Withdrawn paper: antibacterial effect of five Zingiberaceae essential oils by Laohakunjit et al., Molecules 2007, 12, 2047- 2060.

In a Letter to the Editor published last year [1] possible factual errors in the paper by Laohakunjit et al. [2] that is the subject of this Editor's Note were brought to our attention. In that paper the major component of the solvent extracts of essential oil of galanga (Alpinia galanga Sw.) was identified as fraesol (ethyl 3-methyl-3-phenylglycidate, 1). In [1] it was suggested that since fraesol is a well known synthetic compound, that exists as two optically active pairs of cis and trans isomers [3] and has never been isolated from a natural source, it was more likely that this component was either acetoxychavicol acetate (2), a reported major component of the essential oil of galanga rhizome [4] or ethyl trans-pmethoxycinnamate (3), which has a related structure and identical molecular weight as fraesol and has been previously identified in the essential oil of Kaempheria galangal L. [5]. Possible additional errors in the identification of other components were also mentioned.