Сreating a precision circuits for discharge of charge integrator for use in spectrometric devices for observations in the far space

Abstract

In this paper was demonstrated the possibility of the use of FAB mass spectrometry on an impulse mass spectrometer VG-70 SEQ ("Fisons VG Analytical", USA) for the study of biosynthetic pathways of 2 H-labeled purine ribonucleoside inosine secreted into the liquid culture (LC) by Gram-positive chemoheterotrophic bacterium Bacillus subtilis VKPM B-3157 when grown on heavy water (HW) medium with 2 % hydrolyzate of deuterated biomass of methylotrophic bacterium Brevibacterium methylicum VKPM B-5662 as a source of growth 2 H-labeled substrates. Isolation of 2 H-labeled inosine from the LC was performed by adsorption/desorption on activated carbon with following extraction by 0.3 M ammonium-formate buffer (pH = 8.9), crystallization in 80 % ethanol and ion exchange chromatography (IEC) on a column with AG50WX 4 cation exchange resin equilibrated with 0.3 M ammonium-formate buffer and 0.045 M NH 4 Cl. The investigation of deuterium incorporation into the molecule of biosynthetic [ 2 H]inosine by FAB mass spectrometry demonstrated the incorporation of 5 deuterium atoms into the molecule (the total level of deuterium enrichment -62.5 atom. % 2 H) with incorporation of 3 deuterium atoms into the ribose and 2 deuterium atoms -into the hypoxanthine residue of the molecule. Three non-exchangeable deuterium atoms were incorporated into the ribose residue owing to reactions of enzymatic izomerization of glucose in 2 H 2 O-medium due to reactions of glycolysis, associated with the Embden-Meyerhof pathway with participation of reactions of isotope ( 1 Н-2 Н) exchange, while two other deuterium atoms at C2, C8-positions in the hypoxanthine residue were synthesized from [ 2 H]amino acids that originated from the deuterated hydrolysate of the methylotrophic bacterium Brevibacterium methylicum VKPM B-5662. named after M. V. Lomonosov, Russia (Shvets V. I.) Moscow State University of Fine Chemical Technology