Many locks to one key: N-acetylneuraminic acid binding to proteins.

Sialic acids play crucial roles in cell surface glycans of both eukaryotic and prokaryotic organisms, mediating various biological processes, including cell-cell interactions, development, immune response, oncogenesis and host-pathogen interactions. This review focuses on the ß-anomeric form of N-acetylneuraminic acid (Neu5Ac), particularly its binding affinity towards various proteins, as elucidated by solved protein structures. Specifically, we delve into the binding mechanisms of Neu5Ac to proteins involved in sequestering and transporting Neu5Ac in Gram-negative bacteria, with implications for drug design targeting these proteins as antimicrobial agents. Unlike the initial assumptions, structural analyses revealed significant variability in the Neu5Ac binding pockets among proteins, indicating diverse evolutionary origins and binding modes. By comparing these findings with existing structures from other systems, we can effectively highlight the intricate relationship between protein structure and Neu5Ac recognition, emphasizing the need for tailored drug design strategies to inhibit Neu5Ac-binding proteins across bacterial species.

Direct White-Light Emitting From a Single Metal-Organic Framework with Dual Phosphorescence Peaks.

Single component white-light-emitting (SCWLE) materials are extremely desired in the field of solid-state lighting. However, pure-phosphorescent SCWLE has rarely been reported. Herein, one halogen-bonding-containing MOF [Cd(5-BIPA)(phen)] (1) has been synthesized, which shows efficient white-light emission originating from dual phosphorescence bands with different wavelengths and lifetimes. The fabrication of a phosphor-converted white-light-emitting diode device driven by pulsing current enables this MOF to be a promising phosphor.

Facile and stereospecific synthesis of diverse ß-N-glycosyl sulfonamide scaffolds via palladium catalysis.

Glycosylation is an important strategy to improve the druggability of lead compounds. Here, we present a palladium-catalysed stereospecific N-glycosylation of sulfonamides. This approach stands out with wide substrate scope, high functional group tolerance, and easy scalability, furnishing a broad spectrum of densely functionalized ß-N-glycosyl sulfonamides with good efficiency and exceptional regio-/stereoselectivity. Diverse drug-like glycosulfonamido scaffolds have been constructed via a late-stage diversification strategy and various facile synthetic transformations of the products. Collectively, the established protocol provides a valuable tool for efficiently preparing glycosyl sulfonamides to facilitate drug discovery.

Microbiota and mycobiota in bronchoalveolar lavage fluid of silicosis patients.

BACKGROUND: The contribution of bronchoalveolar lavage fluid (BALF) microbiota and mycobiota to silicosis has recently been noticed. However, many confounding factors can influence the accuracy of BALF microbiota and mycobiota studies, resulting in inconsistencies in the published results. In this cross-sectional study, we systematically investigated the effects of "sampling in different rounds of BALF" on its microbiota and mycobiota. We further explored the relationship between silicosis fatigue and the microbiota and mycobiota. METHODS: After obtaining approval from the ethics board, we collected 100 BALF samples from 10 patients with silicosis. Demographic data, clinical information, and blood test results were also collected from each patient. The characteristics of the microbiota and mycobiota were defined using next-generation sequencing. However, no non-silicosis referent group was examined, which was a major limitation of this study. RESULTS: Our analysis indicated that subsampling from different rounds of BALF did not affect the alpha- and beta-diversities of microbial and fungal communities when the centrifuged BALF sediment was sufficient for DNA extraction. In contrast, fatigue status significantly influenced the beta-diversity of microbes and fungi (Principal Coordinates Analysis, P = 0.001; P = 0.002). The abundance of Vibrio alone could distinguish silicosis patients with fatigue from those without fatigue (area under the curve = 0.938, 95% confidence interval [CI] 0.870-1.000). Significant correlations were found between Vibrio and haemoglobin levels (P < 0.001, ρ = -0.64). CONCLUSIONS: Sampling in different rounds of BALF showed minimal effect on BALF microbial and fungal diversities; the first round of BALF collection was recommended for microbial and fungal analyses for convenience. In addition, Vibrio may be a potential biomarker for silicosis fatigue screening.

Stereospecific Palladium-Catalyzed Direct Glycosylation of Oximes: Access to N-O-Linked Glycosides.

A highly efficient, palladium-catalyzed glycosylation between 3,4-O-carbonate glycals and acid-labile oximes is disclosed. This approach features broad substrate scope, high functional group tolerance, and easy scalability, delivering glycosyl oximes in excellent yields with exclusive ß-selectivity and retention of Z/E geometries. The power of this method is demonstrated by a set of site-selective transformations of glycosylation products and late-stage glycodiversification of bioactive molecules. Overall, our strategy provides an efficient toolkit for facile access to valuable N-O-linked glycosides.

A New Dual-peak Fluorescent Probe for Water Content Detection Made From Taxus.

In this paper, the leaves of Taxus were used as the sole carbon source, and two kinds of carbon dots blue and red, with different properties, were synthesized by the hydrothermal method under different conditions. The red carbon dots were quenched in the water, and the blue carbon dots had stable fluorescence properties in water environment. The bimodal fluorescence probe formed by mixing could accurately and stably measure the water content in ethanol, which was in the range of 82.5%-100%, is highly correlated with the fluorescence intensity ratio (I481/I678) of mixed carbon dots under 390 nm excitation light, with R2 = 0.995 and the detection limit as low as 0.31%. The experimental materials are environmentally friendly, low in cost, and simple to operate, as well as the water content measured by proportional fluorescence has high accuracy, which provides a new method for measuring moisture in ethanol.