Functional monomers and polymers. CXXXII. Template polymerization of methacrylamide derivatives containing nucleic acid bases

Free-radical polymerizations of methacrylamide derivatives containing nucleic acid bases were studied in the presence of the polymethacrylamide having complementary nucleic acid bases as template polymers. The rate of the polymerization did not show remarkable difference in the presence or the absence of the template polymer. A stable polymer complex, however, was precipitated from the polymerization system, and was found to be different in a thermal analysis from the polymer complex which was obtained by mixing of the complementary polymers in solution. Free-radical copolymerizations in the presence of the template polymers also supported the template polymerization.     

Functional monomers and polymers. CXXXI.. Synthesis and interaction studies on polyacrylamide and polymethacrylamide derivatives containing nucleic acid bases

Acrylamide and methacrylamide derivatives of nucleic acid bases were prepared from the corresponding aminoethyl derivatives. Free-radical polymerization of these monomers in water or in organic solvents gave their polymers. From the studies of the polymer complex formation by UV spectroscopy, it was found that extremely stable polymer complexes were formed between complementary polymers containing nucleic acid bases.     

Functional monomers and polymers. XXXXI. Template polymerization of methacryloyl-type monomers containing nucleic acid bases

In due consideration of the specific base–base interaction that exists between nucleic acid molecules, the free radical polymerization of N-β-methacryloyloxyethyl derivatives of adenine, thymine, and theophylline initiated by azobisisobutyronitrile (AIBN) was studied in the presence of N-β-methacryloyloxyethyl-type polymers which have complementary nucleic acid bases as template polymers. The rate of polymerization of N-β-methacryloyloxyethyladenine was accelerated when poly(N-β-methacryloyloxyethyluracil) or -thymine was present in the polymerization system. The effect of the stereoregularity of the template polymers, as well as polymerization temperature and the sort of solvents used on the rate of polymerization, was studied and discussed in some detail. The results suggest that the interaction between complementary bases plays a role in template polymerization behavior.     

Functional Monomers and Polymers. XLV. Activation Parameters for Polymerization of N-[btilde]-Methacryloyloxyethyl Type Monomers Containing Nucleic Acid Bases

In order to determine the effect of functional structure of ester groups on the stereoregularity of polymers, polymerization of N-[btilde]-methacryloyloxyethyl type monomers containing nucleic acid bases was made by using a free-radical initiator. From the NMR spectrometric determination of the stereoregularity of the polymers obtained, it was found that for polymerization of the monomer with adenine as the side group in dimethyl sulfoxide solution, syndiotactic placement appears to be favored by the additional enthalpy of activation required for isotactic placement.     

γ-核酸碱基取代丙基甲基二乙氧基硅烷的合成及其聚合反应研究

本文以Υ-溴丙基甲基二乙氧基硅烷分别与尿嘧啶、胸腺嘧啶、腺嘌呤和5-氟尿嘧啶进行烷基化反应,制得了四种含有核酸碱基或5-氟尿嘧啶的新型有机硅单体。通过它们的缩聚反应,合成了六种侧基含核酸碱基或5-氟尿嘧啶的聚硅氧烷。     

Synthesis and Properties of Hydrophilic Copolymers Containing 5-Fluorouracil,Thymine, or Adenine

Hydrophilic copolymers containing 5-fluorouracil (5-FU), thymine, or adenine were prepared by the free-radical copolymerization of methacryloyl-type monomers containing them with water-soluble vinyl monomers such as acrylic acid, methacrylic acid, vinylpyrroli-done, acrylamide, and 4(5)-vinylimidazole with AIBN as initiator. Complex formation between the copolymers and RNA and between the copolymers having complementary nucleic acid bases in aqueous solution and a DMSO-ethylene glycol was studied by means of UV spectroscopy. These copolymers were found to release the N-hydroxyethyl derivatives of 5-FU, thymine, or adenine by hydrolysis of the ester of the polymer side chain under mild conditions. The effects of the kind of water-soluble comonomer, temperature, pH, and the imidazole group as catalyst on the hydrolysis of the ester are discussed.     

Functional monomers and polymers. XXXXVII. Complex formation of stereoregular methacryloyl-type polymers containing nucleic acid bases

The complex formation between a poly(N-β-methacryloyloxyethyl) derivative of adenine with one of thymine or uracil was studied in dimethyl sulfoxide and ethylene glycol mixture by ultraviolet (UV) spectroscopy. For the polymer pairs containing complementary nucleic acid bases both hypochromicity and hyperchromicity were found. Stereoregularity of the polymers, as well as the conditions for measurement of, for example, solvent, temperature, and time, affected the complex formation. Both inter- and intramolecular interaction of polymers in solution were discussed in some detail.     

Spacer effect of novel bifunctional organophosphorus monomers in metal-imprinted polymers prepared by surface template polymerization

The interfacial activity and the molecular structure of functional monomers are critical factors that determine the success of synthesizing metal-imprinted polymers by surface template polymerization. From this point of view, first we prepared three distinct novel bifunctional organophosphorus monomers that are interspaced, in each case, by an alkyl spacer having a specific length. Each monomer carries two phosphonic acid groups and two aromatic groups in its molecular structures. Further, by using the synthesized bifunctional monomers, we prepared highly selective Zn(II)-imprinted polymers by the surface template polymerization initiated from a water-in-oil emulsion. To evaluate the template effect, we conducted diagnostic adsorption studies on Zn(II)-imprinted and unimprinted polymers with zinc ions. A high interfacial activity was found to be required for the functional monomers to create the predominant template effect. It became clear that Zn(II)-imprinted polymers having bifuctional monomers with 12-length alkyl chains (1,12-dodecanediol-O, O′-diphenyl phosphonic acid: DDDPA) yielded the best results. Moreover, analysis results of adsorption behavior supported a high-performance of the Zn(II)-imprinted polymers with DDDPA. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2727–2734, 1998     

Nonenzymatic synthesis of RNA and DNA oligomers on hexitol nucleic acid templates: the importance of the A structure.

Hexitol nucleic acid (HNA) is an analogue of DNA containing the standard nucleoside bases, but with a phosphorylated 1,5-anhydrohexitol backbone. HNA oligomers form duplexes having the nucleic acid A structure with complementary DNA or RNA oligomers. The HNA decacytidylate oligomer is an efficient template for the oligomerization of the 5'-phosphoroimidazolides of guanosine or deoxyguanosine. Comparison of the oligomerization efficiencies on HNA, RNA, and DNA decacytidylate templates under various conditions suggests strongly that only nucleic acid double helices with the A structure support efficient template-directed synthesis when 5'-phosphoroimidazolides of nucleosides are used as substrates.     

DyNAs: constitutional dynamic nucleic acid analogues

Dynamic cationic polymers were generated in aqueous media from functionally complementary monomers bearing nucleobase groups. (1)H NMR spectroscopy was used to follow the polycondensation reaction of the nucleobase-appended dihydrazides 1 and 2 with the dialdehydes B and C. The reversibility of these polymers was established by proton NMR spectroscopy through exchange of the dihydrazide 2 with polymer 1 B. The polymers 1 B, 2 B, 1 C, and 2 C represent dynamic biopolymers of nucleic acid type, DyNAs. Electrostatic interaction of these polymers with polyanionic entities, such as polyphosphates, polynucleotides, and polyaspartic acid, was shown to take place. It induces a change in size of the dynamic polymer, as it responds by an increase in degree of polymerization to an increase of the overall anionic charge introduced, that is, to the total electrostatic interaction.     

SYNTHESIS AND POLYMERIZATION OF γ-NUCLEIC ACID BASE SUBSTITUTED PROPYLMETHYLDIETHOXYSILANES

Four new organosilicon monomers containing nucleic acid bases or 5-fluorouracil (5-Fu) weresynthesized by the alkylation of γ-bromopropylmethyldiethoxysilane with uracil, thymine, adenineand 5-Fu, respectively. Polymerization of the monomers resulted in the formation of six new poly-siloxanes with nucleic acid bases as the pendant groups.     

Functional monomers and polymers. XXXXVI. A copolymerization study of methacryloyl-type monomers containing nucleic acid bases in chloroform solution

Behavior of the free radical copolymerization of N-β-methacryloyloxyethyl derivatives of adenine with that of thymine was studied in chloroform solution, taking account of the specific base-base interaction of these monomers. Hydrogen bonding interaction between such monomers was observed by NMR spectroscopy. The acceleration of copolymerization was found to be greater either at lower monomer concentration or at lower polymerization temperature. When N-β-methacryloyloxyethylcarbazole was used as a comonomer, the rate of copolymerization showed a similar trend as in the case of usual free radical copolymerizations. From r₁ and r₂ values obtained, the copolymerization was found to be alternating, particularly in the case of copolymerization between monomers having complementary nucleic acid bases. The results suggest that the hydrogen bonding interaction between adenine and thymine plays a role in the propagation step.     

Analytical followup of the gamma initiated synthesis of a molecularly imprinted polymer

A molecularly imprinted polymer (MIP) for the template phenytoin has been prepared by gamma initiated copolymerization of methacrylamide and ethylene glycol dimethacrylate. The progress of polymerization was studied by measuring the monomer conversions and the template binding properties of the resulting polymers, respectively. The consumption rate of the two monomers showed different course. There was no difference observed in the polymerization rates of the MIP and the control polymer (NIP). The template binding properties of the MIP and the NIP changed considerably with the progress of the polymerization process and became similar to those of the thermally initiated polymers after full conversion.     

反乌头酸分子印迹聚合物微球的制备及其分子识别功能

以乙腈为分散剂,采用沉淀聚合法合成了反乌头酸分子印迹聚合物微球。研究了合成反应条件对聚合物形貌的影响,发现聚合前主客体氢键络合物和功能单体氢键低聚体是控制微球形成及其粒径大小的关键因素。通过振荡吸附法对聚合物的结合特性进行了评价,发现印迹聚合物微球对模板分子的识别选择性优于块状印迹聚合物和非印迹聚合物。     

Copolymers containing alternating sequences of nucleic acid base pairs. II. Polymerization studies

The objective of this project was to utilize the alternating copolymerizability of electrondonor monomers with electron-acceptor monomers to selectively introduce nucleic acid bases into copolymers in a controlled sequence distribution. To this end, maleimide monomers containing the adenine, thymine, cytosine, and 6-chloropurine moieties were converted to their hompolymers. The homopolymer of 1-(vinyloxyethoxy)thymine was also prepared. Alternating copolymers of the adenine maleimide monomer and the corresponding 6-chloropurine maleimide monomer with 1-(vinyloxyethoxy)thymine were prepared. The latter copolymer was converted to the alternating adenine–thymine copolymer by reaction with ammonia. Characterization of the polymers and copolymers via spectroscopic methods and physical measurements confirm their proposed structures. Monomer syntheses and characterization, as well as studies designed to establish the extent and nature of adenine–thymine interactions in the copolymers, are reported in accompanying papers.     

Preparation and application of molecularly imprinted polymer for isolation of chicoric acid from Chicorium intybus L. medicinal plant

Molecularly imprinted polymer (MIP) was synthesized and applied for the extraction of chicoric acid from Chicory herb (Chicorium intybus L.). A computational study was developed to find a suitable template to functional monomer molar ratio for MIP preparations. The molar ratio was chosen based on the comparison of the binding energy of the complexes between the template and functional monomers. Based on the computational results, eight different polymers were prepared using chicoric acid as the template. The MIPs were synthesized in a non-covalent approach via thermal free-radical polymerization, using two different polymerization methods, bulk and suspension. Batch rebinding experiments were performed to evaluate the binding properties of the imprinted polymers. The best results were obtained with a MIP prepared using bulk polymerization with 4-vinylpyridine (4-VP) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the crosslinker with a molar ratio of 1:4:20. The best MIP showed selective binding ability toward chicoric acid in the presence of the template’s structural analogues, caffeic acid, caftaric acid and chlorogenic acid.     

Properties of dendronized acrylic polymers: Effect of composition and structure of peripheral groups

Two series of new acrylic polymers carrying L-aspartic acid-based dendrons in side chains with terminal hexyloxycarbonyl groups that are both directly and indirectly, via a rigid spacer, attached to polymer chains have been synthesized by the free-radical polymerization of monomers. The polymerization ability of the monomers has been studied. The properties of new polymers are compared with the properties of polymer analogs containing terminal methoxycarbonyl groups of dendrons. Upon incorporation of the rigid spacer, the shielding of reactive centers decreases and the polymerizability of the monomers increases. The replacement of terminal methyl groups in dendrons with hexyl groups in spacer-free polymers leads to a reduction in the degree of polymerization, while in the case of polymers containing spacers, high-molecular-mass products arise. This phenomenon is facilitated by the amphiphilic nature of the polymers and the additional enhancement in the rigidity of chains. A polymer carrying a third-generation dendron has been synthesized only for the latter series.     

Graft copolymers of nucleic acid bases on polyethyleneimine: Interaction of the polymers

Interactions of the graft copolymers of nucleic acid bases on polyethyleneimine with polynucleotides were studied. The backbone of the polymer is linear or branched polyethyleneimine. The nucleic acid bases are adenine and thymine. The polynucleotides used were polyadenylic acid (poly-A) and polyuridylic acid (poly-U). Interactions between these polymers were measured by ultraviolet (UV) absorption and the results were compared with the vinyl-type nucleic acid model polymer.     

Theoretical and experimental research on the self‐assembled system of molecularly imprinted polymers formed by salbutamol and methacrylic acid

The quantum chemical method was applied for screening functional monomers in the rational design of salbutamol‐imprinted polymers. Salbutamol was the template molecule, and methacrylic acid was the single functional monomer. The LC‐WPBE/6–31G(d,p) method was used to investigate the geometry optimization, active sites, natural bond orbital charges, binding energies of the imprinted molecule, and solvation energy. The mechanism of action between salbutamol and methacrylic acid was also discussed. The theoretical results show that salbutamol interacts with functional monomers by hydrogen bonds, and the salbutamol‐imprinted polymers with a ratio of 1:4 (salbutamol/methacrylic acid) in acetonitrile had the highest stability. The salbutamol‐imprinted polymers were prepared by precipitation polymerization. The experimental results indicated that the maximum adsorption capacity for salbutamol toward molecularly imprinted polymers was 7.33 mg/g, and the molecularly imprinted polymers had a higher selectivity for salbutamol than for norepinephrine and terbutaline sulfate. Herein, the studies can provide theoretical and experimental references for the salbutamol molecular imprinted system.     

Side‐chain ferrocene‐containing (meth)acrylate polymers: Synthesis and properties

A comprehensive investigation on the synthesis and properties of a series of ferrocene‐containing (meth)acrylate monomers and their polymers that differ in the linkers between the ferrocene unit and the backbone was carried out. The side‐chain ferrocene‐containing polymers were prepared via atom transfer radical polymerization. The kinetic studies indicated that polymerization of most monomers followed a “controlled”/living manner. The polymerization rates were affected by the vinyl monomer structures and decreased with an increase of the linker length. Methacrylate polymerization was much faster than acrylate polymerization. The optical absorption of monomers and polymers was affected by the linkers. Thermal properties of these polymers can be tuned by controlling the length of the linker between the ferrocene unit and the backbone. By increasing the length of the linker, the glass transition temperature ranged from over 100 to ?20 °C. Electrochemical properties of both monomers and polymers were characterized. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011