Chemodiversity and antibacterial activity of the essential oil of leaves of Croton argyrophyllus Kunth.

The Croton argyrophyllus leaf essential oil has anti-inflammatory, antioxidant, cytotoxic among other activities, but there are chemical composition variations in the literature. This work reports the first study of the intraspecific chemical variation of C. argyrophyllus population from Pernambuco state, Brazil. The essential oils of nine specimens (OCA1 to OCA9) were analyzed by GC/MS and NIR to identify the chemical composition and to verify the similarity between the analyzed samples. These analyses resulted in the identification of bicyclogermacrene (mean 38.42%), (Z)-caryophyllene (mean of 14.06%), epi-longipinanol (mean of 9.78%) and germacrene B (mean of 9,1%) as the major constituents as well as the same chemical markers for all oil samples, but different to those previously registered in the literature for C. argyrophyllus essential oil. The data obtained from the analysis by NIR spectroscopy were treated by PCA and HCA, and showed similarity of the chemical samples' profile. Statistical analyzes made it possible to form three clusters: OCA1-6, OCA7-8 and OCA9. All these groups were potentially active against Staphylococcus aureus , however the OCA7-8 group was the most active.