“谱-效-性”关联分析探讨不同姜汁炮制黄连的作用差异

目的：建立姜制黄连炮制前后的＂谱-效-性＂关系,阐明不同姜汁炮制黄连的作用差异。方法：采用灰色关联度分析,将不同姜汁炮制黄连对其药性和药效作用参数进行转换,将姜黄连炮制前后的指纹图谱共有峰的峰面积分别和药效指标、药性指标进行关联分析。结果：姜黄连炮制前后指纹图谱的共有峰均为9个,生姜汁制黄连中盐酸药根碱、盐酸黄连碱、盐酸小檗碱、表小檗碱4种成分的含量均高于生黄连和干姜汁制黄连,干姜汁制黄连中盐酸巴马汀的峰面积低于生黄连和生姜汁制黄连。生姜汁制黄连在抑制金黄色葡萄球菌、止呕和抑制胃黏膜损伤方面作用更强,干姜汁制黄连对白色念珠菌和改善胃肠动力方面作用更加明显,干姜汁制黄连降低寒性作用优于生姜汁制黄连;这些作用与盐酸小檗碱、盐酸药根碱、盐酸黄连碱、表小檗碱和盐酸巴马汀等生物碱类成分的含量变化相关。结论：研究结果与姜制黄连＂缓寒,增强清胃和胃止呕＂的传统理论相一致,采用不同姜汁炮制黄连会使物质群存在差异,进而导致药效和药性的差异。

Pharmacokinetics of nifedipine sustained-release tablets in healthy Chinese volunteers

Aim To establish a LC-MS method for determining the concentration of nifedipine in human plasma and to evaluate the pharmacokinetic characteristics of nifedipine sustained-release tablets. Methods A XB-C18 （5 μm, 4.6 mm ×150 mm） column and a mobile phase of methanol： 0.01 mol·L^-1ammonium acetate （60：40, V/V） were used to separate nifedipine, the detections was accuracy under atmosperic pressure electronic spray ionization （AP-ESI） mode and ion mass spectrum （m/z） of 314.9 [M＋H]^＋ for nifedipine, and 320.8 [M＋H]^＋ for lorazepam （Internal Standard, IS）. Results The linear range of nifedipine was 0.3 - 80 ng·mL^-1 （ r = 0.9997）, and the limit of quantitation （LOQ） was 0.3 ng·mL^-1. The nifedipine pharmacokinetic parameters after a single dose of 20 mg nifedipine sustained-release tablets test （T） or reference （R） were as the followings, t1/2 （6.73 ± 2.00） h and （7.04 ± 2.18） h, Tmax （4.28 ± 0.70） h and （4.48 ± 0.70） h, Cmax（39.66 ± 10.58） ng·mL^-1 and （40.19 ± 10.97） ng·mL^-1, AUC0-36 （391.63 ± 108.55） ng·mL^-1·h and （387.57 ± 121.51） ng·mL^-1·h, and AUC0-∞ （408.28 ± 121.16） ng·mL^-1·h and （406.15 ± 133.13） ng·mL^-1·h. The relative bioavailability of nifedipine sustained-release tablets （test） was （103.02 ± 13.93） %. Conclusion LC-MS method for the determination of concentrations of nifedipine in human plasma was sensitive and accurate, and could be used in nifedipine bioavailability and pharmacokinetic studies.

Effects of alga polysaccharide capsule shells on in-vivo bioavailability and disintegration

Gelatin has been used in hard capsule shells for more than a century, and some shortcomings have appeared, such as high moisture content and risk of transmitting diseases of animal origin to people. Based on available studies regarding gelatin and vegetable shells, we developed a new type of algal polysaccharide capsule (APPC) shells. To test whether our products can replace commercial gelatin shells, we measured in-vivo plasma concentration of 12 selected volunteers with a model drug, ibuprofen, using high performance liquid chromatography (HPLC), by calculating the relative bioavailability of APPC and Qualicaps referenced to gelatin capsules and assessing bioequivalence of the three types of shells, and calculated pharmacokinetic parameters with the software DAS 2.0 (China). The results show that APPC shells possess bioequivalence with Qualicaps and gelatin shells. Moreover, the disintegration behavior of four types of shells (APPC, Vegcaps , Qualicaps and gelatin shells) with the content of lactose and radioactive element (99mTc) was observed via gamma-scintigraphic images. The bioavailability and gamma-scintigraphic studies showed that APPC was not statistically different from other vegetable and gelatin capsule shells with respect to in-vivo behavior. Hence, it can be concluded that APPCs are exchangeable with other vegetable and gelatin shells.

MHD mixed convective stagnation-point flow of Eyring-Powell nanofluid over stretching cylinder with thermal slip conditions

The optimal design of heating and cooling systems must take into account heat radiation which is a non-linear process.In this study,the mixed convection in a radiative magnetohydrodynamic Eyring-Powell copperwater nanofluid over a stretching cylinder was investigated.The energy balance is modeled,taking into account the non-linear thermal radiation and a thermal slip condition.The effects of the embedded flow parameters on the fluid properties,as well as on the skin friction coefficient and heat transfer rate,are analyzed.Unlike in many existing studies,the recent spectral quasi-linearization method is used to solve the coupled nonlinear boundary-value problem.The computational result shows that increasing the nanoparticle volume fraction,thermal radiation parameter and heat generation parameter enhances temperature profile.We found that the velocity slip parameter and the fluid material parameter enhance the skin friction.A comparison of the current numerical results with existing literature for some limiting cases shows excellent agreement.

Validation of Metformin Hydrochloride in Human Plasma by HPLC-Photo Diode Array （PDA） for Application of Bioequivalence Study

A sensitive and specific high performance liquid chromatography （HPLC） method was developed and validated for the simultaneous determination of metformin hydrochloride （HCI） in human plasma. The HPLC method consists of isocratic eluation with a mixture of 60% buffer （10 mM sodium dihyrogenphosphate-10 mM sodium dodecyl sulphate） and 40% acetonitrile with final pH 7.0 with flow rate of 1.0 mL/min on a Kromasil~ Akzo Nobel RP-18 （4.6 mm ID ~ 250 mm, 5 ~tm） column at an ambient temperature. Photo diode array detection was performed in program mode at 234 rim. The analyte and diazepam as internal standard （IS） were extracted from plasma using 10% trichloroacetic acid. The assay was linear over the therapeutic concentration range of 20-2,500 ng/mL for metformin HCI with correlation coefficient of r = 0.9999. Limit of quantitation was 20 ng/mL. The results obtained for intraJinter day accuracy and precision complied very well with the generally accepted criteria for bio-analytical assay. The method was applied to bioequivalence （BE） study of metformin HCI in healthy Indonesian volunteers after treatment with 750 mg XR metformin HCI. This BE study shows that the two formulations are equivalent so that they were therapeutically interchangeable for each other.

Deletion of a Non-Catalytic Region Increases the Enzymatic Activity of a β-Agarase from Flammeovirga sp. MY04

A Glycoside hydrolase （GH） typically contains one catalytic module and varied non-catalytic regions （NCRs）. However, effects of the NCRs to the catalytic modules remain mostly unclear except the carbohydrate-binding modules （CBMs）. AgaG4 is a GH16 endo-β-agarase of the agarolytic marine bacterium Flammeovirga sp. MY04. The enzyme consists of an extra sugar-binding peptide within the catalytic module, with no predictable CBMs but function-unknown sequences in the NCR, which is a new characteristic of agarase sequences. In this study, we deleted the NCR sequence, a 140-amino acid peptide at the C-terminus and expressed the truncated gene, agaG4-T140, in Escherichia coli. After purification and refolding, the trtmcated agarase rAgaG4-T140 retained the same catalytic temperature and pH value as rAgaG4. Using combined fluorescent labeling, HPLC and MS/MS techniques, we identified the end-products of agarose degradation by rAgaG4-T140 as neoagarotetraose and neoagarohexaose, with a final molar ratio of 1.53：1 and a conversion ratio of approximately 70%, which were similar to those of rAgaG4. However, the truncated agarase rAgaG4-T140 markedly decreased in protein solubility by 15 times and increased in enzymatic activities by 35 times. The oligosaccharide production of rAgaG4-T140 was approximately 25 times the weight of that produced by equimolar rAgaG4. This study provides some insights into the influences of NCR on the biochemical characteristics of agarase AgaG4 and implies some new strategies to improve the properties of a GH enzyme.

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.

Chromatographic fingerprint analysis of Fructus Aurantii Immaturus by HPLC-DAD and chemometric methods

An efficient method for quality control of Fructus Aurantii Immaturus (FAI),a famous traditional Chinese medicine (TCM) was established. A simple and reliable high-performance liquid chromatography-photodiode array detector (HPLC-DAD) procedure coupled with chemometric methods was developed for fingerprint analysis,qualitative analysis and quantitative determination of this herb. In qualitative and quantitative analyses,heuristic evolving latent projection (HELP) method was employed to resolve the overlapping peaks of the tested samples. Two bioactive components,namely hesperidin and naringin,are confirmed and determined,together with four flavonoids compounds tentatively identified including two new ones. From fingerprint analysis,the fingerprint data were processed with correlation coefficients for quantitative expression of their similarity and dissimilarity. The developed method based on an integration of chromatographic fingerprint and quantitative analysis is scientific,and the obtained results can be applied to the quality control of herb medicine.

Aerobic biodegradation of di-n-butyl phthalate by Xiangjiang River sediment and microflora analysis

Di-n-butyl phthalate (DBP),one of phthalate acid esters (PAEs),was investigated to determine its biodegradation rate using Xiangjiang River sediment and find potential DBP degraders in the enrichment culture of the sediment. The sediment sample was incubated with an initial concentration of DBP of 100 mg/L for 5 d. The biodegradation rate of DBP was detected using HPLC and the degraded products were analyzed by GC/MS. Subsequently,the microbial diversity of the enrichment culture was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results reveal that almost 100% of DBP is degraded after merely 3 d,generating two main degraded products:mono-butyl phthalate (MBP) and 9-octadecenoic acid. After a six-month enrichment period under the pressure of DBP,the dominant family in the final enrichment culture is clustered with the Comamonas sp.,the remaining are affiliated with Sphingomonas sp.,Hydrogenophaga sp.,Rhizobium sp.,and Acidovorax sp. The results show the potential of these bacteria to be used in the bioremediation of DBP in the environment.

Biodegradation of Acid Anthraquinone Dye in a Facultative-aerobic Process:Kinetics and Products

The transformation of an anthraquinone dye blue 324 in a facultative-aerobic(F-A) system was investigated.Kinetic parameter study showed that higher Vmax coupled with more recalcitrant chemical oxygen demand(COD) were found in the facultative biofilm reactor(FBR) than in the aerobic reactor(AR).Results of the product analyses indicated that most of dye molecular could be facultatively broken down into simple intermediates,which would be further degraded under subsequent aerobic condition.The main metabolites in each reactor were detected by infrared(FT-IR) and high performance liquid chromatography and mass spectrometry(HPLC-MS).Comparison of the toxicities among the dye and its metabolites was conducted,surprisingly,the colorless intermediates from FBR possessed less inhibitory than original dye and the median effective luminescence concentration(EC50) in 15 min for aerobic effluent could not be detected,showing that hardly toxic products existed in the aerobic process effluent.

On-Line Pyrolysis-Liquid Chromatography of （Meth-） Acrylic Acid in Waterborne Polymers Using Cryogenic Injection

Pyrolysis gas chromatography is not a comprehensive analysis method for the determination of acrylics. Polar acrylic monomers show low abundance by gas chromatography. Because of this, a home-made pyrolysis liquid chromatographic injector by means of cryogenic-focussing is developed to determine the presence and concentration of hydroxyl and carboxyl functional monomers present in water- and solvent-borne acrylics. We have shown the prove-of-principle of using cryogenic-focussing for UPLC （pyrolysis-ultra-performance liquid chromatography） injection.

Study of Linearization of Hill Dose-Effect Curve with Metabolic Velocity Instead of Drug Concentration

Objective To explore the velocity-effect relationship in order to the establish linearization of effect on an equation with regard to the consistency of the Hill dose-effect expression with the metabolic kinetics of receptors.Methods The linear velocity-effect expression was obtained by solving multivariant differential equation groups,which were established to compare the coincidences and basic relations between the Hill dose-effect and metabolic kinetic Michaelis-Menten equation for receptors.The validation test was conducted with acetylcholine,adrenaline,and their mixture as model drugs.Results The linear velocity-effect modelling was represented in vivo or in vitro,for single and multidrug systems.Pharmacodynamic parameters,especially suitable for multicomponent CMM formulas,could be determined and calculated for single or multicomponent formulas at high saturating or low linear concentration for receptors.The validation test showed that the pharmacodynamic parameters of acetylcholine were:k,2.675×10^-3s^-1;ka,5.786×10^-9s^-1;km,2.500×10^-7s^-1;α,4.619×10^9张s·mg^-1;E0,13张(P<0.01)and those of adrenaline were:k,1.415×10^-3s^-1;ka,5.846×10^-9s^-1;km,2.300×10^-7s^-1;α,-1.627×10^9张s·m g^-1;E0,9.2张(P<0.01).For the mixture of the two components,the values were:α,1.375×1010张s·m g^-1;-6.150×10^9张s m g^-1for acetylcholine and adrenaline,respectively,and E0was7.08张in both,with the other parameters unchanged(P<0.01).Conclusion The velocity-effect equation can linearize the Hill dose-effect relationship,which can be applied to study the pharmacodynamics and availability of CMM formulations in vivo and in vitro.

A New Approach for the Measurement of Digestible Carbohydrates in Different Food Samples with HPLC-RI

This paper gives an impetus in quantifying digestible carbohydrates, which are important components of cereals, legumes and vegetables. The HPLC method was applied for the first time in India to estimate the digestible carbohydrates such as sugars and starches in different branded rice, legumes and vegetable samples which were procured from local market of twin cities of Hyderabad and Secunderabad in Andhra Pradesh State, India. In the present study, we estimated carbohydrates in vitro, mimicking the in vivo condition by incorporating enzymatic digestion. Among the rice varieties the analyzed total soluble sugars were in the range of 5.69% to 9.62%, vegetables 0.0% to 3.72% and legumes 0.04% to 0.98%. Soluble starches in rice samples ranged from 12.51% to 17.64%, in vegetables from 1.73% to 7.28% and in legumes from 23.76% to 38.71%. Insoluble starches in rice samples were observed to be bracketed in between 52.53% to 60.43%, where as in vegetables from 0.58% to 8.83% and in legumes from 16.13% to 29.22%. Concluding our observation, the total amount of starches and total sugars in rice fell in between 74.32% to 80.75%, in vegetables from 1.74% to 16.11%, and in legumes from 39.93% to 68.91%.

Pharmacokinetics and Bioequivalence of Cefprozil Granules and Cefprozil Tablets in Healthy Chinese Volunteers

Aim To develop a rapid, simple, and sensitive high-performance liquid chromatographic (HPLC) method for the determination of cefprozil in human plasma and to study its pharmacokinetics and bioequivalence after 0.5 g oral doses of cefprozil granules and tablets. Methods The blood concentration of cefprozil was analyzed after extracted with 6% trichloroacetic acid, using tinidazole as internal standard (I.S.). A C_ 18 column was used to separate cefprozil with mobile phase of methanol, purified water and glac...

Enantioseparation of Zolmitriptan by HPLC

Aim To establish a HPLC method for the separation of the enantiomers of zolmitriptan. Methods The separations were performed on Chiralcel OJ column with hexane-ethanol-diethylamine（85：15：0.2） as mobile phase at a flow rate of 0.8 mL·min^-1 and detecttion wavelength of 227 nm at 35 ℃. Several related parameters for separation were studied. Results Baseline separation （Rs 〉 1.5） was easily obtained in the case, and the R-isomer impurity in zolmitriptan was determined. Conclusion The method developed in this study has been successfully applied for quality-control purposes.

Use of Delayed Channel Estimation Results in Adaptive Modulation

In this paper,potential use of perfect but delayed channel estimates for variable-power discrete-rate adaptive modulation is explored.Research is concentrated on block by block adaptation.At first,a new quantity-TAUD(Tolerable Average Use Delay)is defined,it quantifies the performance of an adaptation scheme in tolerating the delay of channel estimates.Then,the research on TAUD shows that the delay tolerating performance declines with the increase in average power,the scheme working with more modulation modes can tolerate a longer delay,and such improvement will be more significant with the increase of average power.Finally,it shows that,as the delay tolerating performance determines the maximum block length,it has a great effect on the maximum spectral efficiency.The criterion for determining the block length appropriate for the target BER is described and a simple method of calculating the maximum block length is presented.

Germline mutation analysis of MLH1 and MSH2 in Malaysian Lynch syndrome patients

AIM: To investigate the protein expression profi le of mismatch repair (MMR) genes in suspected cases of Lynch syndrome and to characterize the associated germline mutations. METHODS: Immunohistochemical analysis of tumor samples was performed to determine the protein expression profile of MMR protein. Germline mutation screening was carried out on peripheral blood samples. The entire exon regions of MLH1 and MSH2 geneswere amplifi ed by polymerase chain reaction, screened by denaturing high performance liquid chromatography (dHPLC) and analyzed by DNA sequencing to characterize the germline mutations. RESULTS: Three out of 34 tissue samples (8.8%) and four out of 34 tissue samples (11.8%) showed loss of nuclear staining by immunohistochemistry, indicating the absence of MLH1 and MSH2 protein expression in carcinoma cells, respectively. dHPLC analysis followed by DNA sequencing showed these samples to have germline mutations of MSH2 gene. However, no deleterious mutations were identifi ed in any of the 19 exons or coding regions of MLH1 gene, but we were able to identify MLH1 promoter polymorphism, -93G > A (rs1800734), in 21 out of 34 patients (61.8%). We identified one novel mutation, transversion mutation c.2005G > C, which resulted in a missense mutation (Gly669Arg), a transversion mutation in exon 1, c.142G > T, which resulted in a nonsense mutation (Glu48Stop) and splice-site mutation, c.2006-6T > C, which was adjacent to exon 13 of MSH2 gene. CONCLUSION: Germline mutations were identified in four Malaysian Lynch syndrome patients. Immunohistochemical analysis of tumor tissue proved to be a good pre-screening test before proceeding to germline mutation analysis of DNA MMR genes.

Direct Optical Resolution of Chiral Pesticides by High Performance Liquid Chromatography

Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb,lambda-cyhalothrin,and simeconazole,were studied on cellulose tris-(3,5-dimethylphenyl-carbamate)-coated chiral stationary phase(CDMPC-CSP) using high-performance liquid chromatography under normal phase condition.The effects of chromatographic conditions,such as the mobile phase composition including the concentration and type of alcohol modifiers in hexane,flow rate and column temperature,on enantiomer separation were examined.The thermodynamical mechanism of enantioseparation and chiral recognition mechanism were discussed.Better separation were achieved using 20% n-propanol for indoxacarb,2% iso-butanol for lambda-cyhalothrin,and 20% iso-propanol for simeconazole as modifiers in hexane at 25℃ with the selectivity factor(a) of 1.69,1.82 and 1.70,respectively.The resolution factor(Rs) decreased as the flow rate increased from 0.4 to 1.1 ml·min-1.The retention factor(k') and selectivity factor for the enantiomers of analytes decreased as temperature increased.The lna-1/T plots for racemic chiral pesticides were linear in the range of 15-35℃ in hexane/iso-propanol and the chiral separation was controlled by enthalpy.Hydrogen bonding,π-π and dipole-dipole interactions between enantiomers and CDMPC-CSP play an important role in chiral identification,and the fitting of the asymmetric portion of solutes in a chiral cavity or channel of the CSP is also important.

Alternaria toxin-induced resistance in rose plants against rose aphid(Macrosiphum rosivorum): effect of tenuazonic acid

Many different types of toxins are produced by the fungus, Alternaria alternata （Fr.） Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography （HPLC） analyses demon- strated that tenuazonic acid （TEA） was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 IJg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated re- sponses in rose plants to intensively enhance the plant＇s resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants.

Molecularly Imprinted Polymers for Selective Extraction of Crystal Violet from Natural Seawater coupled with HighPerformance Liquid Chromatographic Determination

Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Sys- tematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high atTmity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction （MISPE） method followed by high-performance liquid chroma- tography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 ~tg L-1 （R2 〉 0.99）. Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation （n=3） being in the range of 2.89%-5.96%.