Composition of volatile oils and antioxidant activity of water extracts of leaves of Ziziphus jujuba mill from Central Iran

Abstract

This study is designed to investigate the volatile oils composition of the leaves of Ziziphus jujuba Mill from Qom province, central region of Iran, in two phenology stages: flowering and fruiting and examine antioxidant activity of its water extract. Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis indicated that Phytol (16.63%), (E)-2-Hexenal (11.26%) and Eugenol (9.58%) were the major constituents of the obtained volatile oil in the flowering period and (E)-2-Hexenal (37.05%) and n-Octane (7.44%) were of the fruiting period. The number of identified compounds in the volatile oil from the flowering season was 19 while the number in the fruiting season was 24. In addition, the antioxidant activity of water extracts of Z. jujuba leaves in two phenology stages were evaluated via 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging test and beta-carotene bleaching method. Also total phenolic compounds were estimated. The results show there is no significant differences in antioxidant properties of leaves’ water extract in the two phenology stages, but total phenolic compounds content of leaf extract of this plant is dependent on the phenology stage that the leaf is from.