Mechanistic study on inhibition of porcine pancreatic α-amylase using the flavonoids from dandelion

Polysaccharides from Flos Sophorae Immaturus ameliorates insulin resistance in IR-HepG2 cells by co-regulating signaling pathways of AMPK and IRS-1/PI3K/AKT

Four polysaccharides, named FSIP, FSIP-I, FSIP-II and FSIP-III, were isolated from Flos Sophorae Immaturus. Structure characterization revealed that FSIP-I and FSIP-II were types of AG-II-like polysaccharides while FSIP-III featured a RG-II-like structure with high content of GalpA. In vitro experiments showed that FSIPs upregulated HK and PK activities in glycolysis while downregulated G-6-Pase activities in gluconeogenesis. This increased glucose utilization while decreased the glucose synthesis in IR-HepG2 cells, potentially reducing elevated blood sugar levels induced by excess insulin. In terms of antioxidant system, FSIPs decreased the levels of ROS and MDA, and increased the activities of SOD and CAT, enhancing antioxidant capacity to counteract damage caused by insulin resistance in IR-HepG2 cells. To further explore the mechanism, related genes expressions were analyzed. The results found that FSIPs ameliorated insulin resistance via regulating AMPK and IRS-1/PI3K/AKT signal pathways. In the case of AMPK, glucose can be channeled into oxidative (catabolic) pathway, whereas, in the case of IRS-1/PI3K/AKT, glucose can be stored as glycogen (anabolic). This co-modulation could ameliorate insulin resistance by upregulating the glycolysis and repressing the gluconeogenesis in catabolism, and upregulating the glycogen synthesis in anabolism. Additionally, FSIP-III exhibited better anti-insulin resistance activity, attributed to its high content of GalpA.

The phytochemical and pharmacological profile of dandelion

Dandelion (Taraxacum genus), a perennial herb belonging to the Asteraceae family is widely distributed in hillside grasslands, roadsides, fields, and river beaches in middle and low-altitude areas. It has a long history of traditional Chinese medicine usage as a heat-clearing and detoxifying agent, often consumed as tea or vegetable. Multiple pharmacological studies have demonstrated the antiviral, antibacterial, anti-inflammatory, immune-regulating, antioxidant, anti-tumor, and other effects of the Taraxacum genus. Bioactive compounds associated with these effects include triterpenes and their saponins, phenolic acids, sterols and their glycosides, flavonoids, organic acids, volatile oils, and saccharides.

Mechanistic study on the inhibition of α-amylase and α-glucosidase using the extract of ultrasound-treated coffee leaves

BACKGROUND

Our previous studies have shown that ultrasound-treated γ-aminobutyric acid (GABA)-rich coffee leaves have higher angiotensin-I-converting enzyme inhibitory activity than their untreated counterpart. However, whether they have antidiabetic activity remains unknown. In this study, we aimed to investigate the inhibitory activities of coffee leaf extracts (CLEs) prepared with ultrasound (CLE-U) or without ultrasound (CLE-NU) pretreatment on α-amylase and α-glucosidase. Subsequently, we evaluated the binding interaction between CLE-U and both enzymes using multi-spectroscopic and in silico analyses.

RESULTS

Ultrasound pretreatment increased the inhibitory activities of CLE-U against α-amylase and α-glucosidase by 21.78% and 25.13%, respectively. CLE-U reversibly inhibits both enzymes, with competitive inhibition observed for α-amylase and non-competitive inhibition for α-glucosidase. The static quenching of CLE-U against both enzymes was primarily driven by hydrogen bond and van der Waals interactions. The α-helices of α-amylase and α-glucosidase were increased by 1.8% and 21.3%, respectively. Molecular docking results showed that the key differential compounds, including mangiferin, 5-caffeoylquinic acid, rutin, trigonelline, GABA, caffeine, glutamate, and others, present in coffee leaves interacted with specific amino acid residues located at the active site of α-amylase (ASP197, GLU233, and ASP300). The binding of α-glucosidase and these bioactive components involved amino acid residues, such as PHE1289, PRO1329, and GLU1397, located outside the active site.

CONCLUSION

Ultrasound-treated coffee leaves are potential anti-diabetic substances, capable of preventing diabetes by inhibiting the activities of α-amylase and α-glucosidase, thus delaying starch digestion. Our study provides valuable information to elucidate the possible antidiabetic capacity of coffee leaves through the inhibition of α-amylase and α-glucosidase activities. © 2023 Society of Chemical Industry.

Three anthocyanin-rich berry extracts regulate the in vitro digestibility of corn starch: Physicochemical properties, structure and α-amylase

This study aimed to compare the regulatory effects of blue honeysuckle anthocyanins (BHA), blueberry anthocyanins (BBA), and blackcurrant anthocyanins (BCA) on the in vitro digestibility of corn starch in terms of starch physicochemical properties and structure, as well as α-amylase inhibition. The results revealed that adding all three anthocyanins lowered digestibility in the following order: BHA > BCA > BBA. The terminal digestibility (C∞) decreased from 73.84 % to 57.3 % with the addition of 10 % BHA, while the resistant starch (RS) content increased from 4.39 % to 48.82 %. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis indicated that anthocyanins and starch interacted through noncovalent bonds. Differential scanning calorimetry (DSC) analysis showed that the gelatinization enthalpy was dramatically lowered in all three anthocyanin groups, with 10 % BHA producing a 38.58 % drop. Rheological property analysis showed that anthocyanins increased the apparent viscosity and modulus with starch. The interaction between anthocyanin and α-amylase was mainly through the formation of hydrogen bonds and hydrophobic forces. This research provides theoretical guidance for developing low glycemic index (GI) anthocyanin starch-based foods.

Dandelion (Taraxacum mongolicum) Extract Alleviated H2O2-Induced Oxidative Damage: The Underlying Mechanism Revealed by Metabolomics and Lipidomics

Dandelion has received wide attention in food and medicine fields due to its excellent antioxidant properties. Nonetheless, the underlying mechanism of this action has not yet been fully clarified, particularly at the metabolic level. Herein, the effects of dandelion extract (DE) on H2O2-induced oxidative damage was investigated. The results indicate that the DE alleviated H2O2-induced cell damage (increased by 14.5% compared to H2O2 group), reduced the reactive oxygen species (ROS) level (decreased by 80.1% compared to H2O2 group), maintained the mitochondrial membrane potential (MMP) level, and increased antioxidant-related enzyme activities. Importantly, the metabolic response of PC12 cells indicates that H2O2 disturbed phospholipid metabolism and damaged cell membrane integrity. In addition, energy metabolism, the central nervous system, and the antioxidant-related metabolism pathway were perturbed. In contrast, DE rescued the H2O2-induced metabolic disorder and further alleviated oxidative damage. Collectively, these findings provide valuable stepping stones for a discussion of the mechanism and show the promise of DE as a suitable additive for functional food products.

Factors influencing the starch digestibility of starchy foods: A review

Starchy foods are a major energy source of the human diet, their digestion is closely related to human health. Most foods require lots of processing before eating, therefore, many factors can influence starch digestibility. The factors that affect the digestibility of starches have been widely discussed previously, but the extracted starches in those studies were different from those present within the actual food matrix. This review summarizes the factors influencing the starch digestibility in starchy foods. Endogenous non-starch components hinder the starch digestive process. Food ingredients and additives decrease starch digestibility by inhibiting the activity of digestive enzymes or hindering the contact between starch and enzymes. Storage induce the retrogradation of starch, decreasing the digestibility of foods. Therefore, preparing starchy foods with whole grains, processing them as little as possible, using food additives reasonably, and storage conditions may all be beneficial measures for the production of low GI foods.

In Vitro Inhibitory Effects of Polyphenols from Flos sophorae immaturus on α-Glucosidase: Action Mechanism, Isothermal Titration Calorimetry and Molecular Docking Analysis

Flos sophorae immaturus (FSI) is considered to be a natural hypoglycemic product with the potential for a-glucosidase inhibitory activity. In this work, the polyphenols with α-glucosidase inhibition in FSI were identified, and then their potential mechanisms were investigated by omission assay, interaction, type of inhibition, fluorescence spectroscopy, circular dichroism, isothermal titration calorimetry and molecular docking analysis. The results showed that five polyphenols, namely rutin, quercetin, hyperoside, quercitrin and kaempferol, were identified as a-glucosidase inhibitors with IC₅₀ values of 57, 0.21, 12.77, 25.37 and 0.55 mg/mL, respectively. Quercetin plays a considerable a-glucosidase inhibition role in FSI. Furthermore, the combination of quercetin with kaempferol generated a subadditive effect, and the combination of quercetin with rutin, hyperoside and quercitrin exhibited an interference effect. The results of inhibition kinetics, fluorescence spectroscopy, isothermal titration calorimetry and molecular docking analysis showed that the five polyphenols were mixed inhibitors and significantly burst the fluorescence intensity of α-glucosidase. Moreover, the isothermal titration calorimetry and molecular docking analysis showed that the binding to α-glucosidase was a spontaneous heat-trapping process, with hydrophobic interactions and hydrogen bonding being the key drivers. In general, rutin, quercetin, hyperoside, quercitrin and kaempferol in FSI are potential α-glucosidase inhibitors.

Structure-activity relationships and the underlying mechanism of α-amylase inhibition by hyperoside and quercetin: Multi-spectroscopy and molecular docking analyses

Inhibiting the activity of α-amylase has been considered an effective strategy to manage hyperglycemia. Hyperoside and quercetin are the main natural flavonoids in various plants, and the inhibition mechanism on α-amylase remains unclear. In this study, the structure-activity relationships between hyperoside/quercetin and α-amylase were evaluated by enzyme kinetic analysis, multi-spectroscopic techniques, and molecular docking analysis. Results showed that hyperoside and quercetin exhibited significant α-amylase inhibitory activities with IC₅₀ values of 0.491 and 0.325 mg/mL, respectively. The α-amylase activity decreased in the presence of hyperoside and quercetin in a competitive and noncompetitive manner, respectively. UV-vis spectra suggested that the aromatic amino acid residues (Trp and Tyr) microenvironment of α-amylase changed in the presence of these two flavonoids. FTIR and CD spectra showed the vibrations of the amide bands and the secondary structure content changes. The fluorescence quenching mechanism of α-amylase by hyperoside and quercetin belonged to the static quenching type. Finally, molecular docking intuitively showed that hyperoside/quercetin formed hydrogen bonds with the key active site residues (Asp197, Glu233, and Asp300) in α-amylase. MD simulation indicated hyperoside/quercetin-α-amylase docked complexes had good stability. Taken together, this research provides new sights to developing potent drugs or functional foods with hyperoside and quercetin, offering new avenues for hyperglycemia treatment.

Inhibition characteristics and mechanism of tyrosinase using five citrus flavonoids: A spectroscopic and molecular dynamics simulation study

This work presents a comparative analysis of the tyrosinase inhibitory effects of five citrus flavonoids, namely hesperetin, hesperidin, neohesperidin, naringenin and naringin. Visbile, fluorescence, and fourier transform infrared (FITR) spectroscopies, and molecular dynamic methods were employed to compare the anti-tyrosinase mechanisms of each flavonoid. Hesperetin, neohesperidin, naringenin and naringin exhibited potent inhibitory activities with IC50 values of 0.74 ± 0.05, 2.19 ± 0.03, 7.50 ± 9.82 and 24.94 ± 8.43 μmol/ml, respectively, all of which were higher than that of kojic acid (0.04 ± 0.02 μmol/ml). The enzymatic kinetics results suggested that hesperetin and naringenin were reversible inhibitors on tyrosinase in the mixed-type manner. H-bond and hydrophobic interactions were found to drive the binding of tyrosinase with hesperetin or naringenin, which subsequently changed the FTIR spectroscopy results by decreasing the α-helix ratio and increasing the β-turn, β-sheet and random coil ratio in tyrosinase. Molecular dynamics simulation not only verified some of the experimental results, but also suggested that the binding of hesperetin and naringenin to tyrosinase was spontaneous. The findings of this study indicate that citrus flavonoids are a promising dietary resource for tyrosinase inhibition. PRACTICAL APPLICATIONS: Hesperetin, hesperidin, neohesperidin, naringenin and naringin were typical citrus flavonoids that have anti-obesity, anti-oxidation, anti-inflammation and anti-diabetes activities. Current study suggested that hesperetin and naringenin were effective reversible inhibitors on tyrosinase in the mixed-type manner. Hesperetin and naringenin might serve as nutritional and chemical agents for regulating the tyrosinase activity to control melanin level in vivo.

Exploring the Inhibition of Quercetin on Acetylcholinesterase by Multispectroscopic and In Silico Approaches and Evaluation of Its Neuroprotective Effects on PC12 Cells

This study investigated the inhibitory mechanism of quercetin in acetylcholinesterase (AChE) and its neuroprotective effects on β-amyloid_25-35-induced oxidative stress injury in PC12 cells. Quercetin inhibited AChE in a reversible mixed manner with an IC₅₀ of 4.59 ± 0.27 µM. The binding constant of quercetin with AChE at 25 °C was (5.52 ± 0.05) × 10⁴ L mol^-1. Hydrogen bonding and van der Waals forces were the main interactions in forming the stable quercetin-AChE complex. Computational docking revealed that quercetin was dominant at the peripheral aromatic site in AChE and induced enzymatic allosterism; meanwhile, it extended deep into the active center of AChE and destabilized the hydrogen bond network, which caused the constriction of the gorge entrance and prevented the substrate from entering the enzyme, thus resulting in the inhibition of AChE. Molecular dynamics (MD) simulation emphasized the stability of the quercetin-AChE complex and corroborated the previous findings. Interestingly, a combination of galantamine hydrobromide and quercetin exhibited the synergistic inhibition effect by binding to different active sites of AChE. In a β-amyloid_25-35-induced oxidative stress injury model in PC12 cells, quercetin exerted neuroprotective effects by increasing the glutathione level and reducing the malondialdehyde content and reactive oxygen species levels. These findings may provide novel insights into the development and application of quercetin in the dietary treatment of Alzheimer's disease.

Structural changes and molecular mechanism study on the inhibitory activity of epigallocatechin against α-glucosidase and α-amylase

In this study, the inhibition and mechanism of epigallocatechin (EGC) on two key glycoside hydrolases (α-glucosidase, α-amylase) were explored from the molecular structure level. The chemical structure of EGC was characterized by X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and proton nuclear magnetic resonance spectroscopy. EGC's inhibition on these enzymes was colorimetrically determined. The effects of EGC on the chemical structure and spatial configuration of the enzymes were explored via FTIR spectroscopy, fluorescence spectroscopy, and molecular docking techniques. The results showed that EGC exhibited the inhibition of α-glucosidase and α-amylase in a non-competitive manner, showing a continuous upward trend as EGC's concentration increased. There was a fluorescence quenching effect of EGC on α-glucosidase and α-amylase. Molecular docking confirmed that EGC can bind to amino acid residues in the enzyme through intermolecular hydrogen bonds and hydrophobic interactions, resulting in the changed chemical structure and spatial conformation of the enzymes. This decreased enzyme activity. This result suggested that EGC has the potential to inhibit two key glycoside hydrolases, and it would be beneficial to incorporate EGC into functional foods for diabetics.

Identification of the effective α-amylase inhibitors from Dalbergia odorifera: Virtual screening, spectroscopy, molecular docking, and molecular dynamic simulation

Inhibiting the activity of α-amylase has been considered as one efficient way to prevent and treat type 2 diabetes recently. Dalbergia odorifera, a kind of Leguminosae plant, has a positive therapeutic effect on type 2 diabetes, possibly contributing by some constituents that can inhibit the activity of α-amylase. In this study, we found that eriodictyol was one potential constituent through virtual screening. The interaction mode between eriodictyol and α-amylase was elucidated by molecular docking, multi-spectroscopic analysis, and molecular dynamic simulation. The results revealed that eriodictyol quenched the intrinsic fluorescence of α-amylase, and the quenching mode was static quenching. Eriodictyol could spontaneously interact with α-amylase, mostly stabilized and influenced by the hydrophobic interaction, while the binding sites (n) was 1.13 ± 0.07 and binding constant (K_b) was (1.43 ± 0.14) × 10⁵ at 310 K, respectively. In addition, FT-IR and CD had been applied to identify that eriodictyol can trigger the conformational change of α-amylase. Taken together, the results provided some experimental data for developing new α-amylase inhibitors from Dalbergia odorifera, which may further prevent and treat diabetes and diabetes complications.

Effect of co-toxicity of lead and nanoplastics on the flavonoid biosynthetic pathway in dandelion (Taraxacum asiaticum Dahlst)

Negatively charged carboxy-polystyrene (CPS) and positively charged amino-polystyrene (NPS) could significantly inhibit the biomass and flavonoid content of dandelion roots and leaves, and the inhibitory effect of NPS was stronger than that of CPS. The increasingly serious pollution of microplastics and heavy metals is likely to affect the efficacy of flavonoids synthesized by dandelion in natural medicine fields. Therefore, we combined hydroponic experiments with computational chemistry (Gaussian and autodock analysis) to explore the mechanism by which amino-polystyrene (NPS), carboxy-polystyrene (CPS), and lead affect the flavonoid biosynthetic pathway in dandelion (Taraxacum asiaticum Dahlst). Our results show that CPS and NPS could significantly inhibit the biomass and flavonoid content of dandelion roots and leaves, and the inhibitory effect of NPS was stronger than that of CPS. Mechanistic studies showed that CPS and NPS increased the content of O₂^- and H₂O₂ in dandelion roots and leaves, causing membrane lipid peroxidation, resulting in cell damage and decreased biomass. CPS and NPS inhibited related enzymatic activities by affecting their tertiary structures, resulting in a decrease in phenolic acid, coumaroyl-CoA, and flavonoid content. Dandelion preferred to absorb positively charged NPS compared to negatively charged CPS, but CPS inhibited the uptake of Pb by dandelion more strongly than NPS. Pb promoted CPS agglomeration and increased the surface positive charge of CPS through coordination bonds and hydrogen bonds, so more CPS entered dandelion under CPS + Pb treatment than under CPS alone. Although NPS and CPS reduced the uptake of Pb by dandelion, the biomass and flavonoid contents of dandelion were lower than those of single Pb treatment because of the higher toxicity of NPS and CPS than Pb. Pb significantly increased the effect of CPS on the root biomass of dandelion compared with CPS alone by increasing the positive charge of CPS. We suggest that microplastics with different charges and lead composite pollution inhibit dandelion flavonoid biosynthesis and provide a reference for the loss of dandelion medicinal components and economic value.

Viscosity-Based Flow Sensor on Paper for Quantitative and Label-Free Detection of α-Amylase and Its Inhibitor

α-Amylase (AMS) in human serum is a critical biomarker for the early diagnosis of pancreatic damage. In addition, the inhibition of α-amylase has long been thought to decrease the occurrence of diabetes. Thus, it is critical to construct a facile and convenient method for the determination of AMS and its inhibitor. In this study, we demonstrate a novel amylase sensor based on translating the viscosity change of the aqueous solution into the difference of the water diffusion length on a pH paper strip. AMS can be quantitatively detected by measuring the viscosity change of the amylopectin solution in the presence of AMS with different concentrations. The paper-based AMS sensor has a very high sensitivity with a detection limit of 0.017 U/mL and also shows excellent specificity. In addition, the inhibitory effect of acarbose on AMS is demonstrated with the IC₅₀ value determined to be 21.66 ± 1.13 μg/mL. Furthermore, it is also evaluated for the detection of AMS in human serum samples of healthy people and acute pancreatitis patients. The difference in amylase levels between the two groups is unambiguously distinguished. Overall, this study provides a very simple, cost-effective, equipment-free, high-throughput, and label-free method for rapid and quantitative detection of α-amylase and may have significant applications in the diagnosis of acute pancreatitis and the screening of AMS inhibitors.

Application of starch-based nanoparticles and cyclodextrin for prebiotics delivery and controlled glucose release in the human gut: a review

Starches are a major constituent of staple foods and are the main source of energy in the human diet (55-70%). In the gastrointestinal tract, starches are hydrolyzed into glucose by α-amylase and α-glucosidase, which leads to a postprandial glucose elevation. High levels of blood glucose levels over sustained periods may promote type 2 diabetes mellitus (T2DM) and obesity. Increasing consumption of starchy foods with a lower glycemic index may therefore contribute to improved health. In this paper, the preparation and properties of several starch-based nanoparticles (SNPs) and cyclodextrins (CDs) derivatives are reviewed. In particular, we focus on the various mechanisms responsible for the ability of these edible nanomaterials to modulate glucose release and the gut microbiome in the gastrointestinal tract. The probiotic functions are achieved through encapsulation and protection of prebiotics or bioactive components in foods or the human gut. This review therefore provides valuable information that could be used to design functional foods for improving human health and wellbeing.

Inhibitory Mechanism of Baicalein on Acetylcholinesterase: Inhibitory Interaction, Conformational Change, and Computational Simulation

Alzheimer’s disease (AD) is the most prevalent chronic neurodegenerative disease in elderly individuals, causing dementia. Acetylcholinesterase (AChE) is regarded as one of the most popular drug targets for AD. Herbal secondary metabolites are frequently cited as a major source of AChE inhibitors. In the current study, baicalein, a typical bioactive flavonoid, was found to inhibit AChE competitively, with an associated IC₅₀ value of 6.42 ± 0.07 µM, through a monophasic kinetic process. The AChE fluorescence quenching by baicalein was a static process. The binding constant between baicalein and AChE was an order of magnitude of 10⁴ L mol⁻¹, and hydrogen bonding and hydrophobic interaction were the major forces for forming the baicalein−AChE complex. Circular dichroism analysis revealed that baicalein caused the AChE structure to shrink and increased its surface hydrophobicity by increasing the α-helix and β-turn contents and decreasing the β-sheet and random coil structure content. Molecular docking revealed that baicalein predominated at the active site of AChE, likely tightening the gorge entrance and preventing the substrate from entering and binding with the enzyme, resulting in AChE inhibition. The preceding findings were confirmed by molecular dynamics simulation. The current study provides an insight into the molecular-level mechanism of baicalein interaction with AChE, which may offer new ideas for the research and development of anti-AD functional foods and drugs.

An on-line detection system for screening small molecule inhibitors of α-Amylase and α-Glucosidase in Prunus mume

High-throughput screening of inhibitors from natural products is an efficient approach to target key enzymes in diabetes progression. In this study, an on-line detection system was established for the first time to rapidly screen inhibitors of α-amylase and α-glucosidase from Prunus mume. Among 28 identified compounds, 26 and 21 compounds showed strong inhibitory effect against α-amylase and α-glucosidase, respectively. Their inhibitory effects were validated by in vitro enzyme assay and fluorescence quenching which demonstrated that these inhibitors effectively interfered enzyme active sites. The inhibition kinetics suggested that chemical structures are of great importance for interfering the enzyme structures and their microenvironment polarity. Among evaluated compounds, isorhamnetin-3-O-glucoside (19) showed the strongest binding activities to α-amylase and α-glucosidase (6.34×10⁶·nmol^-1 and 6.28×10⁶·nmol^-1, respectively) by the on-line detection system. Its IC₅₀ values were 0.16 ± 0.06 and 0.09 ± 0.01 µM against α-amylase and α-glucosidase, respectively. 19 gave a much higher K_i for α-amylase (0.1307 mM) than α-glucosidase (0.0063 mM), indicating its selectivity towards α-glucosidase. This reported method was rapid and reliable to identify prototype inhibitors against key enzymes in diabetes, and thus might serve as a general platform to screen enzyme inhibitors from natural products.

The mechanism of delaying starch digestion by luteolin

In this study, the mechanisms of the delay of starch digestion by luteolin were revealed by studying the luteolin-PPA (porcine pancreatic α-amylase) interaction and luteolin-starch interaction. The luteolin-PPA interaction was investigated by inhibitory kinetics analysis, fluorescence quenching, circular dichroism (CD), Fourier transform infrared (FT-IR) spectroscopy and molecular docking. The results of the inhibitory kinetics revealed that luteolin was a mixed-type inhibitor of PPA and that the inhibitory action was reversible. Fluorescence spectroscopy (including fluorescence quenching and thermodynamics) and molecular docking analyses indicated that hydrogen bonds and hydrophobic forces were the main forces between PPA and luteolin. CD and FT-IR spectroscopy analyses showed that the interaction between luteolin and PPA changed the secondary structure of PPA and induced a decline in its activity. In addition, the luteolin-starch interaction was also studied using UV-visible absorption and X-ray diffraction analyses. These indicated that luteolin could bind with PPA, and that hydrogen bonds and van der Waals forces may be present. Overall, luteolin delayed starch digestion not only by binding with PPA but also by binding with starch. Thus, luteolin has the potential to prevent and control diabetes by being added into starch-based food to delay starch digestion.

Application of fingerprint combined with quantitative analysis and multivariate chemometric methods in quality evaluation of dandelion (Taraxacum mongolicum)

A quality assessment method based on quantitative analysis of multi-components by single marker (QAMS) and fingerprint was constructed from 15 batches of dandelion (Taraxacum mongolicum), using multivariate chemometric methods (MCM). MCM were established by hierarchical cluster analysis (HCA) and factor analysis (FA). HCA was especially performed using the R language and SPSS 22.0 software. The relative correction factors of chlorogenic acid, caffeic acid, p-coumaric acid, luteolin and apigenin were calculated with cichoric acid as a reference, and their contents were determined. The differences between external standard method (ESM) and QAMS were compared. There was no significant difference (t-test, p > 0.05) in quantitative determination, proving the consistency of the two methods (QAMS and ESM). Dandelion material from Yuncheng, Shandong was used as a reference chromatogram. The fingerprints in 15 batches of dandelion were established by HPLC analysis. The similarity of the fingerprints in different batches of dandelion material was greater than or equal to 0.82. A total of 10 common peaks were identified. This strategy is simple, rapid and efficient in multiple component detection of dandelion. It is beneficial in simplifying dandelion's quality control processes and providing references to enhance quality control for other herbal medicines.