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Mesoscopic Systems
Published in James J Y Hsu, Nanocomputing, 2017
There are two types of nucleic acids: DNA and RNA. These are the molecules that enable living organisms to reproduce their complex components. The monomer units of nucleic acids are nucleotides. There are three building blocks in each nucleotide: a nitrogenous base, a pentose sugar and a phosphate group. There are two families of nitrogenous bases: pyrimidines and purines. A pyrimidine has a six-membered ring of carbon and nitrogen atoms. Purines fuse a sixmembered ring with a five-membered ring. There are four different types of nucleotides in DNA. These four nucleotides are given oneletter abbreviations as shorthand for the four bases:A is for adenine, T is for thymine, G is for guanine, and C is for cytosine. Cytosine and thymine are pyrimidines and adenine and guanine are purines. In the RNA, thymine is replaced with uracil (U) which is also apyrimidine.DNAserves as the template for the synthesis of the RNA, which in turn, controls protein synthesis.
Biomolecules and Complex Biological Entities
Published in Simona Badilescu, Muthukumaran Packirisamy, BioMEMS, 2016
Simona Badilescu, Muthukumaran Packirisamy
Because of the presence of hydrogen-bond-forming groups in their molecules, there are two types of base pairs. Usually, the bases are identified by the first letter in their names, like A, T, G., C. The possible base pairs are A-T and G-C, as shown in Figure 3.32. Most DNAs exist in the form of a double helix, in which two linear strands are wound around each other, as seen in Figure 3.32. In double-stranded nucleic acids, base pairs are always formed between a purine and a pyrimidine. Thymine (T) is found only in DNA, while uracil (U) is found only in RNA, as seen in Figure 3.33. There is a phosphodiester linkage between the 5’-phosphate group of one nucleotide unit and the 3’-hydroxyl group of the next one. The backbone of nucleic acids is formed of alternating pentose and phosphate residues, which are both hydrophilic, while at near-neutral pH, the bases are hydrophobic. The bases may be regarded as side groups of the backbone, as can be seen in Figure 3.32. Nucleic acids are synthesized in a 5’ to 3’ direction. During the synthesis in cells, the enzymes (DNA and RNA polymerases) add nucleotides to the 3’ end of the previously incorporated base. By convention, a short nucleic acid, with fifty or less nucleotides, is called an oligonucleotide.
Biopolymers
Published in Mihai V. Putz, New Frontiers in Nanochemistry, 2020
Lorentz Jäntschi, Sorana D. Bolboacă
Cytosine (C), guanine (G), adenine (A), and thymine (T) are used for building of the biological memories in DNA (deoxyribonucleic acid) and Cytosine (C), guanine (G), adenine (A), and uracil (U) – a demethylated form of thymine (T) are used for building of the biological memories in the RNA (ribonucleic acid) being paired when the nucleic acids have double strands (see Figure 2.3). Cytosine (C), thymine (T), and uracil (U) are pyrimidine (C4H4N2) derivatives.
Advancement of corrosion inhibitor system through N-heterocyclic compounds: a review
Published in Corrosion Engineering, Science and Technology, 2023
Rashika Batra, Ashish Kumar Singh, Manjeet Singh, Sanjeeve Thakur, Balaram Pani, Savas Kaya
Pyrimidine, a class of N-heterocyclic compound constituting aromatic ring composed of carbon and nitrogen with general molecular formula of C4H4N2. Pyrimidine and associated derivatives are ubiquitous in nature and found in vitamins, nucleic acids, amino acids, etc. Certain applications like pharmaceuticals, agro-chemicals prefer the use of pyrimidine and additionally these days the anti-corrosive scope of this heterocyclic compound is being investigated due to availability of nitrogen atom and along with aromatic pair of electrons [139]. Benhiba et al. studied the anti-corrosion potency of 8-(4-methoxyphenyl)-3,6-dioxo-2-(p-tolyl)-3,6-dihydro-2H-thiazolo[3′,2′:2,3][1,2,4]triazolo[1,5-a]pyrimidine-7-carbonitrile (HTPC) on mild steel in acidic media. It was assessed from polarisation curves; it behaved as mixed-type inhibitor and its inhibition efficiency primarily depended upon the amount of inhibitor and temperature. The mode of adsorption adopted was chemisorption and it followed Langmuir adsorption isotherm. The maximal inhibition efficiency was found out to be 87.8% at inhibitor concentration of 10−3 M [145].
Supramolecular assembly in designing co-crystals of fumaric acid and pyrimidine/picolinate derivatives
Published in Green Chemistry Letters and Reviews, 2022
Sevgi Kansız, Mohammad Azam, Necmi Dege, Nihal Ermiş, Saud I. Al-Resayes, Mahboob Alam
Fumaric acid, the trans isomer of butenedioic acid, is abundantly found in nature (23) and acts as an essential intermediary in the formation of organic acids as an adduct with a wide range of amines, resulting in a variety of fascinating one-, two-, and three-dimensional supramolecular structures (23). Moreover, fumaric acid is an essential part of the paper and food industries because of its role in the manufacture of polymeric materials and as an important component of cell culture medium (24,25). Pyrimidine and its derivatives are biologically essential compounds that occur naturally as nucleic acid components and have a wide range of pharmacological properties, including antiviral, anti-inflammatory, anticancer, and antidepressant effects (26–30). Meanwhile, pyridines and pyrimidines are commonly used in the field of crystal engineering due to their flexibility. The well-known synthons HT (hetero-trimers) and LHT (linear hetero-tetramers) are formed in the presence of pyrimidines and carboxylic acids (31–33).
Solvatochromic behavior of a pyrene-pyrimidine-based Schiff base and detection of heavy metal ions in aqueous media
Published in Journal of Coordination Chemistry, 2021
Swadesh Ghosh, Dipti Singharoy, Saugata Konar, Jnan Prakash Naskar, Subhash Chandra Bhattacharya
Pyrimidine containing Schiff bases are promising with broad spectrum of biological activity and for the detection of toxic heavy metal ions [15]. To develop the Schiff base as a sensor, pyrene derivatives are widely used due to their excellent photoluminescence and chemical stabilities. Among heterocycles, pyrimidines represent a particularly important class of compounds due to their diverse applications for pharmaceutical properties. Schiff bases have biological activity, such as antitumor [16, 17], anticancer [18], antifungal, and antimicrobial activities [19–21]. Biological activity is related to hydrogen bonding through the imino group of Schiff bases with the active centers of the cell constituents [22]. Based on these factors we focus on Schiff bases, which are prepared using simple steps and can be applied to many cation and anion sensors. Pyrimidine is the structural unit of DNA and RNA playing a vital role with the most abundant pyrimidines uracil, cytosine and thymine. Pyrene has also a remarkable range of biological activity as anti-bacterial agents, [23] anti-tumor [24] and anti-fungal [25] compounds.