Chemical composition and antibacterial activity of essential oils from the rhizomes of Cyperus papyrus L. grown in South Africa

Abstract

Essential oils hydrodistilled from the rhizomes of Cyperus papyrus L. growing wild in two localities (KwaDlangezwa and Richard’s Bay) of uMhlathuze City, KwaZulu-Natal Province, South Africa has been studied. The major components of KwaDlangezwa oil were caryophyllene oxide (12.7%), cyperene (10.2%) and 1,8-cineole (8.4%). The oil of Richard’s Bay comprised mainly of caryophyllene oxide (24.4%), humulene epoxide II (13.2%), aristolene (9.1%) and aromadendrene epoxide II (7.3%). The antibacterial activity of the oils was assayed using agar-disc diffusion and broth-microdilution methods. The minimum inhibitory concentration (MIC) revealed that the oil samples inhibited the growth of Staphylococcus aureus (ATCC 3983 and ATCC 6538), with MIC of 1.25 and 0.31 mg/mL for each oil. Streptococcus faecalis (ATCC 29212; MIC of 1.25 and 0.6 mg/mL, respectively) and Escherichia coli (ATCC 4983; MIC of 1.25 mg/mL for both oils). Only the Richard Bay oil showed activity against Bacillus cereus and Bacillus pumilus with MIC of 1.25mg/mL, respectively.