Enzymatic synthesis of acylated quercetin 3-O-glycosides: a review / 生物工程学报

Quercetin 3-O-glycosides (Q3Gs) are important members of quercetin glycosides with excellent pharmacological activities such as anti-oxidation, anti-inflammation, anti-cancer and anti-virus. Two representatives of Q3Gs, rutin and troxerutin, have been developed into clinical drugs, demonstrating Q3Gs have become one of the important sources of innovative drugs. However, the applications of Q3Gs in food and pharmaceutical industries are hampered by its poor bioavailability. Of the known means, selective acylation modification of Q3Gs through enzymatic catalysis to obtain Q3G esters is one of the effective ways to improve its bioavailability. Herein, the enzyme-mediated acylation of Q3Gs were reviewed in details, focusing on the four tool enzymes (acyltransferases, lipases, proteases and esterases) and the whole-cell mediated biotransformation, as well as the effect of acylations on the biological activities of Q3Gs. Furthermore, the highly efficient synthesis and diversification of acylated site for Q3G esters were also discussed. Taken together, this review provides a new perspective for further structural modifications of Q3Gs towards drug development.

Quality control of Prunella vulgaris based on HPLC fingerprints combined with chemical pattern recognition and content determination / 中草药

Objective: The quantitative method for the quality makers screened by a chemical pattern recognition method combined with the HPLC fingerprint was established, so as to provide reference for scientific and comprehensive quality evaluation of Prunella vulgaris. Methods: Fingerprints of 30 batches of P. vulgaris were established by HPLC. Similarity evaluation was performed by using Similarity Evaluation System for Fingerprint Chromatogram of TCM (2004A) to confirm the common peak. Principal component analysis and orthogonal partial least squares discriminant analysis were used to screen out the components that caused the quality differences in the batches. Quantitative method of the screened quality makers was established, and its content in 61 batches of samples was determined. Results: The HPLC fingerprints of P. vulgaris were obtained, and a total of 28 common peaks were marked. The similarity of 30 batches of samples was higher than 0.970, which indicated that the overall quality of P. vulgaris was relatively stable. Caffeic acid (F5), hyperoside (F9), isoquercitrin (F10), salviaflaside (F11), and rosmarinic acid (F12) were recognized as the quality makers using principal component analysis and orthogonal partial least squares discriminant analysis. Five markers, which showed good linear relationship, were used as indicators for content determination. The average recovery was 95.0%-105.0%, with the RSD value less than 3%. Conclusion: The analysis method established was scientific, accurate, and reliable. A more perfect, reasonable, and effective method for quality evaluation of P. vulgaris was constructed using a fingerprint combined with chemical pattern recognition technique.

Content determination of five flavonoids in Abelmoschus esculentus from different habitats by HPLC / 中草药

Objective: To establish a method for determination of quercetin-3-O-gentiobioside, quercetin-3-O-rutinoside, isoquercitrin, quercetin, and 5,7,4'-trihydroxyflavone in Abelmoschus esculentus from 12 different regions of China. Methods: COSMOSIL column (250 mm × 4.6 mm, 5.4 μm) was used. The gradient elution was carried out with acetonitrile and 0.2% phosphoric acid aqueous solution. The detection wavelength was 353 nm and the flow rate was 1 mL/min. Results: The contents of quercetin-3-O-gentiobioside, quercetin-3-O-rutinoside, isoquercitrin, quercetin and 5,7,4'-trihydroxyflavone had good linear relationship in the ranges of 15.72- 251.50 μg/mL (r = 0.999 5), 15.47-247.50 μg/mL (r = 0.999 6), 14.41-230.50 μg/mL (r = 0.999 5), 21.88-350.00 μg/mL (r = 0.999 7), and 17.25-276.00 μg/mL (r = 0.999 1). The average sample recovery rate was 97.46%, 96.74%, 100.21%, 95.66%, 98.35%, and RSD was 1.97%, 1.37%, 1.86%, 2.72%, 2.23%, respectively. Conclusion: This method is simple and accurate. It is suitable for simultaneous determination of quercetin-3-O-gentiobioside, quercetin-3-O-rutinoside, isoquercitrin, quercetin and 5,7,4'-trihydroxyflavone. The content of the five flavones can be used as one of the methods for evaluating the quality of A. esculentus.

Study on quality control of Miao medicine Laportea bulbifera based on fingerprint analysis and quantitative analysis of multi-components / 中草药

Objective: To establish a rational method for Laportea bulbifera quality control. Methods: The fingerprint technique and multi-component quantitation were used to study the quality control of L. bulbifera by UHPLC. The 12 batches of L. bulbifera UHPLC fingerprint were evaluated by the evaluation system on similitude degree of chromatogram fingerprint of traditional Chinese medicine. Results: The quality control methods of Miao medicine L. bulbifera for simultaneous determination of 10 components (including neochlorogenic acid, cryptochlorogenic acid, chlorogenic acid, rutin, isoquercitrin, luteoloside, kaempferol-3-O-rutinoside, quercitrin, epigallocatechin and epicatechin) were established. The linear, precision, repeatability and stability are good. The standard recoveries were 95.89%-98.62%, with RSD less than 3%. The common mode of fingerprint was established after determination fingerprints of 12 batches of samples of L. bulbifera by UHPLC. There were 20 common peaks in these samples. The similarity of the 12 batches fingerprints were in the range from 0.805 to 0.931. Conclusion: The fingerprinting and multi-index content determination methods for quantitative control of Miao medicine L. bulbifera have high sensitivity, good accuracy, stability and reliability, which can provide a theoretical and experimental foundation for quantitative control of Miao medicine L. bulbifera.

Study on HPLC characteristic spectra of Lygodii Herba and chemical compositions of different parts from Lygodii Herba / 中草药

Objective: To establish the HPLC characteristic spectrum of Lygodii Herba from different habitats in Guangxi Province, and to evaluate the difference of components in different parts of medicinal materials. Methods: HPLC was performed on Waters symmetry C18 (250 mm × 4.6 mm, 5 μm) column, with the mobile phase of acetonitrile-0.2% phosphoric acid at flow rate of 1.0 mL/min; Detection wavelength was 354 nm; The column temperature was 30 ℃ and the sample size was 20 μL. Twelve batches of Lygodii Herba samples were determined and the characteristic spectrum of those were established, and the content of rutin, isoquercetin, and astragalin were determined to evaluate the difference of chemical components in different parts of medicinal materials. Results: There were seven characteristic peaks identified in the characteristic spectra of Lygodii Herba samples. Peak 1 was caffeic acid, peak 2 was Rutin, peak 3 was Isoquercitrin and peak 5 was astragalin. The similarities of 11 batches of samples were proved to be higher than 0.900 and one batch of them was proved to be less than 0.900. The chemical component of stem was richer than that of leaves of Lygodii Herba, and the content of the component was higher in the stem than that of the leaves. Conclusion: The method is simple, accurate, and reproducible, which can provide the scientific evidence for controlling the internal quality standards effectively. The preferred harvest season of Lygodii Herba is autumn and winter.

Protective effect and mechanism of extracts and main components from stem and leaves of Salvia miltiorrhiza on HUVECS / 中草药

Objective: To investigate the protective effects of the extracts and active components from stems and leaves of Salvia miltiorrhiza on oxidative stress and high glucose-injured human umbilical endothelial cells (HUVECs). Methods: The models of oxidative stress and high glucose injury in HUVECs were established. The ethanol extract of S. miltiorrhiza stems and leaves (CJ), ethanol extract of S. miltiorrhiza roots (CG), water extract of S. miltiorrhiza stems and leaves (SJ), water extract of S. miltiorrhiza roots (SG), rosmarinic acid, salvianolic acid B, rutin, isoquercitrin, cryptotanshinone, aminoguanidine and VC were administrated to cells. MTT were used to observe the cell viability. The levels of glutathione peroxidase (GSH-Px), catalase (CAT), nitric oxide (NO), endothelin (ET-1), ICAM-1 and TNF-α were detected. Result:s Compared with the control group, H2O2 decreased the levels of GSH-Px, CAT and NO (P < 0.01) and increased the level of ET-1 (P < 0.01), glucose increased the levels of ICAM-1 and TNF-α (P < 0.01) and decreased the level of NO (P < 0.01). Compared with the model group, the levels of GSH-Px, CAT and NO in CJ, CG, SJ and SG groups were increased, and the levels of ET-1, ICAM-1 and TNF-α were decreased (P < 0.05, P < 0.01). VC, rosmarinic acid, salvianolic acid B and rutin high and medium dose groups, and isoquercitrin, cryptotanshinone high dose group significantly increased the levels of GSH-Px, CAT and NO (P < 0.05, P < 0.01) and decreased the level of ET-1 (P < 0.05, P < 0.01). ICAM-1 levels were significantly decreased in the high dose groups of salvianolic acid B, isoquercitrin and rutin as well as in the high and medium dose groups of rosmarinic acid (P < 0.01). In addition to the aminoguanidine group, the levels of TNF-α of other groups were significantly lower than the model group (P < 0.05, P < 0.01). Except the aminoguanidine group and isoquercetin low dose group, the levels of NO of other groups were significantly higher than the model group (P < 0.05, P < 0.01). Conclusion: In certain concentration range of alcohol extract and water extract of stems, leaves and roots of S. miltiorrhiza, rosmarinic acid, salvianolic acid B, rutin and isoquercitrin have protective effects on HUVECs injured by H2O2 and glucose. And the mechanisms are related to inhibition of intercellular adhesion molecule expression and regulation of NO and TNF-α production. This study will provide reference for the discovery and transformation of the resource value of non-medicinal stems and leaves produced during the production of S. miltiorrhiza.

Simultaneous Determination of 6 Flavonoids in the Roots of Tetrastigma hemsleyanum by HPLC / 中国药房

OBJECTIVE： To establish a method for simultaneous determination of rutin， isoquercitrin， kaempferol-3-O- rutinoside， daunorubicin， quercetin and kaempferol in the roots of Tetrastigma hemsleyanum.  METHODS： HPLC method was adopted. The determination was performed on Alliance SilGreen C18 column with mobile phase consisted of 0.2％ phosphoric acid solution-acetonitrile solution （gradient elution） at the flow rate of 1.0 mL/min. The detection wavelength was 360 nm and the column temperature was at 35 ℃. The sample size was 15 μL. RESULTS： The linear range of rutin， isoquercitrin， kaempferol-3- O-rutinoside， daunorubicin， quercetin and kaempferol were 21.77-217.77， 12.37-123.75， 13.23-132.31， 4.63-46.30， 5.75-57.50， 3.36-33.66 μg/mL （all r＝0.999 9）， respectively. limit of detection of them were 0.217 8， 0.123 8， 0.066 2， 0.046 3， 0.191 7， 0.112 3 μg/mL， respectively. limit of quantitation of them were 0.435 6， 0.247 5， 0.165 4， 0.154 3， 0.575 0， 0.421 2 μg/mL， respectively. RSDs of precision （n＝6）， stability （24 h， n＝7） and reproducibility tests （n＝6） were lower than 3.20％. The average recoveries of them were 96.23％， 86.88％， 97.51％， 97.67％， 97.50％， 87.46％， RSDs were 1.85％， 1.90％， 1.84％， 1.87％， 1.25％， 2.01％ （n＝9）， respectively. CONCLUSIONS： The method is fast and simple， and could be applied for simultaneous determination of rutin， isoquercitrin， kaempferol-3-O-rutinoside， daunorubicin， quercetin and kaempferol in the roots of T. hemsleyanum.  

Simultaneous Determination of Isoquercitrin ，Astragalin and Salvianolic Acid B in Moringa oleifera Leaves Granules by HPLC / 中国药房

OBJECTIVE： To establish a method for simultaneous determination of isoquercitrin， astragalin and salvianolic acid B in Moringa oleifera leaves granules. METHODS： HPLC method was adopted. The determination was performed on Cosmosil-C18 column with mobile phase consisted of acetonitrile-0.1％ phosphoric acid solution （gradient elution） at flow rate of 1.3 mL/min. The column temperature was 40 ℃ and detection wavelength was set at 260 nm. The sample size was 10 μL. RESULTS： The linear ranges of isoquercitrin， astragalin and salvianolic acid B were 0.017-0.341， 0.010-0.194， 0.010-0.195 mg/mL， respectively （all r＞0.999 0）. The detection limits were 0.085， 0.143， 0.117 μg/mL， and the limits of quantitation were 0.283， 0.476， 0.392 μg/mL， respectively. RSDs of precision， stability （24 h） and reproducibility tests were all lower than 2.0％ （n＝6）. Average recoveries were 101.22％， 98.76％ and 98.72％， and RSDs were 0.66％，0.30％，0.30％ （n＝6）， respectively. CONCLUSIONS： The established method is simple， accurate and reproducible. It can be used for simultaneous determination of isoquercitrin， astragalin and salvianolic acid B in M. oleifera leaves granules.

Optimization of Extraction Conditions and Quantitative Analysis of Isoquercitrin and Caffeic Acid from Aster scaber

To determine the optimum extraction conditions that give the highest yield of isoquercitrin and caffeic acid from Aster scaber, the effects of four extraction variables (solvent concentrations, extraction time, number of repeated extraction, and solvent volumes) on isoquercitrin and caffeic acid yield was examined via HPLC-UV. Our results showed that the highest extract and isoquercitrin yield were observed when A. scaber was extracted with 450 mL distilled water for 8 hr repeatedly for three times. In case of caffeic acid, the content was higher in the two repeated extracts. Also, content analysis of isoquercitrin in Aster species was performed in which A. fastigiatus, A. ageratoides, and A. scaber exhibited the highest isoquercitrin content at 6.39, 5.68, and 2.79 mg/g extract, respectively. In case of caffeic acid, the highest content of A. scaber and A. glehni was 0.64 and 0.56 mg/g extract, respectively. This study reports an optimized method for extraction of isoquercitrin and caffeic acid from A. scaber and evaluates potential sources of the compounds.

Determination of seven effective constituents in crude and processed Cuscuta australis by quantitative analysis of multi-components with single marker / 中草药

Objective To establish a quantitative analysis of multi-components with single marker (QAMS) for the simultaneous determination of chlorogenic acid, cryptochlorogenin acid, caffeic acid, hyperoside, isoquercitrin, astragalin, kaempferol in crude and processed Cuscuta australis, which is proved to be a scientific and feasible method in the quality analysis in C. australis. Methods Six relative correction factors (RCFs) of chlorogenic acid, cryptochlorogenin acid, caffeic acid, isoquercitrin, astragalin, kaempferol was established in the HPLC method with the hyperoside as the internal standard (IS), which was to calculate the mass fraction of each. The mass fraction of seven effective constituents in crude and processed C. australis was calculated by the external standard method (ESM) at the same time. Compared with the content results determined by the ESM and QAMS, the feasibility and accuracy of QAMS method were verified. Results The relative correction factor (RCF) was perfect. The detection calculated by QAMS was consistent with the results by ESM. Conclusion The method with a single marker, using the hyperoside as IS, is accurate and feasible for the quantitative analysis of six other effective constituents in C. australis.

Optimization of extraction and purification technology for phenolic acids and flavonoids in stems and leaves of Salvia miltiorrhiza / 中草药

Objective To study the optimum condition for the extraction and purification of phenolic acids and flavonoids in the stems and leaves of Salvia miltiorrhiza. Methods The contents of phenolic acids and flavonoids were determined by ultra performance liquid chromatography (UPLC). The extraction process was evaluated by single factor test and orthogonal design with yield of dry extract and the content of phenolic acids (including danshensu, protocatechuic acid, protocatechualdehyde, caffeic acid, salvianolic acid B, rosmarinic acid, and lithospermic acid) and flavonoids (including rutin, isoquercitrin, kaempferol-3-O-rutinoside, and astragalin) as index. The effects of extraction method, extraction solvent, ratio of material to liquid, extracting time, and extracting times on the extraction of stems and leaves of S. miltiorrhiza were investigated. Macroporous adsorption resin was used to purify the sample, and the purification process parameters were investigated to determine the optimum purification process. Results The optimum condition for the extraction of the stems and leaves of S. miltiorrhiza is that eight times of 50% ethanol for three times reflux extraction and 1 h for each time and AB-8 macroreticular resin was selected for the purification. Optimum process was as following:The concentration of sample solution was 1.0 g/mL; The loading quantity of the sample was 0.15 g dried extract of per gram; The resin column chromatography was eluted with 3 BV of 40% ethanol. Under these conditions, the total purity of phenolic acids and flavonoids could reach 40.83%. Conclusion The optimum technology is stable and feasible for the extraction and purification of phenolic acids and flavonoids in the stems and leaves of S. miltiorrhiza, and can provide reference for further development and utilization.

Study on HPLC specific chromatograms of effective parts and determination of five components of Filifolium sibiricum / 中草药

Objective: To establish the HPLC specific chromatograms of the ethyl acetate layer in ten batches of effective parts of Filifolium sibiricum and to determine the contents of five components. Methods: The analysis of effective parts of F. sibiricum was performed on a Thermo AcclaimTM120 C18 column (250 mm × 4.6 mm, 5 μm) with acetonitrile (B)-PBS (A) (0.1 mol/L sodium dihydrogen phosphate-2% glacial acetic acid, 1∶1) as the mobile phase in a gradient elution mode, the detection wavelength was set at 360 nm, the flow rate was 0.8 mL/min, and the column temperature was 35 ℃. Results: The specific chromatograms of F. sibiricum effective parts were established and ten common peaks were designated. Among them, five components including isorientin, isovitexin, isoquercitrin, luteoloside and isorhamnetin-3-O-β-D-glucose all showed good linear relationship within the ranges of 0.018—0.108, 0.066 8—0.400 8, 0.088—0.528, 0.118 4—0.710 4 and 0.017 6—0.105 6 μg, respectively. The average recovery was 98.67%, 97.93%, 98.95%, 99.81%, and 97.33% with the RSD value at 1.10%, 0.93%, 1.10%, 0.62%, and 1.48%, respectively. Moreover, the similarity of the eight batches of samples was above 0.9 in the ten batches of medicinal herbs, the similarity of the two batches of which was 0.688 and 0.695, indicating that its content was lower and the difference was greater. In addition, there were significant differences in the content of five components in each harvest time. The content of flavonoids in medicinal herbs was higher with high flower percentage. It was suggested that the content of flavonoids in F. sibiricum was related to the flower percentage of harvest period. Conclusion: The HPLC specific chromatograms of the F. sibiricum effective parts were established and the common characteristic peaks were determined, which could be used for quality control of the F. sibiricum.

Pharmacokinetics of rutin, quercitrin, and isoquercitrin in Hedyotis diffusa in normal and tumor-bearing rats / 中草药

Objective: Based on the tumor-bearing rat model, using rutin, quercitrin, and isoquercitrin from Hedyotis diffusa as the research object, the pharmacokinetics of those three flavonoid glycosides in the pathological state was studied. Methods: Establishing a method for the comparison of the pharmacokinetics of flavonoid extracts in normal rats and tumor-bearing rats, which was analyzed by HPLC-MS/MS in subcutaneous tumor models of SD rat made with tumour cell of Walker-256. Results: Compared with the pharmacokinetics parameters of flavonoid glycosides in normal rats, the Cmax and AUC0-∞ of rutin, quercetin, and isoquercitrin in the tumor-bearing rats were significantly decreased, t1/2z was prolonged, and the metabolic time of three components was prolonged to 24 h, which revealed the effect of pathological condition on the pharmacokinetic characteristics of flavonoid glycosides. Conclusion: The method established in this study is simple, fast, sensitive, and suitable for the pharmacokinetic study of flavonoid glycosides in rats in vivo. The pharmacokinetic characteristics of flavonoids in normal and tumor-bearing rats are different.

The inhibitory effect of isoquercitrin onRaf/MEK/ERK signaling pathway in HepG2 cells / 中国药理学通报

Aim To study the inhibitory effect of isoquercitrin on Raf/MEK/ERK signaling pathway in HepG2 cells.Methods MTT was used to detect the proliferation of human liver cancer HepG2 cells after the treatment of isoquercitrin.The morphology and growth of cells were observed under inverted microscope after the different concentrations of isoquercitrin(0, 40, 80, 160, 320 μmol·L-1) to treat HepG2 cells for 24 and 48 h.Cell cycle was assessed by flow cytometry.Ras, Raf, MEK, ERK expression was assayed by Western blot, and mRNA expression was detected by quantitative fluorescence PCR.Results Isoquercitrin could inhibit the growth of HepG2 cells in a concentration-and time-dependent manner.Typical morphological changes of apoptosis were observed by inverted microscopy after HepG2 cells were treated with different concentrations of of isoquercitrin for 24 h or 48 h.The cell cycle assay showed that with the increasing concentration of isoquerditrin, the number of cells that was arrested in G1 phase gradually increased.Compared with the blank group, the expressions of Ras, Raf, MEK, ERK mRNA were down-regulated, and related proteins expression were also down-regulated(P<0.05), and these results had statistical significance.Conclusion Isoquercitrin can induce the apoptosis of HepG2 cells, which may be related to the Raf/MEK/ERK signaling pathway.

Regulation Effects of Isoquercitrin on Inflammatory in LPS-induced RAW264.7 Cell / 医药导报

Objective To investigate the influence of isoquercitrin on the inflammatory factors in LPS-induced RAW264.7 cells.Methods MTT method was used to detect inhibition ratio of RAW264.7 cells induced by isoquercitrin.The level of TNF-α in culture medium was measured by ELISA.Nitric oxide (NO) was detected by Nitrate Assay Kit.Western blotting was used to investigate the influence on the productions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2).Results The half inhibitory concentration (IC50) of isoquercitrin was 65.73 μmol·L-1.LPS had no inhibitory effect on the cells.Compared with LPS group,the level of TNF-α was decreased to 74.80% and 60.57% in isoquercitrin (20,10 μmol·L-1) groups in a dose-dependent manner.The results measured by Nitrate Assay Kit revealed that isoquercitrin (20,10 μmol·L-1) could suppress production of NO,the level of NO decreased to 79.34% and 68.81%(P<0.05).The Western blotting results showed that isoquercitrin (20,15,10 μmol·L-1) inhibited the productions of iNOS and COX-2 (P<0.05).Conclusion Isoquercitrin has anti-inflammatory effects by inhibiting the productions of TNF-α,NO,iNOS and COX-2,and the most effective dose for the inhibition is 10 μmol·L-1.

Simultaneous determination of five flavonoids in Duchesnea indica at five picking time by HPLC / 中成药

AIM To establish an HPLC method for the simuhaneous content determination of five flavonoids in Duchesnea indica (Andr.) Focke at five picking time (April,May,June,July and August).METHODS The analysis of D.indica methanol extract was performed on a 25 ℃ thermostatic Agilent ZORBAX SB-C18 column (250 mm×4.6 mm,5 μm),the mobile phase comprising of acetointrile-0.1％ methanoic acid flowing at 1.0 mL/min in a gradient elution manner,and the detection wavelength was set at 350 nm.RESULTS Rutin,hyperoside,isoquercitrin,celereoin and kaempferol showed good linear relationships within their own ranges (R2 ≥0.998 6),whose average recoveries were 97.1％-101.5％ with the RSDs of 1.37％-2.37％.The contents of five constituents in samples at different picking time exhibited obvious differences,among which lutin and hyperoside contents were the highest in June,isoquercitrin content was the highest in July,and celereoin and kaempferol contents were the highest in August.CONCLUSION The suitable picking time of D.indica is June and July.

Simultaneous quantification of eight constituents in the seed of Forsythia suspense (Thunb.) Vahl by HPLC-MS/MS method / 中草药

Objective: To develop an HPLC-MS/MS method for the simultaneous determination of forsythoside A, phillyrin, forsythiaside, rutin, quercetin, isoquercitrin, ferulic acid, and hesperidin in the seed of Forsythia suspense (Thunb.) Vahl. Methods: Chromatographic separation was performed on a Diamonsil C18 column (150 mm × 4.6 mm, 5 μm) with linear gradient elution of methanol and 0.1% formic acid at a flow rate of 800 μL/min, and the injection volume was 10 μL. Multiple-reaction monitoring (MRM) was employed with switching electrospray ion source polarity in negative mode. The ion spray voltage was set at-4 500 V and the turbo spray temperature was maintained at 650℃. Results: All calibration curves showed good linearity within the test ranges. The average recoveries of the compounds ranged from 98.1% to 101.8%. The precisions (RSD) for the investigated components were less than 0.84%. The contents of forsythoside A, phillyrin, forsythiaside and rutin are higher than quercetin, isoquercitrin, ferulic acid and hesperidin. And the average contents of forsythoside A, phillyrin, forsythiaside and rutin are 1 609.78, 80.08, 86.64 and 373.86 μg/g, respectively. Conclusion: An efficient, rapid, and sensitive method is first established for the qualitation and quantification of eight major components in the seed of Forsythia suspense (Thunb.) Vahl. The satisfactory results demonstrate that the method could be applied as a reliable quality control method for the seed of Forsythia suspense (Thunb.) Vahl.

Chemical constituents from Rubus caesius and their inhibitory activities on PTP 1B / 中草药

Objective: To investigate the chemical constituents from the stem and leaves of Rubus caesius and the inhibitory activities on PTP 1B. Methods: Compounds were separated and purified by silica gel column chromatography, Sephadex LH-20 column chromatography, and preparative liquid chromatography. Their structures were identified by spectral methods. The PTP1B inhibitory activities were screened by microplate reader. Results: Five compounds were obtained from the stems of R. caesius respectively, elucidated as naringin (1), apigenin-7-O-β-D-glucopyranoside (2), isoquercitrin (3), hyperoside (4), and (-)-epicatechin 3-O-gallate (ECG) (5), and two compounds were obtained from the leaves respectively, elucidated as acteoside (6) and ellagic acid (7) respectively. Conclusion: Compounds 1-7 are isolated from this plant for the first time. Different fractions and compounds showed different PTP1B inhibitory activities and acteoside showed high PTP1B inhibitory activity with the IC50 value of (27.41 ± 0.61) μg/mL. This compound may be the main active composition of leaves ethyl acetate fraction.

Study on quality of Diospyros kaki leaves based on chemical fingerprint and multi index determination / 中草药

Objective: To establish the HPLC fingerprint and to determine multiple components of leaves of Diospyros kaki, in order to provide a scientific basis for quality control for the D. kaki leaves and related products. Methods: The chromatographic separate was achieved on a Diamonsil C18 (250 mm × 4.6 mm, 5 μm) column with acetonitrile and 0.2% formic acid in water as the mobile phase for gradient elution; Volume flow rate was 1.0 mL/min; Column temperature was 35 oC; Detection wavelength was 360 nm; And injection was 10 μL; On 22 batches of persimmon leaf medicinal materials of fingerprint study, was evaluated with a chromatographic fingerprint similarity evaluation system (version 2004A), the 22 batches of persimmon leaf are divided into two categories by system cluster analysis and PCA analysis. And the determination method of hyperoside, isoquercitrin, quercetin, and kaempferol was also investigated at the same time. Results: The fingerprint of D. kaki leaves was established. There were 12 common peaks in the fingerprint of D. kaki leaves. Hyperoside, isoquercitrin, quercetin and kaempferol were baseline seperated with good linearity relationships between concentration and peak areas over the linear ranges, within 0.044-0.880, 0.078-1.560, 0.040-0.800 and 0.035-0.700 μg(r > 0.999 8). The average recoverys of the investigated compounds were 97.59%, 98.97%, 100.55%, 99.96%. Conclusion: HPLC fingerprint binding index component determination can provide a reference for the quality of D. kaki leaves and related products control.

Dynamic changes of development and active ingredients content of male flower of Eucommia ulmoides / 中草药

Objective: To establish a method for the determination of six active ingredients in Eucommia ulmoides male flowers, and analyze the dynamic changes of male flower development and active ingredients content of E. ulmoides. Methods: The active ingredients were extracted by the ultrasound-assisted process, the content of total flavonoids was determined by AlCl3 colorimetric method and other six ingredients were determined by HPLC, the samples were separated on a Thermal hypersil gold column (250 mm × 4.6 mm, 5 μm) with gradient elution of methanol-0.5% phosphoric acid at a flow rate of 1.0 mL/min, the UV wavelength was set at 206 nm (0-15 min), 236 nm (15-55 min), and 255 nm (55-100 min). Results: Flower diameter, flower height, fresh weight, dry weight, stamen length and stamen number all reached the maximum at full bloom stage; The contents of total flavonoids, chlorogenic acid and total active ingredients were the highest at the bud stage and the lowest at the initial flowering stage; The content of aucubin showed a tendency of graudal decreasement; The content of geniposidic acid was the lowest at the bud stage and reached the highest at full bloom stage, and decreased at the end of flowering phase; The content of geniposide, isoquercitrin and astragaline were the highest at full bloom stage and the lowest at the initial flowering stage. Conclusion: Flowering stage had a great impact on morphology, yield, active ingredients content and quality of E.ulmoides male flowers, which could provide important information for quality control and product development of E.ulmoides male flowers.