Thymine-containing polymers

The photodegradation and photo-oxidation of poly(organosiloxanes), poly(iV-vinylcarbazole), polyCalkoxyphosphazones)," thymine-containing polymers/ cellulose triacetate, cellulose acetophthalate complexes with poly(vinyl alcohol)/ acrylonitrile-butyl acrylate-vinylene chloride terpoly-... 

Takemoto, K. and Inaki, Y, Photodimerization of thymine-containing polymers applicability to reversible photoresists, /. Macromol. Sci. Chem., A25, 757,1988. 

Lloyd-Kindstrand, L. Warner, J. C. Thymine-Containing Styrene Polymers as Environmentally Benign Photoresists. Biopolymers 2002, 8, 165-174. 

Kita, Y, Inaki, Y, and Takemoto, K., Photochemical reactions on the synthetic polymers containing thymine bases, /. Polymer ScL, Polymer Chem. Ed., 18, 427,1980. 

The molecular weights of the polymers before and after irradiation were followed by GPC to determine changes in the molecular weights of the polyamides. It was found that photolysis of the polymer resulted in polymer chain scission, leading to the appearance of oligomers containing thymine bases at the end of the molecules. 

Figure 9. Photoreversal of the polymers containing isomers of thymine photodimer.

Polyamides containing thymine photodimer units in the main chains showed excellent resolution values (0.3 p m) and behaved as positive photoresists. It is concluded that polymers containing pyrimidine bases displayed high resolution and high sensitivity when used in both negative and positive photoresists formulations. 

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 %(,] ). 

The concept of supramolecular polymers containing multiple hydrogen bonding units was introduced over a decade ago by Jean-Marie Lehn (Lehn 1993). In this smdy, three-point hydrogen bonding between bifunctional diamidopyridine and thymine... 

Spijker and colleagues (2005) synthesized nucleobase-functionalized block copolymers containing thymine via ATRP of a thymine methacrylate monomer from a poly(ethylene glycol) (PEG) macroinitiator. This polymer was introduced into the polymerization of an adenine containing an alkyl methacrylate... 

There are three major types of RNA that participate in the process of protein synthesis ribosomal RNA (rRNA), transfer RNA (tRNA), and messenger RNA (mRNA). They are unbranched polymers of nucleotides, but differ from DNA by containing ribose instead of deoxyribose and uracil instead of thymine. rRNA is a component of the ribosomes. tRNA serves as an adaptor molecule that carries a spe dfic amino acid to the site of protein synthesis. mRNA carries genetic information from the nuclear DNA to the cytosol, where it is used as the template for protein synthesis. The process of RNA synthesis is called transcription, and its substrates are ribonucleoside triphosphates. The enzyme that synthesizes RNA is RNA polymerase, which is a multisub-irit enzyme. In prokaryotic cells, the core enzyme has four subunits—... 

There are three major types of RNA that participate in the process of protein synthesis ribo-somal RNA (rRNA) transfer RNA (tRNA), and messenger RNA (mRNA). They are unbranched polymers of nucleotides, but differ from DNA by containing ribose instead of deoxyribose and uracil instead of thymine. 

There are four types of nucleotides in a DNA polymer (Figure 13.27a). These four nucleotides differ from one another in the nitrogenous base they contain, which may be adenine (A), guanine (G), cytosine (C), or thymine (T). There are also four types of RNA nucleotides used to build the RNA polymer (Figure 13.27b). The RNA nucleotides contain the same nitrogenous bases as found in DNA nucleotides except for thymine. Instead of thymine, RNA nucleotides contain the nitrogenous base uracil (U), whose structure is only slightly different from that of thymine. 

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