Topic Review
Xanthones
Xanthone is an aromatic oxygenated heterocyclic molecule, with a dibenzo-γ-pirone scaffold, known as 9H-xanthen-9-one, with the molecular formula of C13H8O2.
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  • 23 Feb 2021
Topic Review
Epoxide Synthesis and Ring-Opening Reactions
This entry concentrates on some examples of success stories from the synthesis of approved medicines and drug candidates using epoxide chemistry in the development of robust and efficient syntheses at large scale. The focus is on those parts of each synthesis related to the substrate-controlled/diastereoselective and catalytic asymmetric synthesis of epoxide intermediates and their subsequent ring-opening reactions with various nucleophiles. These are described in the form of case studies of high profile pharmaceuticals spanning a diverse range of indications and molecular scaffolds such as heterocycles, terpenes, steroids, peptidomimetics, alkaloids and main stream small molecules. Representative examples include, but are not limited to the antihypertensive diltiazem, the antidepressant reboxetine, the HIV protease inhibitors atazanavir and indinavir, efinaconazole and related triazole antifungals, tasimelteon for sleep disorders, the anticancer agent carfilzomib, the anticoagulant rivaroxaban the antibiotic linezolid and the antiviral oseltamivir. Emphasis is given on aspects of catalytic asymmetric epoxidation employing metals with chiral ligands particularly with the Sharpless and Jacobsen–Katsuki methods as well as organocatalysts such as the chiral ketones of Shi and Yang, Pages's chiral iminium salts and typical chiral phase transfer agents.
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  • 09 Oct 2020
Topic Review
Chinese Alchemy
Chinese alchemy is an ancient Chinese scientific and technological approach to alchemy, a part of the larger tradition of Taoist body-spirit cultivation developed from the traditional Chinese understanding of medicine and the body. According to original texts such as the Cantong qi, the body is understood as the focus of cosmological processes summarized in the five agents, or wu xing, the observation and cultivation of which leads the practitioner into greater alignment with the operation of the Tao, the great cosmological principle of everything. Therefore, the traditional view in China is that alchemy focuses mainly on the purification of one's spirit and body in the hopes of gaining immortality through the practice of Qigong and/or consumption and use of various concoctions known as alchemical medicines or elixirs, each of which having different purposes. Pao zhi (Pao chi) cites the pharmacological processing (of Chinese materia medica) as used in the practice of Traditional Chinese Medicine, such as honey or wine frying and roasting with toxic metals such as mercury, lead, and arsenic. According to J.C. Cooper's Chinese Alchemy: The Taoist Quest for Immortality, Taoism had two distinct parts, the classical Tao Chia, which was mystical and stemmed primarily from Laozi and Zhuangzi, and the more popular Tao Chiao, which was the popular, magical and alchemical side of Taoism. Cooper states that a common viewpoint is that "classical Taoism [Daoism] was the original but was too austere and rarefied for the general populace ... [but] Tao Chiao fulfilled the day-to-day needs of the people."
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  • 16 Nov 2022
Topic Review
Transition Metal Dichalcogenides
In recent years, the material characteristics and properties of transition metal dichalcogenide (TMDCs) have gained research interest in various fields, such as electronics, catalytic, energy storage. In particular, many researchers have been focusing on the applications of TMDCs in dealing with environmental pollution. TMDCs provide a unique opportunity to develop higher-value applications related to environmental matters. This work highlights the applications of TMDCs contributing to pollution reduction in (i) gas sensing technology, (ii) gas adsorption and removal, (iii) wastewater treatment, (iv) fuel cleaning, and (v) carbon dioxide valorisation and conversion. Overall, the applications of TMDCs have successfully demonstrated the advantages of contributing to environmental conversation due to their special properties. The challenges and bottlenecks of implementing TMDCs in the actual industry are also highlighted. More efforts need to be devoted to overcoming the hurdles to maximize the potential of TMDCs implementation in the industry.
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  • 27 Oct 2020
Topic Review
AgNPs
Elementary silver nanoparticles (AgNPs) are of great interest because of their various probable medical application. Due to their antimicrobial activity, low toxicity and inexpensive cost, the mechanism of silver nanoparticles biosynthesis in bacterial, fungal and plant cells is extremely exciting from the point of view of the different cellular compounds participation in it: proteins, enzymes, acids, etc.
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  • 15 Dec 2020
Topic Review
Electrochemical Glucose Sensing
The research field of glucose biosensing has shown remarkable growth and development since the first reported enzyme electrode in 1962. Extensive research on various immobilization methods and the improvement of electron transfer efficiency between the enzyme and the electrode have led to the development of various sensing platforms that have been constantly evolving with the invention of advanced nanostructures and their nano-composites. Examples of such nanomaterials or composites include gold nanoparticles, carbon nanotubes, carbon/graphene quantum dots and chitosan hydrogel composites, all of which have been exploited due to their contributions as components of a biosensor either for improving the immobilization process or for their electrocatalytic activity towards glucose. This review aims to summarize the evolution of the biosensing aspect of these glucose sensors in terms of the various generations and recent trends based on the use of applied nanostructures for glucose detection in the presence and absence of the enzyme.
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  • 13 Nov 2020
Topic Review
Hole-Transporting Layer in Perovskite Solar Cells
Organic-inorganic halide perovskite solar cells (PSCs) have received particular attention because of the high-power conversion efficiencies (PCEs), facile fabrication route and low cost. The hole-transporting layer (HTL) play an important role in PSCs to effectively extract holes from the perovskite film and to transport holes to the metal electrode in normal PSCs. 
  • 2.3K
  • 09 Aug 2022
Topic Review
Advances in Electrochemical Glucose Sensing
The detection of glucose is crucial in the management of diabetes and other medical conditions but also crucial in a wide range of industries such as food and beverages. The development of glucose sensors in the past century has allowed diabetic patients to effectively manage their disease and has saved lives. First-generation glucose sensors have considerable limitations in sensitivity and selectivity which has spurred the development of more advanced approaches for both the medical and industrial sectors.
  • 2.3K
  • 21 Jul 2021
Topic Review
Lignin Biopolymer in Biomaterials Synthesis
Lignin is one of the wood and plant cell wall components that is available in large quantities in nature. Its polyphenolic chemical structure has been of interest for valorization and industrial application studies. Lignin can be obtained from wood by various delignification chemical processes, which give it a structure and specific properties that will depend on the plant species. Due to the versatility and chemical diversity of lignin, the chemical industry has focused on its use as a viable alternative of renewable raw material for the synthesis of new and sustainable biomaterials. 
  • 2.3K
  • 08 Apr 2021
Topic Review
Palm Oil Mill Effluent Treatment
POME is considered as one of the major problems that has generated voluminously from the palm oil industries. Pre-treatment is utmost required prior discharge to the environment. This review deals with current POME treatment techniques.
  • 2.3K
  • 26 May 2021
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