Identification and quantification of free radical scavengers in the flower buds of Lonicera species by online HPLC-DPPH assay coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Quality Evaluation of Lonicerae Flos Produced in Southwest China Based on HPLC Analysis and Antioxidant Activity

Lonicera macranthoides, the main source of traditional Chinese medicine Lonicerae Flos, is extensively cultivated in Southwest China. However, the quality of L. macranthoides produced in this region significantly varies due to its wide distribution and various cultivation breeds. Herein, 50 Lonicerae Flos samples derived from different breeds of L. macranthoides cultivated in Southwest China were collected for quality evaluation. Six organic acids and three saponin compounds were quantitatively analyzed using HPLC. Furthermore, the antioxidant activity of a portion of samples was conducted with 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging experiments. According to the quantitative results, all samples met the quality standards outlined in the Chinese Pharmacopoeia. The samples from Guizhou, whether derived from unopened or open wild-type breeds, exhibited high quality, while the wild-type samples showed relatively significant fluctuation in quality. The samples from Chongqing and Hunan demonstrated similar quality, whereas those from Sichuan exhibited relatively lower quality. These samples demonstrated significant abilities in clearing ABTS and DPPH radicals. The relationship between HPLC chromatograms and antioxidant activity, as elucidated by multivariate analysis, indicated that chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C are active components and can serve as Q-markers for quality evaluation.

An on-line stop-flow RPLC × SEC-MS/DPPH radical scavenging activity analysis system and its application in separation and identification of antioxidant peptides

Food-derived antioxidant peptides have become the focus of research due to their high safety and low cost. However, the discovery is suffering from a low efficient and empirical approach, involving multi-step off-line separation and identification. In this work, an on-line stop-flow RPLC × SEC-MS/DPPH radical scavenging activity analysis system was developed. For optimization, the conditions: 10 m reaction loop, 200 μM DPPH radical concentration, 40℃ temperature and 0.06 % formic acid were recommended. The system was fully validated by its application in glutathione analysis. The system was further applied in analysis of complex mixed standards, and the dipeptides GC (Gly-Cys) and CW (Cys-Trp) with relatively strong DPPH radical scavenging activity were validated. Maize protein hydrolysates were used for tests and the peptide AC (Ala-Cys) of high probability with strong DPPH radical scavenging activity was identified, demonstrating a high potential of the system. This would help to facilitate the discovery of antioxidative peptides in the future.

Anxiolytic and Antidepressant Potential of Methanolic Extract of Neurada procumbens Linn. in Mice

Neurada procumbens Linn. possesses a wide range of phytochemical and bioactive entities such as flavonoids and polyphenols that decrease the oxidative stress and enhance synaptic plasticity, resulting in accelerated healing processes. Almost all parts of the plant have been used in the traditional system of medicine for various disorders including its use as an anticonvulsant, sexual tonic, and anti-rheumatic agent. This study is designed to evaluate the anxiolytic and antidepressant activities of the methanolic crude extract of N. procumbens (Np.Cr) based on its use in traditional medicine and presence of the phytochemical constituents. Aqueous methanolic extract of Np.Cr was prepared under reduced pressure using rotary evaporator, and different chemical constituents were identified by phytochemical screening. Light/dark exploration, elevated plus maze (EPM), and hole board tests were used to assess the anxiolytic activity, while forced swim and tail suspension tests were used to assess the antidepressant potential of the crude extract. Treatment groups treated individually with 3 different doses; i.e., 50, 100, and 200 mg/kg of Np.Cr, showed a dose-dependent increase in time spent in light compartment and in open arms as well as increased number of head poking by the experimental animals. Np.Cr showed significant antidepressant potential (P < .05) as evident from marked decrease in behavioral despair. Findings of the present study assure that N. procumbens possess significant anxiolytic and antidepressant potential with the demands of further investigations to identify the active compound(s) responsible for these pharmacological effects.

Pharmacological evaluation of analgesic, anti-inflammatory and antipyretic activities of ethanolic extract of Indigofera argentea Burm. f

ETHNOPHARMACOLOGICAL RELEVANCE

Indigofera argentea Burm. f.; commonly known as neel, jantari, hathio; is traditionally used for the treatment of headache, fever, inflammation and body pain. Local communities also used this plant for the treatment of malaria, jaundice, vertigo and gastric disorders.

AIM OF THE STUDY

This study is aimed to evaluate the toxicity and possible analgesic, anti-inflammatory and antipyretic activities of the ethanolic crude extract of Indigofera argentea (IaCr) to support its use in folk medicine and to screen the phytochemical constituents and antioxidant activity.

MATERIALS AND METHODS

Aqueous ethanolic (30:70) extract of whole plant of Indigofera argentea (IaCr) was prepared and phytochemical study was performed by preliminary methods followed by HPLC and DPPH method. In vivo experiments were performed in Wistar albino rats including hot plate, tail immersion, formalin and capsaicin-induced pain tests in rats and acetic acid-induced writhing test in mice. Anti-inflammatory activity was assessed by using in vitro human red blood cell (HRBC) membrane stabilization and carrageenan-induced rat paw edema test, while antipyretic activity was evaluated by Brewer's yeast-induced pyrexia test.

RESULTS

The crude extract of Indigofera argentea confirmed the presence of flavonoids, glycosides, alkaloids, saponins and tannins as soluble ethanolic constituents in preliminary study. The maximum quantity of gallic acid equivalent (GAE) phenolics, and quercetin equivalent (QE) flavonoid content found was 81 ± 2 mg GAE/g and 56 ± 1.4 mg QE/g of extract respectively. Quantification based on HPLC exposed the presence of phenols and flavonoids, quercetin, gallic acid, caffeic acid, chlorogenic acid, benzoic acid, ferulic acid and coumaric acid. In vivo experiments revealed significant P < 0.05) dose-dependent inhibition in hot plate, tail immersion and capsaicin-induced pain test. IaCr showed significant inhibition of pain latency against both phases in formalin test and considerably decreased the number of writhes caused by acetic acid at the doses of 30, 100 and 300 mg/kg. In the in vitro anti-inflammatory (HRBC) assay, IaCr showed good membrane stability with maximum percentage hemolysis inhibition of 49.29% while in carrageenan-induced paw edema test in rats the IaCr showed significant anti-inflammatory action in a dose-dependent fashion. Statistical significant reduction in rectal temperature was observed at the doses of 100 and 300 mg/kg in yeast-induced pyrexia test in rats.

CONCLUSION

The results of the experimental studies proved the analgesic, anti-inflammatory and antipyretic activities of Indigofera argentea and supported the traditional use of this plant.

Application of Traditional Chinese Herbal Medicine By-products as Dietary Feed Supplements and Antibiotic Replacements in Animal Production

BACKGROUND

Misuse of synthetic antibiotics in livestock leads to the transfer of antibiotic resistant pathogens into humans and deposits toxic residues in meat and milk. There is therefore an urgent need for safe and viable alternative approaches to improve the nutrition and wellbeing of farm animals. An alternative source that has been widely exploited is Traditional Chinese Herbal Medicine (TCHM). These herbs contain several but less toxic bioactive compounds which are generally regarded as biodegradable. Recently, advances in the knowledge of the importance of TCHM have led to a rapid increase in its production and hence, increasing the amount of by-products generated. Such by-products have become a serious environmental challenge because producers regard them as industrial waste and discard them directly. This review summarizes scientific findings on the bioactive compounds in TCHM and TCHM by-products, discusses functional dietary patterns and outlines challenges that may hinder full utilization of TCHM by-products in animal production.

METHODS

Information for this review was obtained through scientific databases and websites such as Pubmed and Google scholar from 2004 to 2017 using experimental studies on bioactive compounds in TCHM and their effects in animal production.

RESULTS

Studies have shown that TCHM by-products contain high amounts of bioactive compounds which confer several nutritional and health benefits to animals and thus could be incorporated as feed additives.

CONCLUSION

The findings for this review indicate that TCHM by-products apart from being a good alternative for synthetic antibiotics could also minimize the current environmental challenges associated with its disposal.

HPLC-CUPRAC post-column derivatization method for the determination of antioxidants: a performance comparison between porous silica and core-shell column packing

BACKGROUND

An HPLC method employing a post-column derivatization strategy using the cupric reducing antioxidant capacity reagent (CUPRAC reagent) for the determining antioxidants in plant-based materials leverages the separation capability of regular HPLC approaches while allowing for detection specificity for antioxidants.

METHODS

Three different column types, namely core-shell and porous silica including two chemically different core-shell materials (namely phenyl-hexyl and C18), were evaluated to assess potential improvements that could be attained by changing from a porous silica matrix to a core-shell matrix. Tea extracts were used as sample matrices for the evaluation specifically looking at catechin and epigallocatechin gallate (EGCG).

RESULTS

Both the C18 and phenyl-hexyl core-shell columns showed better performance compared to the C18 porous silica one in terms of separation, peak shape, and retention time. Among the two core-shell materials, the phenyl-hexyl column showed better resolving power compared to the C18 column.

CONCLUSIONS

The CUPRAC post-column derivatization method can be improved using core-shell columns and suitable for quantifying antioxidants, exemplified by catechin and EGCG, in tea samples.

Comparison of the Chemical Profiles and Antioxidant Activities of Different Parts of Cultivated Cistanche deserticola Using Ultra Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry and a 1,1-Diphenyl-2-picrylhydrazyl-Based Assay

In this study, a sensitive ultra-performance liquid chromatography-photodiode array coupled to quadruple time-of-flight mass (UPLC-PDA-Q/TOF-MS) method and a 1,1-diphenyl-2-picrylhydrazyl (DPPH)-based assay were used to determine the chemical constituents and screen the antioxidant activity profiles of the methanol extracts of different parts of cultivated Cistanche deserticola (C. deserticola). First, qualitative and quantitative chemical composition analyses of the different parts of cultivated C. deserticola were conducted. Obvious differences were observed between the chemical profiles and content distribution of phenylethanoid glycosides (PhGs) from the different cultivated C. deserticola parts. The average contents of the six PhGs parts varied from 4.91 to 72.56 mg/g DW (milligrams of extract per gram of plant dry weight) in the six different parts of Cistanche deserticola, displaying a significant decreasing trend from the bottom to the top of cultivated C. deserticola and the highest content in the stems. From the bottom to the top of the plant, the echinacoside and cistanoside A content decreased and the 2′-acetylacteoside content increased. Second, an offline DPPH assay revealed that the total scavenging activities of all parts within the range of 20–500 µg/mL increased in a concentration-dependent manner and that good antioxidant activities were found in all plant parts, particularly in the stems, which could be related to their higher PhG content. Additionally, a DPPH-UPLC-PDA method was successfully applied to rapidly screen the antioxidant profiles and antioxidant components of the different cultivated C. deserticola parts. According to the antioxidant profiles before and after the DPPH reaction, there were wide variations in the antioxidant activities of different cultivated C. deserticola parts. Moreover, the antioxidant profiles revealed the presence of major free radical scavengers identified as PhGs using UPLC-Q/TOF-MS. Finally, the established DPPH-UPLC-PDA method was reagent saving, rapid and feasible for correlating the chemical profile of traditional chinese medicines (TCMs) with their bioactivities without isolation and purification and may be used for multicomponent analysis of active substances in other foods and herbs. Therefore, to better harness C. deserticola resources, using this method to evaluate cultivated C. deserticola, a promising herb material with obvious antioxidant activity, is crucial.

Influence of the geometric isomers on the radical scavenging properties of 3,5-dicaffeoylquinic acid: A DFT study in vacuo and in solution

3,5-Dicaffeoylquinic acid (diCQA) is a part of the chlorogenic acid group of compounds, largely isolated from food sources and possessing potent antioxidant activity. Only the trans–trans isomer exists in nature, however, abiotic stresses, such as UV-radiation, give rise to cis isomers. There have been no reports on the antioxidant activity of the cis isomers. The current study, performed using the B3LYP/6-311[Formula: see text]G(d,p) method, is aimed at investigating and comparing the antioxidant properties of the geometrical isomers of 3,5-diCQA. The study is conducted by checking the molecules’ ability for two main radical scavenging mechanisms, hydrogen atom transfer (HAT) and electron transfer (ET). A separate DPPH assay experimental study performed in this study shows that all the geometrical isomers are potent radical scavengers. The lowest O[Formula: see text]H bond dissociation enthalpy value (70.599 kcal/mol) corresponds to the trans–trans isomer and is comparable to that of gallic acid, a commercially available antioxidant. The lowest ionization potential value corresponds to the cis–cis isomer (149.54[Formula: see text]kcal/mol), indicating that it is best antioxidant, in terms of ET mechanism.

Antioxidant Activity/Capacity Measurement. 3. Reactive Oxygen and Nitrogen Species (ROS/RNS) Scavenging Assays, Oxidative Stress Biomarkers, and Chromatographic/Chemometric Assays

There are many studies in which the antioxidant potential of different foods have been analyzed. However, there are still conflicting results and lack of information as a result of unstandardized assay techniques and differences between the principles of the methods applied. The measurement of antioxidant activity, especially in the case of mixtures, multifunctional or complex multiphase systems, cannot be evaluated satisfactorily using a simple antioxidant test due to the many variables influencing the results. In the literature, there are many antioxidant assays that are used to measure the total antioxidant activity/capacity of food materials. In this review, reactive oxygen and nitrogen species (ROS/RNS) scavenging assays are evaluated with respect to their mechanism, advantages, disadvantages, and potential use in food systems. On the other hand, in vivo antioxidant activity (AOA) assays including oxidative stress biomarkers and cellular-based assays are covered within the scope of this review. Finally, chromatographic and chemometric assays are reviewed, focusing on their benefits especially with respect to their time saving, cost-effective, and sensitive nature.

Screening of peroxynitrite scavengers in Flos Lonicerae by using two new methods, an HPLC-DAD-CL technique and a peroxynitrite spiking test followed by HPLC-DAD analysis

INTRODUCTION

Peroxynitrite is involved in the pathogenesis of a number of significant diseases. Peroxynitrite scavengers thus have potential application in understanding and treating these diseases. It is, therefore, important to establish screening methods able to rapidly identify peroxynitrite scavengers from herbal plants.

OBJECTIVE

To develop effective and easily operable screening methods for identifying peroxynitrite scavengers in complex matrices, including Chinese herbal medicines.

METHODS

Two simple and efficient screening methods have been developed for the identification of natural peroxynitrite scavengers in Flos Lonicerae Japonicae (FLJ). Method I used HPLC-DAD-(luminol-peroxynitrite)-CL techniques combined with Q-TOF MS/MS analysis, while Method II used pre-column reaction of the sample with peroxynitrite, followed by HPLC separation and Q-TOF MS/MS analysis.

RESULTS

Five peroxynitrite scavengers (neochlorogenic acid, chlorogenic acid, 3,4-O-dicaffeoyl quinic acid, 3,5-O-dicaffeoyl quinic acid and 4,5-O-dicaffeoyl quinic acid) were identified in FLJ using Method I. Besides the compounds identified using Method I, three additional peroxynitrite scavengers (rutin, isoquercitrin and luteoloside) were identified using Method II.

CONCLUSION

The two new methods proved to be complementary and the use of these methods should allow rapid detection of peroxynitrite-scavenging natural products from FLJ and other complex matrices.

Advanced development in phytochemicals analysis of medicine and food dual purposes plants used in China (2011-2014)

In 2011, we wrote a review for summarizing the phytochemical analysis (2006-2010) of medicine and food dual purposes plants used in China (Zhao et al., J. Chromatogr. A 1218 (2011) 7453-7475). Since then, more than 750 articles related to their phytochemical analysis have been published. Therefore, an updated review for the advanced development (2011-2014) in this topic is necessary for well understanding the quality control and health beneficial phytochemicals in these materials, as well as their research trends.

Rapid Identification and Quantification of Natural Antioxidants in the Seeds of Rhubarb from Different Habitats in China Using Accelerated Solvent Extraction and HPLC-DAD-ESI-MSn-DPPH Assay

In this study, the 10 accessions of rhubarb seeds from different habitats in China were investigated. Lipids were removed using petroleum ether, and the effective components were then separated using accelerated solvent extraction with 80% aqueous methanol. An off-line 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging method was used as the marker to evaluate the total antioxidant capability of extracts. On-line high-performance liquid chromatography-diode-array detectors-electrospray ionization-tandem mass spectrometry (HPLC-DAD-ESI-MS(n)) and HPLC-DAD-DPPH assays were developed for rapid identification and quantification of individual free-radical scavengers in extracts of rhubarb seeds. Ten free-radical scavengers from methanolic extracts of the rhubarb seeds were screened, five of which were identified and quantitatively analyzed: epicatechin, myricetin, hyperoside, quercitrin and quercetin. All were identified in rhubarb seeds for the first time and can be regarded as the major potent antioxidants in rhubarb seeds due to representing most of the total free-radical scavenging activity. Preliminary analysis of structures was performed for another five antioxidants. Based on our validation results, the developed method can be used for rapid separation, convenient identification and quantification of the multiple antioxidative constituents in rhubarb seeds, featuring good quantification parameters, accuracy and precision. The results are important to clarify the material basis and therapeutic mechanism of rhubarb seeds.

Qualitative and quantitative analysis of the major constituents in Chinese medical preparation Lianhua-Qingwen capsule by UPLC-DAD-QTOF-MS

Lianhua-Qingwen capsule (LQC) is a commonly used Chinese medical preparation to treat viral influenza and especially played a very important role in the fight against severe acute respiratory syndrome (SARS) in 2002-2003 in China. In this paper, a rapid ultraperformance liquid chromatography coupled with diode-array detector and quadrupole time-of-flight mass spectrometry (UPLC-DAD-QTOF-MS) method was established for qualitative and quantitative analysis of the major constituents of LQC. A total of 61 compounds including flavonoids, phenylpropanoids, anthraquinones, triterpenoids, iridoids, and other types of compounds were unambiguously or tentatively identified by comparing the retention times and accurate mass measurement with reference compounds or literature data. Among them, twelve representative compounds were further quantified as chemical markers in quantitative analysis, including salidroside, chlorogenic acid, forsythoside E, cryptochlorogenic acid, amygdalin, sweroside, hyperin, rutin, forsythoside A, phillyrin, rhein, and glycyrrhizic acid. The UPLC-DAD method was evaluated with linearity, limit of detection (LOD), limit of quantification (LOQ), precision, stability, repeatability, and recovery tests. The results showed that the developed quantitative method was linear, sensitive, and precise for the quality control of LQC.

Chemical profiling of Jinqi Jiangtang tablets by HPLC-ESI-Q-TOF/MS

AIM

To profile the chemical constituents in Jinqi Jiangtang tablets.

METHOD

Based on the chromatographic retention behavior, fragmentation patterns of chemical components, and published literatures, a high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-Q-TOF/MS) method was established to characterize and identify components in Jinqi Jiangtang tablets.

RESULTS

A total of 52 chemical compounds, including eight iridoid glycosides, seven phenolic acids, twelve alkaloids, six flavonoids, and nineteen saponins, were identified in Jinqi Jiangtang tablets.

CONCLUSION

The established method could serve as a powerful tool for structural characterization and quality control of this Chinese herbal preparation.

Identification and characterization of chlorogenic acids, chlorogenic acid glycosides and flavonoids from Lonicera henryi L. (Caprifoliaceae) leaves by LC-MSn

The chlorogenic acids, chlorogenic acid glycosides and flavonoids of the leaves of Lonicera henryi L. (Caprifoliaceae) were investigated qualitatively by liquid chromatography tandem mass spectrometry. Thirty-one chlorogenic acids and their glycosides were detected and characterized to their regioisomeric level on the basis of their unique fragmentation pattern in the negative ion mode tandem MS spectra. All of them were extracted for the first time from this source and thirteen of them were not reported previously in nature. For the positive identification of chlorogenic acid glycosides by LC-MS(n), multiple reaction monitoring and targeted MS(n) experiments were performed. We have developed an LC-MS(n) method for the systematic identification of chlorogenic acid glycosides and were also able to discriminate between chlorogenic acids and their isobaric glycosides. It was also possible to discriminate between 5-O-(3'-O-caffeoyl glucosyl)quinic acid and 5-O-(4'-O-caffeoyl glucosyl)quinic acid by LC-MS(n). This method can be applied for the rapid and positive identification of chlorogenic acids and their glycosides in plant materials, food and beverages.

Extraction and Bioactivity Analysis of Major Flavones Compounds from Scutellaria baicalensis Using In Vitro Assay and Online Screening HPLC-ABTS System

The extraction efficiency of a number of solvent compositions for the improvement of bioactive compounds yield from S. baicalensis has been investigated. Also, free radical scavengers in the glycoside baicalin (BG), wogonoside (WG), aglycon baicalein (B), and wogonin (W) compounds of S. baicalensis were screened, identified, and quantified using coupled offline ABTS and online screening HPLC-ABTS assay. Increasing ethanol content fractions resulted in decreased extract yield of bioactive compounds. In this case, the best yield of 37.01 mg/g in BG, WG, B, and W compounds was obtained by a dipping method with an extraction time of 4 h. In addition, the yield (43.05%) and IC50 (34.04 μg/mL) determined through ABTS assay of the 60% aqueous ethanol extract were the most satisfactory of all solvent solutions tested. This result shows that an online screening HPLC-ABTS assay can be a powerful technique for the rapid characterization of bioactivity compounds in plant extracts. Moreover, their anti-inflammatory activities were evaluated via analyzed inhibitory effect on NO and inflammatory cytokine production. Furthermore, WG and W exhibited the strong inhibitory effects on inflammatory mediator production including NO, IL-6, and IL-1β in LPS-stimulated RAW 264.7 macrophages.

The screening research of anti-inflammatory bioactive markers from different flowering phases of Flos Lonicerae Japonicae

Flos Lonicerae Japonicae (FLJ) is an important cash crop in eastern Asia, and it is an anti-inflammatory Traditional Chinese Medicine. There are large variations in the quality of the marketed FLJ products. To find marker ingredients useful for quality control, a tandem technology integrating ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF), principal component analysis (PCA), heat map analysis and hierarchical cluster analysis coupled with a NF-κB luciferase reporter gene assay were used to identify the different ingredients from the green bud, white bud, flowering stage and leaf stages, as well as to screen the anti-inflammatory activity of FLJ compositions. As flowering progressed, the anti-inflammatory effects of FLJ gradually decreased; however, chlorogenic acid, swertiamarin and sweroside should be used to evaluate the quality of FLJ products.

HPLC-DPPH screening method for evaluation of antioxidant compounds extracted from Semen Oroxyli

Semen Oroxyli, derived from the seed of Oroxylum indicum L., is a commonly used Traditional Chinese Medicine with beneficial effects against several respiratory disorders. Antioxidative flavonoids may be partly responsible for its medicinal functions. The aim of this study was to rapidly determine the antioxidants in Semen Oroxyli based on a HPLC-DPPH method. Four major flavonoids, baicalein-7-O-gentiobioside, baicalein-7-O-glucoside, baicalein, and baicalin, were identified as the active components against DPPH free radicals, which is in accord with the results of our former traditional activity-guided phytochemical study. The oxidative products of the four antioxidant flavonoids were studied in the DPPH spiking HPLC assay, it was suggested that the three active flavonoid glycosides were converted into 5,6-dihydroxy-7-methoxyflavone, which implied that an additional hydroxyl at C-6 in 5,7-dihydroxyflavones plays an important role in the DPPH assay.