Zingiber chrysanthum Rosc. : Essential oil composition, antioxidant and antispasmodic activity on isolated rat duodenum

A combination of GC and GC/MS analysis of essential oil from rhizomes of Zingiber chrysanthum Rosc. (ZCREO) revealed the presence of 79 compounds, out of which 34 compounds contributing 80.2% of the oil were identified. The major compounds being [beta]-humulene (20.3%), terpinen-4-ol (10.0%), [beta]-phellandrene (7.4%), sabinene (7.0%) and [beta]-caryophyllene (6.8%). The unique feature is the dominant presence of mono-and sesquiterpene hydrocarbons that make about 52.4 % of the oil. The oil showed myorelaxant activity on isolated rat duodenal smooth muscle. The (ZCREO) relaxed both carbachol-and KCI-induced contractile responses with similar [IC.sub.50] values. The result suggests a probable inhibitory effect of ZCREO on influx of [Ca.sup.++] through the cell membrane of rat duodenal smooth muscle. Keywords: Zingiber chrysanthum, essential oil, [beta]-humulene, antispasmodic, antioxidant