title: Ribonucleoside 3'-di- and -triphosphates. Synthesis of guanosine tetraphosphate (ppGpp).
abstract: A procedure has been outlined for the synthesis of ribonucleoside 3'-di- and -triphosphates. The synthetic scheme involves the conversion of a ribonucleoside 3'-monophosphate to its 2'-(5'-di)-O-(1-methoxyethyl) derivative, followed by successive treatments of the blocked ribonucleotide with 1,1'-carbonyldiimidazole and mono(tri-n-butylammonium) phosphate or pyrophosphate. The resulting ribonucleoside 3'-di- and -triphosphate derivatives are then deblocked by treatment with dilute aqueous acetic acid, pH 3.0. The use of this procedure is illustrated for adenosine 3'-monophosphate, which has been converted to its corresponding 3'-di- and -triphosphates in 61% overall yield. The decomposition of adenosine 3'-di- and -triphosphates to adenosine 2'-monophosphate, adenosine 3'-monophosphate, and adenosine cyclic 2',3'-monophosphate as a function of pH at 100 degrees has been studied as has the attempted polymerization of adenosine 3'-diphosphate with polynucleotide phosphorylase. Also prepared was guanosine 5'-diphosphate 3'-diphosphate (guanosine tetraphosphate; ppGpp), which was accessible via treatment of 2'-O-(1-methoxyethyl)guanosine 5'-monophosphate 3'-monophosphate with the phosphorimidazolidate of mono(tri-n-butyl ammonium) phosphate. The resulting blocked tetraphosphate was deblocked in dilute aqueous acetic acid to afford ppGpp in an overall yield of 18%.
mesh_terms: D000227:Adenine Nucleotides / Q000138:chemical synthesis; D002848:Chromatography, DEAE-Cellulose; D006150:Guanine Nucleotides / Q000138:chemical synthesis*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008722:Methods; D009708:Nucleotidases; D010944:Plants / Q000201:enzymology; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism; D011755:Pyrophosphatases; D012265:Ribonucleotides / Q000138:chemical synthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D012434:Secale / Q000201:enzymology
chemical_list: D000227:Adenine Nucleotides; D006150:Guanine Nucleotides; D012265:Ribonucleotides; D011117:Polyribonucleotide Nucleotidyltransferase; D009708:Nucleotidases; D011755:Pyrophosphatases