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Efonidipine HCl Ethanolate is an antihypertensive drug with 1,4 dihydropyridine and phosphinane derivative. Forceddegradation study was performed in Efonidipine as per the guidelines by International Conference on Harmonization(ICH) Q1A (R2). Extensive degradation and slight degradation were observed in alkaline and photolytic conditions,respectively, whereas acidic, oxidative, and thermal conditions did not show any degradation. Degradation productswere separated on Thermo Hypersil BDS C18 column (250 × 4.6 mm, 5 µ), mobile phase in gradient mode usingammonium acetate buffer and acetonitrile with detection at a wavelength of 254 nm. Six degradation products in alkalinecondition and four degradation products in photolytic condition were identified by HPLC and characterized by massspectrometry using LC-Q-TOF-MS, and degradation pathway was proposed. This is the typical case of degradation,where co-solvent methanol reacts with Efonidipine to form pseudo degradation products such as DP1, DP4, DP5, andDP6. Three degradation products DP1, DP3, and DP4 in alkaline condition were isolated by preparative HPLC andwere characterized by LC-Q-TOF-MS, 1H/13C NMR, and IR techniques. By characterization with these techniques,DP1 is characterized as 3-2-(N-benzylanilino)ethyl 3-oxo-2,2-dimethylpropyl hydrogen 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl) pyridin-3-yl-3-phosphonate, DP3 is characterized as 2-(N-benzyl-N-phenylamino) ethanol, and DP4is characterized as 3-methoxy-2,2-dimethylpropyl hydrogen 1,4-dihydro-2,6-dimethyl-5-methyloxycarbonyl-4-(3-nitro)phenylpyridin-3-yl-3-phosphonate. The developed method was validated as per guidelines by ICH with respectto linearity, accuracy, precision, limit of detection, and robustness.
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Pavetta crassipes leaf (Fam. Rubiaceae) is used as part of a combination herbal remedy for the treatment of tuberculosis (TB) and other respiratory infections in Nigerian ethno medicine. However, little scientific data is available to support the use in ethnomedical therapy so the objective of the study was to assess the anti-tubercular property and to identify the bioactive components. The dried powdered leaf was sequentially extracted with solvents to obtain hexane, dichloromethane, methanol and water extracts. Following which, the extracts were then screened against Mycobacterium aurum, a rapidly growing saprophytic mycobacterium species for activity. The methanol extract exhibited inhibitory activity at an MIC value of 250 µg/mL against M. aurum and two known polyphenolic compounds were isolated as 5-O-caffeoylquinic acid methyl ester and quercetin-3-rutinoside (rutin). Reversed phase semi-preparative HPLC, mass spectrometry and 1H and 13C NMR techniques were utilized in isolating and characterizing the two components. The assignments of the structures were consistent with data from the literature. The study has shown that the methanol extract has some activity and hyphenation of LC-MS can be used for the isolation of polyphenols from the methanol fraction without a rigorous purification process.
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The present study was carried out to evaluate the antibacterial and antioxidant potential of acetone and methanol extracts of lichen (Parmotrema praesorediosum, P. rampoddense, P. tinctorum and P. reticulatum) and isolated chemical constituents which are praesorediosic acid, protocetraric acid, usnic acid, α–collatolic acid, β-alectoronic acid, atranorin and chloroatranorin. The antibacterial activity was evaluated using broth dilution method. Acetone extracts (except for P. reticulatum) showed good inhibitory activity against S. aureus and B. subtilis with MIC values ranging from 500–125 µg/mL, whereas, no activity was observed for the methanol extracts. Extracts exhibited zero inhibitory activity against E. coli. The antioxidant ability was measured using a DPPH free radical scavenging activity assay. Only methanol extract of P. praesorediosum exhibited more than 50% scavenging activity. Among the isolates, usnic acid exhibited the strongest antibacterial activity against S. aureus and B. subtilis with MIC value 7.81 µg/mL. Praesorediosic acid and protocetraric acid isolates exclusively inhibited E. coli at concentration 125 µg/mL and displayed results exceeding 50% scavenging activity (57.57% and 63.97%, respectively). Hitherto, it is the first evaluation of antibacterial activity on lichens of Malaysian origin and to our knowledge; the first reported study on the biological activity of praesorediosic acid and Parmotrema rampoddense.
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Objective:To simultaneously separate 5 phenylpropanoids from Cinnamomum cassia by semi-preparative HPLC, and explore their immunosuppressive activity. Methods:After extracted by ethanol, the ethyl acetate part of Cinnamomum cassia was isola-ted by semi-preparative HPLC. The separation was conducted on an Ultimate XB-C18 (250 mm × 10 mm, 5μm) semi-preparative chro-matographic column and the mobile phase was acetonitrile-water with gradient elution. The detection wavelength was 330 nm, and the flow rate was 2. 5 ml·min-1 . The sample volume was 0. 3 ml. MS and NMR spectroscopic analysis were used to determine the config-urations. A CCK-8 method was used to detect the immunosuppressive activity of phenylpropanoids. Results: Totally 5 phenylpro-panoids were separated from Cinnamomum cassia by the semi-preparative HPLC, and identified as erythro-guaiacylglycerol, (7R,8S)-syringoylglycerol, (7S,8S)-syringoylglycerol, 3-methoxyphenyl-acrylaldehyde and O-methoxy cinnamaldehyde. The inhibitory rates of T cells and B cells of the compound 3 was more than 20% at the concentration of 800μmol·L-1 . Conclusion:The method is conven-ient with good separation effect, which can simultaneously separate 5 phenylpropanoids from Cinnamomum cassia, and among them, the compound 3 shows immunosuppressive effect to some extent.
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Objective: To study the chemical constituents from Peperomia dindygulensis. Methods: The chemical constituents in chloroform fraction of ethanol extract from P. dindygulensis were isolated and purified by column chromatography over silica gel column, preparative TLC, and semi-preparative HPLC. Their chemical structures were elucidated on the basis of physicochemical and spectral data. Results: Two new polyketides were isolated from the chloroform extracting fraction of P. dindygulensis and identified as (4S)-1,4-dihydroxy-2-(1′, 13′-diketone-octadec-14′E-ene)-1-cyclohexen-3-one (1) and (4S)-1,4-dihydroxy-2-(1′,14′-diketone-octadec-12′E-ene) -1-cyclohexen-3-one (2). Conclusion: Compounds 1 and 2 are new compounds and named as peperomadinone A and peperomadinone B.
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Objective: Isolation and identification of chemical components from the root bark of Ailanthus altissima by HPLC method. Methods: Crude products which were extracted with ethanol were separated and purified by preparative HPLC, and the structures of the compounds were identified by mass spectrometry (MS), 1H-NMR, and 13C-NMR. Results: Under the above conditions, ailanfhone (1), shinjulactone A (2), and a new β-carboline alkaloid (3) were successfully obtained, and the purities of the compounds are all above 95%. Conclusion: A rapid and simple method is set up to isolate and identify lower content components from A. altissima.
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Objective: To establish a method to isolate and prepare timosaponin B II reference substance from Anemarrhenae Rhizoma. Methods: Raw material of Anemarrhenae Rhizoma was extracted with 80% ethanol. The concentrated crude extract was separated on a D-101 macroporous resin column, by eluting the macroporous resin column with 30% ethanol, total saponins were collected. The timosaponin B II was separated by preparative reversed-phase high performance liquid chromatography (RP-HPLC) coupled with ELSD and collected according to the chromatography. Results: The prepared product was identified by nuclear magnetic resonance and chemical method. The purity of timosaponin B II was > 99% assayed by analytical HPLC-ELSD. Conclusion: The preparation method is simple and rapid, and it can be used for preparation of timosaponin B TJ reference substance.
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Objective:To develop a method for the isolation and purification of suavissimoside R1 from Herb Rubi Parvifolii. Methods:Macroporous adsorption resin and preparative RP-HPLC,the water extract sedimentated by ethanol was pre-isolated by adsorption resin,and then fractionated by column chromatography on silica gel ( 100-200 mesh )using chloroform-methanol-water-acetic acid(40:10:1:0.4%).The collected fraction was purified for suavissimoside R1 by preparative RP-HPLC were combined as pre- pareation method.Results:Suavissimoside R1 was identified by mass spectrometry(MS),infrared spectrometry(IR),ultraviolet spectrometry(UV),nuclear magnetic resonance (NMR) and high performance liquid chromatography(HPLC),and compared with the relevant literature.The final purity of the compound was more than 98%.Conclusion:The developed method is simple,and reproducible.The solvent is cheap,low in boiling point and easily recovered.The product of suavissimoside R1 can be used as reference substance for analysis.
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Object To establish an isolation method of theanine reference substance by preparative HPLC. Methods After raw material extracted by water, the water phase was extracted by chloroform saturated with water, then concentrated on a thermostat. After centrifuged, supernatant was isolated and purified by preparative HPLC. Fraction was frozen and dried by Flexi Drier. Crude product was rinsed by methanol. The purity of product was determined by analytical HPLC. Results The purity of product is higher than 98% and theanine yield from raw material by this method exceeds 60%. Conclusion The developed method is simple, rapid, and at low production cost. The product owns the quality of reference substance.
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Objective To establish a preparative method for rupestonic acid reference substance from Artemisia rupestris by HPLC.Methods After raw material being extracted with 95% ethanol,the ethanol extracts were evaporated to dryness under reduced pressure.Then the dry powder was extracted by ethyl acetate,the ethyl acetate extract was fractionated by column chromatography on silica gel(100—200 mesh) using petroleumbenzine-ethyl acetate(3∶1) as the eluent.The collected fraction was purified by preparative HPLC.Results The purity of the product quantitated by normality was over 98%.Conclusion The developed method is simple and rapid and the product of rupestonic acid can be used as reference substance.
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98%. Conclusion The developed method is simple, reproducible and easy to operate. The solvent is cheap, with low boiling point and easy to recovery property.
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AIM: To identify an unknown peak in Guanxinning Injection(Radix et Rhizome Salviae Miltiorrhizae,Rhizoma Chuanxiong) chromatographic fingerprint. METHODS: The elution(44-46 min) separated and collected by HPLC was analyzed by GC-MS and HPLC-PDA-MS-MS. RESULTS: The unknown peak was corresponding to senkyunolidel I. CONCLUSION: It is quick method to identify the reported chemical in herbal medicine based on a small quantity of sample by GC-MS and HPLC-PDA-MS-MS.