A new and sensitive pre-column derivatization method was developed for the analysis of melamine leached from tableware by high performance liquid chromatography (HPLC) with fluorescence detection. The HPLC sensitivity was greatly enhanced by introducing 10-methyl-acridone-2-sulfonyl chloride (MASC) with excellent fluorescence property into the melamine molecule. Meanwhile, derivatization also greatly increased the hydrophobicity of melamine. Therefore, the common reversed phase column can be used for the HPLC analysis of highly hydrophilic melamine. The detection limit obtained by the proposed method was lower than 0.40 μg/L. This is the first time that HPLC with fluorescence detection was applied to the analysis of melamine. The proposed method was successfully applied to the analysis of melamine leached from tableware. The results indicated that the leaching of melamine from tableware was obvious when hot water or milk was added.<br>• HPLC with fluorescence detection was applied to the analysis of melamine for the first time. • Reversed phase HPLC analysis of melamine was achieved with no ion-pair reagents needed. • HPLC sensitivity was greatly enhanced through derivatization.
A capillary zone electrophoresis method was developed for simultaneous determination of nine flavonoids, including two rare flavonols, in Tibetan medicine Anaphalis margaritacea. Baseline separation was performed at pH 9.6 with 25 mM Na(2)B(4)O(7) and 10 mM NaH(2)PO(4) buffer solution, 20 kV as driving voltage and 275 nm as detection wavelength. Repeatability tests showed that the R.S.D. of both intra- and inter-day migration times and peak areas were less than 5%. Recovery results ranged from 87.9% to 106.1%. Samples of A. margaritacea extracts were analyzed using the validated method, which is useful for its quality control.
A capillary zone electrophoresis method was developed for simultaneous determination of nine flavonoids, including two rare flavonols, in Tibetan medicine Anaphalis margaritacea. Baseline separation was performed at pH 9.6 with 25 mM Na(2)B(4)O(7) and 10 mM NaH(2)PO(4) buffer solution, 20 kV as driving voltage and 275 nm as detection wavelength. Repeatability tests showed that the R.S.D. of both intra- and inter-day migration times and peak areas were less than 5%. Recovery results ranged from 87.9% to 106.1%. Samples of A. margaritacea extracts were analyzed using the validated method, which is useful for its quality control.
A simple, sensitive and selective method based on one-step fluorescence labeling and ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) was developed for the determination of biogenic amines (BAs) in foodstuff samples by high-performance liquid chromatography (HPLC) with fluorescence detection (FLD). In this work, fluorescence probe 2-(11H-benzo[a]carbazol-11-yl) ethyl carbonochloridate (BCEC-Cl) was applied to label BAs. What followed was the UA-DLLME procedure that was carried out using chloroform and acetone as extraction and disperser solvents, respectively. A response surface methodology (RSM) based on a Box-Behnken design (BBD) was employed to optimize the main parameters affecting the fluorescence labeling and DLLME efficiency. Under the optimal conditions, this method offered low limits of detection (LODs) of 1.1-7.8 ng/mL and limits of quantification (LOQs) of 3.5-26.1 ng/mL. Finally, the method was successfully used for the determination of trace BAs in real samples and exhibited powerful potential in the high-throughput sample screening.
Purpose: To develop an ultra-high performance liquid chromatography (UPLC) - photodiode array (PDA) method to compare the chemical composition of two different medicinal components of Pterocephalus hookeri. Methods: Samples were chromatographically separated in succession using Waters Acquity UPLCR BEH C18 column (2.1 × 100 mm, 1.7 µm) and gradient elution (0.2% phosphoric acid aqueous - acetonitrile). Using partial least squares discriminant analysis and one-way analysis of variance, attempts were made to distinguish different medicinal parts of P. hookeri. Results: Regression equation for 10 compounds showed good linear regression (R² > 0.9994). The relative standard deviations of precision, stability, repeatability and recovery were under 5%. Compared with the aerial plant part, the root had significantly higher levels of sylvestroside I (p < 0.01), cantleyoside (p < 0.001), dipsanosides B (p < 0.01) and dipsanosides A (p < 0.01), but significantly lower levels of loganic acid (p < 0.001), chlorogenic acid (p < 0.01), and isochlorogenic acid (p < 0.01). There were no significant differences between loganin, sweroside and isochlorogenic acid C. Conclusion: The described method is simple, accurate and reproducible, and can be used for the simultaneous determination of 10 major compounds of P. hookeri. The results demonstrate that there is variation in the chemical composition of the aerialpart and root of P. hookeri and that loganic acid and cantleyoside are the primary chemical biomarkers.
This study is to develop an UPLC-PDA method for determination of 10 major components in Pterocephalus. The UPLC-PDA assay was performed on a Waters Acquity UPLCR BEH C₁₈（2.1 mm ×100 mm,1.7 μm）, and the column temperature was at 30 ℃. The mobile phase consists of water containing 0.2% phosphoric acid (A) and acetonitrile (B) in gradient elution at a flow rate of 0.4 mL•min⁻¹. The detection wave length was set at 237 and 325 nm, and the injection volume was 1 μL in the UPLC system. The linear range of 10 detected compounds were good (r≥0.999 7), and the overall recoveries ranged from 96.30% to 103.0%, with the RSD ranging from 0.72% to 2.9%. The method was simple, accurate and reproducible, which can be used for the simultaneous determination of the content of ten major components in P. hookeri.
Emissions of nitrous oxide (N₂O) contribute to global warming and stratospheric ozone depletion. Anthropogenic N₂O emissions predominately result from the addition of synthetic nitrogen (N) fertilizers to terrestrial ecosystems. Usually, an exponential increase in N₂O emissions occurs as N addition rates increase to exceed plant demands. However, most evidence to date is from temperate areas, with little information available for alpine ecosystems. Here we examined the changes in N₂O flux under eight N addition levels and the mechanisms regulating these changes in a Tibetan alpine steppe. Our results showed that N₂O emission rate increased linearly with increasing N additions. Even when soil N availability exceeded plant N uptake, no sharp N₂O emissions were observed. The likely explanation was that decreased soil temperature limited the growth of nitrification-related microorganisms, mainly ammonia-oxidizing archaea, which further attenuated the positive response of N₂O emissions to excess N supply. These findings suggest that the N-induced changes in soil temperature regulate the growth of nitrifying microorganisms and the subsequent N₂O fluxes in this alpine steppe, and the exponential N₂O emission-N rate relationship observed in warm regions may not be simply extrapolated to alpine ecosystems.<br>N₂O emission exhibited a linear, rather than an exponential, response to increasing N additionsN₂O flux was explained by the changes in AOA along this N addition gradientDecreased soil temperature limited the growth of AOA, weakening the positive response of N₂O flux to excess N supplies
An imbalance in osteogenesis and osteoclastogenesis is a crucial pathological factor in the development of osteoporosis. Osteoclasts (OCs) play a pivotal role in osteoporosis, whose new therapy exploration has been focused on the suppression of OC formation. Sophoridine is found from the Chinese traditional food sophora flower to exhibit anti-osteoporosis capacity by screening. This study is focused on its anti-osteoporosis mechanism evaluation. The anti-osteoporosis effect of sophoridine, (15 mg kg-1 body), was evaluated in ovariectomized (OVX) mice by monitoring changes in bone histomorphometry index, formation of osteoclasts from blood-derived mononuclear cells, and changes in the synthesis of pro-osteoclastogenic cytokines. Signal pathways were investigated by QPCR, Western blot, and immunofluorescence. Sophoridine has a significant anti-osteoporosis effect in vivo, which can inhibit RANKL-induced OC formation, the appearance of OC-specific marker genes, and OC marker protein in vitro. Mechanistically, sophoridine dose- and time-dependently blocks the RANKL-induced OC formation and the activation of ERK and c-Fos as well as the induction and nucleus translocation of NFATc1. Sophora flower might be a useful alternative functional food in preventing or treating osteoporosis.
Objective: To establish an HPLC-ELSD fingerprint of the whole herbs of Morina nepalensis and perform the correlation analysis of chemical components of the herb and nitric oxide (NO) production inhibition.; Method: HPLC-ELSD assay was performed to evaluate 10 batches of M. nepalensis herbs. The chromatographic conditions were as following: Eclipse XDB C18 column (4.6 mm x 150 mm, 5 microm), water (A) and acetonitrile (B) as a gradient mobile phases, flow rate 1.0 mL x min(-1), and column temperature at 35 degress C. Evaporative light-detection conditions: atomization temperature at 104 degrees C, the flow rate of N2 2.8 L x min(-1) and 10 microL sample injection. Chromatographic fingerprint was developed, and the inhibition activity of production of NO in lipopolysaccharide-induced macrophages was also analyzed. The similarity and correlation analysis between the HPLC-ELSD fingerprints and NO production inhibition were carried out by PLS method.; Result: The common mode for M. nepalensis herb fingerprint was established, including 15 common characteristic peaks. Among them, 7 peaks were positively correlated with the NO production inhibition. According to the assessment on the similarity of 10 batches of samples, a similarity of over 0.90 were shown in HPLC-ELSD fingerprint and all samples were separated into two groups.; Conclusion: This method can be used to assess the quality of M. nepalensis, which provides a reliable method for scientific assessment and quality control.;
Abstract Ethnopharmacological relevance Srolo Bzhtang (SBT), a traditional Tibetan medicine formula, was composed of three herbs, Solms-Laubachia eurycarpa , Bergenia purpurascens , Glycyrrhiza uralensis , and one lac, and was first documented in the ancient Tibetan medical work Four Medical Tantras (rGyud-bzhi) in the eighth century AD. It has been widely used to treat lung "phlegm-heat" syndromes such as chronic bronchitis and chronic obstructive pulmonary disease (COPD). Objective The aim of this study was to evaluate the potential influences of aqueous extract of SBT on airway inflammation and mucus secretion and to reveal the underlying mechanism in a rat model of cigarette smoke (CS)-induced chronic bronchitis (CB). Materials and methods Sixty male Sprague-Dawley rats were randomly divided to six groups: control (room air exposure), model (CS exposure), DEX (CS exposure and 0.2 mg/kg/day dexamethasone), and three SBT (CS exposure and 1.67, 2.50, and 3.34 g/kg/day SBT) groups. DEX and the three doses of SBT were administered by oral gavage every day for eight weeks. Pathological changes and mucus expression in the lung tissue were determined by hematoxylin and eosin (H&E), Alcian blue-periodic acid-Schiff (AB-PAS) and immunohistochemical staining. The levels of cytokines in bronchoalveolar lavage fluid (BALF) were assessed by ELISA. Western blot analysis and qRT-PCR were performed to explore the effects of SBT on the expression of IL-13, STAT6 and MUC5AC. Results Pretreatment with SBT attenuated the TNF-α, IL-8, IL-13 expression levels in BALF and the inflammatory cell infiltration in bronchial walls and peribronchial lung tissue. SBT exhibited a dose-dependent downregulation of MUC5AC expression as assessed by AB-PAS and immunohistochemical staining. The protein and mRNA levels of IL-13, STAT6/p-STAT6 and MUC5AC were also downregulated by SBT preconditioning. Conclusion These results for the first time demonstrated that SBT exhibited protective effects on CS-induced airway inflammation and MUC5AC hypersecretion, which might be related to the downregulation of the IL-13/STAT6 signaling pathway. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]
A new stable isotope labeling (SIL) reagent pair, 10-methyl-acridone-2-sulfonohydrazide (MASH) and its deuterated counterpart d3-MASH was synthesized and successfully applied to the analysis of perfluorinated carboxylic acids (PFCAs) in serum samples. The limits of detection (LODs) were in the range of 0.07-0.42μg/L, and the limits of quantitation (LOQs) were in the range of 0.25-1.38μg/L. Besides ionization enhancing effect, MASH also showed excellent fluorescence property. Therefore, the mass spectrometer operation cost was greatly lowered by carrying out parameter optimization experiments on HPLC which is easier to operate and maintain. The SIL strategy was confirmed to be effective in reducing matrix effect. The developed multiple-reaction monitoring (MRM) condition of PFCAs was also suitable for other carboxylic acid due to the introduction of MASH which is more prone to fragmentation than the analytes. With the MRM conditions obtained from PFCAs, fatty acids were also found in serum samples. This feature made the proposed method show powerful potential in the identification of acidic compounds in complex samples in the absence of corresponding standard.
Context: Standardized myrtol, an essential oil containing primarily cineole, limonene and α-pinene, has been used for treating nasosinusitis, bronchitis and chronic obstructive pulmonary disease (COPD).Objective: To investigate the effects of standardized myrtol in a model of acute lung injury (ALI) induced by lipopolysaccharides (LPS).Materials and methods: Male BALB/c mice were treated with standardized myrtol for 1.5 h prior to exposure of atomized LPS. Six hours after LPS challenge, lung injury was determined by the neutrophil recruitment, cytokine levels and total protein concentration in the bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) activity in the lung tissue. Additionally, pathological changes and NF-κB activation in the lung were examined by haematoxylin and eosin staining and western blot, respectively.Results: In LPS-challenged mice, standardized myrtol at a dose of 1200 mg/kg significantly inhibited the neutrophile counts (from 820.97 ± 142.44 to 280.42 ± 65.45, 103/mL), protein concentration (from 0.331 ± 0.02 to 0.183 ± 0.01, mg/mL) and inflammatory cytokines level (TNF-α: from 6072.70 ± 748.40 to 2317.70 ± 500.14, ng/mL; IL-6: from 1184.85 ± 143.58 to 509.57 ± 133.03, ng/mL) in BALF. Standardized myrtol also attenuated LPS-induced MPO activity (from 0.82 ± 0.04 to 0.48 ± 0.06, U/g) and pathological changes (lung injury score: from 11.67 ± 0.33 to 7.83 ± 0.79) in the lung. Further study demonstrated that standardized myrtol prevented LPS-induced NF-κB activation in lung tissues.Discussion and conclusion: Together, these data suggest that standardized myrtol has the potential to protect against LPS-induced airway inflammation in a model of ALI.
In the present study, structural characterization and antioxidant activity of a fraction (AAP-2A) of polysaccharides from angelica and astragalus (AAP) were investigated. Characteriztion assay showed that AAP-2A had molecular weight (Mw), root-mean square (RMS) radius and polydispersity index (Mw/Mn) of 2.252 × 10(3)kDa, 28.4 nm and 1.038, respectively. There were infrared characteristic absorption peaks of polysaccharides in FT-IR spectroscopy. AAP-2A was composed of rhamnose (Rha), galactose (Gal), arabinose (Ara) and glucose (Glc) with a molar ratio of 1:2.13:3.22:6.18 in GC analysis. Methylation analysis combined with NMR spectroscopic analysis demonstrated that a preliminary structure of AAP-2A was proposed as follows: 1,3-linked Rhap, 1,3-linked Galp, 1,3-linked Araf, 1,5-linked Araf, 1,3,5-linked Araf, 1,4-linked Glcp and 1,4,6-linked Glcp interspersed with terminal Glcp. AAP-2A exhibited a surface with a sheet-like appearance in scanning electron microscope and stronger antioxidant capacity compared with AAP.
OBJECTIVE: To investigate the chemical constituents of Tibetan medicine Phyllanthus emblica.METHOD: Various chromatographic techniques were employed for isolation and purification of the constituents, and the structures were elucidated by chemical and spectral analyses.
RESULT: 11 compounds were isolated and identified as gallic acid (I), ellagic acid (II), 1-O-galloyl-beta-D-glucose (III), 3,6-di-O-galloyl-D-glucose (IV), chebulinic acid (V), quercetin (VI), chebulagic acid (VII), corilagin (VIII), 3-ethylgallic acid (3-ethoxy-4,5-dihydroxy-benzoic acid, IX), isostrictiniin (X), 1,6-di-O-galloyl-beta-D-glucose (XI).
CONCLUSION: 3-Ethylgallic acid (3-ethoxy-4,5-dihydroxy-benzoic acid) is a novel compound, and isostrictiniin was found from P. emblica for the first time.
Objective: To study the chemical constituents of the Tibetan medicine Caryopteris toroetii.; Method: The crude drug was extracted with 95% EtOH and isolated by repeatedly chromatographic methods. The structures of the isolated compounds were elucidated by spectral analysis.; Result: Six compounds were yielded and identified as: phenethyl cinnamide (1), 1-hydroxy-2, 3, 4, 5-tetramethoxy-xanthone (2), 1-hydroxy-2, 3, 5-trimethoxy-xanthone (3), (2S)-5-hydroxy-7-methoxyflavanone (4), 2', 4'-dihydroxydihydrochalcone (5) and rutin (6).; Conclusion: All the above compounds were obtained from C. toroetii for the first time.;
To evaluate the efficacy and safety associated with anti-hypoxia effect and establish the quality standard for Brassicea Radix extract, the investigations of acute toxicity and subacute toxicity were carried out to preliminarily appraise the toxicity, and the models of normal pressure hypoxia, acute cerebral ischemia and sodium nitrite poisoning in mice were used to evaluate the effect of enhancing anoxia endurance. Then according to the methods described in the Appendix of Chinese Pharmacopoeia (2010 edition), the sulfuric acid-phenol method was applied to determine the content of polysaccharide, and the water, ash and insoluble matter in water inspections were carried out and the control medicinal herb was identified with the samples by qualitative TLC. The results indicated that ① the toxic effects (LD₅₀) of mice was 56.73 g•kg⁻¹ by oral administration of Brassicea Radix extract, while Dm and Dn were respective 86.80 g•kg•d⁻¹ and 35.55 g•kg•d⁻¹;②the determined effective dosage of Brassicea Radix extract which could enhance anoxia endurance was 0.388 g•kg⁻¹•d⁻¹; ③ the methods of TLC and the content of polysaccharide were established. The method of quality control has been recorded in Sichuan Province Standard for Tibetan Medicine, which is reliable, accurate and simple, with good reproducibility. Meanwhile, given the prominent effect on anti-hypoxia and good safety, it provided important basis for clinic safe and effective usage and the development of health products.
Recent studies on chemical constituents of Dali and their pharmacological activities were reviewed. Dali, a Tibetan medicine, consists of two Tibetan plants: Rhododendron anthopogoniodes Maxim. and R. primulaeflorum Bur. et Franch. Dali mainly contains essential oils, flavonoids and triterpenoids. The pharmacological activities of Dali are widely proved in eliminating phlegm, relieve cough and anti-asthmatic activities. As a clinical drug, it is also used for treatment of chronic bronchitis and coronary artery disease.
Graphical abstract Highlights • The anti-hyperuricemia effects and active components of the traditional Tibetan medicine formula TFTS were investigated. • Total 106 compontents were identified or characterized in TFTS by UHPLC-Q-TOF-MS/MS. • It was summarized the diagnostic ion and neutral loss patterns of MS/MS cracking of tannic compounds. Abstract TongFengTangSan (TFTS), a traditional Tibetan medicine comprising of Tinospora sinensis (TS), Terminalia chebula Retz (TC) and Trogopterori faeces (TF), is used to treat joint diseases like gout, gout arthritis, swelling, pain etc. Despite the significant therapeutic effects of TFTS, its pharmacological components have not been analyzed so far. Therefore, the chemical composition of the effective part of TFTS was analyzed by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). The results show that the ethanol extract (EE) of TFTS was more effective in reducing the serum uric acid (SUA) and XOD (Serum and Liver) levels in a hyperuricemic rats model compared to the TFTS raw powder (RP). UHPLC-Q-TOF-MS/MS identified a total of 106 compounds in the positive and negative ion mode, of which 87 were from TC, 13 from TS and 6 from TF. In addition, 106 compounds contained 57 tannins, 6 triterpenoids, 10 alkaloids, 7 flavonoids, 22 organic acids and 4 phenylpropanoids. The preliminary results indicate that the EE of TFTS includes the active anti hyperuricemic substances. The present study first investigated the efficacy and the active components of TFTS in hyperuricemic treatment, and further summarized the diagnostic ion and neutral loss patterns of MS/MS cracking of tannic compounds. These findings lay the foundation for the further study and clinical application of TFTS. [ABSTRACT FROM AUTHOR]
Four common traditional tibetan medicine prescription preparations "Anzhijinghuasan, Dangzuo, Renqingchangjue and Rannasangpei" in tibetan areas were selected as study objects in the present study. The purpose was to try to establish a kind of wet digestion and flow injection-hydride generation-atomic absorption spectrometry (FI-HAAS) associated analysis method for the content determinations of lead and arsenic in traditional tibetan medicine under optimized digestion and measurement conditions and determine their contents accurately. Under these optimum operating conditions, experimental results were as follows. The detection limits for lead and arsenic were 0.067 and 0.012 µg · mL(-1) respectively. The quantification limits for lead and arsenic were 0.22 and 0.041 µg · mL(-1) respectively. The linear ranges for lead and arsenic were 25-1,600 ng · mL(-1) (r = 0.9995) and 12.5-800 ng · mL(-1) (r = 0.9994) respectively. The degrees of precision(RSD) for lead and arsenic were 2.0% and 3.2% respectively. The recovery rates for lead and arsenic were 98.00%-99.98% and 96.67%-99.87% respectively. The content determination results of lead and arsenic in four traditional tibetan medicine prescription preparations were as fol- lows. The contents of lead and arsenic in Anzhijinghuasan are 0.63-0.67 µg · g(-1) and 0.32-0.33 µg · g(-1) in Anzhijinghua- san, 42.92-43.36 µg · g(-1) and 24.67-25.87 µg · g(-1) in Dangzuo, 1,611. 39-1,631.36 µg · g(-1) and 926.76-956.52 µg- g(-1) in Renqing Changjue, and 1,102.28-1,119.127 µg-g(-1) and 509.96-516.87 µg · g(-1) in Rannasangpei, respectively. This study established a method for content determination of lead and arsenic in traditional tibetan medicine, and determined the content levels of lead and arsenic in four tibetan medicine-prescription preparations accurately. In addition, these results also provide the basis for the safe and effective use of those medicines in clinic.
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