Identification and determination of chemical constituents of Citrus reticulata semen through ultra high performance liquid chromatography combined with Q Exactive Orbitrap tandem mass spectrometry

The Phytochemical Screening and Biological Properties of Brassica napus L. var. napobrassica (Rutabaga) Seeds

Rutabaga, also known as swede and scientifically classified as Brassica napus napobrassica, is a biennial edible root vegetable that belongs to the Brassica genus and is widely cultivated in North Europe and North America. The present study highlights both the phytochemical profile and the in vitro biological properties of rutabaga seed extracts obtained through maceration using solvents of increasing polarity, namely, cyclohexane (CYHA), dichloromethane (DCM), ethyl acetate (EtOAc), methanol (MeOH), and water (H2O). HPLC-DAD was used to identify and quantify phenolic compounds, while volatile compounds were detected using GC-MS. The in vitro antioxidant capacity of the rutabaga seed extracts was evaluated through DPPH free radical scavenging activity. The in vitro anti-inflammatory activity (15-lipoxygenase (15-LOX) enzyme) was determined spectrophotometrically at the same concentration. Additionally, the cytotoxicity of the seed extracts was evaluated against human colon adenocarcinoma cells (Caco-2) and human embryonic kidney cells (HEK-293) using the MTT assay. The rutabaga seed extracts obtained from EtOAc, MeOH, and H2O were particularly rich in reducing sugars, ranging from 189.87 to 473.75 mg/g DW. The MeOH extract displayed the highest concentration of both sugars and polyphenols. Phytochemically, the HPLC-DAD analysis revealed the presence of four phenolic compounds in the tested extracts, including (±) synephrine, gallic acid, p-coumaric acid, and trans-ferulic acid, newly discovered in rutabaga organs. Moreover, a total of ten volatile compounds were identified through GC-MS analysis, both before and after derivatization. At a concentration of 50 µg/mL, the methanol extract exhibited high antioxidant activity with 52.95% inhibition, while CYHA, DCM, and EtOAc exhibited moderate anti-15-LOX activity with less than 30% inhibition. Except for DCM and aqueous extracts, rutabaga seeds did not exhibit any anti-proliferative potential against Caco-2 cell lines. Interestingly, no cytotoxicity was registered for any of the seed extracts against the normal cell line HEK-293. Overall, the obtained data highlight the potential utilization of rutabaga seeds as a source of bioactive compounds in various fields, including pharmaceuticals, nutraceuticals, and functional foods.

Comparative flavonoid profile of orange (Citrus sinensis) flavedo and albedo extracted by conventional and emerging techniques using UPLC-IMS-MS, chemometrics and antioxidant effects

Introduction

Citrus fruits are one of the most frequently counterfeited processed products in the world. In the juice production alone, the peels, divided into flavedo and albedo, are the main waste product. The extracts of this by-product are enriched with many bioactive substances. Newer extraction techniques generally have milder extraction conditions with simultaneous improvement of the extraction process.

Methods

This study presents a combinatorial approach utilizing data-independent acquisition-based ion mobility spectrometry coupled to tandem mass spectrometry. Integrating orthogonal collision cross section (CCS) data matching simultaneously improves the confidence in metabolite identification in flavedo and albedo tissues from Citrus sinensis. Furthermore, four different extraction approaches [conventional, ultrasonic, High Hydrostatic Pressure (HHP) and Pulsed Electric Field (PEF)] with various optimized processing conditions were compared in terms of antioxidant effects and flavonoid profile particularly polymethoxy flavones (PMFs).

Results

A total number of 57 metabolites were identified, 15 of which were present in both flavedo and albedo, forming a good qualitative overlapping of distributed flavonoids. For flavedo samples, the antioxidant activity was higher for PEF and HHP treated samples compared to other extraction methods. However, ethyl acetate extract exhibited the highest antioxidant effects in albedo samples attributed to different qualitative composition content rather than various quantities of same metabolites. The optimum processing conditions for albedo extraction using HHP and PEF were 200 MPa and 15 kJ/kg at 10 kV, respectively. While, HHP at medium pressure (400 MPa) and PEF at 15 kJ/kg/3 kV were the optimum conditions for flavedo extraction.

Conclusion

Chemometric analysis of the dataset indicated that orange flavedo can be a valid source of soluble phenolic compounds especially PMFs. In order to achieve cross-application of production, future study should concentrate on how citrus PMFs correlate with biological engineering techniques such as breeding, genetic engineering, and fermentation engineering.

Metabolomic Analysis of Phytochemical Compounds from Ethanolic Extract of Lime (Citrus aurantifolia) Peel and Its Anti-Cancer Effects against Human Hepatocellular Carcinoma Cells

Lime peels are food waste from lime product manufacturing. We previously developed and optimized a green extraction method for hesperidin-limonin-rich lime peel extract. This study aimed to identify the metabolomics profile of phytochemicals and the anti-cancer effects of ethanolic extract of lime (Citrus aurantifolia) peel against liver cancer cells PLC/PRF/5. The extract’s metabolomics profile was analyzed by using LC-qTOF/MS and GC-HRMS. The anti-cancer effects were studied by using MTT assay, Annexin-PI assay, and Transwell-invasion assay. Results show that the average IC50(s) of hesperidin, limonin, and the extract on cancer cells’ viability were 165.615, 188.073, and 503.004 µg/mL, respectively. At the IC50 levels, the extract induced more apoptosis than those of pure compounds when incubating for 24 and 48 h (p < 0.0001). A combination of limonin and hesperidin showed a synergistic effect on apoptosis induction (p < 0.001), but the effect of the combination was still less than that of the extract at 48 h. Furthermore, the extract significantly inhibited cancer cell invasion better than limonin but equal to hesperidin. At the IC50 level, the extract contains many folds lower amounts of hesperidin and limonin than the IC50 doses of the pure compounds. Besides limonin and hesperidin, there were another 60 and 22 compounds detected from the LCMS and GCMS analyses, respectively. Taken altogether, the superior effect of the ethanolic extract against liver cancer cells compared to pure compound likely results from the combinatorial effects of limonin, hesperidin, and other phytochemical components in the extract.

Comprehensive analysis of dihydromyricetin metabolites in rats using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry

As the most abundant and bioactive constituent in vine tea (Ampelopsis grossedentata), dihydromyricetin possesses numerous biological activities. A rapid profiling and identification method for dihydromyricetin metabolites in rats after the oral administration has been established using UHPLC-Q-Exactive Orbitrap MS coupled with multiple data-mining methods. Herein, an efficient analytical strategy characterized by parallel reaction monitoring mode combining diagnostic fragment ions filtering techniques was developed for the comprehensive identification of dihydromyricetin metabolites in rat plasma, urine and faeces. And then, the biotransformation pathways of dihydromyricetin were further revealed. As a result, a total of 49 metabolites were finally identified by comparing diagnostic fragment ions, chromatographic retention times, neutral loss fragment ions, and accurate mass measurement with those of dihydromyricetin reference standard. These metabolites were presumed to be dominantly generated through hydroxylation, dehydroxylation, methylation, reduction, sulfation, decarbonylation, glucuronidation, glucosylation, and their composite reactions. In a word, our present results not only supplied solid foundation to better understand the action mechanism of dihydromyricetin, but also provided some models for metabolism study of the other compounds in traditional Chinese medicines or other natural plants. This article is protected by copyright. All rights reserved.

Citri Reticulatae Semen extract promotes healthy aging and neuroprotection via autophagy induction in Caenorhabditis elegans

Nutrition intervention has emerged as a potential strategy to delay aging and promote healthy longevity. Citri Reticulatae Semen (CRS) has diverse beneficial effects and has been used for thousands of years to treat pain. However, the health benefits of CRS in prolonging healthspan and improving aging-related diseases and the exact mechanisms remain poorly characterized. In this study, Caenorhabditis elegans (C. elegans) was used as a model organism to study the anti-aging and healthspan promoting activities of 75% ethanol extract of CRS (CRSE). The results showed that treatment with CRSE at 1000 μg/mL significantly extended the lifespan of worms by 18.93% without detriment to healthspan and fitness, as evidenced by the delayed aging-related phenotypes and increased body length and width and reproductive output. In addition, CRSE treatment enhanced the ability of resistance under heat, oxidative, and pathogenic bacterial stress. Consistently, heat shock proteins and antioxidant enzyme-related and pathogenesis-related (PR) genes were up-regulated by CRSE treatment. Furthermore, CRSE supplementation also improved α-synuclein, 6-OHDA, and polyQ40-induced pathologies in transgenic C. elegans models of Parkinson's disease (PD) and Huntington's disease (HD). The mechanistic study demonstrated that CRSE induced autophagy in worms, while the RNAi knockdown of 4 key autophagy-related genes including lgg-1, bec-1, vps-34, and unc-51 remarkably abrogated the beneficial effects of CRSE on the extending of lifespan and healthspan and neuroprotection, demonstrating that CRSE exerts beneficial effects via autophagy induction in worms. Together, our current findings provide new insights into the practical application of CRS for the prevention of aging and aging-related diseases.

Comparative analysis of chemical constituents in Citri Exocarpium Rubrum, Citri Reticulatae Endocarpium Alba, and Citri Fructus Retinervus

Citri Exocarpium Rubrum (CER), Citri Reticulatae Endocarpium Alba (CREA), and Citri Fructus Retinervus (CFR) are used as medicine and food, which derive from three different parts of the pericarp of Citrus reticulata Blanco through natural drying. To systematically investigate similarities and differences in phytochemicals about the three herbs, a series of analytic approaches were applied for the qualitative and quantitative analysis of chemical constituents in them. The results indicated a total of 48 volatile compounds were determined representing 99.92% of the total relative content of CER extracts, including 24 alkenes, 11 alcohols, 6 aldehydes, 2 ketones, and 2 phenols, while volatile compounds were not extracted from CREA and CFR. CER was abundant in volatile components that mainly existed in the oil gland. And a total of 32, 35, and 28 nonvolatile compounds were identified from CER, CREA, and CFR extracts, respectively. The total content of flavonoids and phenolic, and hesperidin in CFR was the highest, followed by CREA and CER. Conversely, CER was a rich source of polymethoxyflavones (PMFs), and the total polymethoxyflavone content (TPMFC), the content of nobiletin, 3,5,6,7,8,3′,4′‐heptamethoxyflavone (HMF), tangeretin, and 5‐hydroxy‐6,7,8,3′,4′‐pentamethoxyflavone (5‐HPMF) in CREA and CFR were extremely low. Besides, CER and CREA had a higher concentration of synephrine than CFR. The phytochemicals of CER, CREA, and CFR were significantly different, which might provide chemical evidence for the comparative pharmacological activities’ research and rational application of them.

Improvement of Antioxidant Properties in Fruit from Two Blood and Blond Orange Cultivars by Postharvest Storage at Low Temperature

Numerous studies have revealed the remarkable health-promoting activities of citrus fruits, all of them related to the accumulation of bioactive compounds, including vitamins and phytonutrients. Anthocyanins are characteristic flavonoids present in blood orange, which require low-temperature for their production. Storage at low-temperature of blood oranges has been proven to be a feasible postharvest strategy to increase anthocyanins in those countries with warm climates. To our knowledge, no studies comparing the effect of postharvest storage effect on phenylpropanoid accumulation in cultivars with and without anthocyanins production have been published. We have investigated the effect of postharvest cold storage in flavonoid accumulation in juice from Citrus sinensis L. Osbeck in two different oranges: Pera, a blond cultivar, and Moro, a blood one. Our findings indicate a different response to low-temperature of fruit from both cultivars at biochemical and molecular levels. Little changes were observed in Pera before and after storage, while a higher production of phenylpropanoids (3.3-fold higher) and flavonoids (1.4-fold higher), including a rise in anthocyanins from 1.3 ± 0.7 mg/L to 60.0 ± 9.4 mg/L was observed in Moro concurrent with an upregulation of the biosynthetic genes across the biosynthetic pathway. We show that postharvest storage enhances not only anthocyanins but also other flavonoids accumulation in blood oranges (but not in blond ones), further stimulating the interest in blood orange types in antioxidant-rich diets.

A Green Extraction Method to Achieve the Highest Yield of Limonin and Hesperidin from Lime Peel Powder (Citrus aurantifolia)

Green extraction is aimed at reducing energy consumption by using renewable plant sources and environmentally friendly bio-solvents. Lime (Citrus aurantifolia) is a rich source of flavonoids (e.g., hesperidin) and limonoids (e.g., limonin). Manufacturing of lime products (e.g., lime juice) yields a considerable amount of lime peel as food waste that should be comprehensively exploited. The aim of this study was to develop a green and simple extraction method to acquire the highest yield of both limonin and hesperidin from the lime peel. The study method included ethanolic-aqueous extraction and variable factors, i.e., ethanol concentrations, pH values of solvent, and extraction temperature. The response surface methodology was used to optimize extraction conditions. The concentrations of limonin and hesperidin were determined by using UHPLC-MS/MS. Results showed that the yields of limonin and hesperidin significantly depended on ethanol concentrations and extraction temperature, while pH value had the least effect. The optimal extraction condition with the highest amounts of limonin and hesperidin was 80% ethanol at pH 7, 50 °C, which yields 2.072 and 3.353 mg/g of limonin and hesperidin, respectively. This study illustrates a green extraction process using food waste, e.g., lime peel, as an energy-saving source and ethanol as a bio-solvent to achieve the highest amount of double bioactive compounds.

Rapid Voltammetric Screening Method for the Assessment of Bioflavonoid Content Using the Disposable Bare Pencil Graphite Electrode

Hesperidin (HESP) is a plant bioflavonoid found in various nutritional and medicinal products. Many of its multiple health benefits rely on the compound’s antioxidant ability, which is due to the presence of oxidizable hydroxyl groups in its structure. Therefore, the present study aimed to investigate the electrochemical behavior of HESP at a cheap, disposable pencil graphite electrode (PGE) in order to develop rapid and simple voltammetric methods for its quantification. Cyclic voltammetric investigations emphasized a complex electrochemical behavior of HESP. The influence of the electrode material, solution stability, supporting electrolyte pH, and nature were examined. HESP main irreversible, diffusion-controlled oxidation signal obtained at H type PGE in Britton Robinson buffer pH 1.81 was exploited for the development of a differential pulse voltammetry (DPV) quantitative analysis method. The quasi-reversible, adsorption-controlled reduction peak was used for HESP quantification by differential pulse adsorptive stripping voltammetry (DPAdSV). The linear ranges of DPV and DPAdSV were 1.00 × 10−7–1.20 × 10−5 and 5.00 × 10−8–1.00 × 10−6 mol/L with detection limits of 8.58 × 10−8 and 1.90 × 10−8 mol/L HESP, respectively. The DPV method was applied for the assessment of dietary supplements bioflavonoid content, expressed as mg HESP.

Flavonoid glycosides and other bioactive compounds in Citrus reticulate 'Chachi' peel analysed by tandem mass spectrometry and their changes during storage

The peel of Citrus reticulate 'Chachiennsis' (Chachi) is a well-known functional food with multiple health benefits in Asia. There is an old saying "the longer time Chachi is stored, the better health benefits it has". Is it convincible? What are the critical bioactive compounds in Chachi? To answer these questions, gas chromatography-mass spectrometry (GC-MS) and ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) were used to qualify and quantify the flavonoid glycosides and other bioactive compounds of Chachi with storage time of 5-20 years. Limonene was the representative volatile compound. The level of most volatile compounds decreased along with storage. Sixteen flavonoids glycosides and twenty flavonoids were identified. Nobiletin, hesperitin, tetramethoxy flavone and pentamethoxy flavone were characteristic bioactive compounds for Chachi. Most of them accumulated during 10-year storage, thereafter decreased. Ten years could be the optimal storage time. These results indicated that the old saying should be corrected.

Chemical profiling of Zilong Jin tablets using ultra high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry

Zilongjin tablets as a traditional Chinese medicine are widely used for primary lung cancer patients with deficiency of "qi " and "blood " syndrome undergoing chemotherapy. It is a compound preparation that consists of eight herbs. To clarify the chemical profiling of Zilong Jin tablets rapidly, a feasible and accurate strategy was developed by the ultra high performance liquid chromatography-quadrupole/orbitrap high resolution mass spectrometry. According to the accurate mass and fragment ion information provided by high resolution mass spectrometry, the compounds were reasonably identified. In total, 74 compounds were characterized, including 20 flavonoids, 14 quinones, 15 organic acids, 6 phthalide compounds, and 19 other compounds. Among them, 34 major compounds were unambiguously confirmed by comparing with reference standards. This study could provide an important scientific basis for further research on quality control, pharmacokinetics and pharmacodynamics, and clinical application of Zilong Jin tablets.

Identification of Components in Citri Sarcodactylis Fructus from Different Origins via UPLC-Q-Exactive Orbitrap/MS

To systematically analyze the chemical constituents of Citri Sarcodactylis Fructus (CSF) from different origins, an efficient approach based on ultraperformance liquid chromatography plus Q-Exactive Orbitrap tandem mass spectrometry (UPLC-Q-Exactive Orbitrap/MS) detection for the discrimination of chemical components from of 15 batches of CSF from four main origins was used in this research. Through parent peaks, fragment peaks, fragmentation characteristics, and comparative analysis with the literature and reference standards, a total of 77 components from the methanol extracts including 18 coumarins, 24 flavonoids, seven organic acids, three limonoids, and 25 other compounds were detected and identified. Among them, 15 components have not been reported previously in the CSF. Notably, the stachydrine peak initially showed a higher content in the total ion current chromatogram. Overall, CSF produced in the Zhejiang province contained a richer variety of chemical compositions. These observations provided a theoretical basis for the further quality assessment and application of CSF.

Remodeling the Epigenetic Landscape of Cancer-Application Potential of Flavonoids in the Prevention and Treatment of Cancer

Epigenetics, including DNA methylation, histone modification, and noncoding RNA regulation, are physiological regulatory changes that affect gene expression without modifying the DNA sequence. Although epigenetic disorders are considered a sign of cell carcinogenesis and malignant events that affect tumor progression and drug resistance, in view of the reversible nature of epigenetic modifications, clinicians believe that associated mechanisms can be a key target for cancer prevention and treatment. In contrast, epidemiological and preclinical studies indicated that the epigenome is constantly reprogrammed by intake of natural organic compounds and the environment, suggesting the possibility of utilizing natural compounds to influence epigenetics in cancer therapy. Flavonoids, although not synthesized in the human body, can be consumed daily and are common in medicinal plants, vegetables, fruits, and tea. Recently, numerous reports provided evidence for the regulation of cancer epigenetics by flavonoids. Considering their origin in natural and food sources, few side effects, and remarkable biological activity, the epigenetic antitumor effects of flavonoids warrant further investigation. In this article, we summarized and analyzed the multi-dimensional epigenetic effects of all 6 subtypes of flavonoids (including flavonols, flavones, isoflavones, flavanones, flavanols, and anthocyanidin) in different cancer types. Additionally, our report also provides new insights and a promising direction for future research and development of flavonoids in tumor prevention and treatment via epigenetic modification, in order to realize their potential as cancer therapeutic agents.

Qualitative and quantitative analysis of phenolic compounds in blueberries and protective effects on hydrogen peroxide-induced cell injury

This work was conducted to optimize an accelerated solvent extraction for ultra high performance liquid chromatography-mass spectrometry/mass spectrometry analysis of blueberry phenolic compounds. The conditions for accelerated solvent extraction were verified using response surface methodology to obtain the following optimized conditions: ethanol concentration (pH = 3), 48%; temperature, 50℃, and static cycle times, 3. Further, ultra high performance liquid chromatography with quadrupole Exactive Orbitrap mass spectrometry and ultra high performance liquid chromatography with triple-quadrupole tandem mass methods for determination of the detailed phenolic composition were developed and validated. Total of 81 phenolic compounds were identified by ultra high performance liquid chromatography with quadrupole Exactive Orbitrap mass spectrometry including 23 anthocyanins, 32 flavonols, 11 proanthocyanidins, 2 other flavonoids, and 13 phenolic acids. Fifty-one of these compounds have been simultaneously quantified by ultra high performance liquid chromatography with triple-quadrupole tandem mass including 31 anthocyanins, 8 flavonols, 6 proanthocyanidins, 2 other flavonoids, and 8 phenolic acids. Malvidin-dinhexoside has, for the first time, been detected in wild. Moreover, by verifying the protection on PC12 cells against oxidative damage, it was showed that the phenolic extracts (500 µg/mL) can improve significantly the viability (9.26-24.78%) of hydrogen peroxide-induced PC12 cells, activities of superoxide dismutase (34.59-37.90 U/mg) and glutathione peroxidase (6.87-14.42 mU/mg) and decrease the content of malonic dialdehyde (13.27-24.62 nmol/mg). Correlation analysis suggested that anthocyanins might contribute most to these activities.

Valorization and extraction optimization of Citrus seeds for food and functional food applications

Valorization of food byproducts has attracted recently considerable attention. Citrus fruits provide considerable non-edible residues reach 80% in juice production. They are considered agri-wastes to comprise peel, pulp and seeds. Previous investigations have focused on peel and pulp to recover value-added products. The review presents for the first-time phytochemical composition of Citrus seeds' products, i.e., oil and extracts. Fatty acids, phytosterols and tocopherols amounted as the major bioactives in Citrus seeds, in addition to limonoids, dietary fibers and flavonoids. Besides their nutritional values, these chemicals have promising applications including production of biodiesel, food enhancers and antioxidants, especially from mandarin and grapefruit seeds. Optimum conditions of the different Citrus seeds' valorization are discussed to improve extraction yield and lessen environmental hazards of solvent extraction. This review presents the best utilization practices for one of the largest cultivated fruit seeds worldwide and its different applications.

In vitro human intestinal microbiota biotransformation of nobiletin using liquid chromatography-mass spectrometry analysis and background subtraction strategy

In this study, the in vitro biotransformation of nobiletin by human intestinal microbiota, which is a bioactive polymethoxyflavone widely presented in Citrus plants, has been investigated via utilizing an anaerobic incubation protocol. The incubation samples were detected using high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry. A background subtraction strategy incorporated in Microsoft Office was employed to eliminate the interferences in medium and feces. The parent and three metabolites sinensetin, 5-hydroxy-6,7,3',4'-tetramethoxyflavone, and 5-demethylnobiletin were detected and identified based on the characteristics of their protonated molecules. The proposed metabolic pathway revealed that nobiletin went through phase I metabolism including demethylation and demethoxylation in human intestinal microbiota. The characterization of nobiletin metabolic profile transformed by human intestinal bacteria would be helpful for understanding its efficacy and action mechanism.

Comparative Research of Chemical Profiling in Different Parts of Fissistigma oldhamii by Ultra-High-Performance Liquid Chromatography Coupled with Hybrid Quadrupole-Orbitrap Mass Spectrometry

The roots of Fissistigma oldhamii (FO) are widely used as medicine with the effect of dispelling wind and dampness, promoting blood circulation and relieving pains, and its fruits are considered delicious. However, Hakka people always utilize its above-ground parts as a famous folk medicine, Xiangteng, with significant differences from literatures. Studies of chemical composition showed there were multiple aristolactams that possessed high nephrotoxicity, pending evaluation research about their distribution in FO. In this study, a sensitive, selective, rapid and reliable method was established to comparatively perform qualitative and semi-quantitative analysis of the constituents in roots, stems, leaves, fruits and insect galls, using an Ultra-High-Performance Liquid Chromatography coupled with Hybrid Quadrupole Orbitrap Mass Spectrometry (UPLC-Q-Exactive Orbitrap MS, or Q-Exactive for short). To make more accurate identification and comparison of FO chemicals, all MS data were aligned and screened by XCMS, then their structures were elucidated according to MSn ion fragments between the detected and standards, published ones or these generated by MS fragmenter. A total of 79 compounds were identified, including 33 alkaloids, 29 flavonoids, 11 phenylpropanoids, etc. There were 54 common components in all five parts, while another 25 components were just detected in some parts. Six toxic aristolactams were detected in this experiment, including aristolactam AII, AIIIa, BII, BIII, FI and FII, of which the relative contents in above-ground stems were much higher than roots. Meanwhile, multivariate statistical analysis was performed and showed significant differences both in type and content of the ingredients within all FO parts. The results implied that above-ground FO parts should be carefully valued for oral administration and eating fruits. This study demonstrated that the high-resolution mass spectrometry coupled with multivariate statistical methods was a powerful tool in compound analysis of complicated herbal extracts, and the results provide the basis for its further application, scientific development of quality standard and utilization.

Fingerprint analysis of phenolic acid extract of Salvia miltiorrhiza by digital reference standard analyzer with one or two reference standards

Background

Fingerprint analysis and simultaneous multi-components determination are crucial for the holistic quality control of traditional Chinese medicines (TCMs). Yet, reference standards (RS) are often commercially unavailable and with other shortages, which severely impede the application of these technologies.

Methods

A digital reference standard (DRS) strategy and the corresponding software called DRS analyzer, which supports chromatographic algorithms, spectrum algorithms, and the combination of these algorithms, was developed. The extensive function also enabled the DRS analyzer to recommend the chromatographic column based on big data.

Results

Various quality control methods of fingerprints of 11 compounds in polyphenolic acid extract of Salvia miltiorrhiza (S. miltiorrhiza) were developed based on DRS analyzer, involving relative retention time (RRT) method, linear calibration using two reference substances (LCTRS) technique, RRT combined with Photon Diode Array (PDA) method, LCTRS combined with PDA method. Additionally, the column database of samples was established. Finally, our data demonstrated that the DRS analyzer could accurately identify 11 compounds of the samples, using only one or two physical RSs.

Conclusions

The DRS strategy is an automated, intelligent, objective, accurate, eco-friendly, universal, sharing, and promising method for overall quality control of TCMs that requires the usage of fewer RSs.

Rapid and comprehensive profiling of α-glucosidase inhibitors in Buddleja Flos by ultrafiltration HPLC-QTOF-MS/MS with diagnostic ions filtering strategy

Buddleja Flos is used as yellow rice colorant and a well-known traditional Chinese medicine. But its biochemical profiling is still lack due to complex matrix. Here, ultrafiltration high-performance liquid chromatograph-quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF-MS/MS) with diagnostic ions filtering strategy was proposed for rapid and comprehensive investigation of its α-glucosidase inhibitors. As a result, 33 bioactive compounds (13 phenylethanoid glycosides and 20 flavonoids) were successfully screened and identified. In addition, α-glucosidase inhibitory activities of twenty-two references were verified. Six flavonoid aglycones (4, 28, and 30-33) showed excellent α-glucosidase inhibitory activities (IC₅₀, from 5.11 ± 0.85 to 32.49 ± 9.76 μg/mL), much higher than that of acarbose (IC₅₀, 195.49 ± 10.05 μg/mL). Five flavonoid-monoglycosides (7, 12, 13, 20, and 22) presented moderate inhibitory activities with IC₅₀ from 160.98 ± 23.19 to 249.37 ± 35.83 μg/mL. Results showcased the high efficiency of proposed strategy in profiling of bioactive compounds from natural products.

Identification of lipophilic components in Citri Reticulatae Pericarpium cultivars by supercritical CO2 fluid extraction with ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry

To systematically identify the lipophilic constituents of Citri Reticulatae Pericarpium from different cultivars, supercritical CO₂ fluid extraction and ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry were integrated for the component analysis of 18 batches of Citri Reticulatae Pericarpium from 12 cultivars for the first time. A total of 57 components from the supercritical CO₂ fluid extracts were demonstrably or tentatively identified by the obtained parent peaks, fragment peaks, and retention times. In total, two flavonoids, six organic acids, nine coumarins, three aldehydes, seven esters, three terpenes, one limonoid, and five other compounds were detected for the first time; notably, coumarin components have not yet been reported in Citri Reticulatae Pericarpium. Furthermore, the extract constituents differed between cultivars. In particular, organic acids were more abundant in Citrus reticulata "Chachi" than in other cultivars, and pterostilbene was exclusively found in Citrus reticulata "Yichangju". The results showed that a greater variety of compounds in Citri Reticulatae Pericarpium could be extracted by supercritical CO₂ fluid extraction and detected by ultra-high-performance liquid chromatography-Q Exactive Orbitrap tandem mass spectrometry. This study provides a more scientific basis for further analysis of the pharmacological activity and quality of Citri Reticulatae Pericarpium components from different cultivars.

UPLC-Q-Exactive Orbitrap MS Analysis for Identification of Lipophilic Components in Citri Sarcodactylis Fructus from Different Origins in China Using Supercritical CO2 Fluid Extraction Method

To thoroughly evaluate the quality of Citri Sarcodactylis Fructus (CSF) and acquire knowledge of the lipophilic components of CSF from different origins, a simple and efficient approach based on supercritical fluid extraction (SFE) combined with ultraperformance liquid chromatography plus Q-Exactive Orbitrap tandem mass spectrometry (UPLC-Q-Exactive Orbitrap/MS) detection for the discrimination of components from CSF was set up for the first time in this work. Eight batches of CSF samples from five main producing areas were extracted by SFE under optimized conditions, and then SFE extracts were dissected via UPLC-Q-Exactive Orbitrap/MS. The results indicated that 39 lipophilic compounds were successfully separated and unambiguously or tentatively identified, where 4 coumarins, 6 polymethoxyflavones, 3 phthalides, 6 terpenes, and 4 phenolics were not reported formerly. It was illustrated that CSF may be abundant in polymethoxyflavones, as in coumarins. Moreover, there were significant differences in the components of CSF from different origins. Especially, coumarin, dehydrocostus lactone, atractylenolide II, and atractylenolide I were exclusively found in CSF from the Guangdong province; isopsoralen was almost exclusively found in CSF from the Guangxi province; and ferulic acid was exclusively found in CSF from the Zhejiang province. These observations indicated that SFE joint with UPLC-Q-Exactive Orbitrap/MS owing to the potential of characterizing the lipophilic components could be used to promote quality assessment and chemotaxonomic investigation in phytology sciences of CSF.