A re-examination of gingerol, shogaol, and zingerone, the pungent principles of ginger (Zingiber officinale Roscoe)

The dried rhizomes of ginger (Zingiber officinale Roscoe) yield, to acetone, a complex mixture of substances including a series of S-(+)- gingerols (i.e. 1-(4?- hydroxy-3?-methoxyphenyl)-5-hydroxyalkan-3-ones) with 10,12, and 14 carbon atom side-chains, essential oil, palmitic and other fatty acids, and other unidentified substances. The substances, shogaol and zingerone, described by Nomura as ginger constituents appear to be absent but are formed by the action of alkalis or heat on gingerol or the oleoresin. The gingerol with the 11-carbon side-chain, claimed by Lapworth, Pearson, and Royle as the principal pungent substance in ginger, is also absent. Ginger oleoresin may be qualitatively analysed by thin-layer chromatography on silica gel with hexane-ether (1 : 1).