterial activity. In conclusion, the results of this investigation will be useful for quality control of these species used indifferently as condiment and as carminative agents.

Acknowledgements: CONACyT (grant C01–018)

References: 1. Adams, R. (1989) Identification of Essential Oils by Ion Trap Mass Spectroscopy, USA.