Polynucleotide analogues

Much attention has been paid to the syntheas of polynucleotide analogues as model compounds for natural ones over last decade in an effort to elucidate functions of nucleic acids in the biological systems. More recently analogues themselves were found to show biological activities, arousing hopes for thdr utilization in chemotherapy as polymeric drugs... 

Despite numerous attempts,it has not previously been possible to synthesize polynucleotide analogues whose structures and physicochemical properties have a close resemblance to those of natural polymers. Most of the synthesized polynucleotide analogues have exhibited neither good solubilities in water due to the lack of hydrophilic groups nor optical properties due to the absence of sugar moieties on the polymer chain. The alternating sequences between nucleoside and diphosphate, observed in the natural polynucleotides, have also been rarely realized in the syntheas of the analogues. 

To synthesize polynucleotide analogues closely resembling natural polymers, we have synthesized several new monomers such as dihydrofuran and dihydropyran derivatives which contained nucleic acid bases (Scheme 1). Copolymerization of the monomers either with maleic anhydride or with vinylene carbonate resulted in the alternating copolymers as shown in Scheme 2. Hydrolysis of the products gave the polymers which were optically active and soluble in water and had alternating sequences along the polymer chain. In this paper we will report synthesis of monomers, their copolymerization either with maleic anhydride or with vinylene carbonate, hydrolysis of the copolymers, and the physicochemical properties of the anhydride and hydrolyzed polymers. 

Biomesogens and Their Models Possibilities of Mesomorphic Order in Polynucleotide Analogues... 

A variety of ssmthetic polynucleotide analogues are presented next. Once the DNA structure and base-pairing rules were identified, synthetic chemists could begin preparing unnatural analogues. These compounds are important for testing various theories regarding the relationship between the primary structiues of DNA/RNA and their tendency to fold into specific three-dimensional structiues. 

The strongest evidence that the proposed conformational abnormalities actually occur in the polynucleotide analogues considered here emerges from the stereochemical analysis of the catalytic specificity of pancreatic RNase. 

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