Isolation and characterization of a unique galactoside from male Drosophila melanogaster

A ninhydrin-positive compound with presumptive hormonal activity, previously considered to be a peptide (Chen, P.S., and Bühler, R. (1970), J. Insect Physiol. 16, 615), has been isolated from adult male Drosophila melanogaster. Chromatographic analysis of the acid-hydrolyzed material revealed the presence of ethanolamine, phosphorus, galactose, and glycerol. Chemical analysis showed these to be present in equimolar amounts. Based on its phosphorus content, the nonreducing material took up 2 equiv of periodate, and released 1 equiv of formaldehyde. Characterization of the compound as 1-O-(4-O-(2-aminoethyl phosphate)-beta-D-galactopyranosyl)-x-glycerol was achieved by gas chromatography-mass spectroscopy and 1H and 31P NMR using model compounds. In vivo synthesis from labeled precursors is in accord with the proposed structure.