Chemical characterization and radical scavenging activity of leaves of Juniperus foetidisima, J. excelsa and J. communis from Macedonian flora

Abstract

Chemical characterization of three Juniperus species: J. foetidisima (JF), J. excelsa (JE) and J. communis (JC) from Macedonian flora enclosed determination of yield and essential oil composition of the oils obtained by hydro-distillation of dried leaves and determination of the content of total phenols and total flavonoids in dried plant material. GC/FID/MS analysis showed mainly monoterpene profile of the JC oil and combined monoterpene/sesquiterpene profile of JF and JE oils. Sesquiterpene cedrol was found as an important constituent of the JF and JE, thus the JF oil was characterized by three main components (a-pinene, limonene and cedrol, in amount up to 67.63%, 27.11% and 33.91%, respectively) and JE oil by four components (a-pinene, sabinene, cis-thujone and cedrol, in amount up to 33.83%, 29.49%, 26.20% and 24.44%, respectively). The JC oil was free of cedrol, but contained relatively large sesquiterpene fraction (sesquiterpene hydrocarbons and oxygen containing sesquiterpenes in amounts up to 28.64% and 13.57%, respectively). The JC oil was characterized by three monoterpene components (a-pinene, sabinene and terpinen-4-ol, presented up to 28.68%, 16.27% and 12.16%, respectively). The content of total phenols determined by Folin-Ciocalteu method ranged from 96.18-122.91 mg GAE/g dw (water extraction) while the content of total flavonoids ranged from 2.05-11.91 mg CE/g dw (ethanol extraction). Both water and ethanol extracts possessed radical scavenging activity against DPPH radical. Water extracts were more powerful with % of inhibition of DPPH ranging up to 64.52%, 67.40% and 78.23% for water extract (10 mg/ml) of JF, JE and JC, respectively. Obtained results showed correlation with the content of total phenols.