Bioids : X. Identification of formose sugars, presumable prebiotic metabolites, using capillary gas chromatography/gas chromatography—mas spectrometry of n-butoxime trifluoroacetates on OV-225

Abstract

Most monosaccharides, including 3-uloses and branched-chain species formed by the autocatalytic condenstation of formaldehyde, have been separated by capillary gas chromatography (GC) and isobutane chemical ionization GC—mas spectrometry (MS) on OV-225 of the trifluoroacetyl n-butoximes, and identified using commercial sugars, oxidation products of alditols and aldolization products of formaldehyde and/or glycolaldehyde and trioses, and by selected ion monitoring. The product pattern of a reaction of 0.156 M formaldehyde with 0.036 M calcuim acetate and 0.087 M sodium hydroxide at 40°C, started by the addition of 0.55 m M glycolaldehyde is reported. In addition to the already known trioses, tetroses, pentoses and hex-2- uloses, also pent-2-uloses (20-% including 13% of 2-xylulose), 6.5% of hex-3-uloses, 5% of d, l-3-C-hydroxymethyltetrose (apiose) and 6.3% of branched hexoses were found; 90.3% of the total volatile derivatives of 3–6-carbon sugars have been identified; conspicuously, 50–80% of the reacted formaldehyde does not afford volatile sugar derivatives. Because of its autocatalytic kinetics, in a prebiotic scenario a formol reaction could evolve into a self-organizing non-enzymatic system steadily producing sugars, including branched-chain sugars, as precursors of amino acids, of the isoprene moiety and of the branched chains of valine and leucines.