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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 10 (1977), S. 221-230 
    ISSN: 1432-1432
    Keywords: Prebiotic ; Acylglycerols ; Tripalmitolglycerol ; Cyanamide ; Imidazole
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The synthesis of palmitoylglycerols in good yields occurs when a solution of glycerol, ammonium palmitate, cyanamide and imidazole is dried and heated at ambient humidity at temperatures ranging from 60°–100°C for 16 h. Much less product is formed in the absence of either or both cyanamide or imidazole. This work suggests that acylglycerols could have been synthesized on the primitive Earth under plausible prebiotic conditions which were similar but not identical to those which have been shown to condense deoxynucleotides into oligodeoxynucleotides and amino acids into peptides.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 14 (1979), S. 235-241 
    ISSN: 1432-1432
    Keywords: Glycerol ; Glycerophosphate ; Cyanamide ; Glycerolipids ; Prebiotic synthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The formation of glycerol occurs when a solution of DL-glyceraldehyde is heated in the presence of hydrogen sulfide at room temperature. DL-glyceraldehyde and dihydroxyacetone treated with hydrazine, as well as DL-glyceraldehyde incubated with formaldehyde are also partially converted to glycerol. The yields of the above reactions are from approximately 1% to about 3%. The formation of glycerophosphates occurs when glycerol is heated with ammonium dihydrogen phosphate and either urea or cyanamide. The yield of glycerophosphates is about 30%, most of which issn-glycero-1 (3)-phosphate. These findings indicate that glycerol andsn-glycero-3-phosphate, which are moieties of glycerolipids, could have been formed under conditions which may have prevailed on the primitive Earth.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 18 (1982), S. 196-202 
    ISSN: 1432-1432
    Keywords: Prebiotic synthesis ; Phospholipids ; Phosphatidylcholine ; Cyanamide ; Liposomes ; Primitive membranes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Using a primitive Earth evaporating pond model, the synthesis of phosphatidylcholine was accomplished when a reaction mixture of choline chloride and disodium phosphatidate, in the presence of cyanamide and traccs of acid, was evaporated and heated at temperatures ranging from 25° to 100°C for 7 hours. Optimum yields of about 15% were obtained at 80°C. Phosphatidylcholine was identified by chromatographic, chemical and enzymatic degradation methods. On enzymatic hydrolysis with phospholipase A2 and phospholipase C, lysophosphatidylcholine and phosphorylcholine were formed, respectively. Alkaline hydrolysis gave glycerophosphorylcholine. The synthesis of phosphatidylcholine as the major compound was accompanied by the formation of lysophosphatidylcholine in smaller amounts. Cyanamide was found to be essential for the formation of phosphatidylcholine, and only traces of HCl, of the order of that required to convert the disodium phosphatidate to free phosphatidic acid were found necessary for the synthesis. This work suggests that phosphatidylcholine, which is an essential component of most biological membranes, could have been synthesized on the primitive Earth.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 11 (1978), S. 279-292 
    ISSN: 1432-1432
    Keywords: Checmical evolution ; Prebiotic synthesis ; Phosphatidic acids ; Phospholipids ; Cyanamide ; Imidazolen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A mixture of ammonium palmitate,14C-sn-glycero-1(3)-phosphate, cyanimide and imidazole when heated for several hours formed significant quantities of phospholipids. These reaction products were shown by chromatographic, chemical and enzymatic procedures to be monopalmitoylglycerophosphate (MPGP), dipalmitoylglycerophosphate (DPGP) and monopalmitoyl cyclic glycerophosphate (cMPGP). A portion of the MPGP and DPGP possessed the same steric configuration as naturally occurring lysophosphatidic acid and phosphatidic acid. The yield of total phospholipid was maximal at temperatures between 60° and 90° after 8 h. When ratios of reactants were varied, up to 45% of radioactive glycerophosphate was converted into phospholipids. The average proportions of individual phosphatidic acids were: 60% MPGP, 27% DPGP and 13% cMPGP. Evidence was obtained for a synergistic relationship between cyanamide and imidazole in promoting the formation of phosphatidic acids. These results suggest that phosphatidic acids, which are essential precursors for the biochemical synthesis of more complex membrane phospholipids, could have been produced on the primitive Earth.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 25 (1987), S. 1-6 
    ISSN: 1432-1432
    Keywords: Chemical evolution ; Prebiotic synthesis ; Phosphatidylethanolamine ; Cyanamide ; Phospholipids ; Protomembranes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The synthesis of phosphatidylethanolamine was accomplished when a mixture of phosphatidic acid, ethanolamine, and cyanamide at pH 7.3 was taken to dryness and heated at temperatures ranging from 25 to 60°C for 6 h. Chromatographic, enzymatic, and chemical techniques were used to identify and confirm that phosphatidylethanolamine had been formed. This work indicates that the synthesis of this compound can occur starting with precursors and conditions that are presumed to have existed on the primitive Earth.
    Type of Medium: Electronic Resource
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