Chemical Composition and Antioxidant Activities of Buds and Leaves of Capers (Capparis ovata Desf. var. canescens) Cultivated in Turkey

Abstract

Essential oils of caper (Capparis ovata Desf. var. canescens) buds and leaves obtained by steam distillation followed by solvent extraction were analyzed by GC and GC/MS. Eighty-six compounds were identified from the caper bud extract and 100 from the caper leaf oil. The major volatile compounds found in caper bud oil were benzyl alcohol (20.4%), furfural (7.4%), ethanal methyl pentyl acetal (5.9%), 4-vinyl guaiacol (5.3%), thymol (5.1%), octanoic acid (4.8%) and methyl isothiocyanate (4.5%). The major volatile compounds found in caper leaves were methyl isothiocyanate (20.0%), thymol (15.5%), 4-vinyl guaiacol (4.3%), hexyl acetate (3.6%) and trans-theaspirane (2.6%). These oils inhibited hexanal oxidation by 80% over 40 days at the level of 200 μg/mL. Also, they inhibited oxidation of 1,1-diphenyl-2-picrylhydrazyl hydrate by over 70% at the 500 μg/mL level. The dichloromethane and methanol extracts from caper buds and leaves exhibited higher antioxidant activities than those of their essential oils in both testing systems.