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Topic Review
Stereoselective Promiscuous Reactions Catalyzed by Lipases
The ability of lipases to display activity beyond their physiological reactions, so-called “catalytic promiscuity”, has gained increasing interest in the last two decades as an important tool for expanding the application of these enzymes in organic synthesis. Some lipases have been shown to be effective in catalyzing a variety of C-C bond formation reactions and most of the investigations have been directed to the optimization of the products yield through a careful tuning of the experimental parameters. Despite the fact that new stereogenic carbons are formed in many of the tested reactions, the target products have been often obtained in racemic form and examples of an efficient asymmetric induction by the used lipases are quite limited.
  • 1.2K
  • 25 Mar 2022
Topic Review
Technical Features of Polysaccharide-Based Hydrogels in Drug Delivery
Hydrogels are a form of highly hydrophilic biomaterials with three-dimensional architecture that can retain a significant amount of water and swell without disintegrating. Hydrogels can be either synthetic, natural, or hybrid forms. Natural polymer hydrogels are those derived from naturally sourced polymers, including polysaccharides, polynucleotides, and proteins. Neutral, cationic, and anionic categories describe the chemical properties of natural sources of polymers. These polymers are easily accessible, ubiquitous, affordable, non-toxic, renewable, and have other appealing biological features.
  • 1.2K
  • 22 Dec 2022
Topic Review
Chikungunya Virus
Arboviruses, in general, are a global threat due to their morbidity and mortality, which results in an important social and economic impact. Chikungunya virus (CHIKV), one of the most relevant arbovirus currently known, is a re-emergent virus that causes a disease named chikungunya fever, characterized by a severe arthralgia (joint pains) that can persist for several months or years in some individuals. Until now, no vaccine or specific antiviral drug is commercially available. Nitrogen heterocyclic scaffolds are found in medications, such as aristeromycin, favipiravir, fluorouracil, 6-azauridine, thioguanine, pyrimethamine, among others. New families of natural and synthetic nitrogen analogous compounds are reported to have significant anti-CHIKV effects. In the present work, we focus on these nitrogen-based heterocyclic compounds as an important class with CHIKV antiviral activity.
  • 1.2K
  • 16 Jan 2021
Topic Review
Xanthones, A Promising Anti-Inflammatory Scaffold
Inflammation is the body’s self-protective response to multiple stimulus, from external harmful substances to internal danger signals released after trauma or cell dysfunction. Many diseases are considered to be related to inflammation, such as cancer, metabolic disorders, aging, and neurodegenerative diseases.  Xanthones, a unique scaffold with a 9H-Xanthen-9-one core structure, widely exist in natural sources. Till now, over 250 xanthones were isolated and identified in plants from the families Gentianaceae and Hypericaceae. Many xanthones have been disclosed with anti-inflammatory properties on different models, either in vitro or in vivo.
  • 1.2K
  • 17 Nov 2021
Topic Review
Electrical Mode Gas Sensing
Among small organic molecules, perylene diimides (PDIs) are an important class of materials due to their outstanding thermal, chemical, electronic, and optical properties, all of which make them promising candidates for a wide range of organic electronic devices including sensors, organic solar cells, organic field-effect transistors, and organic light-emitting diodes. This is mainly due to their electron-withdrawing nature and significant charge transfer properties. Perylene-based sensors of this type show high sensing performance towards various analytes, particularly reducing gases like ammonia and hydrazine, but there are several issues that need to be addressed including the selectivity towards a specific gas, the effect of relative humidity, and operating temperature.
  • 1.2K
  • 19 Feb 2021
Topic Review
Deconstructive and Divergent Synthesis of Bioactive Natural Products
Deconstructive synthesis, namely building new, challenging structures through bond cleavage of easily accessible moieties, has emerged as a useful design principle in synthesizing bioactive natural products. Divergent synthesis, namely synthesizing many natural products from a common intermediate, can improve the efficiency of chemical synthesis and generate libraries of molecules with unprecedented structural diversity.
  • 1.2K
  • 29 Aug 2023
Topic Review
Encapsulation of Dyes in Luminescent Metal-Organic Frameworks
White light emitting diodes (WLEDs), as solid-state lighting sources, have attracted increasing attention in the past decades owing to their potential applications in displays and lighting. WLEDs are energy saving and environmentally friendly, and have higher luminous efficiency than conventional incandescent and fluorescent lamps. Moreover, WLEDs emit polychromatic light rather than monochromatic light that was emitted by traditional light emitting diodes (LEDs).
  • 1.2K
  • 29 Oct 2021
Topic Review
Proteolysis-Targeting Chimeras
The ubiquitin–proteasome system (UPS) is an essential part of the cellular machinery responsible for maintaining intracellular protein homeostasis. A network of proteins that comprises the proteolytic system and chaperones calculates cellular protein homeostasis. Chaperones are in charge of correcting protein misfolding, but the proteolytic system, which converges on the 26S proteasome, is in charge of removing damaged or unfolded proteins to maintain a healthy environment inside the cell. Using proteolysis-targeting chimera (PROTAC) technology for targeted protein degradation, a novel technique of treatment is emerging that stems from an aberrant expression of a protein that causes disease. PROTAC molecules are tiny, bifunctional molecules that bind an E3-ubiquitin ligase and a target protein at the same time, causing ubiquitination and proteasome destruction of the target protein.
  • 1.1K
  • 22 May 2023
Topic Review Peer Reviewed
Cycloadditions and Cyclization Reactions via Post-Synthetic Modification and/or One-Pot Methodologies for the Stabilization of Imine-Based Covalent Organic Frameworks
Interest in covalent organic frameworks as high-value materials has grown steadily since their development in the 2000s. However, the great advantage that allows us to obtain these crystalline materials—the reversibility of the bonds that form the network—supposes a drawback in terms of thermal and chemical stability. Among the different strategies employed for the stabilization of imine-based Covalent Organic Frameworks (COFs), cycloaddition and other related cyclization reactions are especially significant to obtain highly stable networks with extended π-delocalization and new functionalities, expanding even further the potential application of these materials. Therefore, this entry gathered the most recent research strategies for obtaining stable COFs by means of cyclization reactions, including the Povarov reaction and intramolecular oxidative cyclization reactions as well as some other recent innovative approaches.
  • 1.1K
  • 26 Jun 2023
Topic Review
Flexible Electrochromic Materials
The application potential of flexible electrochromic materials for wearable devices, smart textiles, flexible displays, electronic paper, and implantable biomedical devices is enormous. These materials offer the advantages of conformability and mechanical robustness, making them highly desirable for these applications.
  • 1.1K
  • 07 Jul 2023
Topic Review
The Pioneers of Carotenoid Chemistry: László Zechmeister
László Zechmeister, one of the most important pioneers of carotenoid chemistry, died 50 years ago. He founded a carotenoid research group in Pécs (Hungary), which is the only place in the world where carotenoid research has been conducted continuously over the past 95 years.
  • 1.1K
  • 24 Apr 2022
Topic Review
The Lewis Acid System
Cycloketones can be oxidized to lactones using molecular oxygen, peroxy acids, or hydrogen peroxide as an oxidant. Hydrogen peroxide is one of the environmental oxidants. Because of the weak oxidation ability of hydrogen peroxide, Bronsted acids and Lewis acids are used as catalysts to activate hydrogen peroxide or the carbonyl of ketones to increase the nucleophilic performance of hydrogen peroxide. The catalytic mechanisms of Bronsted acids and Lewis acids differ in the Baeyer–Villiger oxidation of cyclohexanone with an aqueous solution of hydrogen peroxide as an oxidant.
  • 1.1K
  • 02 Feb 2023
Topic Review
Extremophilic Fungi from Marine Environments
Marine environments are underexplored terrains containing fungi that produce a diversity of natural products given unique environmental pressures and nutrients. While bacteria are commonly the most studied microorganism for natural products in the marine world, marine fungi are also abundant but remain an untapped source of bioactive metabolites. Given that their terrestrial counterparts have been a source of many blockbuster antitumor agents and anti-infectives, including camptothecin, the penicillins, and cyclosporin A, marine fungi also have the potential to produce new chemical scaffolds as leads to potential drugs. Fungi are more phylogenetically diverse than bacteria and have larger genomes that contain many silent biosynthetic gene clusters involved in making bioactive compounds. However, less than 5% of all known fungi have been cultivated under standard laboratory conditions. While the number of reported natural products from marine fungi is steadily increasing, their number is still significantly lower compared to those reported from their bacterial counterparts.
  • 1.1K
  • 29 Mar 2022
Topic Review
Phytocannabinoids, Endocannabinoids and Synthetic Cannabinoids
Generally, the term ‘cannabinoids’ refers to a heterogeneous family of compounds that exhibit activity upon particular human cannabinoid receptors, namely CB1 and CB2. They encompass the natural compounds present in the Cannabis plants, lipid mediators called ECs naturally produced by human cells, as well as by all vertebrates on planet Earth, and the synthetic analogs of both groups designed by scientist, called SCs.
  • 1.1K
  • 01 Sep 2023
Topic Review
AIE Material Design Strategy Based on Functional Groups
The common fluorescent conjugated materials present weak or quenching luminescent phenomena in the solid or aggregate state (ACQ), which limits their applications in medicine and biology. Certain materials, named aggregation-induced emission (AIE) fluorescent materials, have exhibited strong luminescent properties in the aggregate state, which can overcome the ACQ phenomenon. Due to their intrinsic properties, the AIE materials have been successfully used in biolabeling, where they can not only detect the species of ions and their concentrations in organisms, but can also monitor the organisms’ physiological activity. In addition, these kinds of materials often present non-biological toxicity. Thus, AIE materials have become some of the most popular biofluorescent probe materials and are attracting more and more attention. 
  • 1.1K
  • 08 Feb 2023
Topic Review
Triacontanol
1-Triacontanol is a fatty alcohol of the general formula C30H62O, also known as melissyl alcohol or myricyl alcohol. It is found in plant cuticle waxes and in beeswax. Triacontanol is a growth stimulant for many plants, most notably roses, in which it rapidly increases the number of basal breaks. 1-Triacontanol or n-triacontanol is a natural plant growth regulator. It has been widely used to enhance the yield of various crops around the world, mainly in Asia. . Triacontanol has been reported to increase the growth of plants by enhancing the rates of photosynthesis, protein biosynthesis, the transport of nutrients in a plant and enzyme activity, reducing complex carbohydrates among many other purposes. The fatty alcohol appears to increase the physiological efficiency of plant cells and boost the potential of the cells responsible for the growth and maturity of a plant.
  • 1.1K
  • 21 Nov 2022
Topic Review
Sweet Boron
Boron neutron capture therapy (BNCT) is a binary type of radiotherapy for the treatment of cancer. Due to recent developments of neutron accelerators and their installation in some hospitals, BNCT is on the rise worldwide and is expected to have a significant impact on patient treatments. Therefore, there is an increasing need for improved boron delivery agents. 
  • 1.1K
  • 03 Mar 2022
Topic Review
C-C and C-Heteroatom Bonds Construction
Acyl-containing organic compounds, including ketones, esters, amides, and so forth, are a huge library of widespread chemical feedstocks which play a vital role in countless fields such as pharmaceuticals, natural products, advanced materials, and fine chemicals.
  • 1.1K
  • 28 Dec 2022
Topic Review
(−)-Methyl-Oleocanthal, a New Oleocanthal Metabolite
The antioxidant and anti-inflammatory responses of (−)-methyl-oleocanthal (met-OLE), a new metabolite of the extra virgin olive oil (EVOO) phenolic oleocanthal (OLE), were explored in lipopolysaccharide (LPS)-induced murine peritoneal macrophages. Possible signaling pathways and epigenetic modulation of histones were studied. Met-OLE inhibited LPS-induced intracellular reactive oxygen species (ROS) and nitrite (NO) production and decreased the overexpression of the pro-inflammatory enzymes COX-2, mPGES-1 and iNOS in murine macrophages.
  • 1.1K
  • 13 Jan 2022
Topic Review
Meso-Formylporphyrins
Insertion of the formyl group into porphyrins is a primary functionalization of the tetrapyrrole ring, opening opportunities for further transformations including, but not limited to, Wittig, Grignard, McMurry, cycloaddition, Knoevenagel reactions, and Schiff bases preparation.
  • 1.1K
  • 23 Aug 2023
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