Detection, isolation, and characterization of a novel impurity from several folic acid products.

Folic acid belongs to the group of water-soluble B vitamins and naturally exists in multiple forms in a wide variety of foods such as legumes, vegetables, liver, and milk (Iyer and Tomar, 2009; Lyon et al., 2020). It is involved in many biochemical reactions critical for cell division, such as purine and pyrimidine biosynthesis, DNA/RNA biosynthesis, and amino acid metabolism (Iyer and Tomar, 2009). Mammals cannot synthesize folic acid and thus they must acquire it from food. Although folic acid is ubiquitous in foods, folic acid deficiency still often occurs due to various causes such as unhealthy diet (Hildebrand et al., 2021; Iimura et al., 2022), disease-related malabsorption (Arcot and Shrestha, 2005), medication-related depletion (Arcot and Shrestha, 2005), or vitamin B12 deficiency (Fishman et al., 2000). Folic acid deficiency has been associated with several health problems, such as anemia (Carmel, 2005; Bailey and Caudill, 2012), cancer (Duthie, 1999), cardiovascular diseases (Wald et al., 2002), neural tube defects in newborns (van der Put et al., 2001), neuropsychiatric dysfunction (Shea et al., 2002), depression (Falade et al., 2021), inflammatory diseases (Suzuki and Kunisawa, 2015; Jones et al., 2019), and eye diseases (Sijilmassi, 2019). To prevent folic acid deficiency, its daily intake (400 µg/d) has been recommended for adults in the European Union, and its increased intake (600 µg/d) is advised for women before and during pregnancy (FAO/WHO, 2002; IOM, 2004). The New Zealand government mandated the fortification of non-organic wheat flour with folic acid in July 2021, and the UK government mandated the fortification of non-wholemeal wheat flour with folic acid in September 2021 (Haggarty, 2021).

Danhong Injection Attenuates Cerebral Ischemia-Reperfusion Injury in Rats Through the Suppression of the Neuroinflammation.

Neuroinflammation is one of the major causes of damage of the central nervous system (CNS) and plays a vital role in the pathogenesis of cerebral ischemia, which can result in long-term disability and neuronal death. Danhong injection (DHI), a traditional Chinese medicine injection, has been applied to the clinical treatment of cerebral stoke for many years. In this study, we investigated the protective effects of DHI on cerebral ischemia-reperfusion injury (CIRI) in rats and explored its potential anti-neuroinflammatory properties. CIRI in adult male SD rats was induced by middle cerebral artery occlusion (MCAO) for 1 h and reperfusion for 24 h. Results showed that DHI (0.5, 1, and 2 ml/kg) dose-dependently improved the neurological deficits and alleviated cerebral infarct volume and histopathological damage of the cerebral cortex caused by CIRI. Moreover, DHI (0.5, 1, and 2 ml/kg) inhibited the mRNA expressions of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), intercellular cell adhesion molecule-1 (ICAM-1), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) in ischemic brains, downregulated TNF-α, IL-1ß, and monocyte chemotactic protein-1 (MCP-1) levels in serum, and reduced the neutrophil infiltration (myeloperoxidase, MPO) in ischemic brains, in a dose-dependent manner. Immunohistochemical staining results also revealed that DHI dose-dependently diminished the protein expressions of ICAM-1 and COX-2, and suppressed the activation of microglia (ionized calcium-binding adapter molecule 1, Iba-1) and astrocyte (glial fibrillary acidic protein, GFAP) in the cerebral cortex. Western blot analysis showed that DHI significantly downregulated the phosphorylation levels of the proteins in nuclear factor κB (NF-κB) and mitogen-activated protein kinas (MAPK) signaling pathways in ischemic brains. These results indicate that DHI exerts anti-neuroinflammatory effects against CIRI, which contribute to the amelioration of CNS damage.

Comparison of the clinical features and therapeutics of COVID-19 in cardio-cerebrovascular disease (CCVD) and non-CCVD patients.

Cardio-cerebrovascular disease (CCVD) is a major comorbidity of Coronavirus disease 2019 (COVID-19). However, the clinical characteristics and outcomes remain unclear. In this study, 102 cases of COVID-19 from January 22, 2020 to March 26, 2020 in Xixi Hospital of Hangzhou were included. Twenty cases had pre-existing CCVD. Results showed that compared with non-CCVD patients, those with CCVD are more likely to develop severe disease (15% versus 1%), and the proportion of pneumonia severity index grade IV was significantly higher (25% versus 3.6%). Computed tomography images demonstrated that the proportion of multiple lobe lesion involvement was significantly higher in the CCVD group than in the non-CCVD group (90% versus 63.4%). Compared with non-CCVD group, the levels of C-reactive protein, fibrinogen, D-dimer, and serum amyloid-A were higher, whereas the total protein and arterial partial PaO2 were lower in the CCVD group. Although no statistical difference was observed in the outcomes between groups, CCVD patients received more intensive comprehensive treatment to improve COVID-19 symptoms compared with non-CCVD patients. Integrated Chinese and Western medicine treatments have certain advantages in controlling the severe conversion rate and mortality of COVID-19. In addition, given that COVID-19 patients are usually related to coagulation disorders and thrombosis risk, the application of Chinese medicine in promoting blood circulation and removing stasis should be strengthened.

Investigation of Invigorating Qi and Activating Blood Circulation Prescriptions in Treating Qi Deficiency and Blood Stasis Syndrome of Ischemic Stroke Patients: Study Protocol for a Randomized Controlled Trial.

Ischemic stroke (IS) is characterized by high morbidity and high mortality. The integration of Traditional Chinese medicine (TCM) and western medicine has shown promising benefits in relieving symptoms, promoting neurological recovery, and improving the quality of life of patients with IS. In TCM, Qi-deficiency along with blood-stasis (QDBS) syndrome is one of the common types of IS that is treated by invigorating Qi and activating blood circulation. In TCM theory, improving the corresponding degree of prescription-syndrome correlation (PSC) is helpful to improve clinical efficacy. In this study, we intend to use similar prescriptions that invigorate Qi and activate blood circulation: Buyang Huanwu granules (BHG), Naoxintong capsules (NXTC), and Yangyin Tongnao granules (YTG). The goal is to evaluate their level of PSC inpatients with IS with QDBS syndrome and find relevant biomarkers to provide an objective basis for precise treatment of TCM and improve the clinical therapeutic effects. A multicenter, randomized, double-blinded, and placebo-controlled intervention trial will be conducted in IS patients with QDBS syndrome, followed by an add-on of Chinese patent medicine. A total of 160 subjects will be randomly assigned to the BHG, NXTC, YTG, and placebo groups in a 1:2:1:1 allocation ratio. All subjects will undergo 28 days of treatment and then followed for another 180 days. The primary outcome is the changes in the National Institutes of Health Stroke Scale score after 28 days of medication. The secondary outcomes include the modified Rankin scale score, activity of daily living scale score, and TCM symptom score. Data will be analyzed in accordance with a predefined statistical analysis plan. Ethical approval of this trial has been granted by the Research Ethics Committee of the First Affiliated Hospital of Zhejiang Chinese Medical University (ID: 2017-Y-004-02). Written informed consent of patients will be required. This trial is registered in the Chinese Clinical Trial Registry (ChiCTR1800015189), and the results will be disseminated to the public through peer-reviewed journals and academic conferences.

Rapid quality control of medicine and food dual purpose plant polysaccharides by matrix assisted laser desorption/ionization mass spectrometry.

With their multiple biological activities and health benefit effects, polysaccharides from medicine and food dual purpose plants (MFDPPPs) have been extensively applied in many fields, including in medical treatments, stock farming, and cosmetics. However, to date, quality issues of MFDPPPs and technologies for the analysis of polysaccharides have posed challenges to chemists. Reported herein is a rapid and high-throughput quality control method for analyzing MFDPPPs, based on matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). For the analysis of illegally added and doped substances, ferroferric oxide nanoparticles were employed as the MALDI matrix to avoid small molecule interference. Qualitatively, high sensitivity was obtained for both illegal drugs and glucose. Quantitatively, the best linear response (R2 > 0.99) was attained in the concentration range from 0.005 to 1 mg mL-1 for glucose. For the analysis of polysaccharides, 2,5-dihydroxybenzoic acid/N-methylaniline was employed as the MALDI matrix to increase the detection sensitivity and mass range coverage. Furthermore, the established method was successfully applied to the analysis of supplements from Astragalus polysaccharides and Lentinan real samples, showing its potential in quality control for MFDPPPs.

Effects of Guanxinshutong Capsules as Complementary Treatment in Patients With Chronic Heart Failure: Study Protocol for a Randomized Controlled Trial.

Chronic heart failure (CHF) is a common cardiovascular disease with high mortality and a poor prognosis, which places heavy burdens upon society and families. Traditional Chinese medicine (TCM) has been used extensively as complementary treatment for CHF. Guanxinshutong (GXST) capsules are used commonly for the treatment of coronary heart disease (CHD). Experimental research and small-sample clinical trials have shown that GXST can attenuate CHF. However, the effects of GXST as complementary medicine in CHF treatment lack high-quality clinical evidence. We have designed a multicenter, randomized, double-blind, placebo-controlled clinical trial that explores the efficacy and safety of using GXST compared with placebo for patients with CHF with reduced left ventricular ejection fraction (LVEF). A total of 480 participants will be assigned randomly to the GXST group or placebo group at a 2:1 ratio. GXST and placebo will be added to standard treatment for 12 weeks, and then followed up for another 40 weeks. The primary outcome is the improvement value of 6-min walk distance, and the secondary outcomes include plasma levels of N-terminal pro-B-type natriuretic peptide, New York Heart Association classification, Minnesota Living with Heart Failure Questionnaire scores, echocardiographic parameters, and clinical endpoint events. Adverse events will be monitored throughout the trial. Data will be analyzed following a predefined statistical analysis plan. This study will show the effects of the specific use of GXST in CHF patients with reduced LVEF. The Research Ethics Committee of the Second Affiliated Hospital of Zhejiang Chinese Medical University has approved this study (2019-Y-003-02). Written informed consent of patients will be required. This trial is registered in the Chinese Clinical Trial Registry (ChiCTR1900023877). Our results will be disseminated to the public through peer-reviewed journals, academic conferences, and the Internet.

A novel strategy to utilize ethylene glycol-ionic liquids for the selective precipitation of polysaccharides.

In the present work, three hydrophilic ionic liquids based on the combination between imidazolium cations attached with ethylene glycol polymers of various lengths and hexafluorophosphate anion were designed and synthesized for the separation of polysaccharides. By employing dextran 100 kDa as model compound, the effects of ionic liquid content, solvent/anti-solvent volume, and temperature on its recovery efficiency were investigated systematically. The ability of these ionic liquids to precipitate dextran 100 kDa, increases with the elongation of ethylene glycol polymer chain. The established ionic liquid-based precipitation system was successfully applied to selectively precipitate polysaccharides from water extracts of three traditional Chinese medicines and the precipitation could be achieved in about 15 min. In addition, the different precipitation responses of acidic, neutral, and basic polysaccharides in the ionic liquid-based precipitation system and theoretical calculations both suggested that the selective precipitation of polysaccharides was probably mediated by interaction between ionic liquids and polysaccharides. The proposed strategy facilitated the isolation and purification of polysaccharides and may trigger a novel application of ionic liquids in carbohydrate research.

High-Speed Counter-Current Chromatography (HSCCC) Purification of Antifungal Hydroxy Unsaturated Fatty Acids from Plant-Seed Oil and Lactobacillus Cultures.

Hydroxy unsaturated fatty acids (HUFA) can function as antifungal agents. To investigate the antifungal spectrum, that is, the scope of the in vitro fungal-inhibition activities of HUFA and their potential applications, three HUFA were produced by microbial transformation or extracted from plant-seed oils; these compounds included coriolic acid (13-hydroxy-9,11-octadecadienoic acid) from Coriaria seed oil, 10-hydroxy-12-octadecenoic acid from cultures of Lactobacillus hammesii, and 13-hydroxy-9-octadecenoic acid from cultures of Lactobacillus plantarum TMW1.460Δlah. HUFA were purified by high-speed counter-current chromatography (HSCCC), characterized by LC-MS and MS/MS, and their antifungal activities were evaluated with 15 indicator fungal strains. The HUFA had different antifungal spectra when compared with unsaturated fatty acids with comparable structures but without hydroxy groups. The inhibitory effects of HUFA specifically targeted filamentous fungi, including Aspergillus niger and Penicillium roqueforti, whereas yeasts, including Candida spp. and Saccharomyces spp., were resistant to HUFA. The findings here support the development of food applications for antifungal HUFA.

Structural characterization and immunomodulatory activity of a water soluble polysaccharide isolated from Botrychium ternatum.

As a folk medicine, Botrychium ternatum has been used for thousands of years in China. In the present work, a water soluble polysaccharide BTp1 was extracted and purified from B. ternatum. Based on the MALDI matrix 3-aminoquinoline-α-cyano-4-hydroxycinnamic acid, the molecular weight of BTp1 was determined to be 11638Da directly. Monosaccharide analysis showed that BTp1 was composed of arabinose (Ara). Combining enzymatic hydrolysis and subsequent MALDI-TOF analysis, a linear backbone of BTp1, consisted of (1→5)-linked α-l-Araf, was inferred quickly. Then according to NMR experiments, the whole structure of BTp1 was established. The repeating unit of BTp1 was deduced as a linear backbone with branches at O-2, O-3 and its neighboring O-2 positions terminated with (1→)-linked α-l-Araf, respectively. The immunomodulatory assay exhibited that BTp1 could significantly enhance the viability and promote the release of NO in RAW 264.7 cells, suggesting that BTp1 could be a potential immunomodulatory agent in pharmacological fields.

Special Effect of Ionic Liquids on the Extraction of Flavonoid Glycosides from Chrysanthemum morifolium Ramat by Microwave Assistance.

A microwave-assisted extraction approach based on ionic liquids of different chain lengths was successfully applied to the extraction of ten flavonoid glycosides from the flowering heads of Chrysanthemum morifolium Ramat. The pretreated sample was quantified by HPLC-ESI-MSn. The main components were identified as flavonoid glycosides, including three luteolin glycosides, three apigenin glycosides, three kaempferide glycosides, and one acacetin glycoside according to the characteristics of the corresponding CID mass spectrometric patterns. Eight ionic liquids from the imidazolium family with different chain lengths, namely, 1-alkyl-3-methylimidazolium bromide, [Cnmim]Br, (n=2-16) were studied as extraction medium in water. Results indicated that alkyl chain length had an irregular impact on the extraction efficiency. Moreover, the best extraction efficiency was achieved by 1-dodecyl-3-methylimidazolium bromide aqueous solution ([C12mim]Br). Besides the alkyl chain length of the cations, other factors influencing extraction efficiency were systematically investigated, including concentration of the IL solutions, extraction time, matrix-to-solvent ratio and irradiation power.

Water-soluble polysaccharides from finger citron fruits (Citrus medica L. var. sarcodactylis).

Four water-soluble polysaccharides, FCp-1, FCp-2, FCp-3, and FCp-4 were obtained from finger citron fruits (Citrus medica L. var. sarcodactylis) by hot-water extraction and ethanol precipitation, followed by routine separation procedure. Based on the calibration curve, molecular weights of them were estimated to be 113.9, 32.6, 140.3, and 177.1 kDa respectively. The acid hydrolysis, methylation, IR, GC-MS, and NMR experiments were used for composition analysis. FCp-1 was a heteropolysaccharide composed of arabinose, galactose, glucose, rhamnose, and xylose, with a molar ratio of 3.0:7.0:4.1:1.0:1.5. FCp-2 and FCp-4 were →4)-α-D-GalpA(1→ linking galacturonan differ in molecular weights. FCp-3 was a →6)-α-D-Glcp(1→ linking glucan. According to the results of in vitro assays, FCp-3 showed significantly and moderately enhancing capacities toward the proliferation of splenocytes and thymocytes respectively. Thus, FCp-3 or analogs may have further use as immunomodulatory agents.

An arabinogalactan from flowers of Chrysanthemum morifolium: structural and bioactivity studies.

A water-soluble polysaccharide (P2) with a molecular weight of 1.7×10(5)Da was isolated from the hot aqueous extract of flowers of the Chrysanthemum morifolium. It was homogeneous for there was only a symmetrical peak on the spectrum of high-performance gel permeation chromatography. Monosaccharide analysis revealed that P2 is an arabinogalactan containing arabinose (38.4% w/w), galactose (58.8% w/w), and glucose (2.8% w/w) in a ratio of 1:1.53:0.07. The GC-MS results of the derived alditol acetates from the permethylated P2 showed some separate peaks corresponding to (1→6)-linked Gal, (1→3,6)-linked Gal, terminal Ara, (1→5)-linked Ara, and (1→3,5)-linked Ara units in a molar ratio of nearly 1.12:1.90:1.84:0.35:0.12. Terminal Glc unit also existed in a trace amount. (1)H, (13)C, DEPT-135 and 2D NMR (including HMQC and HMBC), as well as graded acid hydrolysis experiment, indicated that the core structure features include a backbone chain consisting of (1→6)-linked and (1→3,6)-linked Galp residues. Side chains which were composed of terminal Glcp, terminal, (1→5)-linked and (1→3,5)-linked Araf residues were located at position 3. Additionally, P2 showed good immunological activity as it significantly enhanced splenocyte proliferation in relatively low 25 and 50µg/mL doses. However, P2 showed little effects of thymocyte proliferation, indicating that it may have two modes of action.

Cytotoxic triterpenoids from Lysimachia parvifolia.

Five new oleanane-type triterpenoids, including two aglycones, 13ß-28-epoxy-3ß,22α,23-trihydroxyolean-16-one (1) and 13ß-28-epoxy-22α,23-dihydroxyolean-3,16-dione (2), and three glycosides, anagalligenone-3-O-α-L-arabinopyranoside (3), anagalligenone-3-O-[ß-D-glucopyranosyl(1 → 4)-α-L-arabinopyranoside] (4) and anagalligenone-3-O-[ß-D-xylopyranosyl(1 → 2)-ß-D-glucopyranosyl(1 → 4)-α-L-arabinopyranoside] (5), were isolated from the aerial parts of Lysimachia parvifolia, together with three known oleanane-type triterpenoid glycosides (6-8). The structures of the new compounds were subsequently elucidated by spectroscopic analysis and their cytotoxicities evaluated against six human cancer cell lines. Compounds 5-8 exhibited significant cytotoxicities against all the cell lines tested, with IC50 values lower than 10 µM. The possible mechanism of action of compound 6 was also studied.

Selective (1)O(2) quenchers, oligostilbenes, from Vitis wilsonae: structural identification and biogenetic relationship.

Two previously unknown resveratrol trimers named wilsonols A-B, as well as a resveratrol tetramer named wilsonol C, were isolated from Vitis wilsonae Veitch, together with 12 known oligostilbenes. Their chemical structures have been elucidated by detailed analyses of 1D and 2D NMR spectroscopic data, as well as chemical evidence obtained via either catalysis with HRP (horseradish peroxidase) and H(2)O(2) (hydrogen peroxide), acid, or UV irradiation. During the chemical processes, a biomimetic resveratrol tetramer named diviniferin B that has not been found in nature was obtained. These oligostilbenes showed potent scavenging abilities towards DPPH radicals and selective quenching effects on (1)O(2) radicals. Furthermore, the biogenetic transformations between the 16 oligostilbenes have been elaborated chemically to provide a comprehensive mechanism of the antioxidative defense system in this plant species.

Comprehensive separation and analysis of alkaloids from Stephania yunnanensis by counter-current chromatography coupled with liquid chromatography tandem mass spectrometry analysis.

The polar compounds such as alkaloid compounds are important bioactive components in traditional Chinese medicines. In present study, a comprehensive method for separation and analysis of polar compounds from the polar fraction of traditional Chinese medicine Stephania yunnanensis was established. Both the major components and minor components were analyzed by counter-current chromatography combined with liquid chromatography tandem mass spectrometry (LC-MS(n)). From 50 mg polar fraction of crude extract, 15.2mg corydine and 4.8 mg stepharine with purities over 90% were successfully separated via a polar solvent system n-butanol: methanol: water (4:1:5, v/v) with 10 mM NaOH as an additive in the lower phase, in one step operation. Their structures were further identified by 1H NMR and FTICR-MS. Besides, three minor components were identified by HPLC-MS(n) based on the fragmentation behavior of the purified compounds.

Differentiation of common diastereoisomeric ursane-type triterpenoids by high-performance liquid chromatography/tandem mass spectrometry.

A rapid and stable method consisting of high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry was established for the identification and differentiation of common diastereoisomeric ursane-type triterpenoids at the C-3 position. Two characteristic fragment ions, [M-H-H(2) O-CO(2)](-) and [M-H-H(2)O-HCOOH](-) , exhibited significant stereochemical effects and were utilized to distinguish 3-OH epimers. Based on reference standards, the abundance of the fragment ion [M-H-H(2)O-HCOOH](-) in 3ß-OH compounds in the MS(3) experiment was dramatically higher compared to [M-H-H(2) O-CO(2)](-); however, for 3α-OH compounds, the product ion [M-H-H(2) O-CO(2)](-) was noted to be higher than [M-H-H(2)O-HCOOH](-). Energy-resolved mass spectrometric experiments were carried out to support the differentiation of these diastereoisomeric triterpenoids at the C-3 position. Using this method, a total of nine ursane-type triterpenoids from a plant crude extract, including four pairs of epimers at the C-3 position, were identified and distinguished rapidly. Furthermore, offline Fourier transform ion cyclotron resonance tandem mass spectrometry was also performed to assign accurate elemental compositions.

Two-dimensional counter-current chromatography: 1st traditional counter-current chromatography, 2nd acid-base elution counter-current chromatography.

An on-line column-switching counter-current chromatography (CCC) with solid-phase trapping interphase is presented in this paper. The large volume injection is avoided using solid-phase trapping interphase. Thereby, totally different chemical composition biphasic solvent system can be utilized to enhance system orthogonality. In the present work, a 140 mL-capacity CCC instrument was used in the first dimension, and a parallel three-coil CCC centrifuge (40 mL each coil) was used in the second dimensional separation allowing three injections at the same time. With biphasic solvent system composed of n-hexane: ethyl acetate: methanol: water (1:1:1:1, v/v), five well-separated fractions were obtained in the first dimension. Two fractions were online concentrated and further separated in the second dimension with solvent system composed of methyl tert-butyl ether: acetonitrile: water (2:2:3, v/v), where trifluoroacetic acid (10 mM) was added to the upper organic phase as a retainer and triethylamine (10mM) to the aqueous mobile phase as an eluter. Four hydroxyanthraquinones were successfully separated and purified from Chinese medicinal plant Rheum officinale in only one step.

Preparative separation of isoquinoline alkaloids from Stephania yunnanensis by pH-zone-refining counter-current chromatography.

In this paper, five isoquinoline alkaloids were successfully separated from a crude extract of Stephania yunnanensis using pH-zone-refining counter-current chromatography in single-step. With a two-phase solvent system composed of methyl-tert-butyl ether (MtBE)-acetonitrile-water (2:2:3, v/v) where triethylamine (10 mM) was added to the upper organic phase as a retainer and hydrochloric acid (5 mM) to the aqueous mobile phase as an eluter. From 1.4 g crude extract, 68.7 mg isocorydine, 78.2 mg corydine, 583.4 mg tetrahydropalmatine, 36.3 mg N-methylasimilobine, and 47.3 mg anonaine were separated with purities over 90%. Their structures were identified by (1)H NMR, (13)C NMR, ESI-MS data.

Preparative separation of anti-oxidative constituents from Rubia cordifolia by column-switching counter-current chromatography.

An effective column-switching counter-current chromatography (CCC) protocol combining stepwise elution mode was successfully developed for simultaneous and preparative separation of anti-oxidative components from ethyl acetate extract of traditional Chinese herbal medicine Rubia cordifolia. The column-switching CCC system was interfaced by a commercial low-pressure six-port switching valve equipped with a sample loop, allowing large volume introduction from the first dimension (1st-D) to the second dimension (2nd-D). Moreover, to extend the polarity window, three biphasic liquid systems composed of n-hexane/ethyl acetate/methanol/water (1:2:1:2, 2:3:2:3, 5:6:5:6 v/v) were employed using stepwise elution mode in the 1st-D. By valve switching technique the whole interested region of 1st-D could be introduced to second dimension for further separation with the solvent system 5:5:4:6 v/v. Using the present column-switching CCC protocol, 500 mg of crude R. cordifolia extract were separated, producing milligram-amounts of four anti-oxidative components over 90% pure. Structures of purified compounds were identified by (1)H and (13)C NMR.

Screening of antioxidant phenolic compounds in Chinese rhubarb combining fast counter-current chromatography fractionation and liquid chromatography/mass spectrometry analysis.

In this paper, an effective method combing fast elution-extrusion counter-current chromatography (CCC) and LC/MS for rapid screening of antioxidative phenolic compounds in Chinese Rhubarb is presented. An integrated three-coil CCC column (40 mL each coil) was used to accomplish the optimization of biphasic liquid system. In a single run (approximately 40 min), the solvent system composed of n-hexane/ethyl acetate/methanol/water (1:1:1:1, v/v) was selected as optimum CCC liquid system for fast fractionation of the crude ethanol extract. With a 140 mL-capacity CCC instrument, 100 mg Chinese Rhubarb extract was separated under the optimized conditions, producing six fractions in only 100 min. The quantities of each fraction were approximately 15 mg. In addition, each fraction was subjected to antioxidant activity assay and characterized by LC/MS analysis. Fifty compounds, including phenolic acids, phenolic glucosides and hydroxyanthraquinones, were detected by LC/MS/MS analysis. As a result, gallic acid together with Fr I showed excellent antioxidant activity, which was well consistent with previous studies and exhibited great potential for natural drug discovery program of the present method.