The pathways of isotopes 2H and 13C inclusion into exometabolites during utilization of glucose by medusomycete

The inclusion of H-2 and C-13 isotopes into the products of glucose utilization by medusomycete during its growth on deuterated media was studied by high-resolution NMR spectroscopy. Both unlabeled and C-13-labeled (in positions 1, 2, 6) glucose was used. If was shown that the glucose-utilization proceeds by the classical Embden-Meyerhof-Parnas pathway. The incorporation. of deuterium to the methyl group of ethanol can occur only during glucose-fructose-6-phosphate and. phosphoenolpyruvate - pyruvate conversion. None of these stages by themselves is responsible-for the existing distribution of deuterium atoms. The maximum, inclusion of deuterium to the methyl group is no more than two atoms for the first glucose fragment (C-1-C-2-C-3) and no more than one, for the second fragment (C-4-C-5-C-6). The methylene group of ethanol is more accessible for deuterons because the proton surroundings of carbon atoms C-2 and C-5 completely changes. It was concluded that the maximum proton exchange occurs at positions C-2 and C-5; at positions C-1, the proton exchange is lesser, and-at position C-6 it is the least. It was also shown that about 10% C-1-C-3 of triose leave the glycolysis cycle and are used in other processes.