Four novel lactams, colletotrilactam A-D (1-4), along with six known compounds (5-10) were isolated from the culture broth of Colletotrichum gloeosporioides GT-7, a fungal endophyte of Uncaria rhynchophylla. The structures of these compounds were elucidated by comprehensive NMR spectroscopy. Isolates were tested for monoamine oxidase (MAO) inhibitory activity and compound 9 showed potent MAO inhibitory activity with IC50 value of 8.93±0.34μg/mL, when the IC50 value of iproniazid as a standard was 1.80±0.5μg/mL.
Liquid chromatography coupled with diode array detector and electrospray ionization mass spectrometry was developed for the qualitative and quantitative comparison of the main constituents in Saussurea laniceps (SL) and S. medusa (SM), two species of plants used under the name "Xuelianhua" in traditional Tibetan medicine. A method validation including linearity, limit of detection, precision and recovery was performed. The results showed that a good linearity with R<sup>2</sup> > 0.99 was achieved, and the limit of detection of the quantified constituents was reported to be between 0.8 and 3.3 ng. The relative standard deviation value was below 3.82% for repeatability, and recovery studies for the quantified compounds were found to be within the range 90.92-103.12%. The unique properties of the present method were evaluated by analyzing twelve related herbal samples including five S. laniceps samples and seven S. medusa samples. Twenty-two compounds including phenolic acids, cumarins, lignanoids and flavonoids were identified by online ESI-MS and by comparison with literature data and standard compounds, and seven of them were quantified by LC-DAD simultaneously. The results demonstrated that the common constituents in the two herbs were protocatechuic acid, syringoside, chlorogenic acid, isoquercitroside, 1,5-dicaffeoylquinic acid, apigenin 7-O-Îø-d-glucoside, chrysoeriol 7-O-Îø-d-glucoside, acacetin 7-O-Îø-d-glucoside, apigenin and chrysoeriol. In the present study, it was found that the characteristic constituents were umbelliferone, scopoletin and their glucosides in S. laniceps, as well as arctiin and arctigenin in S. medusa. It was feasible to choose these characteristic compounds for the quality evaluation as well as chemical authentication of the two related herbs. The results also support discrimination between the two species when using them in folk medicine.
Erigeron breviscapus (Vant.) Hand-mazz (EB), Erigeron multiradiatus (Lindl.) Benth (EM), and Aster brachytrichus Franch (AB), confused under the vernacular name "meiduoluomi" by native people and traditional healers, have been used for the treatment of meningitis, polyneuritis, hepatitis, adenolymphitis, and enteronitis in traditional Tibetan medicine. In this study, the antiinflammatory activity of methanol extracts of all three plants was investigated in the xylene-induced ear edema model, carrageenan-induced paw edema model, and cotton pellet-induced granuloma model. It was found that the methanolic extracts of both EB and EM had strong inhibitory effects on the acute phase of inflammation in carrageenan-induced paw edema in rats. On the other hand, the methanolic extract of EM showed stronger effects than those of EB in xylene-induced ear edema. In the chronic test, the methanolic extracts of EB and EM resulted in a significant reduction in granuloma weight in rats. In addition, myeloperoxidase (MPO) activity was strongly reduced in the EB-treated and EM-treated groups, which indicated that EB and EM can inhibit certain inflammatory modulator factors that cause neutrophil aggregation in inflamed tissue, e.g., nuclear factor-kappaB. However, the methanolic extracts of AB had no antiinflammatory effects in the tested models and MPO assay. The similar effects of EM and EB in tested models provided some scientific basis for the traditional usage of meiduoluomi in inflammatory disease. However, the results also suggest that further study is needed to investigate the antiinflammatory profile of AB and provide a scientific basis for the use of AB in inflammatory diseases.
ETHNOPHARMACOLOGICAL RELEVANCE: Saussurea involucrata (Kar. et Kir.) Sch.-Bip. (Compositae) has long been used under the herbal name "Snow Lotus" for the treatment of rheumatoid arthritis, stomachache and dysmenorrhea in Uighur folk medicine. In traditional Tibetan medicine, Saussurea laniceps Hand.-Mazz. and Saussurea medusa Maxim. have also been used under the name "Snow Lotus" and prescribed for the treatment of pain and inflammatory conditions.AIM OF THE STUDY: The present study evaluated the pharmacological effects of three species of "Snow Lotus" in experimental inflammation and pain models, and determined the chemical compounds that may correlate with their pharmacological activities.
MATERIALS AND METHODS: The anti-inflammatory activities of the three herbs were observed by using carrageenan-induced paw edema in rats and xylene-induced ear edema in mice. Investigations on the analgesic effects were conducted, including acetic acid-induced writhing and hot-plate test. An UPLC-MS method was developed to analyze the chemical composition of the three herbs and of plasma samples after herb administration.
RESULTS: In rat paw edema model, the peak inhibitory effects of Saussurea laniceps and Saussurea involucrata (55.1% and 42.2%, respectively) were recorded with the dose of 400mg/kg at 3h post-carrageenan injection. In mouse ear edema model, oral administration of Saussurea laniceps, Saussurea involucrata and Saussurea medusa extract (400mg/kg) resulted in a significant inhibition of ear edema by 40.9%, 33.3%, and 9.1%, respectively. In the writhing test, oral administration of Saussurea laniceps extract (100, 200 and 400mg/kg) resulted in a significant inhibition of writhings by 13.5%, 22.3%, and 43.5%, respectively. In the hot-plate test, Saussurea laniceps extract significantly increased the latency of jumping response by 38.2% and 52.7% when treated orally at 200 and 400mg/kg in mice, respectively. Flavonoids, coumarins and lignins were found to be present in plasma after administration of the extracts and may be the basis of the observed pharmacological effects.
CONCLUSION: The results clearly demonstrated that Saussurea laniceps was most effective; Saussurea involucrata exhibited a moderate potency, whereas Saussurea medusa possessed little effect against the experimental edema and pains. This study also supported discrimination among the three herbs when using them in folk medicine.
The present study evaluated the pharmacological effects of three species <b>Saussurea</b> commonly used as the traditional herbal drug “Snow Lotus” in experimental inflammation and pain models, and determined the chemical compounds that may correlate with their pharmacological activities. The results clearly demonstrated that <b>Saussurea laniceps</b> was most effective; <b>Saussurea involucrata</b> exhibited a moderate potency, whereas <b>Saussurea medusa</b> possessed little effect against the experimental edema and pains. Flavonoids, coumarins and lignins were found to be present in plasma after administration of the extracts and may be the basis of the observed pharmacological effects.<br>Ethnopharmacological relevance: <b>Saussurea involucrata</b> (Kar. et Kir.) Sch.-Bip. (Compositae) has long been used under the herbal name “Snow Lotus” for the treatment of rheumatoid arthritis, stomachache and dysmenorrhea in Uighur folk medicine. In traditional Tibetan medicine, <b>Saussurea laniceps</b> Hand.-Mazz. and <b>Saussurea medusa</b> Maxim. have also been used under the name “Snow Lotus” and prescribed for the treatment of pain and inflammatory conditions.<br>Aim of the study: The present study evaluated the pharmacological effects of three species of “Snow Lotus” in experimental inflammation and pain models, and determined the chemical compounds that may correlate with their pharmacological activities.<br>Materials and methods: The anti-inflammatory activities of the three herbs were observed by using carrageenan-induced paw edema in rats and xylene-induced ear edema in mice. Investigations on the analgesic effects were conducted, including acetic acid-induced writhing and hot-plate test. An UPLC-MS method was developed to analyze the chemical composition of the three herbs and of plasma samples after herb administration.<br>Results: In rat paw edema model, the peak inhibitory effects of <b>Saussurea laniceps</b> and <b>Saussurea involucrata</b> (55.1% and 42.2%, respectively) were recorded with the dose of 400 mg/kg at 3 h post-carrageenan injection. In mouse ear edema model, oral administration of <b>Saussurea laniceps</b>, <b>Saussurea involucrata</b> and <b>Saussurea medusa</b> extract (400 mg/kg) resulted in a significant inhibition of ear edema by 40.9%, 33.3%, and 9.1%, respectively. In the writhing test, oral administration of <b>Saussurea laniceps</b> extract (100, 200 and 400 mg/kg) resulted in a significant inhibition of writhings by 13.5%, 22.3%, and 43.5%, respectively. In the hot-plate test, <b>Saussurea laniceps</b> extract significantly increased the latency of jumping response by 38.2% and 52.7% when treated orally at 200 and 400 mg/kg in mice, respectively. Flavonoids, coumarins and lignins were found to be present in plasma after administration of the extracts and may be the basis of the observed pharmacological effects.<br>Conclusion: The results clearly demonstrated that <b>Saussurea laniceps</b> was most effective; <b>Saussurea involucrata</b> exhibited a moderate potency, whereas <b>Saussurea medusa</b> possessed little effect against the experimental edema and pains. This study also supported discrimination among the three herbs when using them in folk medicine.
A novel hyphenated method based on ultrasound-assisted dispersive liquid-liquid microextraction coupled to precolumn derivatization has been established for the simultaneous determination of bisphenol A, 4-octylphenol, and 4-nonylphenol by high-performance liquid chromatography with fluorescence detection. Different parameters that influence microextraction and derivatization have been optimized. The quantitative linear range of analytes is 5.0-400.0 ng/L, and the correlation coefficients are more than 0.9998. Limits of detection for soft drinks and dairy products have been obtained in the range of 0.5-1.2 ng/kg and 0.01-0.04 μg/kg, respectively. Relative standard deviations of intra- and inter-day precision for retention time and peak area are in the range of 0.47-2.31 and 2.76-8.79%, respectively. Accuracy is satisfactory in the range of 81.5-118.7%. Relative standard deviations of repeatability are in the range of 0.35-1.43 and 2.36-4.75% for retention time and peak area, respectively. Enrichment factors for bisphenol A, 4-octylphenol, and 4-nonylphenol are 170.5, 240.3, and 283.2, respectively. The results of recovery and matrix effect are in the range of 82.7-114.9 and 92.0-109.0%, respectively. The proposed method has been applied to the determination of bisphenol A, 4-octylphenol, and 4-nonylphenol in soft drinks and dairy products with much higher sensitivity than many other methods.
A novel hyphenated technique based on ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME) coupled with derivatization has been established for the determination of brassinolide (BL, a representative of brassinosteroids) by HPLC fluorescence detection. 9-Phenanthreneboronic acid is used as labeling reagent of BL. UA-DLLME parameters containing type and volume of extraction and disperser solvent, pH and ultrasonication time are optimized. Derivatization parameters are optimized included amount of 9-phenanthreneboronic acid, volume ratio of pyridine, derivatization time and temperature. Under optimal conditions, quantitative linear range of BL is 50-1,000 ng L<sup>−1</sup> and excellent linear response is observed with correlation coefficient of 0.9996. Limit of detection and limit of quantification are calculated as 8.0 and 25.0 ng L<sup>−1</sup>, respectively. RSDs of retention time and peak area are in the range of 0.68-0.97 % and 4.61-6.54 % for intra-day precision, 1.32-1.94 % and 7.28-9.75 % for inter-day precision, respectively. Accuracy is satisfactory in the range of 82.3-125.1 %. RSDs’ values of repeatability are in the range of 0.82-1.79 and 3.95-8.53 % for retention time and peak area, respectively. Enrichment factor for BL is 189. The results of recovery and matrix effect are in the range of 82.0-108.6 and 90.0-115.3 %, respectively. The proposed method has been applied for the determination of BL in <i>Arabidopsis thaliana</i>, <i>Daucus carota</i> and <i>Brassica campestris</i> L. leaves with much higher sensitivity than many other methods.
ETHNOPHARMACOLOGICAL RELEVANCE: Dioscorea zingiberensis C. H. Wright (D. zingiberensis), Dioscoreaceae, is used extensively in traditional Chinese medicines. The aim of the current review paper is to give a comprehensive overview of the traditional usage and phytochemistry of the plant. Clinical studies performed and products prepared from the plant and active principles will be mentioned. In addition a review of the taxonomy of the genus Dioscorea is given.MATERIALS AND METHODS: A systematic search on literature has been performed in databases like Google Scholar, Science Direct, Scifinder, Web of Science, and in Chinese databases (China Knowledge Resource Integrated, i.e., CNKI and Wanfang) including Ph.D. and M.Sc. dissertations. These from the period 1983-2016 have been searched.
RESULTS: D. zingiberensis is an endemic plant in China widely distributed in some provinces, especially Hubei and Shaanxi. The rhizomes are the medicinal part in Dun-Ye-Guan-Xin-Ning tablets and are used for isolation of diosgenin. Steroidal saponins are believed to be the active principles. More than 70 compounds have been identified. Several of these have been tested in preclinical assays and clinical trials. A wide spectrum of biological effects including cardiovascular, anti-thrombosis, hyperlipidemia, neuroprotection, anti-inflammatory, and anthelmintic effect has been verified.
CONCLUSIONS: Because of the promising results from the investigations on the plant material of D. zingiberensis, further in depth analyses ought to be performed to evaluate its potential as either a traditional drug or a source of bioactive principle. The presently performed studies do not explain mechanism of action, pharmacokinetics (ADME properties), or toxicity. All of these topics need more elaborate investigations.
• A new low toxic dual-UADLLME coupled with microwave-assisted derivatization was proposed. • 4′-Carboxy-substituted rosamine was firstly used as derivatization reagent. • Simultaneous determination of PPD and PPT in rat plasma was achieved by UHPLC-MS/MS. • This method was successfully applied to pharmacokinetics study.<br>This paper, for the first time, reported a speedy hyphenated technique of low toxic dual ultrasonic-assisted dispersive liquid-liquid microextraction (dual-UADLLME) coupled with microwave-assisted derivatization (MAD) for the simultaneous determination of 20(<b>S</b>)-protopanaxadiol (PPD) and 20(<b>S</b>)-protopanaxatriol (PPT). The developed method was based on ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) detection using multiple-reaction monitoring (MRM) mode. A mass spectrometry sensitizing reagent, 4′-carboxy-substituted rosamine (CSR) with high reaction activity and ionization efficiency was synthesized and firstly used as derivatization reagent. Parameters of dual-UADLLME, MAD and UHPLC-MS/MS conditions were all optimized in detail. Low toxic brominated solvents were used as extractant instead of traditional chlorinated solvents. Satisfactory linearity, recovery, repeatability, accuracy and precision, absence of matrix effect and extremely low limits of detection (LODs, 0.010 and 0.015 ng/mL for PPD and PPT, respectively) were achieved. The main advantages were rapid, sensitive and environmentally friendly, and exhibited high selectivity, accuracy and good matrix effect results. The proposed method was successfully applied to pharmacokinetics of PPD and PPT in rat plasma.
BackgroundMeditation has been increasingly evaluated as an important complementary therapeutic tool for the treatment of depression. The present study employed resting-state functional magnetic resonance imaging (rs-fMRI) to examine the effect of body–mind relaxation meditation induction (BMRMI) on the brain activity of depressed patients and to investigate possible mechanisms of action for this complex intervention.
Method
21 major depressive disorder patients (MDDs) and 24 age and gender-matched healthy controls (HCs) received rs-fMRI scans at baseline and after listening to a selection of audio designed to induce body–mind relaxation meditation. The rs-fMRI data were analyzed using Matlab toolbox to obtain the amplitude of low-frequency fluctuations (ALFF) of the BOLD signal for the whole brain. A mixed-design repeated measures analysis of variance (ANOVA) was performed on the whole brain to find which brain regions were affected by the BMRMI. An additional functional connectivity analysis was used to identify any atypical connection patterns after the BMRMI.
Results
After the BMRMI experience, both the MDDs and HCs showed decreased ALFF values in the bilateral frontal pole (BA10). Additionally, increased functional connectivity from the right dorsal medial prefrontal cortex (dmPFC) to the left dorsal lateral prefrontal cortex (dlPFC) and the left lateral orbitofrontal cortex (OFC) was identified only in the MDDs after the BMRMI.
Limitation
In order to exclude the impact of other events on the participants׳ brain activity, the Hamilton Rating Scales for Depression (HDRS) was not measured after the body–mind relaxation induction.
Conclusion
Our findings support the hypothesis that body–mind relaxation meditation induction may regulate the activities of the prefrontal cortex and thus may have the potential to help patients construct reappraisal strategies that can modulate the brain activity in multiple emotion-processing systems.
BackgroundMeditation has been increasingly evaluated as an important complementary therapeutic tool for the treatment of depression. The present study employed resting-state functional magnetic resonance imaging (rs-fMRI) to examine the effect of body–mind relaxation meditation induction (BMRMI) on the brain activity of depressed patients and to investigate possible mechanisms of action for this complex intervention.
Method
21 major depressive disorder patients (MDDs) and 24 age and gender-matched healthy controls (HCs) received rs-fMRI scans at baseline and after listening to a selection of audio designed to induce body–mind relaxation meditation. The rs-fMRI data were analyzed using Matlab toolbox to obtain the amplitude of low-frequency fluctuations (ALFF) of the BOLD signal for the whole brain. A mixed-design repeated measures analysis of variance (ANOVA) was performed on the whole brain to find which brain regions were affected by the BMRMI. An additional functional connectivity analysis was used to identify any atypical connection patterns after the BMRMI.
Results
After the BMRMI experience, both the MDDs and HCs showed decreased ALFF values in the bilateral frontal pole (BA10). Additionally, increased functional connectivity from the right dorsal medial prefrontal cortex (dmPFC) to the left dorsal lateral prefrontal cortex (dlPFC) and the left lateral orbitofrontal cortex (OFC) was identified only in the MDDs after the BMRMI.
Limitation
In order to exclude the impact of other events on the participants׳ brain activity, the Hamilton Rating Scales for Depression (HDRS) was not measured after the body–mind relaxation induction.
Conclusion
Our findings support the hypothesis that body–mind relaxation meditation induction may regulate the activities of the prefrontal cortex and thus may have the potential to help patients construct reappraisal strategies that can modulate the brain activity in multiple emotion-processing systems.
The separation of minor compounds, especially those with similar polarities from a complex sample, remains challenging. In the proposed study, an effective method based on medium-pressure liquid chromatography and recycling high-speed counter-current chromatography was developed for the enrichment and separation of three minor components from <i>Dracocephalum tanguticum</i>. The crude extract was directly introduced to medium-pressure liquid chromatography for the enrichment of the three minor components. Based on high-performance liquid chromatography analysis, the total content of these three compounds increased from 0.48% in the crude extract to 85.3% in the medium-pressure liquid chromatography fraction. In addition, high-speed counter-current chromatography was employed to separate the enriched compounds using the solvent system hexane/ethyl acetate/methanol/water (1.18:8.82:1.18:8.82, v/v/v/v). As a result, compound <b>3</b> and a mixture of compounds <b>1</b> and <b>2</b> were obtained. In order to improve the resolution of compounds <b>1</b> and <b>2</b> while saving separation time, a recycling and heart-cut mode was used. Finally, compounds <b>1</b> and <b>2</b> were obtained after five cycles. These compounds were identified as 3-phenylethyl β-d-glucopyranoside (<b>1</b>), tazettoside E (<b>2</b>), and cirsiliol-4′-glucoside (<b>3</b>). Compounds <b>1</b> and <b>2</b> were primarily separated from <i>D. tanguticum</i>. Moreover, the developed method provided a reference for the separation of minor components from the complex sample.
Background: Heart rate variability (HRV) as an accurate, noninvasive measure of the Autonomous Nervous System (ANS) can reflect mental health (e.g., stress, depression, or anxiety). Tai Chi and Yoga (Tai Chi/Yoga), as the most widely practiced mind-body exercises, have shown positive outcomes of mental health. To date, no systematic review regarding the long-lasting effects of Tai Chi/Yoga on HRV parameters and perceived stress has been conducted. Objective: To critically evaluate the existing literature on this topic. Methods: Five electronic databases (Web of Science, PubMed, Scopus, SportDiscus and Cochrane Library) were searched from the start of the research project to July 2018. Study selection, data extraction, and study quality assessment were independently carried out by two reviewers. The potentially identified randomized controlled trials (RCT) reported the useful quantitative data that were included only for meta-analysis. Results: meta-analysis of 17 medium-to-high quality RCTs showed significantly beneficial effects on HRV parameters (normalized low-frequency, Hedge's g = -0.39, 95% CI -0.39 to -0.56, p < 0.001, I2 = 11.62%; normalized high-frequency, Hedge's g = 0.37, 95% CI 0.22 to -0.52, p < 0.001, I2 = 0%; low-frequency to high-frequency ratio, Hedge's g = -0.58, 95% CI -0.81 to -0.35, p < 0.001, I2 = 53.78%) and stress level (Hedge's g = -0.80, 95% CI -1.17 to -0.44, p < 0.001, I2 = 68.54%). Conclusions: Stress reduction may be attributed to sympathetic-vagal balance modulated by mind-body exercises. Tai Chi/Yoga could be an alternative method for stress reduction for people who live under high stress or negative emotions.
Background: Heart rate variability (HRV) as an accurate, noninvasive measure of the Autonomous Nervous System (ANS) can reflect mental health (e.g., stress, depression, or anxiety). Tai Chi and Yoga (Tai Chi/Yoga), as the most widely practiced mind-body exercises, have shown positive outcomes of mental health. To date, no systematic review regarding the long-lasting effects of Tai Chi/Yoga on HRV parameters and perceived stress has been conducted. Objective: To critically evaluate the existing literature on this topic. Methods: Five electronic databases (Web of Science, PubMed, Scopus, SportDiscus and Cochrane Library) were searched from the start of the research project to July 2018. Study selection, data extraction, and study quality assessment were independently carried out by two reviewers. The potentially identified randomized controlled trials (RCT) reported the useful quantitative data that were included only for meta-analysis. Results: meta-analysis of 17 medium-to-high quality RCTs showed significantly beneficial effects on HRV parameters (normalized low-frequency, Hedge's g = -0.39, 95% CI -0.39 to -0.56, p < 0.001, I2 = 11.62%; normalized high-frequency, Hedge's g = 0.37, 95% CI 0.22 to -0.52, p < 0.001, I2 = 0%; low-frequency to high-frequency ratio, Hedge's g = -0.58, 95% CI -0.81 to -0.35, p < 0.001, I2 = 53.78%) and stress level (Hedge's g = -0.80, 95% CI -1.17 to -0.44, p < 0.001, I2 = 68.54%). Conclusions: Stress reduction may be attributed to sympathetic-vagal balance modulated by mind-body exercises. Tai Chi/Yoga could be an alternative method for stress reduction for people who live under high stress or negative emotions.
An efficient preparative procedure for the separation of four antibacterial diterpenes from a Salvia prattii crude diterpenes-rich sample was developed. Firstly, the XION hydrophilic stationary phase was chosen to separate the antibacterial crude diterpenes-rich sample (18.0 g) into three fractions with a recovery of 46.1%. Then, the antibacterial fractions I (200 mg), II (200 mg), and III (150 g) were separated by the Megress C18 preparative column, and compounds tanshinone IIA (80.0 mg), salvinolone (62.0 mg), cryptotanshinone (70.0 mg), and ferruginol (68.0 mg) were produced with purities greater than 98%. The procedure achieved large-scale preparation of the four diterpenes with high purity, and it could act as a reference for the efficient preparation of active diterpenes from other plant extracts.
The separation of high-purity compounds from traditional Tibetan medicines plays an important role in investigating their bioactivity. Nevertheless, it is often quite difficult to isolate compounds with high purity because of the complexity of traditional Tibetan medicines. In this work, an offline two-dimensional reversed-phase preparative method was successfully developed for the separation of high-purity compounds from Oxytropis falcata. Based on the analysis results, an ODS C18 prep column was used for first-dimensional preparation, and 14.8 g of the crude sample was separated into five fractions with a recovery of 74.6%. Then, an XAqua C18 prep column was used to isolate high-purity compounds in the second-dimensional preparation because its separation selectivity is different with the ODS C18 stationary phase. As a result, eight compounds in the crude sample were isolated in more than 98% purity. This is the first report of trans-cinnamic acid (1) and trifolirhizin (2) from Oxytropis falcata. This method has the potential to be an efficient separation method of high-purity compounds from Oxytropis falcata and it shows great promise for the separation of high-purity compounds from complex samples.
The separation of high-purity compounds from traditional Tibetan medicines plays an important role in investigating their bioactivity. Nevertheless, it is often quite difficult to isolate compounds with high purity because of the complexity of traditional Tibetan medicines. In this work, an offline two-dimensional reversed-phase preparative method was successfully developed for the separation of high-purity compounds from Oxytropis falcata. Based on the analysis results, an ODS C18 prep column was used for first-dimensional preparation, and 14.8 g of the crude sample was separated into five fractions with a recovery of 74.6%. Then, an XAqua C18 prep column was used to isolate high-purity compounds in the second-dimensional preparation because its separation selectivity is different with the ODS C18 stationary phase. As a result, eight compounds in the crude sample were isolated in more than 98% purity. This is the first report of trans-cinnamic acid (1) and trifolirhizin (2) from Oxytropis falcata. This method has the potential to be an efficient separation method of high-purity compounds from Oxytropis falcata and it shows great promise for the separation of high-purity compounds from complex samples.
Diabetes mellitus (DM) is a serious metabolic disorder, where impaired postprandial blood glucose regulation often leads to severe health complications. The natural chemical erythritol is a C4 polyol approved by the U.S. Food and Drug Administration for use as a sweetener. Here, we examined a potential role for erythritol in the control of postprandial blood glucose levels in DM. An anti-postprandial hyperglycemia effect upon erythritol administration (500 mg kg-1) was demonstrated in alloxan-induced DM model mice by monitoring changes in blood glucose after intragastric administration of drugs and starch. We also found that erythritol most likely exerts its anti-postprandial hyperglycemic activities by inhibiting α-glucosidase in a competitive manner. This was supported by enzyme activity assays and molecular modeling experiments. In the latter experiments, it was possible to successfully dock erythritol into the catalytic pocket of α-glucosidase, with the resultant interaction likely driven by electrostatic interactions involving Asp215, Asp69, and Arg446 residues. This study suggests that erythritol may not only serve as a glucose substitute but also be a useful agent in the treatment of DM to help manage postprandial blood glucose levels.
Lycium ruthenicum Murr. (LRM, Solanaceae), also called "black wolfberry" in China, is extremely tolerant drought. Although black wolfberry has seeds that are rich in oil, being considered as a potential alternative for edible oil production, little information has been found regarding its characterization. The present study evaluated the fatty acid profile of the seed oil and its phytosterol contents. Moreover, its antioxidant potential and its inhibition activities on pancreatic lipase, and cholesterol esterase (CEase) were also determined. The key fatty acids of studied oil were linoleic (74.58%), oleic (11.82%), γ-linolenic (6.60%), palmitic (4.88%), and stearic (1.40%) acids, which together comprised 99.28% of the total fatty acids. Phytosterols including 24-methylenecholesterol, campesterol, stigmasterol, dihydrolanosterol, 24-methyldesmosterol, β-sitosterol, Δ5 -avenasterol, cycloartenol, and Δ7- avenasterol were identified for the 1st time. The inhibition values (IC50 ) for the DPPH and ABTS radical scavenging capacities of the oil were 7.86 and 15.49 mg/mL, respectively. Additionally, LRM seed oil was also demonstrated to possess strong pancreatic lipase, and CEase inhibition activities with IC50 values of 12.38 and 2.63 mg/mL, respectively. The mechanism study indicated that the inhibitory manner of the oil on CEase belonged to uncompetitive inhibition of reversible inhibition. The results derived from above studies suggest that LRM seed oil could be a potential source of high value phytochemicals for developing novel functional food.
BACKGROUND: Our previous studies on Asterothamnus centrali-asiaticus Novopokr. (ACN) and Arenaria kansuensis Maxim. (AKM) had led to the isolation of some phytochemical constituents and evaluation of anticonvulsant effect based on their extracts. ACN and AKM have been widely used in traditional Tibetan herbs for neuropsychiatric diseases and cardiopulmonary disorders.PURPOSE: The purpose is to investigate structure-activity relationships of flavonoids isolated from ACN and AKM, for binding to the benzodiazepine site (BZ-S) of γ-aminobutyric acid type A (GABAA) receptor complex, and to search for anticonvulsant compounds without undesirable effects such as myorelaxation and sedation.
STUDY DESIGN AND METHODS: The affinities of these flavonoids for the BZ-S of GABAA receptors were determined by [3H]flunitrazepam binding to mouse cerebellum membranes in vitro. And the anticonvulsant, myorelaxant and sedative effects were determined by pentylenetetrazol (PTZ)-induced seizure and electrogenic seizure protection, rotarod test and locomotor activity test, respectively.
RESULTS: Fifteen and thirteen flavonoids were isolated from ACN and AKM, respectively. Structure-activity relationships analysis indicated that 6-and/or 8-OMe flavones exhibited the most potent binding affinity to GABAA receptors. Furthermore, 2',4',5,7-tetrahydroxy-5',6-dimethoxyflavone (DMF, IC50 value of 0.10 μM), a flavone isolated from ACN, presented high anticonvulsant activity against chemical-induced seizures and electrogenic seizures, without myorelaxation and sedation.
CONCLUSION: This study suggested that these flavones, especially DMF, are new BZ receptor ligands and prospective therapeutic candidates for seizures.
<br>Display Omitted<br>• The effect of organic sample solvents in SCX mode were systematically studied. • Organic sample solvents affect the separation efficiency in SCX mode seriously. • Elution strength of organic solvents affect efficiency of later-eluted analyte. • Retention of organic solvents affected efficiency of earlier-eluted analyte. • The results can be used for the optimization of SCX methods.<br>This study investigated the influence of organic sample solvents on separation efficiency of basic compounds under strong cation exchange (SCX) mode. The mixtures of acidic aqueous solution and organic solvent such as acetonitrile, ethanol, methanol and dimethyl sulfoxide (DMSO) were tested as sample solvents. For later-eluting analytes, the increase of sample solvent elution strength was responsible for the decrease of separation efficiency. Thus, sample solvents with weak elution strength could provide high separation efficiencies. For earlier-eluting analytes, the retention of organic sample solvents was the main factor affecting separation efficiency. Weakly retained solvents could provide high separation efficiency. In addition, an optimized approach was proposed to reduce the effect of organic sample solvent, in which low ionic solvent was employed as initial mobile phase in the gradient. At last, the analysis of impurities in hydrophobic drug berberine was performed. The results showed that using acidic aqueous methanol as sample solvents could provide high separation efficiency and good resolution (<b>R</b> > 1.5).
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