China
Africa
Explore chapters and articles related to this topic
Natural Product Compounds from Plants in Neurodegenerative Diseases
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Priya Darshani, Md TanjimAlam, Prem P. Tripathi, V.S. Pragadheesh
Several synthetic, semisynthetic and phytochemicals have shown significant effects on different therapeutic strategies. Among the strategies mentioned earlier, only anticholinesterase inhibitors like galantamine (phytocompound), rivastigmine (semisynthetic) and donepezil (synthetic) were approved by the FDA for the treatment of AD (Masters et al., 2015).
Antibiotics: The Need for Innovation
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
The need to develop new drugs is essential to overcome the challenges of bacterial resistance. Sequencing genomes of proteins may elucidate new targets in the ever-present battle against pathogenic bacteria. Many of the compounds produced to combat pathogenic bacteria are semisynthetic, derived from microorganisms, and rely on fermentation for manufacturing them. By employing innovative research, targeting on a molecular-level approach might aid in designing novel compounds to battle infection, and overcome one of the leading challenges of medicinal chemistry today.
On Biocatalysis as Resourceful Methodology for Complex Syntheses: Selective Catalysis, Cascades and Biosynthesis
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Andreas Sebastian Klein, Thomas Classen, Jörg Pietruszka
Semisynthesis is the oldest way of diversifying natural products, as it does not require knowledge of biosynthetic pathways or genetic constructs. Semisynthesis combines classical biosynthesis and organic chemistry and generates derivatives by consecutive chemical modification of the extracted natural substance (Fig. 21.10A) (Von Nussbaum et al., 2006; Eichner et al., 2012; Kennedy, 2008; Mahoney et al., 2014). For this approach, mostly complex natural products or intermediates are used as a starting material, and either these are completed to bioactive natural metabolite or the specific bioactivity is improved by (non-biological) functional groups. However, this approach is hampered by a limited range of subsequent chemical transformations. With structurally highly complex natural products, the synthetic modification must be highly efficient as well as chemo- and regioselective in order to avoid a subsequent separation problem and the associated loss of yield. Well-known examples of semisynthetic products are the penicillin (27) derivatives amoxicillin and methicillin, the antitumor therapeutic paclitaxel (25, taxol), the antimalarial therapeutic artemisinin (26) and the cholesterol-lowering simvastatin (a lovastatin derivative) (Kennedy, 2008; Patel, 1998; Kung et al., 2018; Paddon and Keasling, 2014).
Glycyrrhetinic acid: a promising scaffold for the discovery of anticancer agents
Published in Expert Opinion on Drug Discovery, 2021
Hidayat Hussain, Iftikhar Ali, Daijie Wang, Faruck L. Hakkim, Bernhard Westermann, Ishtiaq Ahmed, Ahmed M. Ashour, Amjad Khan, Amjad Hussain, Ivan R. Green, Syed Tasadaque Ali Shah
The structural diversity and complexity of natural molecules are derived from numerous fascinating multistep enzymatic conversions. Natural products present themselves as attractive scaffolds for an intriguing drug discovery process because of the complex nature and structural chemical diversity of these molecules. Inspired by the interesting biosynthetic routes which create complex natural products, numerous authors prepared GA semisynthetic derivatives via chemical diversification. This review on semi-synthetic derivatives of GA demonstrates that numerous chemical modifications have been accomplished on the GA scaffold, which showed significant cytotoxic effects toward various cancer cells. In addition, GA is a very interesting model of skeletal chemical diversity as this compound has a C-3 hydroxyl group, C-11 keto moiety and a C-30 carboxylic acid.
Chemopreventive role of arabinogalactan against experimentally induced pulmonary carcinogenesis: a study in relation to its initiation phase
Published in Drug and Chemical Toxicology, 2021
Ashwani Koul, Shaffy Garg, Vandana Mohan
Polysaccharides (PS), a biopolymer of monosaccharides are categorized into two main classes depending upon their source (Silva et al.2014). Natural PS are obtained from natural sources such as algae, plants, microorganisms, and animals. In contrast, semisynthetic PS are produced by the chemical or enzymatic modification of the parent macromolecules. Being a structurally diverse class of macromolecules, PS plays an important role in many biological processes such as signal recognition, cell-cell communications etc. (Karaki et al.2016). So far, it has been demonstrated that PS have a broad spectrum of pharmacological properties including anticancer and anti-inflammatory (Talero et al.2015). The use of PS as a chemopreventive agent is suggested because they do not pose any severe side effects on the body and help the body to adapt to different biological and environmental stressors (Lovegrove et al.2017). Numerous studies have indicated that bioactive PS can inhibit tumor growth through the following common mechanisms: (1) by induction of apoptosis in tumor cells; (2) by immunopotentiation activity in combination with chemotherapy; and (3) By cell-cycle arrest (Zhang et al.2014).
Natural compounds and extracts as novel antimicrobial agents
Published in Expert Opinion on Therapeutic Patents, 2020
Paolo Guglielmi, Virginia Pontecorvi, Giulia Rotondi
The insurgence of microbial resistance is one of the most challenging issue of the last years. The ability of the microorganisms to adapt and develop mechanisms of resistance to the actually used drugs requires an effort to overcome this obstacle [48–50]. Indeed, the risk associated with the increasingly widespread of resistant microorganisms is the inability to threat infections, thus formally coming back to a pre-antibiotic era. Nature is often the main supplier of substances/scaffolds endowed with pharmaceutical properties, that make them suitable for specific use [51]. In this regard, the discovery of penicillin isolated from Penicillium mold is a great example. Furthermore, in order to improve both pharmacokinetic and pharmacodynamic properties, semisynthetic approach is often exploited [52,53]. Nevertheless, the decreased development of new antibiotic compounds observed in these years represents a real problem.