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A Brief Background
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
Life is based on carbon. Organic chemistry is dedicated to this element, whose properties are defined by the nature of the carbon atom. Carbon is in group 4 of the periodic table, which identifies that there are four valence electrons. These are the outer electrons involved in bonding, so a further four electrons are required through bonding to other atoms to satisfy the octet rule; hence, carbon atoms characteristically form four covalent bonds, and each bond comprise of shared pairs of electrons with partner atoms. These may be single bonds, with one shared pair of electrons, or double bonds and even triple bonds, with two and three pairs of electrons being shared. It is common for carbon atoms to bond together in chains and rings to produce the carbon skeleton that defines an organic molecule; the remaining valences are often satisfied by hydrogen atoms, which offer their single electron to form a bonding pair. This produces the simplest class of organic compounds: hydrocarbons, typically separated according to molecular mass through fractional distillation of crude oil.
Whence the Drugs?
Published in Mickey C. Smith, E.M. (Mick) Kolassa, Walter Steven Pray, Government, Big Pharma, and the People, 2020
Mickey C. Smith, E.M. (Mick) Kolassa, Walter Steven Pray
Among the allied sciences which have contributed to recent advances in Drug therapy are organic chemistry and physiology. Organic chemistry has been and continues to be a source of many new chemical structures with exciting therapeutic possibilities. The physiologists have been responsible for conceptualizing the physiologically active principles in certain organs. Examples of contributions of this type of study are insulin, cortisone, and estrogen therapy.
Quick Methods: Structure-Activity Relationships and Short-Term Bioassay
Published in Samuel C. Morris, Cancer Risk Assessment, 2020
Faced on one hand with thousands of potential chemical carcinogens in the environment and more being generated continuously as new chemical products or byproducts, and on the other with long-term animal testing requiring two years and half a million dollars just to get the beginnings of an answer on carcinogenicity on each chemical, regulators, policy makers, and scientists sought quicker answers. Organic chemists looked toward structure-activity relationships. What could be better than to be able to predict whether a compound was carcinogenic, and perhaps even its quantitative carcinogenic potency, simply from its molecular structure? The biologist looked to simpler lifeforms and biological indicators or precursors of tumors. With the development of the Ames test, which exposed a mutated bacterial culture to the chemical agent and measured revertants (back-mutation) as an index of the mutagenicity of the chemical, the biologists made a spectacular success. This test, and numerous others that followed, revolutionized our ability to test suspected carcinogenic agents. Compared to the half-million dollars or more for long-term animal tests, short-term bioassays can be conducted quickly for $1000 to $10,000 per chemical. In a period of about one decade, nearly 10,000 compounds have been tested in at least one short-term mutagenicity assay (Guidelines, 1986). While not as spectacular, the chemists made steady gains and structure-activity relationships have found an important niche in the process of identifying carcinogens.
An update on late-stage functionalization in today’s drug discovery
Published in Expert Opinion on Drug Discovery, 2023
Andrew P. Montgomery, Jack M. Joyce, Jonathan J. Danon, Michael Kassiou
Historically, the C–H bond is known as the ‘un-functional group’ or a chemical group lacking reactivity, a conception exemplified by their frequent obfuscation in organic structures [7]. Unlike typical polar reactions where regions possessing contrasting electron-density are the impetus for bond-forming and breaking, C–H functionalization relies on the precise nature of a given C–H bond and its bond dissociation energy (BDE) [8]. Unfortunately, the mechanistic underpinnings of these reactions are complex, and the reaction conditions required for their transformation have proven elusive. However, in recent decades, significant progress in C–H functionalization methodology has been made [9,10]. The development of new methodologies to improve the scope and functional group tolerance, as well as functionalization of previously inaccessible C–H bonds, has taken LSF from a chemical curiosity to a useful tool for organic chemists.
Critical assessment of AI in drug discovery
Published in Expert Opinion on Drug Discovery, 2021
W. Patrick Walters, Regina Barzilay
One of the first applications of computers in organic chemistry was the development of programs that proposed routes for organic synthesis. Beginning with the work of the Corey group in the early 1970s [107,108], scientists designed programs that chained together sets of chemical reactions to define a path from a set of readily available starting materials to a complex organic molecule [109]. For the first 45 years of the field, most of these programs operated in a similar fashion. A set of reactions were defined that would transform one molecule into another, and strategies were proposed for combining these reactions to generate the desired product. Most of these strategies employed retrosynthetic disconnections similar to those employed by a human chemist. While a tremendous amount of work went into the development of these methods, they failed to achieve mainstream acceptance by the majority of organic chemists and have not been widely applied.
Synthesis of thiazolidin-4-ones and thiazinan-4-ones from 1-(2-aminoethyl)pyrrolidine as acetylcholinesterase inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Adriana M. das Neves, Gabriele A. Berwaldt, Cinara T. Avila, Taís B. Goulart, Bruna C. Moreira, Taís P. Ferreira, Mayara S. P. Soares, Nathalia S. Pedra, Luiza Spohr, Anita A. A. dE Souza, Roselia M. Spanevello, Wilson Cunico
Heterocyclic compounds, with nitrogen and sulphur atoms and five-member and six-member rings, are of great interest in the field of synthetic organic chemistry and medicinal chemistry10,11. Thiazolidinone belongs to this class and is a versatile scaffold to the development of new bioactive compounds. Numerous studies describe a wide range of pharmacological properties of thiazolidinones: anti-HIV12, antitumor13,14, anti-inflammatory15, antimicrobial16, antihyperglycemic17, and acetyl/butyrylcholinesterase inhibition5. Thiazinanones (six-membered heterocycle) also show important biological activity such as anticancer18, antimalarial19, antihypertensive20, antibacterial21, and antihyperglycemic17.