Stability of Baicalin Aqueous Solution by Validated RP-HPLC

Aim In the present study a RP-HPLC method was developed and validated toinvestigate the stability of baicalin aqueous solution. Methods The influences of temperature and pHon the stability of baicalin aqueous solution were investigated by classic homoiothermicacceleration test, and the pH for the most stable solution was determined. Results The time whenbaicalin suffered 10% loss was found to be 18.1 h, and the degradation activation energy of baicalinwas 79.1 kJ·moL^(-1) . The pH at which baicalin is most stable is 4.28. Conclusion The temperatureshould be kept at a lower level and the pH should be adjusted to near that for the most stablesolution in the production of baicalin preparations.

RP-HPLC Determination of Pinoresinol Diglucopyranoside in Qing′e Pill Extract

Aim To develop and determine pinoresinol diglucopyranoside in Qing'e Pill, atraditional Chinese compound preparation containing Eucommia ulmoides Oliv. as the principal drug,by a reverse-phase high-performance liquid chromatographic method (RP-HPLC) . Methods The extract ofQing'e Pill was refluxed with 75% ethanol, purified on an AB-8 macroporous adsorption resin columnand then injected into HPLC system. The HPLC assay was performed on an ODS analytical column with amixture of methanol-acetonitrile-water (24:3:78, V/V/V) as the mobile phase at a flow-rate of 1.0mL·min^(-1), and a UV detector set at 227 nm. Results Good linearity between peak area andconcentration was found in the range of 5.5 - 170 μg·mL^(-1) for pinoresinol diglucopyranoside ( r> 0.9998) . The average recovery was 99.3%. The intra-day assay RSD and the inter-day assay RSDwere 1.3% and 2.8%, respectively (n = 5). The content of pinoresinol diglucopyranoside in Qing'ePill was determined to be 0.446 +- 0.012 mg·g^(-1) (n = 10). Conclusion The RP-HPLC method wasproved to be sensitive, specific, accurate and precise for the determination of pinoresinoldiglucopyranoside in Qing' e Pill.

RP-HPLC determination of lycopene in microcapsules

Aim A RP- HPLC method for determination of lycopene in microcapsules was established. Methods The HPLC assay was performed on an Alltima Cls （4.6 mm × 250 mm, 5μm） column with a mixture of methanol-THF-water （66：30：4, V/V/V） as mobile phase at a flow rate of 1.5 mL·min^-1 and the UV detection wavelength was 472 nm. Results The linear range of lycopene was 3.6-18 μg·mL^-1, r = 0.999 8, the average recovery was from 99.81% to 101.06% with RSD less than 1.83%. The RSD of intra-day and interday precision were less than 3.34%. Conclusion The method is simple, accurate and suitable for the determination of lycopene in microcapsules.

Determination of Sulphonylurea Glimepiride in Dog Serum by RP-HPLC with Pre-column Derivatization

Aim A simple, sensitive and rapid RP HPLC method with pre column derivatization has been developed for the determination of sulphonylurea glimepiride in dog serum. Methods The sulphonylurea glimepiride was extracted from the dog serum using dichlromethane followed by derivatization with DNBF for 20 min at 100℃. The solvent was then evaporated at 60℃ under nitrogen, and the residue was taken up in 100 μL of mobile phase consisting of acetonitrile water (75∶30, v/v). The separation was performed on a Hypersil BDS C18 column with a flow rate of 0 8 mL·min -1 , and the ultraviolet detector wavelength was set at 350 nm. Results Extraction recovery ranged from 75.9% to 83.2%, and methodological recovery was between 96.5% and 109.3%. Within day RSD ranged from 1.5% to 6.3%, and inter day RSD was between 2 9% and 14.8%. The method showed good linearity (R=0.9998). Conclusion The method was simple, convenient and sensitive. The reaction of derivatization was reproducible.

Hypertonic stimulation induces synthesis and release of glutamate in cultured rat hypothalamic astrocytes and C6 cells

Objective To investigate whether hypertonic saline （HS） can induce the synthesis and release of glutamate in cultured hypothalamic astrocytes or C6 cell line. Methods Astrocytes were isolated, cultured, purified and identified from the hypothalamus of newborn rat （1 day）. The astrocytes were randomly divided into five groups： isotonic （IS） and HS groups, astrocytes were incubated by IS and HS （320 mosM NaCl） medium, respectively, for 1, 3, 5, 10 or 15 rain; carbenoxolone （CBX） ＋IS and CBX＋HS groups, astrocytes were pre-treated with CBX （100 mmol/L） for 1 h at 37℃ in a 5% CO2 / 95% atmosphere, then removed to IS and HS medium, respectively, for 1, 3, 5, 10 or 15 min; Ca2＋＋HS group, astrocytes were pre-incubated with Ca2＋ （1 000 μmol/L） for 1 h at 37℃ in a 5% CO2 / 95% atmosphere, followed by a wash with isotonic FBS/DMEM, and then removed to hypertonic saline for 1, 3, 5, 10 or 15 min. The media of five groups were collected to analyze the medium glutamate concentration with high performance liquid chromatography. The astrocytes were fixed and double immunofluorescent stained with anti-glial fibrillary acidic protein （GFAP） and anti-glutamate. The C6 cells were divided into four groups： IS, HS, CBX＋IS and CBX＋HS groups, and used for quantitative measurement of glutamate in cells by flow cytometry （FCM）. Results （1） Anti-GFAP immunofluorescent signal revealed no significant difference among various time points in each group, or among the five groups. （2） The anti-glutamate immunofluorescent signal was increased in HS group and peaked at 5 min, and decreased and returned to the level of IS group at 15 rain （P 〈 0.01 vs the 5 min of HS group）. In CBX＋HS group, the glutamate intensity was higher than that in CBX＋IS and HS groups. （3） The medium glutamate concentration had no change after treatment with HS for 1 and 3 min, while increased markedly after treatment for 5 min to 15 min （P 〈 0.01 vs 1 min and 3 min）. On the contrary, the medium glutamate concentrations in the CBX＋HS or Ca2＋＋HS group were significant lower than that in the HS group （P 〈 0.01）. （4） FCM showed HS and CBX＋HS induced glutamate increase in C6 cells. Conclusion HS induced cultured rat hypothalamic astrocytes or C6 cells to synthesize and release glutamate; CBX could block glutamate release, but could not disrupt glutamate synthesis.

Determination of Candicidin/FR-008 and Related Components in Fermentation Broth by RP-HPLC

Aim A liquid chromatographic method for the determination ofcandicidin/FR-008 and related components in fermentation broth has been developed. Methods Therewere four major components in the candicidin/FR-008 complex, which were separated by HPLC under thefollowing conditions: SB-C8 column (4.6 mm x 250 mm, 5 μm) was used, the mobile phase consisted ofacetonitrileam-monium acteate (20 mmol·L^(-1) , pH 4.0) (40:60, V/V) , with a flow rate of 1 .0mL·min^(-1) , the UV detection wavelength was 380 nm, and the whole process was performed at 25℃ .Results The linearity was obtained in the range of 6.25 - 500 μg· mL^(-1) candicidin/FR-008 withthe regression equation of Y = 20 461 x + 30 748 and the correlation coefficient of 0.999 1. Theinstrument precision was 1.84% and the method precision was 3.8%. Conclusion This method isaccurate, rapid and simple; it can be used for determination of candicidin/FR-008 and relatedcomponents in fermentation broth.

A Pre-column Derivatization HPLC Method for the De-termination of Peimine and Peiminine in Bulbus Fritillar-iae

A pre-column derivatization HPLC method for the determination of peimine(P)and peiminine(PE)in Bulbus Fritillariae has been developed. Under the derivatization conditions optimized,the calibration curve is Y1=-3.83×103+1.33 ×105X1,r=0.998 for P and Y2=-7.86 × 102+6.33 × 104X2,r=0995 for PE,where Y is the peak area and X is the weight of the alkaloid; the average recovery is 98.0%(n=5, RSD=2.1%) for P and 101.0%(n=5,RSD=4.1%)for PE,the linear range is from 0.504 μg to 3.126μg for P and from 0.520μgto 3.328μgfor PE,respectively. Results of the determination of the two alkaloids in several samples of different Fritillaria species from various parts ofthe country are presented.The results suggest that P and PE are two major chemical constituents in bulbs of different Fritillaria species,and that the method developed is generally appli-cable to the determination of the hydroxy group on aliphatic fused ring systems without steric hin-drance.

Determination of Lycopene Concentration in Dog Plasma by RP-HPLC

A method for determination of lycopene concentration in dog plasma wasestablished. Methods RP-HPLC was used; the mobile phase consisted of methanol-acetonitrile-methylenechloride (40:30:30, V/V) , the wavelength of detection was 472 nm, the column temperature wasambient temperature, and the flow rate was 1.0 mL·min^(-1). Results The standard curve was linearin the range from 0.012 4 to 0.496 μg·mL^(-1) with r=0.9992. The average extraction recovery was97.6% +-4.2%. The intra-day and inter-day RSD were 1.52% -4.95% and 2.31% -7.38%, respectively.Conclusion This method is sensitive, rapid, reproducible, and of good selectivity for the analysisof lycopene in dog plasma.

Simultaneous Determination of Ceftazidime and Tazobactam in Injectable Powder by Reversed-Phase High Performance Liquid Chromatography

A reversed-phase high performance liquid chromatographic (RP-HPLC) method wasdeveloped and validated for the simultaneous deteimination of ceftazidime and tazobactam ininject-able powder. Methods Chromatography was carried out on Zorbax 300SB-C_(18) column using amixture of methanol and aqueous solution of phosphate buffer (pH = 5.6) as mobile phase. The UVdetection wavelength was 220 run. Results The linear ranges of ceftazidime and tazobactam were 0.62- 631.8 μg·mL^(-1) and 0.66 - 677.50 μg·mL^(-1), respectively. The average recoveries were 98.8%- 101.4% for ceftazidime, and 99,1% - 100.2% for tazobactam. The RSD values of inter-day andintra-day assays were lower than 1.5% for ceftazidime and 2.6% for tazobactam. Conclusion Thismethod is reproducible, simple, precise, and rapid for the quality control of ceftazidime andtazobactam in injectable powder.

A RP-HPLC method for determination of paclitaxel in its solid dispersion

Aim To develop and validate a RP-HPLC method for the analysis of paclitaxel in a solid dispersion. Methods Paclitaxel and the internal standard norethisterone were separated using a Phenomenex ODS 3 column and monitored at a wavelength at 227 nm. The isocratic mobile phase consisting of methanol-acetonitrile-water （40：30：30, V/V） was pumped at a flow-rate of 1.0 mL·min^-1. The dissolution studies were performed according to published studies. Results Under these chromatographic conditions, the calibration curve was linear in the range of 4-40 μg·mL ^-1 with the correlation coefficient of 0.9999. The mean recovery was 98.42 % （RSD = 1.19 %）. At the 60 min time point, the dissolution of paclitaxel from the solid dispersion was nearly 100 %, however, the original form of paclitaxel was about 30 %. Conclusion The method was proven to be specific, accurate and precise for determining the dissolution of paclitaxel from solid dispersion.

Development and Validation of a Novel Reverse Phase HPLC for Determination of Aloperine in Aloperine Tablets

Aim To develop a reverse phase HPLC method for the determination of aloperine, an alkaloid that is newly extracted from Sophora alopecuraides and has shown wide pharmacological effects including antibacterial and antiinflammatory actions. Methods The samples were analyzed on a ODS column with methanol water triethylamine (3∶97∶0 1 V/V) as a mobile phase. The flow rate was 1 0 mL·min -1 , and UV detection wavelength 205 nm. Results Linear regression equation was A=1 6920C+1 7455 (r 2=0 9999, n =5) in concentratins ranging from 20 to 120 μg·mL -1 . The recoveries were 101 2±1 46 % at 80 μg·mL -1 , 100 5±0 75% at 100 μg·mL -1 , and 100 7±1 10% at 120 μg·mL -1 , respectively, and the precisions of aloperine within or between run were from 0 80% to 1 98% ( n =5). The relative contents of aloperine in three lots of tablets were 101 59±1 38%, 98 46±0 23%, and 99 41±1 09% ( n =3). Conclusion The newly developed reverse phase HPLC method is simple and useful for daily assay of aloperine tablets and can overcome the interference from excipient and other alkaloids in titration and UV detection.

The Use of HPLC in Determination of Endogenous Hormones in Anthers of Bitter Melon

A simple, rapid and perfect extraction and determination method for the endogenous hormones in anthers of bitter melon with reversed-phase high performance liquid chromatography （HPLC） has been developed. The HPLC system consisted of Hypersil ODS C 18 reverse phase column （150 mm × 4.6 mm, 5 μm） with a methanol gradient in 0.6% acetic acid and UV detector set at 254 nm. The results showed that the method was accurate and efficient.

Purification and Characterization of Angiotensin I Converting Enzyme Inhibition Peptides from Sandworm Sipunculus nudus

Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography(RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC_(50) values of the purified peptides for ACE inhibition activity were 34.72 μmol L^(-1), 20.55 μmol L^(-1) and 22.77 μmol L^(-1), respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.

Enantiomeric separation of phenylsuccinic acid by cyclodextrin-modified reversed phase high-performance liquid chromatography

The chiral separation of phenylsuccinic acid(PSA)was studied by reversed phase high-performance liquid chromatography(RP-HPLC)with cyclodextrins(CDs)as chiral mobile phase additives.The effects of types of CDs,concentration of hydroxypropyl-β-cyclodextrin(HP-β-CD),percentage of organic modifier,pH value and column temperature on enantioselective separation were investigated.The quantification property of the developed RP-HPLC method was examined.The chiral recognition mechanism of PSA was also discussed.The results show that a baseline separation of PSA enantiomers is achieved on a Lichrospher C18 column(4.6 mm(inner diameter)×250 mm,5μm)with HP-β-CD as chiral mobile phase additive.The capacity factors of R-PSA and S-PSA are 3.94 and 4.80,respectively.The separation factor and resolution are respectively 1.22 and 8.03.The mobile phase is a mixture of acetonitrile and deionized water(20-80,volume ratio)containing 10 mmol/L HP-β-CD and 0.05% trifluoroacetic acid(pH 2.5,adjusted with triethylamine)with a flow rate of 1.0 mL/min.The ultraviolet(UV)detector is set at 254 nm.The likely roles are inclusion interaction,induction and hydrogen bonding between HP-β-CD and PSA enantiomers.

Production and Purification of Antioxidant Peptides from Flatfish Skin Protein Hydrolysates

Antioxidant peptides of flatfish skin protein hydrolyzed by four enzymes （Papain, Pepsin, Trypsin and Neutrase, respectively）were investigated. The Trypsin hydrotysate obtained by hydrolysis exhibited the highest 1,1- dipheny-l-2-picrylhydrazyl（DPPH） radical scavenging activity （DRSA） compared with other hydrolysates. Re- sponse surface method ology （RSM）, based on Box-Behnken design, was used to study the influence of hydrolysis conditions on the DRSA. The optimal hydrolysis conditions were as follows： pH 7.38, temperature 48.2~C and en- zyme/substrate （E/S）ratio 2 840 U/g. Under these conditions, the maximum DRSA was （22.85 ＋ 0.57）%. The experimental values agreed with the value （23.09%） predicted by the model within a 95% confidence interval. By using gel filtration chromatography and reversed-phase high performance liquid chromatography （RP-HPLC）, anti- oxidant peptide （D2-P）was isolated from flatfish skin protein hydrolysates （FSPH）and could exhibit a （54.28 ± 1.37） % scavenging activity on DPPH radical at the concentration of 5 mg/mL. This is the first report of a scientific basis for the preparation of antioxidant peptides from flatfish skin. The results suggested that the antioxidant pep- tides can be exploited into functional foods or used as a novel source of nutraceuticals.

Changes of Metabolites and Macro- and Micro-elements in Hungarian Potatoes under Organic and Conventional Farming

To study the effect of cultivation system （conventional and organic） on potato tuber components, 42 parameters （anti-nutritives, micro- and macro-elements and 23 metabolites） were studied in three multi-resistant Hungarian potato varieties for three years in 2007-2009. Discriminant analysis of data proved that all investigated factors （farming technology, genotype and season/year） had significant effect on metabolites. Reversed phase high performance liquid chromatographic （HPLC-DAD, HPLC-MS） and elemental analysis methods have been adapted to quantify the major components, i.e., steroidal alkaloids, nitrite, nitrate, sugars, amino acids and micro-elements, in potato tubers. The absolute amount and changes of tuber components were influenced differentially by the technology, genotype and season in a complex manner. Any examined component, except nitrate content, was found to be significantly higher or lower consistently in relation to the production practice （organic or conventional） during the three years trials. Under the examined circumstances, no consequent positive effect of organic fanning on the total amount of anti-nutritive components, vitamins or micro- and macro-elements of potato tubers could be proven.

同时分析黄金菊片剂中药效组分的方法(英文)

目的:建立用薄层色谱法(TLC)同时定性分析和反相高效液相色谱法(RP-HPLC)同时定量分析黄金菊片剂中药效组分黄芩苷-绿原酸-荭草苷-牡荆苷的方法,为建立中药与临床疗效对应的药效组分质量评价体系奠定基础。方法:TLC鉴别是以聚酰胺薄膜为固定相,以氯仿-乙酸乙酯-甲醇-甲酸(5:5:4:0.6)为展开剂,喷以1%三氯化铝乙醇溶液,置紫外光灯365nm下检视。RP-HPLC法以Agela Venusil为色谱柱,以0.2%磷酸水(A)-乙腈(B)(0-30min,B 15%-30%线性洗脱)为流动相,流速1mL/min,检测波长为340nm,并对专属性、线性、准确度和精密度等进行了方法学验证。结果:4种成分TLC法检测分离度较好,RP-HPLC法标准曲线线性关系良好,R2均大于0.9995,平均回收率为98.99%-100.33%,相对标准偏差RSD均小于1.79%。结论:两种方法均操作简便、结果准确、灵敏度高,可用于黄金菊片剂的质量控制。

Determination of silymarin in microemulsion by RP-HPLC

We established a RP-HPLC method for the analysis of silymarin in microemulsion. Silymarin was separated using a ODS C18 column and monitored at the wavelength 288 nm. The mobile phase consisting of methanol-water-acetic acid （42：58：0.5, v/v/v） was pumped at a flow rate of 1.0 mL/min. The linear range of calibration curve was 10-1000 μg/mL. The average recovery was 99.0%-100.7% for silybin isomers. The RSD values of inter-day and intra-day assays were lower than 1.6% for silybin isomers. The method is simple, rapid, reproducible and precise for the quantitative determination of silymarin in microemulsion.

Safety of Individual Medication of Ma Qian Zi (Semen Strychni) Based upon Assessment of Therapeutic Effects of Guo's Therapy Against Moderate Fluorosis of Bone

Objective: To assess the safety of individual medication of Guo's Ma Qian Decoction on the basis of effective treatment of fluorosis of bone with Guo's therapy. Methods: One hundred and fourteen cases of moderate fluorosis of bone were randomly divided into a treatment group (n=60) and a control group (n=54) between December 2007 and August 2009 by using the block randomized method and a central random system. At the same time of basic treatment, the patients in the treatment group were orally administrated with Guo's Ma Qian Decoction. The initial dose of Ma Qian Zi (Semen Strychni) was 0.4 g and increased by 0.05 g every two days, with the doses of other drugs unchanged, until the patient had "nux vomica response". For the patients with no "nux vomica response", the dosage was continued to increase and the maximum dosage was not more than 1.2 g/day. The control group was treated with decoction placebo. The changes of strychnine and brucine contents before and after processing and after decoction of Ma Qian Zi (Semen Strychni) were determined with reversed-phase high-performance liquid chromatography, which were controlled within ranges stipulated in the Pharmacopeia; Adverse events were analyzed; Blood strychnine and brucine contents in 10 cases who had taken the drugs were determined. Results: 1) Strychnine (2.125%) and brucine (1.425%) contents before processing of Ma Qian Zi and 1.88% and 1.31% after processing all conformed with the standards of strychnine (1.2-2.2%) and brucine (no less than 0.8%) stipulated in the Pharmacopeia. When the maximum dosage of Ma Qian Zi was 1.2 g/day, strychnine in the decoction was 11.17 mg and brucine was 7.44 mg, which all conformed with the maximum limited amount (strychnine 13.32 and brucine no less than 4.8 mg) stipulated in the Pharmacopeia. 2) Eight cases had "nux vomica response" in the treatment group and one case in the control group, with a significant difference between the two groups (P<0.05). 3) Altogether 18 cases had adverse events, with an incidence rate of 15.38% (8 cases) in the treatment group and 18.52% (10 cases) in the control group, with no difference between the two groups (P>0.05); Among them, 10 cases (8.77%) with the adverse event were not related with therapeutic drugs, with an incidence rate of 6.67% (4 cases) in the treatment and 11.11% (6 cases) in the control group, with no significant difference between the two groups (P>0.05). Seven cases had suspicious relative adverse events, the risk in the treatment group was 0.658 times of the control group, with no significant difference (P>0.05), and one case had the toxic reaction of nux-vomica seed. 4) Strychnine and brucine were unable to be detected in the blood in all points of time in the 10 cases who had taken the drugs, indicating that plasma strychnine and brucine contents were lower than the minimum detectable amount (10 ng), and accumulation of strychnine and brucine were not found in blood of the patient during and after administration for 8 weeks. Conclusion: The individual medication of Ma Qian Zi (Semen Strychni) in the Guo's therapy has a better safety.

Expression and purification of bioactive high-purity human midkine in Escherichia coli

Midkine is a heparin-binding growth factor, which plays important roles in the regulation of cell growth and differentiation. The non-tagged recombinant human midkine （rhMK） is therefore required to facilitate its functional studies of this important growth factor. In the present work, rhMK was expressed in Escherichia coli （E. coli） BL21 （DE3）. The expression of midkine was efficiently induced by isopropyl-13-D-thiogalactopyranoside （IPTG）. After sonication, midkine was recovered in an insoluble form, and was dissolved in guanidine hydrochloride buffer. Renaturation of the denatured protein was carried out in the defined protein refolding buffer, and the refolded protein was purified using S-Sepharose ion-exchange chromatography. The final preparation of the rhMK was greater than 98% pure as measured by sodium dodecylsulfate-polyacrylamid gel electrophoresis （SDS-PAGE） and reverse phase high performance liquid chromatography （RP-HPLC）. The purified rhMK enhanced the proliferation of NIH3T3 cells.