1 Introduction As already known, complex prescription has been the outstanding feature of traditional Chinese medicine（TCM）. This fact therefore brings complicated formula with multicomponents from multimaterals, wh...1 Introduction As already known, complex prescription has been the outstanding feature of traditional Chinese medicine（TCM）. This fact therefore brings complicated formula with multicomponents from multimaterals, which produces some difficulties to detect the components and to control the quality. Shuanghuanglian preparations（SHLs）, including oral liquid, injection powder, capsule, and tablet, belong to a family of refined traditional Chinese patent medicine and a combined herbal remedy comprised of three herbs：展开更多
Simple and sensitive stability-indicating high performance thin layer chromatography (HPTLC) assay was developed and validated for quantitative determination of the antibacterial drug, gemifloxacin mesylate (GFX) in p...Simple and sensitive stability-indicating high performance thin layer chromatography (HPTLC) assay was developed and validated for quantitative determination of the antibacterial drug, gemifloxacin mesylate (GFX) in presence of its degradation products and ambroxol hydrochloride. The chromatographic separation was performed on HPTLC precoated silica gel plate 60F254 as stationary phase. The mobile phase consisted of a mixture of ethyl acetate: methanol: 25% ammonia, (8:4.5:3, v/v/v). The detection was performed using fluorescence mode and the emission intensity was measured using optical filter K400 after excitation at 342 nm. The Rf value for GFX was 0.47 ± 0.03. Good correlation coefficient was obtained over the concentration range of 1.5 - 180 ng/band. The LOD and LOQ of the proposed method were 0.28 and 0.86 ng/band, respectively. The proposed method was successfully applied for the analysis of GFX in its single and combined dosage forms. Moreover, it was utilized to investigate the kinetics of acidic, alkaline, neutral, oxidative and photolytic degradation of the drug. The apparent kinetic-order rate constants and half-life times of the degradation process were calculated. Furthermore, the proposed method was successfully applied for investigating the factors affecting the storage of GFX.展开更多
Rice false smut is an emerging plant disease worldwide.Ustiloxin A(UstA)is the major mycotoxin found in rice false smut balls,which are fungal colonies in rice florets.In this study,a new method consisting of macropor...Rice false smut is an emerging plant disease worldwide.Ustiloxin A(UstA)is the major mycotoxin found in rice false smut balls,which are fungal colonies in rice florets.In this study,a new method consisting of macroporous resin column chromatography and high-speed countercurrent chromatography(HSCCC)was developed for UstA separation.UstA was extracted by a 3.81%HCOOH solution and adsorbed by XAD-4 resin.UstA was then eluted by a 40%methanol solution supplemented with 0.1%trifluoroacetic acid(TFA).Further purification was achieved by HSCCC using a two-phase solvent system consisting of n-butanol/TFA/H_(2)O(1/0.05/1,v/v/v).Under the optimized conditions,225 mg of UstA was obtained with a purity of 97.39%in a single run,with a final recovery of 65.2%.An inhibitory effect on seed germination of wheat and maize caused by UstA was observed in a preliminary phytotoxicity assay.展开更多
基金Supported by the National S&T Supporting Project in the 11th Five-Year Period(No.2006BAI08B04-01).
文摘1 Introduction As already known, complex prescription has been the outstanding feature of traditional Chinese medicine（TCM）. This fact therefore brings complicated formula with multicomponents from multimaterals, which produces some difficulties to detect the components and to control the quality. Shuanghuanglian preparations（SHLs）, including oral liquid, injection powder, capsule, and tablet, belong to a family of refined traditional Chinese patent medicine and a combined herbal remedy comprised of three herbs：
文摘Simple and sensitive stability-indicating high performance thin layer chromatography (HPTLC) assay was developed and validated for quantitative determination of the antibacterial drug, gemifloxacin mesylate (GFX) in presence of its degradation products and ambroxol hydrochloride. The chromatographic separation was performed on HPTLC precoated silica gel plate 60F254 as stationary phase. The mobile phase consisted of a mixture of ethyl acetate: methanol: 25% ammonia, (8:4.5:3, v/v/v). The detection was performed using fluorescence mode and the emission intensity was measured using optical filter K400 after excitation at 342 nm. The Rf value for GFX was 0.47 ± 0.03. Good correlation coefficient was obtained over the concentration range of 1.5 - 180 ng/band. The LOD and LOQ of the proposed method were 0.28 and 0.86 ng/band, respectively. The proposed method was successfully applied for the analysis of GFX in its single and combined dosage forms. Moreover, it was utilized to investigate the kinetics of acidic, alkaline, neutral, oxidative and photolytic degradation of the drug. The apparent kinetic-order rate constants and half-life times of the degradation process were calculated. Furthermore, the proposed method was successfully applied for investigating the factors affecting the storage of GFX.
基金This work was financially supported by the National Key Research and Development Project(2018YFE0206000)National Natural Science Foundation of China(31901805,U1604234,31872914)Jiangsu Agriculture Science and Technology Innovation Fund(CX(19)3004).
文摘Rice false smut is an emerging plant disease worldwide.Ustiloxin A(UstA)is the major mycotoxin found in rice false smut balls,which are fungal colonies in rice florets.In this study,a new method consisting of macroporous resin column chromatography and high-speed countercurrent chromatography(HSCCC)was developed for UstA separation.UstA was extracted by a 3.81%HCOOH solution and adsorbed by XAD-4 resin.UstA was then eluted by a 40%methanol solution supplemented with 0.1%trifluoroacetic acid(TFA).Further purification was achieved by HSCCC using a two-phase solvent system consisting of n-butanol/TFA/H_(2)O(1/0.05/1,v/v/v).Under the optimized conditions,225 mg of UstA was obtained with a purity of 97.39%in a single run,with a final recovery of 65.2%.An inhibitory effect on seed germination of wheat and maize caused by UstA was observed in a preliminary phytotoxicity assay.
