Correlation analysis between the chemical contents and bioactivity for the quality control of Alismatis Rhizoma

Late-stage modification of bioactive compounds: Improving druggability through efficient molecular editing

Synthetic chemistry plays an indispensable role in drug discovery, contributing to hit compounds identification, lead compounds optimization, candidate drugs preparation, and so on. As Nobel Prize laureate James Black emphasized, "the most fruitful basis for the discovery of a new drug is to start with an old drug"1. Late-stage modification or functionalization of drugs, natural products and bioactive compounds have garnered significant interest due to its ability to introduce diverse elements into bioactive compounds promptly. Such modifications alter the chemical space and physiochemical properties of these compounds, ultimately influencing their potency and druggability. To enrich a toolbox of chemical modification methods for drug discovery, this review focuses on the incorporation of halogen, oxygen, and nitrogen-the ubiquitous elements in pharmacophore components of the marketed drugs-through late-stage modification in recent two decades, and discusses the state and challenges faced in these fields. We also emphasize that increasing cooperation between chemists and pharmacists may be conducive to the rapid discovery of new activities of the functionalized molecules. Ultimately, we hope this review would serve as a valuable resource, facilitating the application of late-stage modification in the construction of novel molecules and inspiring innovative concepts for designing and building new drugs.

Advanced data post-processing method for rapid identification and classification of the major triterpenoids of Alismatis rhizoma by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry

INTRODUCTION

Alismatis rhizoma (AR), a distinguished diuretic traditional Chinese herbal medicine, is widely used for the treatment of diarrhea, edema, nephropathy, hyperlipidemia, and tumors in clinical settings. Most beneficial effects of AR are attributed to the major triterpenoids, whose contents are relatively high in AR. To date, only 25 triterpenoids in AR have been characterized by LC-MS because the low-mass diagnostic ions are hardly triggered in MS, impeding structural identification. Herein, we developed an advanced data post-processing method with abundant characteristic fragments (CFs) and neutral losses (NLs) for rapid identification and classification of the major triterpenoids in AR by UPLC-Q-TOF-MS^E .

OBJECTIVE

We aimed to establish a systematic method for rapid identification and classification of the major triterpenoids of AR.

METHODS

UPLC-Q-TOF-MS^E coupled with an advanced data post-processing method was established to characterize the major triterpenoids of AR. The abundant CFs and NLs of different types of triterpenoids were discovered and systematically summarized. The rapid identification and classification of the major triterpenoids of AR were realized by processing the data and comparing with information described in the literature.

RESULTS

In this study, a total of 44 triterpenoids were identified from AR, including three potentially new compounds and 41 known ones, which were classified into six types.

CONCLUSION

The newly established approach is suitable for the chemical profiling of the major triterpenoids in AR, which could provide useful information about chemical constituents and a basis for further exploration of its active ingredients in vivo.

Extraction and determination of terpenoids from Zexie Decoction based on a porous organic cage-doped monolithic cartridge

A monolithic solid-phase extraction (SPE) cartridge packed with a composite adsorbent was fabricated via polymerization using dodecene as the monomer with the porous organic cage (POC) material doped, combing with an analytical column through a high-performance liquid chromatography (HPLC) instrument, which was used for the online extraction and separation of 23-acetyl alismol C, atractylodes lactone II and atractylodes lactone III from Zexie Decoction. The POC-doped adsorbent shows porous structure with a relatively high specific surface area of 85.50 m²/g, which was obtained from the characterizations of a scanning electron microscope and an automatic surface area and porosity analyser. Efficient extraction and separation of three target terpenoids was achieved by an online SPE-HPLC method based on the POC-doped cartridge, which exhibits strong matrix-removal ability and good terpenoids-retention ability with a high adsorption capacity, due to the interactions of hydrogen bond and hydrophobicity between the terpenoids and the POC-doped adsorbent. Method validation shows good linearity (r ≥ 0.9998) of the regression equation, and high accuracy with the spiked recovery in the range of 99.2 %-100.8 % of the proposed method. Compared to the generally disposable adsorbent, this work fabricated a reusable monolithic cartridge, which can be used for at least 100 times, with the RSD based on the peak area of the three terpenoids less than 6.6 %.

Alismatis Rhizoma methanolic extract—Effects on metabolic syndrome and mechanisms of triterpenoids using a metabolomic and lipidomic approach

Alismatis rhizoma is a traditional Chinese medicine. Studies have demonstrated that Alismatis rhizoma also has therapeutic effects on metabolic syndrome. However, the pharmacodynamic material basis and mechanism are still unclear. First, UHPLC/Q-Orbitrap MS was used to detect the chemical components of the Alismatis rhizoma extract, and 31 triterpenoids and 2 sesquiterpenes were preliminarily identified. Then, to investigate the mechanism of the Alismatis rhizoma extract on metabolic syndrome, a mouse model of metabolic syndrome induced by high-fructose drinks was established. The results of serum biochemical analysis showed that the levels of TG, TC, LDL-C, and UA after the Alismatis rhizoma extract treatment were markedly decreased. ¹H-NMR was used to conduct non-targeted metabolomics studies. A total of 20 differential metabolites were associated with high-fructose–induced metabolic syndrome, which were mainly correlated with 11 metabolic pathways. Moreover, UHPLC/Q-Orbitrap MS lipidomics analysis found that a total of 53 differential lipids were screened out. The results showed that Alismatis rhizoma extract mainly reduces the synthesis of glycerophospholipid and ceramide and improves the secretion of bile acid. This study shows that the Alismatis rhizoma extract can treat metabolic syndrome mainly by inhibiting energy metabolism, amino acid metabolism, and regulating bile acid to reduce phospholipid content.

Network pharmacology combined with metabolomics and lipidomics to reveal the hypolipidemic mechanism of Alismatis rhizoma in hyperlipidemic mice

Alismatis rhizoma (AR), the dried rhizome of Alisma orientale (Sam) Juzep, is effective in treating hyperlipidemia, but the mechanisms involved require further exploration. This study evaluated the hypolipidemic properties of AR using an integrated strategy combining network pharmacology with metabolomics and lipidomics. Firstly, a hyperlipidemia mouse model induced by a high-fat diet was established to evaluate the therapeutic effects of AR. Secondly, plasma metabolomics and lipidomics were used to identify differential metabolites and lipids, and metabolic pathway analysis was performed using MetaboAnalyst. Thirdly, network pharmacology, based on the metabolic profile of AR in vivo, was used to discover potential therapeutic targets. Finally, key targets were obtained through a compound-target-metabolite network, which was verified by molecular docking and quantitative real-time PCR (qPCR). Biochemistry analysis and histological examinations showed that AR exerted hypolipidemic effects on hyperlipidemic mice. Seventy potential biomarkers for the AR treatment of hyperlipidemia were identified by metabolomics and lipidomics, which were mainly involved in lipid metabolism, energy metabolism and amino acid metabolism. Eighteen potentially active compounds were identified in the plasma of mice after oral administration of AR, which were associated with 83 potential therapeutic targets. The PPAR signaling pathway was considered a crucial signaling pathway of AR against hyperlipidemia by KEGG analysis. The joint analysis showed that 6 upstream key targets were regulated by AR, including ALB, TNF, IL1B, MMP9, PPARA and PPARG. Molecular docking showed that active compounds of AR had high binding affinity with these key targets. qPCR further demonstrated that AR could reverse the mRNA expression of these key targets in hyperlipidemic mice. This study integrates network pharmacology with metabolomics and lipidomics to reveal the regulatory effects of AR on endogenous metabolites and validates key therapeutic targets, and represents the most systematic and in-depth study on the hypolipidemic activity of AR.

A strategy for rapid discovery and validation of active diterpenoids as quality markers in different habitats of Langdu using ultra-high performance liquid chromatography-tandem mass spectrometry with multivariate statistical analysis

Langdu known as a Traditional Chinese Medicine was identified as the roots of species of Euphorbia ebracteolata Hayata and Euphorbia fischeriana Steud, displaying anti-tuberculosis activity. In order to clarify the potent quality markers of Langdu, this research firstly developed a fast and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry method for the quantification of thirteen diterpenoids existed in Langdu. The developed method was further applied in the analyses of 12 authentic E. ebracteolata and E. fischeriana samples collected in the North and Southeast of China. Then, the anti-tuberculosis evaluation of 12 batches of Langdu samples was performed in vitro. Finally, Partial least squares discrimination analysis was used in the discrimination of E. ebracteolata and E. fischeriana from different origins and processing methods. Jolkinolide A (1), jolkinolide E (3), yuexiandajisu D (6), Ebractenone A (11) were identified as the key, potent diterpenoids for quality control of E. ebracteolata Hayata and E. fischeriana Steud. The present study established a qualitative chemical analysis method for Langdu (E. ebracteolata and E. fischeriana), and suggested the key bioactive components which will improve qualitative control methodology for this important medicine. This article is protected by copyright. All rights reserved.

Rapid and simultaneous quality analysis of the three active components in Lonicerae Japonicae Flos by near-infrared spectroscopy

Lonicerae Japonicae Flos (LJF) has historically been widely utilized as a tea and health food. To better understand and evaluate its quality evaluate its quality, a near-infrared spectroscopy (NIRS) method was developed for the rapid and simultaneous analysis of the 3 main active components (chlorogenic acid, isochlorogenic acid A and isochlorogenic acid C). The NIRS model was built using 2 different strategies: partial least squares (PLS) as a linear regression method and artificial neural networks (ANN) as a nonlinear regression method. Furthermore, the NIRS method was applied to analyze the 4 main quality factors, which included 5 processing methods (shade drying, sun drying, vacuum drying, freeze drying and hot-air drying), 2 kinds of harvest time (flower bud stage and florescence stage), 2 species and 8 geographical origins. Collectively, NIRS is a promising method for the quality analysis of LJF.

Limitation standard of toxic aconitines in Aconitum proprietary Chinese medicines using on-line extraction electrospray ionization mass spectrometry

Development of rapid analytical methods and establishment of toxic component limitation standards are of great importance in quality control of traditional Chinese medicine. Herein, an on-line extraction electrospray ionization mass spectrometry (oEESI-MS) coupled with a novel whole process integral quantification strategy was developed and applied to direct determination of nine key aconitine-type alkaloids in 20 Aconitum proprietary Chinese medicines (APCMs). Multi-type dosage forms (e.g., tablets, capsules, pills, granules, and liquid preparation) of APCM could be determined directly with excellent versatility. The strategy has the characteristics of high throughput, good tolerance of matrix interference, small amount of sample (∼0.5 mg) and reagent (∼240 μL) consumption, and short analysis time for single sample (<15 min). The results were proved to be credible by high performance liquid chromatography-mass spectrometry (LC-MS) and electrospray ionization mass spectrometry, respectively. Moreover, the limitation standard for the toxic aconitines in 20 APCMs was established based on the holistic weight toxicity (HWT) evaluation and the Chinese Pharmacopoeia severally, and turned out that HWT-based toxicity evaluation results were closer to the real clinical applications. Hence, a more accurate and reliable APCM toxicity limitation was established and expected to play an important guiding role in clinics. The current study extended the power of ambient MS as a method for the direct quantification of molecules in complex samples, which is commonly required in pharmaceutical analysis, food safety control, public security, and many other disciplines.

Establishing a rapid classification and identification method for the major triterpenoids of Alisma orientale

INTRODUCTION

Alismatis Rhizoma (AR) has been widely used to treat various diseases. Its complex chemical composition has caused certain difficulties in the analysis of this traditional Chinese medicine. Therefore, it is necessary to establish a method for the rapid classification and identification of the chemical constituents of AR.

OBJECTIVE

This article describes a method for the rapid classification and identification of major triterpenoids in AR.

METHODOLOGY

The samples were analysed by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The assay was performed on a Waters ACQUITY UPLC BEH C₁₈ column (100 mm × 2.1 mm, 1.7 μm) with 0.1% formic acid in water (A), and acetonitrile (B) as mobile phase by gradient elution at a flow rate of 0.3 mL/min. In the positive ion mode, the fragment information was obtained and compared with the characteristic fragments and neutral losses described in the literature. Then, the rapid classification and identification of the chemical components from AR were achieved.

RESULTS

Finally, 25 triterpene compounds of AR were identified.

CONCLUSIONS

The method established in this study achieved the rapid classification and identification of chemical components in AR, which promotes the development of research methods to study the constituents of traditional Chinese medicine.

HPLC-Based Qualitative and Quantitative Analyses of Alkaloids in Chewable Areca Products from Different Geographic Regions

Background

Chewable areca products are popular in Asian countries, including India, Pakistan, Malaysia, and China. The major alkaloids present in areca products are guvacine, arecaidine, guvacoline, and arecoline which cause carcinogenicity and addiction.

Objective

The objective of this study was the quantitative analysis of the alkaloid content of areca chewable products from different countries and regions using HPLC-UV, as well as the benefit of their safety evaluation products.

Method

An HPLC-UV method was established for qualitative and quantitative analyses of 65 batches of areca chewable products from different countries and regions. Additionally, similarity evaluation of chromatographic fingerprints was applied for data analysis.

Results

These results reveal a significant variation in the levels of areca alkaloids among tested products, specifically guvacoline (0.060–1.216 mg/g), arecoline (0.376–3.592 mg/g), guvacine (0.028–1.184 mg/g), and arecaidine (0.184–1.291 mg/g). There were significant differences in the alkaloid content of areca chewable products from different producing areas.

Conclusions

The method will be useful in the safety evaluation of different areca chewable products.

Highlights

The established HPLC-UV method can be adopted for safety evaluation of areca chewable products from different countries and regions due to its general applicability.

High Resolution Mass Profile of Bufadienolides and Peptides Combing with Anti-Tumor Cell Screening and Multivariate Analysis for the Quality Evaluation of Bufonis Venenum

In order to evaluate the quality of Bufonis Venenum commercial herbs, a three-step qualitative and quantitative research study was performed. Firstly, we tried to identify small molecules and peptides in Bufonis Venenum using pre-fractionation chromatography and high-resolution mass spectrometry. The database search of the small molecules and peptides of Bufonis Venenum revealed that the dried venom consisted of free/conjugated-type bufadienolides and peptides with a mass range of 0.4–2 kDa. Secondly, we used partial least squares (PLS) multivariate statistical analysis to screen bufadienolides markers (VIP > 1.5) responsible for the anti-tumor cell activity of Bufonis Venenum, including 21 identified bufadienolides and 7 unknown compounds. It is noticeable that these bufadienolide markers could not be recognized by traditional HPLC-UV based spectrum-effect relationship analysis (correlation coefficient ranging from −0.24 to 0.40). Finally, we proposed a weight coefficient-based corrected total contents of 9 bufadienolides as a quality evaluation indicator, which had good correlation with inhibitory effects on tumor cells of commercial Bufonis Venenum. The correlation coefficient increased from 0.4 to 0.6. Thus, our pre-fractionation chromatography and mass spectrometry strategy had significant advancement over the traditional spectrum–effect relationship method for chemical marker identification. These results could be crucial and helpful in the development of a quality evaluation method that could reflect the pharmacological activity of Bufonis Venenum.

Quantitative Analysis of Eight Triterpenoids and Two Sesquiterpenoids in Rhizoma Alismatis by Using UPLC-ESI/APCI-MS/MS and Its Application to Optimisation of Best Harvest Time and Crude Processing Temperature

Rhizoma Alismatis (RA), widely known as "Ze-Xie" in China, is the tuber of Alisma orientale (Sam.) Juzep (Alismaceae), a Chinese herbal medicine that has been used to treat hyperlipidemia, diabetes, hypertension, dysuria, and inflammation. In this study, a sensitive and reliable method based on an ultra-performance liquid chromatography (UPLC) couple with two ionisation modes, including electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI) tandem mass spectrometry (MS), namely, UPLC-ESI/APCI-MS/MS was developed and validated to simultaneously determine 8 triterpenoids (ESI mode) and 2 sesquiterpenoids (APCI mode) in RA. Ten marker compounds were analysed with a Waters' CORTECS UPLC C18 column (200 mm × 2.1 m, 1.6 μm) and gradient elution with water (contained 0.1% formic) and acetonitrile within 7 min. The established method was validated for linearity, intra- and interday precisions, accuracy, recovery, and stability. The calibration curve for 10 marker compounds showed good linear regression (r > 0.9971). The limits of detection and quantification for analytes were 0.14-1.67 ng/mL and 0.44-5.65 ng/mL, respectively. The relative standard deviations (RSD, %) and accuracy (RE, %) of intra- and interday precisions were less than 3.83% and 1.21% and 3.22% and 1.46%, repeatability and stability for real samples were less than 2.78% and 3.19%, respectively. All recoveries of the 10 marker compounds ranged from 97.24% to 102.49% with RSDs less than 4.05%. The developed method efficiently determined the 10 marker compounds in RA and was subsequently applied to optimise harvest time and crude processing temperature. The result indicated the 90% wilted phase and 70°C (or lower) may be the best harvest time and the processing temperature of RA.

Arenobufagin is a novel isoform-specific probe for sensing human sulfotransferase 2A1

Human cytosolic sulfotransferase 2A1 (SULT2A1) is an important phase II metabolic enzyme. The detection of SULT2A1 is helpful for the functional characterization of SULT2A1 and diagnosis of its related diseases. However, due to the overlapping substrate specificity among members of the sulfotransferase family, it is difficult to develop a probe substrate for selective detection of SULT2A1. In the present study, through characterization of the sulfation of series of bufadienolides, arenobufagin (AB) was proved as a potential probe substrate for SULT2A1 with high sensitivity and specificity. Subsequently, the sulfation of AB was characterized by experimental and molecular docking studies. The sulfate-conjugated metabolite was identified as AB-3-sulfate. The sulfation of AB displayed a high selectivity for SULT2A1 which was confirmed by in vitro reaction phenotyping assays. The sulfation of AB by human liver cytosols and recombinant SULT2A1 both obeyed Michaelis-Menten kinetics, with similar kinetic parameters. Molecular docking was performed to understand the interaction between AB and SULT2A1, in which the lack of interaction with Met-137 and Tyr-238 of SULT2A1 made it possible to eliminate substrate inhibition of AB sulfation. Finally, the probe was successfully used to determine the activity of SULT2A1 and its isoenzymes in tissue preparations of human and laboratory animals.

Quality assessment of Penthorum chinense Pursh through multicomponent qualification and fingerprint, chemometric, and antihepatocarcinoma analyses

An efficient method combined with fingerprint and chemometric analyses was developed to evaluate the quality of Penthorum chinense Pursh.