An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
... Annulations that combine diacceptors with bis-nucleophiles are uncommon. Here, we report the synthesis of 1,4-dioxanes from 3-aryloxetan-3-ols, as 1,2-bis-electrophiles and 1,2-diols. Brønsted acid Tf₂NH catalyzes both the selective activation of the oxetanol, to form an oxetane carbocation that reacts with the diol, and intramolecular ring opening of the oxetane. High regio- and diastereoselectiv ...
... Contact lenses (CLs) offer a wide variety of advantages as ocular drug-releasing platforms, but the feasibility of medicated CL development is constrained by numerous scientific, technological, and regulatory challenges. One main difficulty is the setting of release rate specifications for each drug, since at present there are no standardized in vitro release models that can appropriately predict ...
... Nowadays, it is a challenge to achieve the controlled directional release of multi-layered dosage forms due to the difficulty of flexible and controllable regulation of the layered structure. Herein, we utilized layer-multiplying co-extrusion (LMCE) technology to construct poly(ε-caprolactone) (PCL)/polyethylene oxide (PEO)/ metoprolol tartrate (MPT) composites with controlled multi-layered struct ...
... An iridium-catalyzed, reductive alkylation of abundant tertiary lactams and amides using 1–2 mol % of Vaska’s complex (IrCl(CO)(PPh₃)₂), tetramethyldisiloxane (TMDS), and difluoro-Reformatsky reagents (BrZnCF₂R) for the general synthesis of medicinally relevant α-difluoroalkylated tertiary amines is described. A broad scope (46 examples), including N-aryl- and N-heteroaryl-substituted lactams, dem ...
... An efficient Ni-catalyzed hydrodifluoroalkylation of unactivated alkenes with bromodifluoroacetate by using PhSiH₃ as hydride source was developed. The transformation affords aliphatic difluorides with anti-Markovnikov regioselectivity. A wide range of highly remote alkenes, simple alkenes, drug molecules, commercially available CF₂ precursors, and even nonfluorinated substrates are competent in t ...
... β²-Amino carbonyls, an α-substituted β-amino scaffold, hold a prominent place in the development of new pharmaceuticals and peptidomimetics. Herein, we report a highly efficient Rh-catalyzed ring-opening amidation of substituted cyclopropanols, which turned out to serve as a linchpin for the selective synthesis of β²-amino ketones to outcompete the formation of β³-isomers. Instead of the generally ...
... Engineered bacteria and yeasts have progressively emerged in the past decade as convenient cell factories for supplying plant and fungal natural products (NPs). A new study by Reimer et al. provides compelling evidence that the amoeba Dictyostelium discoideum could be also engineered in favor of the production of plant drug precursors. ...
... The use of flow methodology allows the use of alkynylphenyl vinyl ethers (benzo-fused 1,7 enynes) as substrates for the intramolecular Pauson–Khand reaction (PKr). Forced temperature and pressure conditions during a short reaction time minimize the substrate decomposition allowing the formation of the PK adduct. Substrates substituted at the internal position of the double bond and with internal t ...
... The synthesized 3,3-di(indolyl)indolin-2-ones 1a-p showed desired higher α-glucosidase inhibitory activities and lower α-amylase inhibitory activities than standard drug acarbose. Particularly, compound 1i showed favorable higher α-glucosidase % inhibition of 67 ± 13 and lower α-amylase % inhibition of 51 ± 4 in comparison to acarbose with % inhibition activities of 19 ± 5 and 90 ± 2, respectively ...
... A general method for the synthesis of a series of previously unknown N-(heteroaryl)- and N-(aryl)aminotetrazoles through the tandem electrocyclization/hydrolysis of azidohydrazones was accomplished. The described protocol was suitable for a wide array of the target N-substituted aminotetrazoles which were prepared in good to high yields under smooth reaction conditions. Importantly, the presented ...
... The coronavirus disease 2019 (COVID-19) has outbreak since early December 2019, and COVID-19 has caused over 100 million cases and 2 million deaths around the world. After one year of the COVID-19 outbreak, there is no certain and approve medicine against it. Drug repositioning has become one line of scientific research that is being pursued to develop an effective drug. However, due to the lack o ...
drugs, etc ; glycosides; stereoselectivity; stereospecificity; therapeutics; Show all 5 Subjects
Abstract:
... S-Glycosides have broad biological activities and serve as stable mimics of natural O-glycoside counterparts and thus are of great therapeutic potential. Herein we disclose an efficient method for the stereospecific synthesis of 1-thioglycosides via a boron-promoted reductive deoxygenation coupling reaction from readily accessible sulfonyl chlorides and glycosyl bromides. Our protocol features mil ...
drugs, etc ; arginine; biotechnology; crystallization; phenylalanine; Show all 5 Subjects
Abstract:
... BACKGROUND: Enantiomerically pure compounds occupy an important position in industrial production of pharmaceuticals, food, chemical engineering, etc. The separation of d and l molecules is an important and challenging task. The ‘tailor‐made’ additive method is a simple and efficient crystallization separation technology. However, according to reports, there is a poor crystal yield when obtaining ...
drugs, etc ; adsorption; cytotoxicity; phosphatidylcholines; silica; Show all 5 Subjects
Abstract:
... The interaction of amorphous silica nanoparticles with phospholipid monolayers and bilayers has received a great deal of interest in recent years and is of importance for assessing potential cellular toxicity of such species, whether natural or synthesized for the purpose of nanomedical drug delivery and other applications. This present communication studies the rate of silica nanoparticle adsorpt ...
drugs, etc ; nanodiamonds; transmission electron microscopy; Show all 3 Subjects
Abstract:
... Detonation nanodiamonds have found numerous potential applications in a diverse array of fields such as biomedical imaging and drug delivery. Here, we systematically characterized non-functionalized and polyglycerol-functionalized detonation nanodiamond particles (DNPs) dispersed in aqueous suspensions at different ionic strengths (∼1.0 × 10–⁷ to 1.0 × 10–² M) via dynamic light scattering and cryo ...
... Target specific drug design has attracted much attention in drug discovery. But, it is a great challenge to efficiently explore the target-focused chemical space. Fragment-based drug design (FBDD) has shown its potential to do this thing. In this study, we introduced a deep learning-based fragment linking method, namely SyntaLinker-Hybrid, for target specific molecular generation. By carrying out ...
drugs, etc ; crosslinking; polymers; polyphenols; tannins; Show all 5 Subjects
Abstract:
... With the thriving of mussel-inspired polyphenol chemistry as well as the demand for low-cost analogues to polydopamine in adhesive design, tannic acid has gradually become a research focus because of its wide availability, health benefits and special chemical properties. As a natural building block, tannic acid could be used as a crosslinker either supramolecularly or chemically, ensuring versatil ...
drugs, etc ; organic chemistry; regioselectivity; sulfur; thioamides; Show all 5 Subjects
Abstract:
... An efficient Cp*Rh(III)-catalyzed regioselective C(sp²)–H mono- and dialkynylation of thioamides was described. This reaction was performed under mild conditions in high yields (up to 98%) with a broad substrate scope. Significantly, the versatility of this method was further demonstrated by controlled mono- and dialkynylation. Application of this protocol in the late stage functionalization of tw ...
drugs, etc ; green chemistry; objectives; research; scientists; Show all 5 Subjects
Abstract:
... Any improvement activity requires the means to assess progress towards the intended goal. Herein, we report how the use of simple metrics has supported the adoption of a more sustainable approach to drug substance processing across AstraZeneca. We describe our journey to this point and highlight some of the key factors behind this culture shift. ...
drugs, etc ; carboxylic ester hydrolases; emulsions; encapsulation; Show all 4 Subjects
Abstract:
... Water-in-oil (W/O) emulsions have numerous applications in many industries like foods, pharmaceuticals, in particular biphasic bio-catalysis. However, most of them are stabilized by surfactants or synthetic particles, which lead to limited uses in foods. Here, a W/O type Pickering emulsion was successfully prepared firstly by ordered ethyl cellulose-chitosan complex particles (ECCPs) and used for ...