Chemical Diversity and Antioxidant Capacity of Essential Oils of Marjoram in Northwest Egypt

Abstract

Origanum majorana “Marjoram” cultivation in Egypt dates back to 3000BC with current global distribution and economic importance in medicinal and herbal products. Plant natural diversity and scattered cultivated populations may harbor chemical diversity useful in agricultural and pharmaceutical industries. To investigate this assumption in Northwest Egypt, leaves essential oil (EO) composition of local accessions of Origanum majoranaL. are examined and in comparison in this study. Antioxidant activities (AA) using both of 2,2′-diphenypicrylhydrazyl (DPPH) and β-carotene-linoleic acid assay were examined for EOs. Main EOs constituent were cis-sabinene hydrate 34.3 %, α-terpinen 18 %, 4-terpineol 15.20 %, terpinolene 11.8 %, and sabinene 7.4 %; α-terpinen 29.2 %, cis-sabinene hydrate 15.40 %, terpinolene 19.50 %, and 4-terpineol 14.40 %; 4-terpineol 35 %, cis-sabinene hydrate 20 %, terpinolene 10.33 %, α-terpinen 8.96 %, and sabinene 8.4 % in the accessions OM550, OM555 and OM560; respectively. Examined accessions were classified into two chemotypes easily using their Eos harboring either sabinene or terpinens as major constituents. High antioxidant capacities were related to high sabinene and terpinens contents. It was concluded that Egyptian marjoram harbor good quality essential oils could be utilized as food additives and for improving human health.