The investigation of the HCN derivative diiminosuccinonitrile as a prebiotic condensing agent.  The formation of phosphate esters.
Diiminosuccinonitrile (DISN) is formed readily by the Fe3+ oxidation of diaminomaleonitrile, a tetramer of HCN.  DISN effects the phosphorylation of uridine in 13% yield to a mixture of the isomers of UMP when the reaction is performed in dimethylformamide solution.  A 4% yield of the UMP isomers is obtained in neutral aqueous solution using 2 times the DISN concentration and 7 times the phosphate concentration used in DMF.  DISN did not effect the conversion of adenosine to AMP or 5'-AMP to 5'-ADP in aqueous solution.  The cyclization of 3'-AMP and 3'-UMP to the corresponding 2'-3'-cyclic phosphates proceeds in yields as high as 40-50% at 60 degrees C in pH 6 aqueous solutions in the presence of divalent metal ions.  Lower yields of the cyclic phosphate are observed when 2'-AMP is the starting material.  Substitution of acetate buffer for imidazole buffer results in a decrease in the yield of cyclic phosphate, the extent of which depends on the metal ion used in the reaction.  No 3'5'-cyclic AMP was detected as a reaction product with either 5'-AMP or 3'-AMP as the starting material except for a 2.4% yield from 3'-AMP in the presence of Zn2+.  BrCN effects the conversion of 3'-AMP to the 2'-3'-cyclic AMP in 37-65% yield depending on the divalent cation used as catalyst.  A mechanism has been proposed for these cyclization reactions and their potential significance to the prebiotic synthesis of ribonucleic acid derivatives is discussed.
Ferris
J P
JP
Department of Chemistry, Rensselaer Polytechnic Institute, Troy, NY 12181, USA.
Yanagawa
H
H
Dudgeon
P A
PA
Hagan
W J
WJ
Mallare
T E
TE
D000241:Adenosine / Q000737:chemistry; D000249:Adenosine Monophosphate / Q000138:chemical synthesis; D002384:Catalysis; D019418:Evolution, Chemical; D019143:Evolution, Molecular; D006856:Hydrogen Cyanide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008670:Metals / Q000737:chemistry; D009570:Nitriles / Q000138:chemical synthesis*; D010766:Phosphorylation; D013696:Temperature; D014529:Uridine / Q000737:chemistry; D014542:Uridine Monophosphate / Q000138:chemical synthesis*
D007477:Ions; D008670:Metals; D009570:Nitriles; C022103:diaminomaleonitrile; C047926:diiminosuccinonitrile; D006856:Hydrogen Cyanide; D000249:Adenosine Monophosphate; D014542:Uridine Monophosphate; D000241:Adenosine; D014529:Uridine