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Introduction: Natural products, the small organic molecules produced by plants, microbes and invertebrates, often present in the form of a mixture, this leads to the structural characterisation of natural extracts often requiring time‐consuming multistep purification procedures. Nuclear magnetic resonance (NMR) technology is traditionally utilised as a tool for the structural elucidation of pure compounds. Contemporarily, an up‐to‐date trend in the application of NMR in natural product research is shifting to the direct NMR analysis of crude mixtures, to obtain molecular structure and biological activity information without performing cumbersome separation. Objective: To review works of literature on the evolution, principle and progress of NMR technologies for analysing mixtures, we focus on the successful application of NMR technologies in direct analysis of natural product extracts. Methodology: Based on our research experience, academic tracking and extensive literature search, which involved, but not limited to, the use of various databases, like Web of Knowledge and PubMed. The keywords used, in various combinations, to retrieve recent literature on the successful application of NMR technologies to sheer natural product extracts, and excluded artificially natural product mixture and biofluid. Results: NMR technologies for direct natural extracts analysis, including two‐dimensional J‐resolved spectroscopy (2D‐JRES), pure shift NMR, diffusion‐ordered NMR spectroscopy (DOSY), statistical correlation spectroscopy (STOCSY), concentration‐ordered NMR spectroscopy (CORDY), saturation transfer difference (STD) and water‐ligand observed via gradient spectroscopy (WaterLOGSY) were illustrated. Conclusions: By these methods, molecular structure and biological activity information will be directly obtained from NMR analysis of natural products extract, aiming to save experimental time and expenses. The evolution, principle and progress of NMR technologies, such as 2D‐JRES, DOSY, STOCSY, CORDY, STD and WaterLOGSY, for direct natural product mixture analysis are reviewed and elucidated with successful application to obtain molecular structure or biological activity information, without performing cumbersome separation. [ABSTRACT FROM AUTHOR]

The collaborative strategy of optical design and charge transport dynamics optimization can provide double guarantee to achieve high‐efficient planar perovskite solar cells (PSCs). Herein, WO3−X nanorods with tunable localized surface plasmon resonance (LSPR) effect are introduced at the interface between perovskite and hole transport layer (HTL) via antisolvent method during the preparation of perovskite films. The photocurrent of WO3−X nanorods‐based devices significantly increases due to the extension of absorption region caused by LSPR effect. The charge transfer at the perovskite/HTL interface is also accelerated due to the electromagnetic near‐field enhancement via the LSPR effect. The synchronized improvement in photocurrent and charge transfer by WO3−X nanorods leads to a power conversion efficiency of 21.14% in MAPbI3‐based PSCs. This work not only provides an effective approach to enhance the photovoltaic performance of PSCs, but also demonstrates the potential application of inorganic oxide semiconductors with LSPR in other optoelectronic devices. [ABSTRACT FROM AUTHOR]

Rationale: The dried roots of Euphorbia kansui L., known as Kansui, are used to treat ascites and edema in traditional Chinese medicine. However, the toxicity of this herb has seriously restricted its clinical application. A unique vinegar‐processing method has been used to reduce its toxicity since the time of ancient China. However, the detoxification mechanism underlying such vinegar processing has not been fully revealed. To find the answer, the process‐induced changes in components should be carefully investigated. Methods: We performed a systematic analysis of chemical components in raw and vinegar‐processed Kansui using ultrahigh‐performance liquid chromatography (UHPLC) diode array detection tandem mass spectrometry and UHPLC high‐resolution mass spectrometry. Thirty‐one chemical components in raw and vinegar‐processed Kansui were found, the chemical structures of 28 components among them were proposed and the process‐induced changes in components were then investigated. Results: A comprehensive conclusion about the process‐induced chemical change was drawn. It was found that jatrophane‐type diterpenoids decreased markedly after vinegar processing, while ingenane‐type diterpenoids were retained during vinegar processing. In silico drug target identification gave hints that jatrophane‐type diterpenoids, which decreased markedly during vinegar processing, may have more intense toxicity involving cholinesterase and mitogen‐activated protein kinases, while ingenane‐type diterpenoids, which were retained during vinegar processing, may have a more intense therapeutic effect involving carbonic anhydrase. Conclusions: The possible detoxification mechanism of vinegar‐processed Kansui is presented. The research has significance for the therapeutic/toxic chemical basis of Kansui. Also, it has significance for drug discovery from terpenoids within the herb. [ABSTRACT FROM AUTHOR]

Introduction: The inherent diversity of natural product extracts has not only made their value for biological activity attractive, but has also presented significant challenges for separation and detection techniques to enable rapid characterisation of the biologically active component present in the complicated mixture. Objective: Nuclear magnetic resonance (NMR) is routinely valued for its ability to shed light on molecular structure, when NMR is used as a promising tool in drug screening, it can detect and quantify molecular interactions, and at the same time provide detailed structural information with atomic level resolution. Here, we introduced an accurate and efficient strategy for discovering ligands from natural product extracts, by taking the advantage of NMR‐based drug screening. Methodology: The characteristic pre‐purified subfraction libraries were brought into screening, and combinatorial ligand‐observed NMR interaction detection experiments were performed, once hits were found from one subfraction, the repository of the subfraction would be subject to separation and preparation, and the structure of the hits would be easily identified. Results: Screening procedure of Radix Polygoni Multiflori water extract against human serum albumin (HSA) was used as an example, to discuss and verify the detailed methodology. Furthermore, human fatty acid binding protein 4 (FABP4) was presented as an example target protein, to illustrate the utility of this method for discovering biologically active component. Conclusions: It is proved that suitable subfraction library and well‐combined ligand‐detected NMR experiments will make the screening streamline more accurate and efficient. NMR is a promising tool to integrate natural product extracts into modern drug screening. A integrated method for NMR‐based screening for natural product extracts were present, to illustrate and verify the utility of the method, screening procedure of Radix Polygoni Multiflori water extract subfraction against human serum albumin (HSA) was showed as example. Besides, one active component was found has interaction with target protein FABP4. [ABSTRACT FROM AUTHOR]

A quantitative 31P-NMR method for the determination of fosfomycin and impurity A in pharmaceutical products of fosfomycin sodium or calcium has been developed. In this method, coaxial inserts containing trimethyl phosphate are used as external standard. The method is convenient and robust, and gives both high accuracy and precision. It is shown that an accurate determination is possible using different probes and coaxial inserts. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A research paper which synthesized resol resin with phenol/formaldehyde (F/P)=2.0 and isolated, purified and identified the structure of three prepolymers from the resin through one-dimensional and two-dimensional nuclear magnetic resonance (NMR) experiments, is presented. Topics covered include NMR experiment, liquid chromatography-mass spectroscopy and synthesis of PF resin.