The synthesis characterization and cytokinin activity of a series of N6-hyperalkylated adenine and adenosine derivatives

Mary Lynn Turner, Atlanta University

Abstract

The hypermodified derivatives in transfer Ribonuclei acid (tRNA) molecules have been the center of numerous research studies within the last fifteen years. These hypermodified tRNA derivatives are important because they are located adjacent to the 3'-end of the anticodon in the tRNA molecule. These hypermodified derivatives are believed to be very fundamental in the mechanism of protein synthesis and to the effective functioning of the nucleic acid molecules in a complex molecular environment. Hypermodification in the tRNA molecule may also be responsible for subtle changes in the chemical, physical, and biological properties of the normal tRNA molecule.

A series of hypermodified adenine and adenosine derivatives have been synthesized. This series of hypermodified purine derivatives was synthesized in an attempt to gain a better understanding of the role(s) that the hypermodified derivatives play in the tRNA molecule. The hypermodified bases and nucleosides were synthesized from commercially available 6-Chloropurine, 6-Chloropurine Riboside, 2-Amino-6-Chloropurine and 2-Amino-6-Chloropurine Riboside respectively. The nucleosides were utilized to synthesize the corresponding nucleoside-5'-monophosphates. The nucleoside-5'-monophosphates were then used as the starting materials for the synthesis of the nucleoside-5'-diphosphates. Each derivative was isolated, purified, and characterized by various chromatographic methods, ultraviolet spectroscopy, and high voltage electrophoresis.

Preliminary biological studies were performed which indicated that most of these synthesized purine derivatives possessed cytokinin activity equal to or greater than the standards, kinetin and kinetin riboside. The physico-chemical properties of these newly synthesized hypermodified adenine and adenosine derivatives were found to differ significantly from those of the parent compounds.