FORMALDEHYDE, AS ITS DIMEDONE ADDUCT, FROM ASCOPHYLLUM-NODOSUM

Formaldehyde, as its dimedone adduct (formaldemethone), has been isola ted from Ascophyllum nodosum and characterised by thin-layer and overp ressured layer chromatography, and from proton nuclear magnetic resona nce spectroscopic and electron impact mass spectrometric data. Formald emethone was detected in extracts of both fresh and dry alga. It is po stulated that during dynamic methylation and demethylation processes i n the cells, hydroxymethyl groups may be formed, which dependent on pH , are in equilibrium with either free formaldehyde or ions such as imi nium, oxonium and thionium; these species will react with dimedone to form formaldemethone. The amount of formaldehyde captured by the dimed one reagent increases as the concentration of dimedone is increased, u ntil a maximum is reached.