Precursor ion scan driven fast untargeted screening and semi-determination of caffeoylquinic acid derivatives in Cynara scolymus L

Targeted discovery and characterization of secoiridoid glycosides from Jasminum pentaneurum Hand.-Mazz by ultra-performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry based on diagnostic ion and neutral loss filtering strategy

In this study, we proposed an integrated analytical strategy for the rapid and comprehensive discovery of a specific class of secoiridoid glycosides from a Yao medicine, Jasminum pentaneurum Hand.-Mazz. The strategy fully took advantage of the accuracy of ultra-performance liquid chromatography coupled with quadruple time-of-flight mass spectrometry, and the efficiency of diagnostic ion filtering and neutral loss filtering. 24 secoiridoid glycosides, including 3 known ones and 21 unreported ones, were rapidly discovered and characterized based on the detail analysis of their MS data. Particularly, 10-syringicoyl-ligustroside (18) was isolated under the guidance of MS analysis. Its chemical structure was elucidated on the base of extensive spectroscopic data analysis, and absolute configuration was further elucidated by comparison of its experimental and electronic circular dichroism spectra. Furthermore, the MS data of 18 was analyzed and the corresponding results indicated that its fragment pathway was fully consistent with the applied diagnostic ion filtering and neutral loss filtering rules and thus the precision and efficiency of the integrated strategy were validated. The result demonstrated that the proposed integrated strategy could serve as a rapid, accurate, and comprehensive targeted components discovery method to effectively screen out those ingredients of interest from the complex herbal medicines. This article is protected by copyright. All rights reserved.

Insight into chemical basis of traditional Chinese medicine based on the state-of-the-art techniques of liquid chromatography-mass spectrometry

Traditional Chinese medicine (TCM) has been an indispensable source of drugs for curing various human diseases. However, the inherent chemical diversity and complexity of TCM restricted the safety and efficacy of its usage. Over the past few decades, the combination of liquid chromatography with mass spectrometry has contributed greatly to the TCM qualitative analysis. And novel approaches have been continuously introduced to improve the analytical performance, including both the data acquisition methods to generate a large and informative dataset, and the data post-processing tools to extract the structure-related MS information. Furthermore, the fast-developing computer techniques and big data analytics have markedly enriched the data processing tools, bringing benefits of high efficiency and accuracy. To provide an up-to-date review of the latest techniques on the TCM qualitative analysis, multiple data-independent acquisition methods and data-dependent acquisition methods (precursor ion list, dynamic exclusion, mass tag, precursor ion scan, neutral loss scan, and multiple reaction monitoring) and post-processing techniques (mass defect filtering, diagnostic ion filtering, neutral loss filtering, mass spectral trees similarity filter, molecular networking, statistical analysis, database matching, etc.) were summarized and categorized. Applications of each technique and integrated analytical strategies were highlighted, discussion and future perspectives were proposed as well.

Current Advances in Naturally Occurring Caffeoylquinic Acids: Structure, Bioactivity, and Synthesis

Caffeoylquinic acids (CQAs) are a broad class of secondary metabolites that have been found in edible and medicinal plants from various families. It has been 100 years since the discovery of chlorogenic acid in 1920. In recent years, a number of naturally derived CQAs have been isolated and structurally elucidated. Accumulated evidence demonstrate that CQAs have a wide range of biological activities, such as antioxidation, antibacterial, antiparasitic, neuroprotective, anti-inflammatory, anticancer, antiviral, and antidiabetic effects. Up to date, some meaningful progresses on the biosynthesis and total synthesis of CQAs have also been made. Therefore, it is necessary to comprehensively summarize the structure, biological activity, biosynthesis, and chemical synthesis of CQAs. This review provides extensive coverage of naturally occurring CQAs discovered from 1990 until 2020. Modern isolation techniques, chemical data (including structure, biosynthesis, and total synthesis), and bioactivity are summarized. This would be helpful for further research of CQAs as potential pharmaceutical agents.

Screening of lignan patterns in Schisandra species using ultrasonic assisted temperature switch ionic liquid microextraction followed by UPLC-MS/MS analysis

The ultrasonic assisted temperature-switch ionic liquid microextraction (UATS-ILME) has been successfully applied in extracting of seven lignans from Schisandra. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4MIM][BF4]) aqueous solution was selected for extracting the target analytes in raw material at 80°C. The lignans were deposited into a single drop by in situ forming 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) by cooling down to 0°C and centrifuging for 10min. The extracts were analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in a robust multiple-reaction monitoring (MRM) mode in five minutes. Meanwhile, the proposed method was validated and successfully applied to the determination of seven lignans in twelve Schisandra species. The results indicated that UATS-ILME combined with UPLC-MS/MS is a powerful and practical tool, which has great potential for comprehensive quality control of herbal medicines.