title: Chemotyping of diverse Eucalyptus species grown in Egypt and antioxidant and antibacterial activities of its respective essential oils.
abstract: The chemical composition of the essential oil from the leaves of Eucalyptus camaldulensis, Eucalyptus camaldulensis var. obtusa and Eucalyptus gomphocephala grown in northern Egypt was analysed by using GC-FID and GC-MS techniques. The antibacterial (agar disc diffusion and minimum inhibitory concentration methods) and antioxidant activities (2,2'-diphenypicrylhydrazyl) were examined. The main oils constituents were 1,8-cineole (21.75%), β-pinene (20.51%) and methyleugenol (6.10%) in E. camaldulensis; spathulenol (37.46%), p-cymene (17.20%) and crypton (8.88%) in E. gomphocephala; spathulenol (18.37%), p-cymene (19.38%) and crypton (16.91%) in E. camaldulensis var. obtusa. The essential oils from the leaves of Eucalyptus spp. exhibited considerable antibacterial activity against Gram-positive and Gram-negative bacteria. The values of total antioxidant activity were 70 ± 3.13%, 50 ± 3.34% and 84 ± 4.64% for E. camaldulensis, E. camaldulensis var. obtusa and E. gomphocephala, respectively. The highest antioxidant activity value of 84 ± 4.64% could be attributed to the high amount of spathulenol (37.46%).
authors.affiliation: a Forestry and Wood Technology Department , Faculty of Agriculture (EL-Shatby), Alexandria University , Alexandria , Egypt.
authors.forename: Mohamed Z M
authors.initials: MZ
authors.lastname: Salem
authors.forename: Nader A
authors.initials: NA
authors.lastname: Ashmawy
authors.forename: Hosam O
authors.initials: HO
authors.lastname: Elansary
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: El-Settawy
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D000975:Antioxidants / Q000737:chemistry*; D004534:Egypt; D005052:Eucalyptus / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D009822:Oils, Volatile; D010938:Plant Oils
keywords: DPPH; GC–MS; antibacterial activity; chemotyping; essential oil; eucalyptus leaves