•Polysaccharide- and Cinchona alkaloid-based chiral stationary phases are studied.•ß-carboline, tetrahydroisoquinoline, and benzazepine analogues were enantioseparated.•Stereoselective retention and ...separation characteristics in HPLC and SFC are discussed.•Effects of structural peculiarities of the studied analytes are revealed.
High-performance liquid chromatographic (HPLC) and subcritical fluid chromatographic (SFC) separations of the enantiomers of structurally diverse, basic ß-carboline, tetrahydroisoquinoline and benzazepine analogues of pharmacological interest were performed applying chiral stationary phases (CSPs) based on (i) neutral polysaccharides- and (ii) zwitterionic sulfonic acid derivatives of Cinchona alkaloids. The aim of this work was to reveal the influence of structural peculiarities on the enantiorecognition on both types of CSP through the investigation of the effects of the composition of the bulk solvent, the structures of the chiral analytes (SAs) and chiral selectors (SOs) on retention and stereoselectivity. As a general tendency, valid for all polysaccharide SOs studied, the increase of the concentration of the apolar component in the mobile phase (n-hexane for LC or liquid CO2 for SFC) was found to significantly increase retention, which in most cases, was accompanied with increased selectivity and resolution. In a way, similar behaviour was registered for the zwitterionic SOs. In polar ionic mode employing eluent systems composed of methanol and acetonitrile with organic acid and base additives, moderate increases in retention factor, selectivity and resolution were observed with increasing acetonitrile content. However, under SFC conditions, an extremely high increase in retention was observed with increased CO2 content, while selectivity and resolution changed only slightly. Thermodynamic parameters derived from temperature dependence studies revealed that separations are controlled by enthalpy.
We report the anion Al(NONAr)(Se)− (NONAr=O(SiMe2NAr)22−, Ar=2,6‐iPr2C6H3), which is an isoelectronic Group 13 metal analogue of the carbonyl group containing an aluminium–selenium multiple bond. It ...was synthesized in a single step from the reaction of the aluminyl anion Al(NONAr)− with elemental selenium. Spectroscopic, crystallographic, and computational analysis confirmed multiple bonding between aluminium and selenium. Addition of a second equivalent of selenium afforded the diselenirane, Al(NONAr)(κ2‐Se2)−, which is an isoelectronic analogue of the dioxirane group.
He ain't heavy, he's my brother: A two‐coordinate aluminyl anion reacts sequentially with elemental selenium to generate isoelectronic analogues of organic functional groups, namely carbonyl and dioxirane moieties. Spectroscopic, crystallographic, and computational analysis confirmed the presence of multiple bonding between aluminium and selenium in the carbonyl analogue.
This is the second of two invited articles reviewing the development of nucleoside analogue antiviral drugs, written for a target audience of virologists and other non-chemists, as well as chemists ...who may not be familiar with the field. As with the first paper, rather than providing a chronological account, we have chosen to examine particular examples of structural modifications made to nucleoside analogues that have proven fruitful as various antiviral, anticancer, and other therapeutics. The first review covered the more common, and in most cases, single modifications to the sugar and base moieties of the nucleoside scaffold. This paper focuses on more recent developments, especially nucleoside analogues that contain more than one modification to the nucleoside scaffold. We hope that these two articles will provide an informative historical perspective of some of the successfully designed analogues, as well as many candidate compounds that encountered obstacles.
•This is the second of two invited articles reviewing the development of nucleoside analogue antiviral drugs.•It is written for a target audience of virologists and other non-chemists, and for chemists unfamiliar with the field.•Numerous modifications have been made to the nucleoside scaffold in order to impart therapeutic benefits.•Current nucleoside analogues employ a combination approach, using multiple modifications to the scaffold.•We examine thought processes, progress in synthetic chemistry and results of antiviral testing that led to approved drugs.
The demand for plant proteins continues to increase due to the growing global population, rising protein deficiency, and their versatile environmental, functional, nutritional, and health benefits. ...Plant proteins represent a more sustainable source to (partially) supplement costly animal-based foods. Many factors can influence protein functionality and application, such as protein sources, production methods, molecular structures, chemical properties, food formulations and environment, and food processing techniques. The potential applications of plant proteins are diverse. This reprint covers diverse topics related to the characterization, chemistry, interaction, processing, modification, functionality, and/or application of various plant proteins in relation to human food.
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•This convergent strategy could allow the obtaining of various derived analogues efficiently.•N-Alkylation allows the formation of analogues with secondary amines under mild ...conditions.•We have developed an efficient synthesis of six novel vitamin D3 analogues.
Six novel vitamin D analogues bearing an aniline moiety in their side chains were designed and synthesized using a convergent route. The CD ring fragments were prepared from Inhoffen-Lythgoe diol in five- or six-steps with high yields. Secondary amines were obtained via a one-pot, two-step transformation with excellent yields.
Aim
To investigate the effects of semaglutide on fasting and postprandial glucose and lipid responses, and on gastric emptying.
Materials and methods
This was a randomized, double‐blind, ...placebo‐controlled, 2‐period, crossover trial. Subjects with obesity (N = 30) received once‐weekly subcutaneous semaglutide, dose‐escalated to 1.0 mg, or placebo. After each 12‐week treatment period, glucose and lipid metabolism were assessed before and after standardized meals. Gastric emptying (paracetamol absorption test) and peptide YY (PYY) response were also assessed.
Results
Semaglutide treatment significantly lowered fasting concentrations of glucose and glucagon, and increased insulin vs placebo (estimated treatment ratio: 0.95 95% confidence interval: 0.91, 0.98; 0.86 0.75, 0.98; 1.45 1.20, 1.75, respectively). Postprandial glucose metabolism significantly improved with semaglutide vs placebo (incremental area under the curve 0 to 5 hours iAUC0‐5h; estimated treatment difference: glucose −1.34 mmol h/L −2.42, −0.27; insulin −921 pmol h/L −1461, −381; C‐peptide −1.42 nmol h/L −2.33, −0.51). Fasting and postprandial lipid metabolism improved with semaglutide vs placebo. First‐hour gastric emptying after the meal was delayed with semaglutide vs placebo (AUC0‐1h; estimated treatment ratio: 0.73 0.61, 0.87); this may have contributed to the lower postprandial glucose increase in semaglutide‐treated subjects. Overall gastric emptying (AUC0‐5h) was not statistically different between treatments. Fasting and postprandial PYY responses were significantly lower with semaglutide vs placebo (P = .0397 and P = .0097, respectively).
Conclusion
Semaglutide improved fasting and postprandial glucose and lipid metabolism. Overall gastric emptying was similar to that with placebo; however, the observed first‐hour delay with semaglutide may contribute to a slower entry of glucose into the circulation.
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•This work systematically summarizes the application of PBA-based materials used in aqueous batteries.•This review provides significant comprehension for construction and optimization ...of high-performance PBAs-based materials.•The future research directions of PBA-based materials in aqueous batteries are prospected.
Prussian blue analogues (PBAs) have been considered as one of the most promising candidates of aqueous batteries owing to their advantages such as large pore size, high safety, low solubility equilibrium constant, and adjustable output voltage. However, controllable synthesis of high-performance PBAs for aqueous batteries remains a challenging task due to the presence of unavoidable crystal defects, coordinated water, metal ion dissolution, and a stable window of limited aqueous solution. To address these challenges and achieve practical applications, significant efforts made and some key progress have been made. The structure and electrochemical behavior of PBA, such as electronic transfer, ion transport, ion diffusion, and material phase transitions, are extensively discussed. In addition, on the basis of a comprehensive introduction to the many challenges faced by the use of PBAs in aqueous batteries, we systematically summarized the synthesis routes of PBAs and modification strategies, such as acid/base chemical etching, inorganic/organic compound, transition metal doping. Finally, an insight into the future research directions and further development prospects of PBAs-based materials are proposed so as to facilitate the extensive application in the filelds of aqueous batteries. This review provides significant comprehension for construction and optimization of high-performance PBAs-based materials used in aqueous batteries.
Limited medication adherence and persistence with treatment are barriers to successful management of type 2 diabetes (T2D). We searched MEDLINE, EMBASE, the Cochrane Library, the Register of ...Controlled Trials, PsychINFO and CINAHL for observational and interventional studies that compared the adherence or persistence associated with 2 or more glucose‐lowering medications in people with T2D. Where 5 or more studies provided the same comparison, a random‐effects meta‐analysis was performed, reporting mean difference (MD) or odds ratio (OR) for adherence or persistence, depending on the pooled study outcomes. We included a total of 48 studies. Compared with metformin, adherence (%) was better for sulphonylureas (5 studies; MD 10.6%, 95% confidence interval CI 6.5‐14.7) and thiazolidinediones (TZDs; 6 studies; MD 11.3%, 95% CI 2.7%‐20.0%). Adherence to TZDs was marginally better than adherence to sulphonylureas (5 studies; MD 1.5%, 95% CI 0.1‐2.9). Dipeptidyl peptidase‐4 inhibitors had better adherence than sulphonylureas and TZDs. Glucagon‐like peptide‐1 receptor agonists had higher rates of discontinuation than long‐acting analogue insulins (6 studies; OR 1.95; 95% CI 1.17‐3.27). Long‐acting insulin analogues had better persistence than human insulins (5 studies; MD 43.1 days; 95% CI 22.0‐64.2). The methods used to define adherence and persistence were highly variable.
Graphene’s success has shown not only that it is possible to create stable, single-atom-thick sheets from a crystalline solid but that these materials have fundamentally different properties than the ...parent material. We have synthesized for the first time, millimeter-scale crystals of a hydrogen-terminated germanium multilayered graphane analogue (germanane, GeH) from the topochemical deintercalation of CaGe2. This layered van der Waals solid is analogous to multilayered graphane (CH). The surface layer of GeH only slowly oxidizes in air over the span of 5 months, while the underlying layers are resilient to oxidation based on X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy measurements. The GeH is thermally stable up to 75 °C; however, above this temperature amorphization and dehydrogenation begin to occur. These sheets can be mechanically exfoliated as single and few layers onto SiO2/Si surfaces. This material represents a new class of covalently terminated graphane analogues and has great potential for a wide range of optoelectronic and sensing applications, especially since theory predicts a direct band gap of 1.53 eV and an electron mobility ca. five times higher than that of bulk Ge.
The rapid increase in antibiotic-resistant bacteria has emphasized the urgent need to identify new treatments for bacterial infections. One attractive approach, reducing the need for expensive and ...time-consuming clinical trials, is to repurpose existing clinically approved compounds for use as antibacterial agents. Nucleoside analogues are commonly used for treating viral and fungal infections, as well as for treating cancers, but have received relatively little attention as treatments for bacterial infections. However, a significant number of clinically approved derivatives of both pyrimidines and purines including halogenated, thiolated, and azolated compounds have been shown to have antibacterial activity. In the small number of studies carried out to date, such compounds have shown promise in treating bacterial infections. Here, we review the mechanisms of action and antibacterial activities of nucleoside analogues that can potentially be repurposed for treating infections as well as considering possible limitations in their usage.
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