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Topic Review
Synthetic Hemorphin Analogs Containing Non-Natural Amino Acids
The endogenous hemorphins are bioactive peptides with activity on opioid receptors. Several research teams have synthesized, characterized, and pharmacologically evaluated synthetic hemorphin analogs containing unusual amino acids, D-amino acids, α-aminophosphonic acids, and their derivatives. Research focuses on the structure-activity relationship analysis, details on specific methods for their characterization, and the advantage of synthetic hemorphin analogs compared to endogenous peptides as potent biologically active compounds with a complex mechanism of action.
  • 1.3K
  • 05 Dec 2022
Topic Review
Spirocyclic Motifs in Natural Products
Natural products play the central role in drug discovery due to their inherent biological activity and because have a wide span of structural diversity. Spirocyclic compounds have also occupied a special place in medicinal chemistry. Spirocycles are thought to possess a good balance of conformational rigidity and flexibility to be, on one hand, free from absorption and permeability issues characteristic of conformationally more flexible, linear scaffolds. On the other hand, spirocycles are more conformationally flexible compared to, for example, flat aromatic heterocycles and can adapt to many proteins as biological targets; thus, increasing the chances of finding bioactive hits. Spirocycles are distinctly three-dimensional and initial hits can be further optimized via manipulation of the molecular periphery whose three-dimensional positioning is well defined. 
  • 1.3K
  • 25 Apr 2022
Topic Review
Withaferin A
Withaferin A (WFA) was identified as the most active phytocompound of the plant Withania somnifera (WS) and as having multiple therapeutic/ameliorating properties (anticancer, antiangiogenic, anti-invasive, anti-inflammatory, proapoptotic, etc.) in case of various diseases.
  • 1.3K
  • 04 May 2021
Topic Review
Synthesis of Fluorescent Five- and Six-Membered Ring Azaheterocycles
The synthesis of fluorescent azaheterocycles continues to arouse strong interest due to their great potential for application as sensors and biosensors, luminophores on in the construction of Organic Light-Emitting Diode (OLED) devices, laser and other semiconductor devices, as well as to their potential biological properties as antimicrobial, antifungal, anticancer, antituberculosis antioxidant and anti-HIV agents. The advantages of the azaheterocyclic fluorophores, such as small size, enriched photostability, a wide and tunable spectral range, and, frequently, high brightness, are the reason why these fluorophores are preferred and used in various medical application. Probe structure can be modified to adjust excitation and emission wavelengths, target-binding affinity, chemical reactivity, and subcellular localization.
  • 1.3K
  • 09 Oct 2022
Topic Review
Biocompounds in Potato Peel
Potato germplasm is characterized by a huge variability in composition and concentration of secondary metabolites that play a role in increasing plant ability to cope with environmental challenges, due to their reported biocide activity on insects, bacteria, and fungi. Their distribution within the tuber is not uniform: Most of them are concentrated in the peel, made of periderm tissue, whose cell layers contain corky cell walls, which confer protection from phytopathogens, especially during tuber growth and storage. Thus, considering that potato peel is constantly exposed to biotic stresses, it is not surprising that it is a precious source of bioactive compounds, mainly phenolics and alkaloids, which have an enormous potential to deliver new bioprotectors.
  • 1.3K
  • 13 Apr 2021
Topic Review
Synthesis of the 1,2,3-Dithiazole Scaffold
The 1,2,3-dithiazole is an underappreciated scaffold in medicinal chemistry despite possessing a wide variety of nascent pharmacological activities. The scaffold has a potential wealth of opportunities within these activities and further afield. The synthesis of Appel salt 1 acted as a catalyst to the field and granted access to many 1,2,3-dithiazole derivatives, and to other heterocycles incorporating sulfur and nitrogen atoms.
  • 1.3K
  • 12 Apr 2023
Topic Review
Biocatalyzed Redox Processes Employing Green Reaction Media
Biocatalysis can be defined in a broad sense as the mediation of chemical reactions by means of biological systems, including isolated enzymes, whole cells or cell-free extracts. In some circumstances, the aqueous buffer medium normally employed in biocatalytic procedures is not the best option to develop these processes, due to solubility and/or inhibition issues, requiring biocatalyzed redox procedures to circumvent these drawbacks, by developing novel green non-conventional media, including the use of biobased solvents, reactions conducted in neat conditions and the application of neoteric solvents such as deep eutectic solvents. 
  • 1.3K
  • 05 Jul 2022
Topic Review
Zearalenone and the Immune Response
Zearalenone (ZEA) is an estrogenic fusariotoxin, being classified as a phytoestrogen, or as a mycoestrogen. ZEA and its metabolites are able to bind to estrogen receptors, 17β-estradiol specific receptors, leading to reproductive disorders which include low fertility, abnormal fetal development, reduced litter size and modification at the level of reproductive hormones especially in female pigs. ZEA has also significant effects on immune response with immunostimulatory or immunosuppressive results. This review presents the effects of ZEA and its derivatives on all levels of the immune response such as innate immunity with its principal component inflammatory response as well as the acquired immunity with two components, humoral and cellular immune response. The mechanisms involved by ZEA in triggering its effects are addressed. 
  • 1.2K
  • 26 Apr 2021
Topic Review
Atropisomers by Oxidative Aromatization
Atropisomers are fascinating objects of study by themselves for chemists but also find applications in various sub-fields of applied chemistry. Among these strategies, oxidative aromatization with central-to-axial conversion of chirality has gained increasing popularity. It consists of the oxidation of a cyclic non-aromatic precursors into the corresponding aromatic atropisomers.
  • 1.2K
  • 18 Apr 2023
Topic Review
Green Tea Catechins
Green tea and green tea catechins have been shown to be strongly inhibitory to cancer formation in rodents. They are believed to do this by altering cells after they have been initiated on the path toward cancer. Green tea and green tea catechin prevention of cancer in humans has been hard to detect. We discuss that the reason for this difference is likely to be the digestive tract microbiome. If green tea catechins are to be continue to be tested for cancer prevention properties in humans it will be necessary to take into account variable digestive tract microbiome metabolism in people so the dose can be optimized for each person thus avoiding toxicity. 
  • 1.2K
  • 03 Nov 2020
Topic Review
Salvigenin
Phytochemical analysis of the Iranian plant Achillea wilhelmsii led to the isolation of 17 pure secondary metabolites belonging to the classes of sesquiterpenoids and phenolics. Two of these compounds, named wilhemsin (7) and wilhelmsolide (9), are new sesquiterpenoids, and the first shows undescribed structural features. Their structures were elucidated through extensive spectroscopic analysis, mainly based on 1D and 2D NMR, and chemical derivatization. Starting from plant traditional use and previous reports on the activity of the plant extracts, all the pure compounds were evaluated on endpoints related to the treatment of metabolic syndrome. The sesquiterpene hanphyllin (8) showed a selective cholesterol-lowering activity (−12.7% at 30 µM), santoflavone (13) stimulated glucose uptake via the GLUT transporter (+16.2% at 30 µM), while the trimethoxylated flavone salvigenin (14) showed a dual activity in decreasing lipid levels (−22.5% palmitic acid biosynthesis at 30 µM) and stimulating mitochondrial functionality (+15.4% at 30 µM). 
  • 1.2K
  • 13 Aug 2021
Topic Review
Synthesis of Heteroaromatic Hybrid Chalcones
Chalcones continue to occupy a venerated status as scaffolds for the construction of a variety of heterocyclic molecules with medicinal and industrial properties. Syntheses of hybrid chalcones featuring heteroaromatic components, especially those methods utilizing green chemistry principles, are important additions to the preparative methodologies for this valuable class of molecules. 
  • 1.2K
  • 21 Aug 2023
Topic Review
Marine Sponges of the Genus Callyspongia
In this entry, information about the common metabolites of the Callyspongia genus were grouped, as well as studies of the biological activity of these compounds. Through NMR data, 212 metabolites were identified from genus Callyspongia (15 species and Callyspongia sp.), belonging to classes such as polyacetylenes, terpenoids, steroids, alkaloids, polyketides, simple phenols, phenylpropanoids, nucleosides, cyclic peptides, and cyclic depsipep-tides. A total of 109 molecules have been reported with bioactive activity, mainly cytotoxic and antimicrobial (antibacterial and antifungal) action. 
  • 1.2K
  • 16 Dec 2021
Topic Review
Direct Synthesis of Functionalized Azahelicenes
As azahelicenes are helicenes bearing one or more nitrogen atom(s) in the molecular framework, parent azahelicenes can be functionalized on carbon atoms by exploiting the presence of the electron-withdrawing nitrogen atom. Moreover, they can be transformed into quaternary salts, whose properties are quite different from those of the parent azahelicenes in terms of the solubility and electronic properties. The synthesis of helicenes can be obtained following different strategies, namely (a) oxidative photocyclization, (b) Diels–Alder reactions, (c) Friedel–Crafts reactions, and (d) metal-mediated reactions. Strategies (a) and (d) have been mainly used to obtain the direct synthesis of functionalized azahelicenes by using appropriate starting materials, bearing functional side substituents compatible with the reaction to be performed.
  • 1.2K
  • 20 Apr 2022
Topic Review
Specific Bifunctionalization on the Phosphorus Dendrimers
Dendrimers are highly branched three-dimensional macromolecules, which properties are essentially dependent on the type of their terminal functions. Dendrimers are synthesized by iterative processes, which afford a new generation at the end of each sequence, characterized by a multiplication of the number of terminal functions. Such processes generate identical terminal functions on the surface of the dendrimers. However, it is sometimes desirable to have two types of surface functions in order to fulfil specific properties. Numerous properties have been explored already, most of them being related to catalysis, materials, or biology/nanomedicine. Strategies to get two types of terminal functions will be illustrated with polyphosphorhydrazone (PPH) dendrimers.
  • 1.2K
  • 13 Sep 2022
Topic Review
Deep Eutectic Solvents for C–H Activation
Green chemistry principles have underpinned the development of deep eutectic solvents (DESs). 
  • 1.2K
  • 28 Jun 2023
Topic Review
Secondary Metabolites of Purpureocillium lilacinum
Fungi can synthesize a wealth of secondary metabolites, which are widely used in the exploration of lead compounds of pharmaceutical or agricultural importance. Beauveria, Metarhizium, and Cordyceps are the most extensively studied fungi in which a large number of biologically active metabolites have been identified. However, relatively little attention has been paid to Purpureocillium lilacinum. P. lilacinum are soil-habituated fungi that are widely distributed in nature and are very important biocontrol fungi in agriculture, providing good biological control of plant parasitic nematodes and having a significant effect on Aphidoidea, Tetranychus cinnbarinus, and Aleyrodidae. At the same time, it produces secondary metabolites with various biological activities such as anticancer, antimicrobial, and insecticidal. 
  • 1.2K
  • 13 Jan 2022
Topic Review
Jatropha Curcas Biodiesel
J. Curcas is a small and medium sized fern tree, rising to around 5–7 m tall, belonging to the Euphorbiaceae genus, consisting of approximately 800 species, around 321 genera. Jatropha is an herb immune to famine, with a lifespan of around fifty years. It is also called physic nut and Ratanjayot. J. Curcas will generate 2000 L/ha of oil annually. JCL oil is transesterified primarily into (m)ethyl esters (biofuels) and glycerol. One of the greatest challenges of the 21st century is to fulfill the growing energy needs sustainably and cost-effectively. Among the different sources of energy, biodiesel is one of the alternative energy sources that has tremendous potential to become a major mainstream renewable energy mix. Jatropha is an important raw input for biodiesel that provides an ecological and sustainable solution for emerging greenhouse gas emissions over the other biomass feedstock. 
  • 1.2K
  • 09 Jul 2021
Topic Review
6-Formylindolo(3,2-b)carbazole
6-Formylindolo[3,2-b]carbazole (FICZ) is a chemical compound with the molecular formula C19H12N2O. It is a nitrogen heterocycle, having an extremely high affinity (Kd = 7 x 10−11M) for binding to the aryl hydrocarbon receptor (AHR). It was originally identified as a photooxidized derivative of the amino acid tryptophan and suggested to be the endogenous ligand of the AHR. Later, also enzymatic formation of FICZ was shown.
  • 1.2K
  • 16 Nov 2022
Topic Review
Heteroelement Analogues of Benzoxaborole
Heteroelement analogues of benzoxaboroles constitute an interesting class of boracyclic compounds and may offer the opportunity for various applications while retaining high stability arising from the presence of a strong B-O bond in the ring structure. The replacement of a carbon atom in the boracycle or an adjacent benzene ring with a heteroatom may result in a significant change of structural behaviour. Moreover,  physicochemical properties, including solubility, lipophilicity, hydrolytic stability, boron Lewis acidity, and others, can be modified. The aim of this review is to highlight several emerging groups of boracyclic systems which comprise various heteroelement atoms such as another boron, silicon, tin, nitrogen, phosphorus, and iodine. The information on synthesis and properties of such systems is complemented by presentation of their practical potential encompassing especially organic synthesis and catalysis as as medicinal chemistry. 
  • 1.2K
  • 22 Sep 2021
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