9- adenin synthesis

Fig. 4.5 The adenine synthesis can be varied to give other purine derivatives. Structures I-IX are those of I aminomalonitrile, II HCN tetramer, III aminoimidazole-carbonitrile, IV 4-aminoimidazole-5-carboxamide, V adenine, VI diaminopurine, VII xanthine, VIII guanine and IX hypo xanthine (Sanchez et al., 1966a)... 

In another study of the problem of the prebiotic adenine synthesis, Leslie Orgel concludes that, in spite of many uncertainties, the formation of these complex heterocyclic bases probably required three preconditions ... 

The purine base guanine is also formed in concentrated solutions of ammonium cyanide, i.e., the same substance which became known from Or6 s adenine synthesis. Or6, as well as Stanley Miller, was involved in a new series of experiments (Levi et al., 1999). The yield of guanine is, however, 10 10 times lower than that of adenine surprisingly, the synthesis is just as effective at 253 K as at 353 K. Low temperatures seem conceivable in certain parts of Earth as well as on the Jovian moon Europa (see Sect. 3.1.5) or in the Murchison meteorite. 

The mechanism of adenine synthesis in these experiments is probably... 

M. J. Robins and S. D. Hawrelak, Nucleic-acid related compounds. 28. 2 -Amino-araA 9-(2-amino-2-deoxy-P-D-arabinofuranosyl)adenine.-synthesis via nucleoside-aziridine or azido intermediates and biological effects. Tetrahedron Lett., 19 (1978) 3653-3656. 

Ferris, J. P. and Orgel, L. (1965) Aminomalononitrile and 4-amino-5-cyanoimidazole in hydrogen cyanide polymerization and adenine synthesis. J. Am. Chem Soc. 87,4976 977. 

Glaser, R., Hodgen, B., Farrelly, D., 8c Mckee, E. (2007). Adenine synthesis in interstellar space Mechanisms of prebiotic pyrimidine-ring formation of monocyclic HCN-pentamers. Astrobi-ology, 7, 455. 

The mode of action has been a subject for research for a number of years. While it was originally thought that maleic hydrazide replaced uracil in the RNA sequence, it has been deterrnined that the molecule may be a pyrimidine or purine analogue and therefore base-pair formation is possible with uracil and thymine and there exists the probabiHty of base-pair formation with adenine however, if maleic hydrazide occurs in an in vivo system as the diketo species, then there remains the possibiHty of base-pairing with guanine (50). Whatever the mechanism, it is apparent that the inhibitory effects are the result of a shutdown of the de novo synthesis of protein. 

Another compound of interest is adenine [73-24-5] or 6-aminopurine (53) derived from pheny1a 2oma1ononitri1e (92). The introduction of the dicyanostyryl moiety has led to the industriali2ation of several methine dyes such as the Cl Disperse Yellow [6684-20-4] (54) (93). The Cl Disperse Blue 354 [74239-96-6] (55) also represents a new class of anTinoarylneutrocyariine dyes with a brilliant blue shade (94). The dimer of malononitrile is also used for the synthesis of new dyes (95). 

Adenine, 9-y3-D-arabinofuranosyl-occurrence, 5, 602 as pharmaceutical, 1, 160 Adenine, N -benzoyl-glycosylation, 5, 536 Adenine, 1-benzyl-benzylation, 5, 530 Adenine, 3-benzyl-benzylation, 5, 530 N NMR, 5, 515 synthesis, 5, 594 Adenine, 6-benzyl- N NMR, 5, 515 Adenine, 7-benzyl-benzylation, 5, 530 Adenine, N -benzyl-methylation, 5, 530 occurrence, 5, 602... 

Adenine, 9-(4-chlorophenoxy-2-hydroxypropyl)-biological activity, 5, 604 Adenine, 9-cyclohexyl-synthesis, 5, 585... 

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