N6-Substituted adenosines

Tracey WR, Magee WP, Oleynek JJ, Hill RJ, Smith AH, Flynn DM, Knight DR (2003) Novel N6-substituted adenosine 5 -N-methyluronamides with high selectivity for human adenosine A3 receptors reduce ischemic myocardial injury. Am J Physiol-Heart Circ Physiol... 

Tracey WR, Magee W, Masamune H, Oleynek JJ, Hill RJ (1998) Selective activation of adenosine A3 receptors with N6-(3-chlorobenzyl)-5 -N-methylcarboxamidoadenosine (CB-MECA) provides cardioprotection via KATp channel activation. Cardiovasc Res 40(1) 138—145 Tracey WR, Magee WP, Oleynek JJ, Hill RJ, Smith AH, Flynn DM, Knight DR (2003) Novel N6-substituted adenosine 5 -N-methyluronamides with high selectivity for human adenosine A3 receptors reduce ischemic myocardial injury. Am J Physiol Heart Circ Physiol 285(6) H2780-H2787... 

Support for this presumed intermediate has been reported in similar systems, see Trivedi, B.K. Blankley, C.J. Bristol, J.A., et al. N6-Substituted adenosine receptor agonists potential antihypertensive agents. J. Med. Chem. 1991, 34, 1043-1049. 

Very interesting information relevant to the stereochemical results of alkylation of DNA comes from studies of nucleosides alkylated by activated PAHs. Eight such structures have been reported (115-118). Three are products of the interaction of chloromethyl PAHs with N6 of adenosine XXX-XXXII, two with deoxyadenosine (XXXIII, XXXIV), two are para-substituted benzyl derivatives of guanosine, alkylated at 0-6 (XXXV, XXXVI) (117) and one is an acetyl aminofluorene derivative of guanosine, alkylated at C8 (XXXVII) (118). 

N6-Substitution of adenosine proved to be determining in affecting intrinsic... 

Cytokinins, N6-substituted derivatives of adenine, are important in the regulation of many processes in plant tissues. Chism et al. (1984) reported an HPLC assay measuring the hydroxylation of 6-(3-methylbut-2-enylamino)purine (IPA) and 6-(3-methylbut-2-enylamino)-8-hydroxypurine by cytokinin nucleosidases and adenosine nucleosidases. 

N6 -position of adenine. Substitution of the N6 position of adenosine has been studied systematically (Fig. 6.4,17-27). It may induce selectivity for the AjAR or A3AR, or in some limited cases for the A AR. /V -Methyl 17 and A6-methyloxy 18 substitution... 

In fact, kinetin was not the natural cell division hormone, although as an adenine derivative it is chemically closely related to the native kinins that have been isolated from plant sources. It was D. S. Letham in New Zealand (1967) who first succeeded with a crystalline cytokinin isolated from the milky stage of immature maize (Zea mays) kernels. It was 6-substituted iso-pentenylamino purine (N6-(A2-isopentenyl)) adenosine (Figure 2d). He called the substance zeatin, and zeatin riboside was, in fact, the major active constituent of coconut milk (Letham, 1974). 

Dihydropyridines 1,9-Pyrazoloanthrone (SP600125) 2-Acetylaminofluorene 2-Arylthiazolidine-4-carboxylic acid amides (ATCAA) 2-Chloro-N6-(3-iodobenzyl)-adenosine-5 -N-methyluronamide 2-Deoxy-D-glucose 2-Fluoro N10-substituted acridones 2n-Propylquinoline 2-Phenyl-5-(pyrrolidin-l-yl)-... 

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