Zierone: A Sesquiterpene Ketone from the Essential Oil of Cyperus distans L. (Cyperaceae)

Aims: The study investigates the essential oil obtained from the rhizomes of Cyperus distans collected from different location, and compared the result with previous sample and other reports on the chemical composition of essential oils from several species of the genus Cyperus.

Study Design: Isolation of essential oil from the rhizomes of Cyperus distans and identification of its chemical constituents.

Place and Duration of Study: Fresh plant materials of Cyperus distans were collected at full flowering stage from Main road, Vulindlela, along KwaDlangezwa road, opposite University of Zululand, KwaDlangezwa, KwaZulu-Natal, South Africa, in October, 2006.

Methodology: Fresh rhizomes of Cyperus distans were hydrodistilled in a Clevenger-type apparatus and the isolated oil analyzed by GC and GC/MS.

Results: Twenty-two constituents were identified, representing over 80.0% of the oil composition. The chemical profile of the oil was very different from the essential oils of several species of the genus Cyperus, with little amount of cyperene (3.1%). The most interesting feature of the oil was the presence of a sesquiterpene ketone, zierone (33.9%). Other significant constituents are caryophyllene oxide (14.2%) and α-cyperone (9.0%).

Conclusion: The chemical pattern of this oil and the previously investigated sample differs greatly, suggesting a chemotype.