Specificity of the 1-methyladenine receptors in starfish oocytes: synthesis and properties of some 1,8-disubstituted adenines, 1,6-dimethyl-1H-purine, and of the 1-(azidobenzyl)adenines

Abstract

A selective synthesis of 1,6-dimethylpurine (16) and the preparations of the 1-(azidobenzyl)adenines (11)–(13), 8-azido-1-benzyladenine (10), and 1-methyladenine derivatives (2)–(9) with various 8-substituents (azido, chloro, bromo, amino, alkyl, and hydroxymethyl) are described. The syntheses were based upon the 1-atkylation of the corresponding 9-substituted purines followed by deprotection at N-9. The ability of those compounds to replace the hormone 1-methyladenine (1) in releasing meiosis inhibition in starfish oocytes was tested, and the earlier hypothesis about structure-activity relationships has been confirmed. The low level of activity of the 8-azido derivatives of 1-methyl- and 1-benzyl-adenines, probably due to blocking of the N-7, N-9 region and reduction of the pK_a, value, precludes their use as photoaffinity labelling reagents for the receptors of 1-methyladenine. The active compounds 1-(4-azidobenzyl)adenine (13) and 1-(3-azidobenzyl)adenine (12) are possibly better candidates for this purpose.