Influence de composés à hétérocycle azoté et particulièrement d'azoles non condensés sur des réactions «prébiotiques» de condensation d'acides α-aminés induites par les polyphosphates en milieu aqueux

✍ Scribed by Joseph Rabinowitz; Aioub Hampai

• Publisher: John Wiley and Sons
• Year: 1980
• Tongue: German
• Weight: 293 KB
• Volume: 63
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19800630424

✦ Synopsis

Influence of Nitrogen Heterocyclic Compounds and of Non Condensed Azoles in Particular on ‘Prebiotic’ Condensation Reactions of α‐Amino Acids Induced by Polyphosphates in Aqueous Solution

In previous experiments aqueous solutions of α‐aminoacids in the presence of cyclic or linear polyphosphates, pH range 7–11, yielded up to 40% of dipeptide but only 0.3‐0.5% of tripeptide [1] [2]. By addition of imidazole the yield of tripeptide could be increased about ten times [2]. Therefore, we have studied for the condensation reaction of glycine the influence of the addition to aqueous solutions 0.1 M in glycine and 0.1 M in trimetaphosphate at room temperature, pH range 6.7–8.9, of several azoles (pyrrole, pyrazole, imidazole, 1,2,4‐triazole and tetrazole), of adenine, guanine, uracil, cytosine, and of several nucleosides (adenosine, guanosine, uridine and cytidine). Among the products studied, only 1,2,4‐triazole and imidazole improve appreciably, by a factor of about 15, the yield of triglycine (up to 7.8%). While it is very likely that imidazole has played an important role during prebiotic chemical evolution, it is not clear at present whether 1,2,4‐triazole has a prebiotic significance.