Antioxidant activity and essential oil composition of Satureja hortensis L. as influenced by sulfur fertilizer.

Abstract

The quantity and quality of essential oils in plants can be influenced by various factors, including genetic traits, agricultural practices and environmental conditions such as nutrient availability. Macronutrients such as sulfur (S) are among the major factors influencing plant growth and development. Therefore this study was carried out to determine the effect of S fertilization at three levels (0, 0.05 and 0.1 g S kg(-1) soil) on the essential oil composition and antioxidant activity of Satureja hortensis L. Application of 0.05 g S kg(-1) soil increased the levels of α-terpinene, p-cymene, myrcene, α-thujene and α-pinene but decreased the level of γ-terpinene in the essential oil. This S application was most suitable for obtaining higher proportions of α-terpinene, p-cymene, myrcene, α-thujene and α-pinene, while application of 0.1 g S kg(-1) soil was preferable for carvacrol. γ-Terpinene was most abundant in the control. All extracts showed a considerable DPPH-inhibitory effect, with IC50 ranging from 0.720 g L(-1) in the control to 0.363 g L(-1) with application of 0.1 g S kg(-1) soil. The maximum antioxidant effect was observed with application of 0.1 g S kg(-1) soil. The results revealed that the use of chemical fertilizers such as S could improve the antioxidant activity of plant extracts significantly. Studying the secondary plant metabolites, mainly essential oils, is an interesting research area, so further studies are recommended to determine the effect of chemical fertilizers on the composition and antioxidant activity of essential oils of other aromatic plants.