Quality Evaluation of Leontopodium franchetii Beauv. from Different Localities Based on Moisture,Ash and Extract Contents and Thin-layer Chromatography

[Objectives] The aim was to determine the moisture,ash and extract contents in Leontopodium franchetii Beauv. from different localities. [Methods] The contents of moisture,total ash,acid-insoluble ash and extract in L. franchetii from different localities were determined according to the methods described in Chinese Pharmacopoeia( 2015 Edition). [Results] In the 10 samples,the contents of moisture were all less than or equal to 15. 0%; the contents of total ash were all below 12. 0%; and the contents of acid-insoluble ash were all less than 3. 0%. The contents of water-soluble extract( by cold-soaked extraction method) in the samples were all below 12. 0% except those from Hongyuan Prairie of Sichuan Province and Xinglong Mountain in Lanzhou City,Gansu Province. [Conclusions]The contents of the four indicators measured in this experiment varied by small margins,indicating that the quality was relatively stable. This study provides theoretical data for the revision of the quality standards for L. franchetii.

ANALYSIS OF HUMAN PLACENTA BY ^(31)P NUCLEAR MAGNETIC RESONANCE AND THIN-LAYER CHROMATOGRAPHY SCANNING COMBINED WITH THE CORRECTIVE METHOD OF ABSORBANCE PROPORTIONAL COEFFICIENT

Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.

Separation of Amino Acids Based on Thin-Layer Chromatography by a Novel Quinazoline Based Anti-Microbial Agent

A newly designed quinazoline based compound, 6-pyridin-2-yl-5,6-dihydro-benzo[4,5]imidazo[1,2-c] quinazoline (PDBIQ) has shown the ability for the easy detection of nineteen amino acids on thin-layer chromatography plates as a spray reagent. This new reagent enabled to produce various distinguishable colors with amino acids with different RF values. The detection limits and the binding ability of PDBIQ with amino acids have been calculated. PDBIQ is also able to detect aminoacids from hydrolised seed protein. The title compound also exhibited profound inhibitory action against some gm (+ve) and gm (-ve) bacterial organisms. This paper deals with synthesis, spectroscopic application and biological evaluation of the organic moity.

Analysis of the Nucleoside Content of Cordyceps sinensis Using the Stepwise Gradient Elution Technique of Thin-Layer Chromatography

Nucleoside is the main class of active components in Cordyceps sinensis. Thin-layer chromatography (TLC) is one of the most commonly used methods in pharmacopoeias for analyzing chemical components of herbal medicine. Since the isocratic elution method cannot be applied successfully in TLC analysis for separating all the nucleoside components, the stepwise gradient elution has been developed in this work to separate eight nucleoside standards with success. In this way, quantitative analyses of the samples of Cordyceps sinensis were achieved via the pro-posed TLC procedure coupled with the scanning densitometric techniques of CAMAG and TLCQA methods for qualitative and quantitative analysis.

Simple and robust differentiation of Ganoderma species by high performance thin-layer chromatography coupled with single quadrupole mass spectrometry QDa

In this study,a high performance thin-layer chromatography/single quadrupole mass spectrometry QDa(HPTLC-QDa)method for robust authentication of Ganoderma lucidum,a popular and valuable herbal medicine,has been developed.This method is simple and practical,which allows direct generation of characteristic mass spectra from the HPTLC plates automatically with the application of in situ solvent desorption interface.The HPTLC silica gel plates were developed with toluene-ethyl formate-formic acid(5:5:0.2,V/V)and all bands were transferred to QDa system directly in situ using 80%methanol with 0.1%formic acid as desorption solvent.The acquired HPTLC-QDa spectra showed that luminous yellow band b3,containing ganoderic acid B/G/H and ganodeneric acid B,the major active components of Ganoderma,could be found only in G.lucidum and G.lucidum(Antler-shaped),but not in G.sinense and G.applanatum.Moreover,bands b13 and b14 with m/z 475/477 and m/z 475/491/495,respectively,could be detected in G.lucidum(Antler-shaped),but not in G.lucidum,thus allowing simple and robust authentication of G.lucidum with confused species.This method is proved to be simple,practical and reproducible,which can be extended to analyze other herbal medicines.

Differentiation of Belamcandae Rhizoma and Iridis Tectori Rhizoma by Thin-Layer Chromatography and High-Performance Liquid Chromatography

Objective:Belamcandae Rhizoma and Iridis Tectori Rhizoma are easily confused with each other.The main objective of this study is to distinguish them using chemical analysis.Materials and Methods:Thin-layer chromatography(TLC)and high-performance liquid chromatography(HPLC)fingerprint methods were established to compare the chemical profile,while HPLC quantitation was used to determine the contents of three isoflavones in thirty batches of Belamcandae Rhizoma and Iridis Tectori Rhizoma samples.Results:The two herbs could be distinguished by TLC using acetic acid-n hexane-ethyl acetate(1:90:80 v/v/v)as the mobile phase,according to the fluorescent band under 366 nm at R_(f) 0.2.In total,12 compounds were identified in the 24-min HPLC fingerprint.The similarity coefficient between the two herbs was 0.54±0.01.Mangiferin(1),tectoridin(2),iridin(3),irigenin(5),irisflorentin(6),and iristectorin A(9)were the main peaks in Belamcandae Rhizoma,while tectoridin(2)and tectorigenin(4)were the major peaks in Iridis Tectori Rhizoma.The contents of 2 in Iridis Tectori Rhizoma(2.50±0.20%)were 8.93 times higher than that of Belamcandae Rhizoma(0.28±0.08%),while the ones of 5 and 6 were slightly lower in Iridis Tectori Rhizoma.Conclusions:The study established fast and effective methods to distinguish Belamcandae Rhizoma from Iridis Tectori Rhizoma.

Simultaneous qualitative identification of all medicinal herbs in Zaoren Anshen capsule by thin-layer chromatography

The holistic characterization and quality control of all the medicinal herbs of proprietary Chinese medicines(PCMs)are of great significance to ensure their safety,efficacy,and consistency.Thin-layer chromatography(TLC),a simple and classic approach for qualitatively characterizing and examining quality markers of natural products,has been widely used in the characterization and quality control of traditional Chinese medicines.Zaoren Anshen(ZRAS)capsule,prepared from three medicinal herbs of fried Ziziphi Spinosae Semen,Salvia Miltiorrhiza Radix et Rhizoma,and vinegar-processed Schisandrae Chinensis Fructus,is a famous PCM in China for the treatment of insomnia,amnesia,and dizziness in clinical practice.However,no effective method is available so far for simultaneous identification and examination of all the three medicinal herbs of ZRAS capsule.In the present study,we developed a TLC method via twice-development and visualization by UV light or chromogenic agent,which could be used for simultaneous qualitative identification of all the three medicinal herbs of ZRAS capsule in one plate.Moreover,the sample preparation method was optimized.The developed TLC method was rapid,simple,low-cost,and effective,and thus it could be used for quality control of ZRAS capsule.

Separation of liquefied product of Salix psammophila by column chromatography and structure analysis of its components

The liquefied product of Salixpsammophila wood was separated by thin-layer chromatography （TLC） and column chromatography, and its structure was identified by nuclear magnetic resonance （NMR） spectra in our study. The separation result indicates that the sample of liquefied S. psammophila contained at least two categories of components. The structure of the main components was guaiacyl C-1, C-2 of the hydroxyphenyl propane, i.e., the aromatic nucleus protons of lignin. Degradation and polycondensation reactions occurred when the S. psammophila wood was liquefied in phenol. Polycondensation reactions occurred among the depolymerization products from cellulose, the aromatic depolymerization products from lignin and the products of the displacement reactions between phenoxide ion and cellulose.

Comparison of liquid-liquid extraction-thin layer chromatography with solid-phase extraction-high-performance thin layer chromatography in detection of urinary morphine

Liquid-liquid extraction-thin layer chromatography （LLE-TLC） has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction （SPE） is gradually replacing the tra- ditional LLE method. High performance thin layer chromatography （HPTLC） has several advantages over TLC. The present work studied the higher efficiency of a new SPE-HPTLC method over that of a routine LLE-TLC method, in extraction and detection of urinary morphine. Fifty-eight urine samples, primarily identified as mor- phine-positive samples by a strip test, ＇were re-screened by LLE-TLC and SPE-HPTLC. The results of LLE-TLC and SPE-HPTLC were then compared with each other. The results showed that the SPE-HPTLC detected 74% of total samples as morphine-positive samples whereas the LLE-TLC detected 48% of the same samples. We further discussed the effect of codeine abuse on TLC analysis of urinary morphine. Regarding the importance of morphine detection in urine, the present combined SPE-HPTLC method is suggested as a replacement method for detection of urinary morphine by many reference laboratories.

Chromatographic fingerprinting and free-radical scavenging activity of ethanol extracts of Muntingia calabura L. leaves and stems

Objective: To determine the thin-layer chromatography(TLC) fingerprint profiles and to evaluate the in vitro antioxidant activity of ethanol extracts of Muntingia calabura(M. calabura) leaves and stems.Methods: The leaves and stems were extracted using ethanol as solvent. The TLC separation of the phytochemical constituents of the leaf and ethanol extracts was carried out in ethyl acetate: n-hexane and chloroform: ethyl acetate mobile phase systems.Distinct spots were visualized under visible light, UV 254 nm, UV 366 nm and after spraying with vanillin-sulfuric acid. The 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging assay was used to evaluate the antioxidant activity of the extracts.Results: Both the leaf and stem ethanol extracts at 4 mg/mL exhibited 2,2-diphenyl-1-picrylhydrazyl inhibition of more than 90%, relative to gallic acid. The results of TLC showed that the degree of resolution between the constituent spots was comparable between the two mobile phase systems using the different visualization wavelengths. Under the 254 nm visualization, few spots were observed in leaf and stem extracts. Visualization at 366 nm yielded the greatest number of observable spots of various colors in both leaf and stem extracts. More spots were visualized upon post-derivatization with vanillinsulfuric acid in the TLC chromatograms using chloroform: ethyl acetate mobile phase,compared to those in ethyl acetate: n-hexane mobile phase.Conclusions: M. calabura exhibited very high antioxidant activity in its leaves and stems ethanol extracts, both of which are used in traditional medicine. The TLC results demonstrated the presence of diverse secondary metabolites in the leaf and stem ethanol extracts, indicating that the antioxidant activity, including other bioactivities may be attributed to these phytochemical constituents. This paper has reported for the first time the TLC fingerprinting of M. calabura using visible light, UV 254 nm, UV 366 and postderivatization with vanillin-spray to visualize separate spots on TLC plates.

Assessment of Poultry Feed Contamination Level by Aflatoxin B1: Quantification by Two Chromatographic Analysis Methods

Aflatoxin B1 is a mycotoxin that can contaminate a wide feedstuffs variety. Ingestion of contaminated feed by poultry can lead to impaired health and zootechnical performances but also a human diet safety problem related to residues presence in animal origin products. Aflatoxin B1 contamination of poultry feed samples marketed in Dakar city and in peri-urban areas (Gorom, Sangalkam) was studied. A total of 15 samples were collected from Dakar city markets as well as from poultry farms in Gorom and Sangalkam areas. Aflatoxin B1 quantification was performed by high performance liquid chromatography and thin-layer chromatography. HPLC results showed that all samples were contaminated with levels ranging from 0.15 to 22 ppb, 0.099 to 2.05 ppb and 0.099 to 4.95 ppb respectively for Gorom, Sangalkam and Dakar. Only the finishing feed from Gorom had an aflatoxin B1 level above the maximum limit set by regulations. TLC is a suitable method for aflatoxins detection. However, it was associated with overestimation for aflatoxin B1 quantification. Results suggest that poultry feed represents a real source of human diet contamination. In addition, HPLC remains the most reliable quantification technique for quality control.

Bio-screening and quantification of methyl paraben in vinegar and coconut juice separated by HPTLC

As a widely used food preservative,methyl paraben was experimentally evidenced with serious hormonelike adverse effects.Herein,a high performance thin-layer chromatography platformed bioluminescent bioautography and image analysis for the selective quantification and confirmation of methyl paraben was proposed and validated in vinegar and coconut juice.First,the detectability of the bioautography to the analyte on different layer materials was estimated,revealing that normal silica gel was the best choice.After that,the liquid of sample extract and working solution were separated to overcome the background noises due to co-extracted matrices.The separation result was then coupled to the optimized bioautography,enabling instant and straightforward screening of the targeted conpound.For accurate quantification,bioluninescent inhibition pattern caused by the analyte was processed by image analysis,giving useful sensitivity(LOD>16 mg/kg),precision(RSD<10.1%)and accuracy(spike-recovery rate 76.9%-112.2%).Finally,the suspected result was confirmed by determining its MS fingerprint,further strengthening the reliability of screening.

TLC Identification and Extraction Process of Rubiasin-1-methyl Ether from Yao Medicine Chuanlianzhu

[Objectives]To establish a thin-layer chromatography(TLC)method for the determination of rubiadin-1-methyl ether in Yao Medicine Chuanlianzhu(Damnacanthus giganteus).[Methods]A silica gel G thin-layer plate was adopted for TLC.Petroleum ether(60-90℃)-chloroform-methanol-water(7:15:3:1)was used as the developing solvent and inspected under ultraviolet lamp(365 nm).The content was determined by Inertsil ODS-3 C 18 column(4.60 mm×250 mm,5μm),mobile phase:acetonitrile-0.2%phosphoric acid gradient elution,detection wavelength 277 nm,flow rate 1.0 mL/min,column temperature 30℃,injection volume 10μL.[Results]The spots of 10 Chuanlianzhu samples from different origins showed the same color at the same position as the control,and the spots were clear and specific.The injection volume of rubiadin-1-methyl ether showed a good linear relationship in the range of 2.90-145μg(R=0.9996).The average recovery rate of rubiadin-1-methyl ether in the low,medium and high dose groups of Yao Medicine Chuanlianzhu was 98.72%,and RSD=1.78%.[Conclusions]This method can effectively identify Yao Medicine Chuanlianzhu medicinal materials and accurately determine the content of rubiadin-1-methyl ether in the medicinal materials.It provides a scientific basis for the development and utilization of Yao Medicine Chuanlianzhu medicinal resources.

薄层色谱法同时测定邻苯二酚、间苯二酚和对苯二酚异构体

研究了在自制硅胶薄板上邻苯二酚、间苯二酚、对苯二酚异构体的薄层色谱特性.展开剂为苯:乙醚:冰醋酸=7:2:1(V/V/V),R_f值分别为0.59,0.53,0.48.检测限分别为1.07×10^(-4),1.64×10^(-4),1.90×10^(-4)mol/L.其他常见酚不干扰测定.可应用于实际样品的测定,回收率为96%～104%.

苯二酚异构体的电动毛细管色谱-玻碳微电极柱上安培检测分析方法研究

在玻碳纤维微电极上研究了电解液中β－环糊精（ＣＤ）的浓度对邻、间、对苯二酚的循环伏安特性的影响，从实验结果和分子结构水平方面考察了β－ＣＤ与邻、间、对苯二酚的包结作用。研究结果表明，β－ＣＤ与邻、间、对苯二酚的包结作用强弱顺序为间苯二酚、邻苯二酚、对苯二酚。讨论了电泳缓冲液中ΝΗ４Ｃｌ，ＳＤＳ，β－ＣＤ的浓度及ｐＨ值对邻、间、对苯二酚迁移时间的影响。建立了苯二酚异构体胶束电动毛细管色谱－玻碳微电极柱上安培检测分析方法，方法的回收率在９８％～１０３％之间。

高效液相色谱-高锰酸钾氧化化学发光法测定水中的痕量苯二酚

基于酸性介质中甲酸对高锰酸钾-苯二酚氧化发光反应的增敏作用建立了高效液相色谱-化学发光柱后检测苯二酚的新方法。优化了高锰酸钾-苯二酚氧化发光反应及高效液相色谱分离苯二酚的条件，用甲醇，0．1mmol／L β-环糊精水溶液（体积比为30：70）作为流动相可实现对水中3种苯二酚异构体的分离，且能与高锰酸钾-苯二酚氧化化学发光反应条件很好地偶合。对所测定的苯二酚异构体，方法的线性范围达两个数量级；以信噪比为3测得邻、间、对苯二酚的检出限（n=3）分别为：5．2，4．7，3．2μg／L，对质量浓度均为0．10mg／L的3种苯二酚混合溶液连续测定11次，邻、间、对苯二酚的相对标准偏差分别为2．8％，3．4％，6．5％。将该方法与固相萃取技术相结合，对河水中的痕量苯二酚进行了测定，加标回收率为92．1％～95．4％。

Methods for in vitro evaluating antimicrobial activity： A review

In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. Therefore, a greater attention has been paid to antimicrobial activity screening and evaluating methods. Several bioassays such as disk-diffusion, well diffusion and broth or agar dilution are well known and commonly used, but others such as flow cy- tofluorometric and bioluminescent methods are not widely used because they require specified equip- ment and further evaluation for reproducibility and standardization, even if they can provide rapid re- sults of the antimicrobial agent＇s effects and a better understanding of their impact on the viability and cell damage inflicted to the tested microorganism. In this review article, an exhaustive list of in vitro antimicrobial susceptibility testing methods and detailed information on their advantages and limita- tions are reported.

Determination of astaxanthin and astaxanthin esters in shrimp shell by HPLC

A method for determination of astaxanthin and astaxanthin eaters in shrimp shell by high performance liquid chromatography is established.Shrimp shell are addressed with 5%hydrochloric acid to remove calcium ions.After shell is dried,organics from shrimp shell are extracted with anhydrous ethanol.The alcohol extrative of the shrimp shell is mixed with the ammonium sulfate to extract astaxanthin by aqueous two-phase extraction.The crude astaxanthin is collected,which is distributed in the middle layer of the aqueous two-phase layer.After distilled water is added to the crude astaxanthin,the aqueous solution is centrifuged,and the previous step is repeated for several times.The precipitation in centrifuge tube is collected and dried.The crude astaxanthin dried is dissolved with acetone,and the sample solution is separated by TLC.Every pigment on the TLC plate is collected and dissolved with acetone.The pigments are determined by high performance liquid chromatograph.The results show that aqueous two-phase system,3 mL alcohol extractive of astaxanthin and 4.5 mL 20%ammonium sulfate,can be used to acquire crude astaxanthin.The wavelength of the maximum peak of astaxanthin in ethanol solution is 472 nm.A variety of pigments can be separated from the crude astaxanthin by thin-layer chromatography,including free astaxanthin,astaxanthin monoester,astaxanthin diester,echinenone and other substances.It can be seen from high performance liquid chromatography that the appearance time of free astaxanthin is from 4 min to 5.5 min,and the appearance time of astaxanthin monoester is from 10.5 min to 27.8 min.The method is simple about the sample pretreatment and feasible about the determination of astaxanthin and astaxanthin esters in shrimp shell.

反相离子对高效液相色谱法分离和测定铝、镓和铟

以芪－４，４′－双（１－偶氮）－３，４－二羟基苯－２，２′－二磺酸铵（芪唑）为柱前衍生试剂，采用反相离子对高效液相色谱法分离和测定铝（Ⅲ）、镓（Ⅲ）和铟（Ⅲ）。在ｓｐｈｅｒｅｘＣ１８柱上，用浓度为１２ｍｍｏｌ／Ｌ的ＳＤＳ，浓度为２０ｍｍｏｌ／ＬｐＨ３．５的ＡＨｃ－ＮａＡｃ的甲醇－水（体积比为６０∶４０）溶液作流动相，检测波长为５０６ｎｍ。同时分离和测定了３种金属络合物。铝（Ⅲ）、镓（Ⅲ）和铟（Ⅲ）离子的检出限分别为１４μｇ／Ｌ、２３μｇ／Ｌ和２８μｇ／Ｌ，方法用于矿石样品分析。

苯酚与苯二酚的胶束电动毛细管色谱分离研究

用十二烷基硫酸钠作胶束，分别在磷酸二氢钠和硼砂缓冲体系中，分离了苯酚与苯二酚的３种同分异构体。详细研究了不同背景电解质同离子体系中，胶束浓度与流动相ｐＨ值对分离效率的影响。优化条件下４ｍｉｎ内完成了苯酚与苯二酚３种异构体的分离，分离效率及理论塔板数为２．１×１０５～３．１×１０５／ｍ，保留时间相对标准偏差在２．６％以内，峰高定量分析精度在３．１％以内。