Eucalyptus gunii Hook. F. new source of valuble bioactive compounds

Due to antiseptic and anti-inflammatory properties, leaves of plants from genus Eucalyptus have found their place in traditional and modern herbal medicine. In this study, a composition, antioxidant, antimicrobial and antimutagenic activity of E. gunnii both essential oil and phenolic compounds were determined for the first time. The oil was obtained by hydrodistillation of leaves in 1.76% yield, and chemically profiled by GC-MS technique. The phenolic componds were isolated by maceration in 70% MeOH (1.63mg/100g extract). The oil was found to contain 77.4% of oxygenated monoterpenes, and 2.5% of sesquiterpenes, with the most abundant terpenoids being 1,8-cineol (67.8%) and α-pinene (14.1%). In MeOH extract phenolic acids, flavonoids and ellagitannins were identified. Antioxidant activity was evaluated by diffrenet test concerning: DPPH, O₂ ^.-, NO, LP, reducing power, XOD. Both essential oil and phenolic compounds demonstrated from moderate to very strong antioxidant activity, depending on the test applied. Methanolic extract exhibited higher antioxidant, but lower antibacterial activity. The oil exhibited high antibacterial activity on S. epidermidis ATCC 12228 and B. subtilis ATCC 10774 strains. Both essential oil and phenolic compounds showed significant antimutagenic activity. A strong inhibition of t-BuOOH-induced mutagenesis is observed in non-toxic concentration range, which can be attributed to radical-scavenging action of antioxidants.