Oligoglyceric acid synthesis by autocondensation of glyceroyl thioester

Abstract

Summary: The autocondensation of the glyceroyl thioester, S-glyceroyl-ethanethiol, yielded oligoglyceric acid. The rates of autocondensation and hydrolysis of the thioester increased from pH 6.5 to pH 7.5 in 2,6-lutidine and imidazole buffers. Autocondensation and hydrolysis were much more rapid in imidazole buffers as compared to 2,6-lutidine and phosphate buffers. The efficiency of ester bond synthesis was about 20% for 40 mM S-glyceroyl-ethanethiol in 2,6-lutidine and imidazole buffers near neutral pH. The size and yield of the oligoglyceric acid products increased when the concentration of the thioester was increased.The relationship of these results to prebiotic polymer synthesis is discussed.

Thermal synthesis and hydrolysis of polyglyceric acid

“…This method allows us to prepare poyglyceric acid of different sizes and enantiomeric compositions for chemical studies of this polymer which may have functioned as an autocatalyst in the origin of life (Weber, 1987a;Weber, 1987b). Our studies show that L-glyceric acid was converted much more rapidly to an insoluble polymer than racemic DL-glyceric acid.…”

“…These model studies showed the conversion of glyceraldehyde and a thiol to activated monomerslactoyl, glyceroyl and alanyl thioesters -which have the energy needed for condensation to polyesters and polypeptides (Weber and Orgel, 1979;Weber 1987a). This ability of glyceraldehyde to act as a source of activated monomers, which possess both the energy and matter needed for polymer synthesis, provided the central idea of a new hypothesis of the origin of life -called the triose model (Weber 1987b).…”

“…DL-Glyceric acid (hemicalcium satto2H20 ) was not recrystallized ([CX]D20 0.2 °, C = 1.25, H20 ). The hemicalcium salts of L-, D-, and DLglyceric acid were converted to the free acid form by passing the salts through a column containing the hydrogen form of Dowex 50W-X4 resin (Weber, 1987a). e-[14C(U)]Glyceric acid (25 mCi/mmole) was prepared from L-[14C(U)]serine by a modified version of the method ofLok et al (1976) as described in Weber (1987a).…”

“…The hemicalcium salts of L-, D-, and DLglyceric acid were converted to the free acid form by passing the salts through a column containing the hydrogen form of Dowex 50W-X4 resin (Weber, 1987a). e-[14C(U)]Glyceric acid (25 mCi/mmole) was prepared from L-[14C(U)]serine by a modified version of the method ofLok et al (1976) as described in Weber (1987a). Since impurities in this preparation inhibited the sulfuric acid-catalyzed polymerization of eglyceric acid, it was further purified on a column containing Bio-Rad AG-1-X8 resin (formate) which was eluted with water, 0.01 M formic acid and 0.10 M formic acid.…”

Energy-rich glyceric acid oxygen esters: Implications for the origin of glycolysis

“…The synthesis of [14C]glyceric acid and the preparation of the acid form of L-glyceric were described previously (Weber, 1987b(Weber, , 1989. [14C]Methanol was purchased from New England Nuclear.…”