A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker.

/pdf/peptide-nucleic-acids-1hpyrn4znw.pdf

Peptide nucleic acids

2.1.6. Tacticity and Sequence: Advanced Control 4967 2.2. Transition Metal Catalysts 4967 2.2.1. Overviews of Catalysts 4967 2.2.2. Ruthenium 4967 2.2.3. Copper 4971 2.2.4. Iron 4971 2.2.5. Nickel 4975 2.2.6. Molybdenum 4975 2.2.7. Manganese 4976 2.2.8. Osmium 4976 2.2.9. Cobalt 4976 2.2.10. Other Metals 4976 2.3. Cocatalysts (Additives) 4977 2.3.1. Overview of Cocatalysts 4977 2.3.2. Reducing Agents 4977 2.3.3. Free Radical Initiators 4977 2.3.4. Metal Alkoxides 4977 2.3.5. Amines 4978 2.3.6. Halogen Source 4978 2.4. Initiators 4978 2.4.1. Overview of Initiators: Scope and Design 4978 2.4.2. Alkyl Halides 4978 2.4.3. Arenesulfonyl Halides 4979 2.4.4. N-Chloro Compounds 4979 2.4.5. Halogen-Free Initiators 4979 2.5. Solvents 4980 2.5.1. Overview of Solvents 4980 2.5.2. Catalyst Solubility and Coordination of Solvent 4981 2.5.3. Environmentally Friendly Solvents 4981 2.5.4. Water 4981 2.5.5. Catalytic Solvents: Catalyst Disproportionation 4981

Transition metal-catalyzed living radical polymerization : toward perfection in catalysis and precision polymer synthesis

Background During the last few decades, progress has been made in manipulating the architecture of synthetic polymer materials. However, the primary structure—that is, the sequential arrangement of monomer units in a polymer chain—is generally poorly controlled in synthetic macromolecules. Common synthetic polymers are usually homopolymers, made of the same monomer unit, or copolymers with simple chain microstructures, such as random or block copolymers. These polymers are used in many areas but do not have the structural and functional complexity of sequence-defined biopolymers, such as nucleic acids or proteins. Indeed, monomer sequence regulation plays a key role in biology and is a prerequisite for crucial features of life, such as heredity, self-replication, complex self-assembly, and molecular recognition. In this context, developing synthetic polymers containing controlled monomer sequences is an important area for research. Precise molecular encoding of synthetic polymer chains. In most synthetic copolymers, monomer units (represented here as colored square boxes A, B, C, and D) are distributed randomly along the polymer chains (left). In sequence-controlled polymers, they are arranged in a speciﬁc order in all of the chains (right). Monomer sequence regularity strongly inﬂuences the molecular, supramolecular, andmacroscopic properties of polymer materials. Advances Various synthetic methods for controlling monomer sequences in polymers have been identified, and two major trends in the field of sequence-controlled polymers have emerged. Some approaches use biological concepts that have been optimized by nature for sequence regulation. For instance, DNA templates, enzymes, or even living organisms can be used to prepare sequence-defined polymers. These natural mechanisms can be adapted to tolerate nonnatural monomers. The other trend is the preparation of sequence-controlled polymers by synthetic chemistry. In the most popular approach, monomer units are attached one by one to a support, which is an efficient method but demanding in practice. Recently, some strategies have been proposed for controlling sequences in chain-growth and step-growth polymerizations. These mechanisms usually allow fast and large-scale synthesis of polymers. Specific kinetics and particular catalytic or template conditions allow sequence regulation in these processes. Outlook The possibility of controlling monomer sequences in synthetic macromolecules has many scientific and technological implications. Information can be controlled at the molecular level in synthetic polymer chains. This opens up interesting perspectives for the field of data storage. In addition, having power over monomer sequences could mean structural control of the resulting polymer, as it strongly influences macromolecular folding and self-assembly. For instance, functional synthetic assemblies that mimic the properties of globular proteins, such as enzymes and transporters, can be foreseen. Moreover, monomer sequence control influences some macroscopic properties. For example, bulk properties such as conductivity, rigidity, elasticity, or biodegradability can be finely tuned in sequence-controlled polymers. The behavior of polymers in solution, particularly in water, is also strongly dependent on monomer sequences. Thus, sequence regulation may enable a more effective control of structure-property relations in tomorrow’s polymer materials.

http://science.sciencemag.org/content/sci/341/6146/1238149.full.pdf

Sequence-controlled polymers.

A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than a corresponding DNA strand, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting of naturally-occurring nucleobases and non-naturally-occurring nucleobases attached to a polyamide backbone, and contain C1-C8 alkylamine side chains. Methods of enhancing the solubility, binding affinity and sequence specificity of PNAs are provided.

https://orbit.dtu.dk/files/58073632/US5736336.pdf

Peptide nucleic acids having enhanced binding affinity, sequence specificity and solubility

A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than the corresponding DNA or RNA strands, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting of naturally-occurring nucleobases and non-naturally-occurring nucleobases attached to a polyamide backbone, and contain alkylamine side chains.

Peptide nucleic acids having amino acid side chains

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. XXXXI. Template polymerization of methacryloyl‐type monomers containing nucleic acid bases

Photodimerization of N-2-isobutyloxyethyl thymine (T-M), bis[2-(5-methyl-1-primidinyl)-ethyl] glutarate (T-T), poly(N-2-methacryloyloxyethyl thymine) (polyMAOT), and poly(N-2-acryloyloxyethyl thymine) (poly AOT) was studied in dimethylformamide solution. The rate of intramolecular photodimerization of polyMAOT and polyAOT was 5.7 and 7.2 times faster, respectively, than that of T-T. In T-M, however, intermolecular photodimerization did not occur under the reaction condition used. Quenching studies with isoprene suggest that the photodimerization of T-T occurs predominantly in an excited triplet state, whereas that of polyMAOT and polyAOT occur in singlet and triplet states. It was concluded that the photodimers of T-T, polyMAOT, and polyAOT are two syn-fused cyclobutane-type dimers (cis-syn and trans-syn). Quantum efficiencies of thymine base disappearance were determined by ultraviolet (UV) analysis to be 0.0012 for T-T, 0.0084 for polyMAOT, and 0.010 for polyAOT.

Functional monomers and polymers. LXI. Photochemical reactions on the synthetic polymers containing thymine bases

Poly-L-lysine (PLL) derivatives containing pendant nucleic acid base, such as thymine or adenine, were bonded successfully to 3-aminopropylsilanized silica (APS-silica) and silica gel. These resins were found to be useful as the column of high performance liquid chromatography (HPLC) for the selective separation of oligoethyleneimine derivatives having pendant thymine or adenine bases.

Functional monomers and polymers. CLIV. Application of nucleic acid base containing polymers to high performance liquid chromatography

The polymerization of acrylonitrile, methyl methacrylate and styrene initiated by copper(II) chelates was studied in the prescence of carbon tetrachloride. A polymeric amine and a monomeric diamine, that is, polyvinylamine and 1,3-diaminopropane, were chosen as ligands. The activity of the polymeric chelate was found to be specific and higher than that of the 1,3-diaminopropane chelate. It was compared with that of the 1,3-diaminopropane chelate, by changing pH values of the system and the reaction temperature. Plots of conversion against pH afforded a peak at pH 8, and trends of increasing of conversion were observed above pH 10. The apparent activation energy of the polymerization initiated by the polymeric chelate was higher than the apparent activation energy of the polymerization initiated by the 1,3-diaminopropane chelate. The fact was attributed to the difference of their chemical structures.



Die Polymerisation von Acrylnitril, Methyl-methacrylat und Styrol durch Kupfer(II)-chelate wurde in Anwesenheit von Tetrachlorkohlenstoff untersucht. Als Liganden wahlte man polymere Amine und monomere Diamine, d. h. Polyvinylamin und 1,3-Diaminopropan. Es ergab sich, das die Aktivitat des polymeren Chelats spezifisch und hoher als die des 1,3-Diamino-propan-Chelats ist. Sie wurde mit den Aktivitaten des 1,3-Diamino-propan-Chelats bei verschiedenen pH-Werten und Temperaturen verglichen. In Diesem Fall zeigte die pH-Umsatz-Kurve ein Maximum bei pH 8, und der Umsatz nahm bei pH > 10 zu. Die scheinbare Aktivierungsenergie des durch das polymere Chelat initiierten Polymerisation war hoher als bei Verwendung des 1,3-Diaminopropan-Chelats. Dieses Ergebnis wurde auf die verschiedene chemische Struktur der beiden Chelate zuruckgefuhrt.

Vinyl polymerization by metal complexes, 10. Initiation by polyvinylamine–copper (II) chelate

In order to clarify the mechanism of catalysis of polyvinylamine-copper(II) chelates on the initiation of vinyl polymerizations, stability constants of these chelates were measured by applying a modification of BJERRUM'S method, and each concentration of the chemical species was estimated on the basis of the chelate theory. From these results, the activity of the polyvinylamine-copper(II) chelates for the polymerization of acrylonitrile and methyl methacrylate at different pH values was discussed.



Um den Mechanismus der Katalyse der Polyvinylamin-Kupfer(II)-Chelate bei der Auslosung der Vinylpolymerisation zu klaren, wurden die Stabilitatskonstanten dieser Chelate durch Anwendung einer modifizierten BJERRUMschen Methode gemessen, und die Konzentration der chemischen Spezies wurde auf Grund der Chelattheorie abgeschatzt. Anhand dieser Ergebnisse wurde die Aktivitat der Polyvinylamin-Kupfer(II)-Chelate bei der Polymerisation von Acrylnitril und von Methylmethacrylat bei verschiedenen pH-Werten diskutiert.

Yoshiaki Inaki

Papers

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

Functional monomers and polymers. LXI. Photochemical reactions on the synthetic polymers containing thymine bases

Functional monomers and polymers. CLIV. Application of nucleic acid base containing polymers to high performance liquid chromatography

Vinyl polymerization by metal complexes, 10. Initiation by polyvinylamine–copper (II) chelate

Vinyl polymerization by metal complexes, 11. Formation of polyvinylamine-copper(II) chelates†‡