Identification of antibacterial and antioxidant constituents of the essential oils of Cynanchum chinense and Ligustrum compactum

Thirty-eight components were identified in essential oils. Based on bioactivity-guided fractionation, guaiacol, linalool and 2-phenylethanol were isolated and identified as active constituents.

Both L. compactum flower oil and 2-phenylethanol showed high antibacterial performance, with inhibition zone from 22.8 ± 0.8 to 11.9 ± 2.0 mm at highest concentration, and minimum inhibitory concentration values ranging from 0.25% to 1%. In both DPPH and ABTS assay, the active constituent guaiacol (IC 50 = 4.15 ± 0.72 and 9.12 ± 0.98 μg mL − 1 , respectively) exhibited high antioxidant activity, and the oils showed moderate antioxidant activity.