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Topic Review
Folic Acid Antimetabolites
Antimetabolites of folic acid represent a large group of drugs and drug candidates, including those for cancer chemotherapy. Antimetabolites, which are antagonists of natural metabolites, belong to a group of highly efficient anticancer drugs. Based on the chemical structure, these groups can be divided into several sub-groups, such as non-natural amino-acids or peptides, including phospha-analogues, analogues of purine and pyrimidine bases, such as competitors in the synthesis of the nucleic acids, as well as vitamin actions including folic acid, hormones, coenzymes, and other substrates responsible for the normal functioning of cells and tissues of the human body.
  • 1.5K
  • 29 Dec 2022
Topic Review
Molecules of the Week
"Molecules of the Week" is a new project to collect and show the discovery of novel molecules, compounds as well as the researchers' story behind it.
  • 1.4K
  • 05 Nov 2021
Topic Review
C,C- and C,N-Chelated Organocopper Compounds
Copper-catalyzed and organocopper-involved reactions are of great significance in organic synthesis. To have a deep understanding of the reaction mechanisms, the structural characterizations of organocopper intermediates become indispensable. Meanwhile, the structure-function relationship of organocopper compounds could advance the rational design and development of new Cu-based reactions and organocopper reagents. Compared to the mono-carbonic ligand, the C,N- and C,C-bidentate ligands better stabilize unstable organocopper compounds. Bidentate ligands can chelate to the same copper atom via η2-mode, forming a mono-cupra-cyclic compounds with at least one acute C-Cu-C angle. When the bidentate ligands bind to two copper atoms via η1-mode at each coordinating site, the bimetallic macrocyclic compounds will form nearly linear C-Cu-C angles. The anionic coordinating sites of the bidentate ligand can also bridge two metals via μ2-mode, forming organocopper aggregates with Cu-Cu interactions and organocuprates with contact ion pair structures. The reaction chemistry of some selected organocopper compounds is highlighted, showing their unique structure–reactivity relationships.
  • 1.4K
  • 08 Oct 2021
Topic Review
Synthesis of Pyrazolo pyrano oxazoles
A simple and efficient synthetic route to the novel 3a,4-dihydro-3H,7H- and 4H,7H-pyrazolo[4′,3′:5,6]pyrano[4,3-c][1,2]oxazole ring systems from 3-(prop-2-en-1-yloxy)- or 3-(prop-2-yn-1-yloxy)-1H-pyrazole-4-carbaldehyde oximes has been developed by employing the intramolecular nitrile oxide cycloaddition (INOC) reaction as the key step.
  • 1.4K
  • 06 Feb 2023
Topic Review
Removal of Pesticides from Waters
Pesticides are pollutants found in wastewater due to increasing agricultural activities over the years. Inappropriate dosing of pesticides results in the dispersal of active ingredients in the environment. The complete removal of pesticides from wastewater is an immediate concern due to their high toxicity and mobility. At present, adsorption is one of the most widely used methods for pesticide removal, in which synthetic zeolites and mesoporous silica materials are extensively applied. This article presents a systematic and comparative review of the applications and comparison of these adsorbents, based on the data reported in the literature.
  • 1.4K
  • 07 Jul 2021
Topic Review
Classification of Various Ligands
Enantioselective gold catalysis has flourished due to its distinct performance. In particular, a series of valuable chiral ligands have been identified, including aryl phosphine ligands bearing the proximal chiral sulfinamide motif, phosphoramidite and phosphonite ligands, phosphine ligands comprising the ferrocene scaffold, bifunctional phosphine ligands, biphosphine ligands, chiral counterion-based ligands derived from chiral phosphoric acids and chiral carbene ligands for gold(I) catalysis, along with unique ligand frameworks for cyclometalated gold(III) catalysis. 
  • 1.4K
  • 25 Sep 2023
Topic Review
Actual Symmetry of Symmetric Adducts
This review discusses molecular adducts, whose composition allows a symmetric structure. Such adducts are popular model systems, as they are useful for analyzing the effect of structure on the property selected for study since they allow one to reduce the number of parameters. The main objectives of this discussion are to evaluate the influence of the surroundings on the symmetry of these adducts, steric hindrances within the adducts, competition between different noncovalent interactions responsible for stabilizing the adducts, and experimental methods that can be used to study the symmetry at different time scales. This review considers the following central binding units: hydrogen (proton), halogen (anion), metal (cation), water (hydrogen peroxide). 
  • 1.4K
  • 10 Feb 2022
Topic Review
Triazole-Modified Nucleic Acids
Locked nucleic acids (LNAs) are widely used in RNA therapeutics as LNA-modified antisense oligonucleotides. From the structural point of view, LNA is an RNA derivative in which the ribose ring is constrained by a methylene linkage between the 2′-oxygen and the 4′-carbon. This conformational restriction causes an increased binding affinity to complementary DNA and RNA sequences, but the susceptibility to RNase H should be optimized for individual applications.
  • 1.4K
  • 17 Jun 2021
Topic Review
Design and Synthesis of Porous Organic Polymers
5-hydroxymethylfurfural (HMF), which can be synthesized from lignocellulose as a raw material, is an important biological platform molecule. Its preparation and the catalytic oxidation of subsequent products have important research significance and practical value. In the actual production process, porous organic polymer (POP) catalysts are highly suitable for biomass catalytic conversion due to their high efficiency, low cost, good designability, and environmentally friendly features.
  • 1.4K
  • 25 Jul 2023
Topic Review
Biosynthesis of Aurones
Natural products are a boundless source for the development of pharmaceutical agents against a wide range of human diseases. Accordingly, naturally occurring aurones possess various biological benefits, such as anticancer, antioxidant, antimicrobial, antidiabetic, anti-inflammatory, antiviral and neuroprotective effects. In addition, various studies have revealed that aurones are potential templates for the regulation of diabetes mellitus and its associated complications. Likewise, certain aurones and their analogues have been found to be remarkable kinase inhibitors of DARK2, PPAR-γ, PTPM1, AGE, α-amylase and α-glucosidase, which represents a promising approach for the treatment of chronic metabolic disorders such as diabetes. 
  • 1.4K
  • 01 Nov 2023
Topic Review
Charge-Compensated Derivatives of Nido-Carborane
Compared with organic analogs, onium derivatives of nido-carborane have increased stability due to the stabilizing electron-donor action of the boron cage. Charge-compensated derivatives are considered according to the type of heteroatom bonded to a boron atom.
  • 1.4K
  • 07 Mar 2023
Topic Review
Aurilide Family
Aurilides are a class of depsipeptides occurring mainly in marine cyanobacteria. Members of the aurilide family have shown to exhibit strong cytotoxicity against various cancer cell lines. These compounds bear a pentapeptide, a polyketide, and an α-hydroxy ester subunit in their structure.
  • 1.4K
  • 18 Mar 2021
Topic Review
Synthesis of Cyclic Sulfoximines via C–H Bond Activation
Sulfoximines, a ubiquitous class of structural motifs, are widely present in bioactive molecules and functional materials that have received considerable attention from modern organic chemistry, pharmaceutical industries, and materials science. Sulfoximines have proved to be an effective directing group for C–H functionalization which was widely investigated for the synthesis of cyclic sulfoximines. C–H activation of sulfoximines has been widely considered to be an efficient method to construct complex scaffolds with potential bioactivities, especially since Bolm discovered the first efficient strategy of Rh-catalyzed annulation of sulfoximines and alkynes in 2013.
  • 1.4K
  • 10 Feb 2023
Topic Review
Fluorescent Organic Small Molecule Probes
Fluorescence imaging technology provides a visual tool for medicine, showing great potential in the fields of molecular biology, cellular immunology and oncology. In recent years, organic fluorescent probes have attracted much attention in the bioanalytical field. Among various organic fluorescent probes, fluorescent organic small molecule probes (FOSMPs) have become a research hotspot due to their excellent physicochemical properties, such as good photostability, high spatial and temporal resolution, as well as excellent biocompatibility. FOSMPs have proved to be suitable for in vivo bioimaging and detection. 
  • 1.4K
  • 17 Jan 2023
Topic Review
Isothiocyanate Synthesis Using Elemental Sulfur
Isothiocyanates (ITCs) are biologically active molecules found in several natural products and pharmaceutical ingredients. Moreover, due to their high and versatile reactivity, they are widely used as intermediates in organic synthesis.This review considers the best practices for the synthesis of ITCs using elemental sulfur, highlighting recent developments. Additionally, we also reveal that in the catalyst‑free reaction of isocyanides and sulfur, two—until this time overlooked and not investigated—different mechanistic pathways exist.
  • 1.4K
  • 28 Sep 2021
Topic Review
Synthesis of N,N'-Chelate Organoboron Derivatives
N,N′-chelate organoboron compounds have been successfully applied in bioimaging, organic light-emitting diodes (OLEDs), functional polymer, photocatalyst, electroluminescent (EL) devices, and other science and technology areas. However, the concise and efficient synthetic methods become more and more significant for material science, biomedical research, or other practical science.
  • 1.4K
  • 31 Mar 2021
Topic Review
Terpyridine-Polyamine Bridging Ligand (dint)
The ligand, 4'-(p-(1,5-bis(amino)-3-azapentane)methylphenyl)-2,2':6',2"-terpyridine (dint) contains a terpyridine fragment and a tri-amine fragment, which may allow synthetic differentiation between the tridentate binding sites at both sides and may offer the benefits of polydentate ligands and minimisation of isomeric possibilities upon coordination to metal ions.
  • 1.4K
  • 20 Feb 2021
Topic Review
Albumin Conjugates as MRI Agents
Human serum albumin (HSA) is the most abundant protein in plasma. It is found at a concentration of roughly 0.7 mM in the vasculature. HSA is a monomeric multidomain biomolecule, representing the main determinant of plasma oncotic pressure and displays an extraordinary ligand binding capacity. HSA represents the main carrier for fatty acids, affects the pharmacokinetics of many drugs, can be a platform for drug discovery, suitable transport for therapy and diagnostics. Here we develop a class of macromolecular constructs from nitroxides conjugated to a human carrier protein as potential Organic radical contrast agents (ORCAs) for magnetic resonance imaging (MRI). MRI is a powerful non-invasive tool for clinics. The MRI specificity can be improved by enhancing by the addition of a contrast agent. The most efficient of the currently-used contrast agents are paramagnetic gadolinium chelates. However, the low stability of some chelates and therefore release toxic metal ions from the chelates provide harmful oxidative stress, mitochondrial membrane dysfunction, changes in gene expression, DNA damage, mutagenicity, etc. Therefore, there is sufficient interest in the production of “metal-free” MRI contrast agents.
  • 1.3K
  • 29 Dec 2021
Topic Review
Oxidative Catalytic Processes for APIs and Precursors Preparation
Active pharmaceutical ingredients (APIs) can be defined as those biological compounds used for the detection, prevention, and treatment of different types of diseases. Asymmetric oxidation processes have constituted a valuable tool for the synthesis of APIs, especially for the preparation of optically active sulfoxides, compounds with interesting biological properties. Biocatalyzed reactions usually occur with high efficiency, excellent selectivity, good yields, environmental sustainability, and lower costs, which make them more attractive from an industrial perspective. However, it must be taken into account that these procedures also present some drawbacks, such as the (relatively) high substrate specificity of biocatalysts or the low substrate loadings required due to their generally low solubility in water.
  • 1.3K
  • 10 Apr 2023
Topic Review
PZT
The ligand, 4'-(4-(2,2,2-tris(1H-pyrazol-1-yl)ethoxymethyl)phenyl)-2,2':6',2"-terpyridine (PZT) contains a terpyridine fragment and a tris(pyrazolyl) fragment, which may allow synthetic differentiation between the tridentate binding sites as a result of the meridional and the facial coordination preferences of these groups around the octahedral metal centres. This designed bridging ligand may offer the benefits of polydentate ligands and minimisation of isomeric possibilities. The tris(pyrazolyl)methane fragment is of interest, because the coordination chemistry of such systems has also been studied. It, too, is easy to prepare, by reaction of pyrazole with chloroform, and to derivatise, for example by reaction with formaldehyde, to give a molecule, 2,2,2-tris(1H-pyrazol-1-yl)ethanol, that can be readily joined to the other binding site, a terpyridine containing synthon.
  • 1.3K
  • 10 Feb 2021
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