Chemical Composition, Antibacterial, Antioxidant and Enzyme Inhibitory Activities of the Essential Oil from Leaves of <i>Psidium guajava</i> L.
Xiaonan Zhang, Jiali Wang, Hongwei Zhu, Jianhao Wang, Huajiang Zhang
Abstract
Abstract Guava ( Psidium guajava L.) leaf essential oil (GLEO) was extracted by water distillation, and its in vitro antioxidant, antidiabetic, and antibacterial properties were evaluated. Using GC/MS to determine the chemical components of GLEO, 27 constituents were identified, accounting for 74.90 % of the total oil content, among which L‐caryophyllene (24.46 %), L‐calamenene (10.82 %), (−)‐globulol (10.69 %), and α ‐copaene (8.71 %) were the main components. Subsequently, the antioxidant activity of GLEO was determined by DPPH, ABTS, and β ‐carotene bleaching tests. The half maximal inhibitory concentration of GLEO for three free radicals were IC 50 =17.66±0.07 μg/mL, IC 50 =19.28±0.03 μg/mL, and IC 50 =3.17±0.01 μg/mL, respectively. Moreover, GLEO exhibited remarkable α ‐amylase (IC 50 =13.99±0.34 μg/mL) and α ‐glucosidase (IC 50 =5.50±1.02 μg/mL) inhibitory activities. It was effective against Streptomyces acidiscabies (MIC=1.25 μg/mL), Ralstonia solanacearum (MIC=5 μg/mL), and Erwinia carotovora subsp carotovora borgey (MIC=2.5 μg/mL), showing significant antibacterial properties. Based on the findings, given the high biological activity of GLEO, it is a biological preservative for food, medicine, and cosmetics and is valuable in natural therapy and crop disease management.