Nucleic acid base pendant

The derivatives of poly-L-lysine having pendant nucleic acid bases, that is, adenine, thymine and uracil were prepared as shown in the following scheme ... 

The contents of the nucleic acid bases in the poly-L-lysine derivatives were determined by UV spectra of the polymers after hydrolysis The polymers were hydrolyzed in 6 N-hydrochloric acid at 105°C for 24 hr, into lysine dihydrochloride and the carboxyethyl derivatives of the nucleic acid bases. The quantitative calculation was made relative to the standard sample of the carboxyethyl derivative of the nucleic acid bases. The analytical data are listed in Table 1. It was found that the thymine and uracil derivatives was completely substituted to polylysine. Low value in case of adenine base in the polymer may be attributed to the unstability of the activated ester, Ade-PNP (2), and may also be explained in terms of the steric interaction among bulky pendant groups of the polymer. When the poly-L-lysine containing about 50 mol % adenine units was again treated with Ade-PNP, the adenine unit content in the polymer increased up to 74 mol %(,] ). 

Synthesis of amino acids having pendant nucleic acid bases and polymerization of their N-carboxyamino acid anhydride ( NCA ) derivatives... 

In 1973, the synthesis of amino acids containing pendant theophylline and other nucleic acid bases, and the polymerization of NCA compounds derived therefrom have studied by our group ( 16). 

As an extension of our systematic works on these subjects, we found successively a convenient route to a series of new amino acid derivatives having pendant nucleic acid bases L-lysine deri-... 

A series of new amino acid derivatives having pendant nucleic acid bases was prepared by the reaction of L-lysine and L-glutamic acid with the nucleic acid bases. These amino acids were further polymerized by using the N-carboxyamino acid anhydride ( NCA ) method. Alternatively, the nucleic acid base substituted poly-L-lysines were also prepared by using polymer reactions which include the reaction of carboxyethyl derivatives of the bases onto poly-L-lysine. Physico-chemical properties of the polymers obtained were given. 

The Michael addition of nucleic acid bases to dimethyl itaconate (137) has been utilized to prepare a number of condensation monomers (Scheme 39) (80MI11110). Reaction of active esters (138) with various diamines produces polyamides having the bases as pendant groups. 

Since 1970s extensive systematic research was done on designing synthetic polymers containing nucleic acid bases [25], Thymine pendant groups were successfully attached to a variety of polymer backbones, including... 

Template Polymerization of Methacryloyl-Type Monomers Containing Pendant Nucleic Acid Bases... 

Template polymerization as seen in replicative biopolymer synthesis has recently received attention. From this point of view, vinyl polymerization has been studied in the presence of polymers that were expected to serve as templates. These template polymerizations, however, do not appear to be strictly selective because interactions between the monomeric or polymeric spedes and the template polymers may not readily be realized. It seems, however, to be one of the most attractive problems if template polymerization can be followed by suitable monomer-polymer pair formation with complementary nucleic acid bases. This section deals with the free-radical polymerization of methyacryloyloxy type monomers with pendant bases in the presence of template polymers with complementary bases41,42). 

Poly-L-lysine derivatives containing pendant nucleic acid bases were prepared by two different methods ... 

Polystyrene resins having pendant nucleic acid bases were prepared. They were found to be suitable high performance liquid chromatography separating effectively N-sub-stituted nucleic acid bases. Retention times and peak resolution values indicate that the specific base-base interaction between the solute and the resin plays an important role in the separation process82. ... 

For the polyureas prepared by the polyaddition reaction of uracil and adenine with hexamethylene diisocyanate, and the polyurethanes containing pendant nucleic acid bases, base-base interactions were studied spectroscopically. The polymers were tested further for their anticlotting property84. ... 

Nucleic acid base and nucleoside derivatives were bonded to 3-aminopropyl silanized silica (APS-silica) and silica gel. These resins were useful as the columns of high performance liquid chromatography (HPLC) for the selective separation of oligoethyleneimine derivatives having pendant thymine or adenine bases. These column systems were also found to be applicable to the separation of nucleosides, nucleotide, and oligonucleotides. 

Peptide nucleic acids (PNAs) are a class of polymers with peptide or pseudopeptide backbones and pendant nucleotide bases. PNAs typically lack the helicity of DNA but benefit from stronger association and solubUity in organic... 

The nucleic acid sensor was prepared by first derivatizing the quartz surface with a 3 1 styrene-acrylic acid copolymer. Poly (A) was then covalently immobilized onto pendant carboxylic acid groups by amide bond formation with the amino groups on the adenine base. Hybridization occurred during incubation with poly(U). Following each of the three steps, the sensor was rinsed and dried and the resonant frequency of oscillation was measured. Prior to any treatment, the quartz crystals exhibited a resonant frequency of 9 MHz. Because each step in the surface treatment involved the addition of mass to the crystal surface, a frequency decrease was expected after each step. Figure 7.9 shows the actual frequency changes measured for a sensor prepared as described above, as well as for a sensor prepared with no poly(A) included in the second step (i.e., a control sensor). 

---