HPLC-DAD Dotaz Zobrazit nápovědu
BACKGROUND: Venotonics are a class of therapeutically active molecules that have vaso-protective effects. They are used to alleviate venous diseases and disorders, particularly venous insufficiency. We compared the composition of prescription versus over-the-counter (OTC) venotonics using high-performance liquid chromatography with UV detection (HPLC-DAD) and simulating their digestion using a static digestive model. METHODS: From each drug, five tablets were weighed. A homogenate was prepared, and 25 mg of crushed homogenized tablets were weighed into 25 ml volumetric flasks. Dissolved in MeOH and added two drops of saturated NaOH solution. The samples were filtered into vials (Teflon, 0.45 μm) and used for analysis. An Ultimate 3000 HPLC system (Thermo Fisher Scientific, Waltham, MA, USA) consisting of a quaternization pump, autosampler, column thermostat and DAD (UV/VIS detector) was used. The composition of the mobile phase proceeded in a linear gradient from 30% methanol and 70% phosphoric acid (0.15%) in water at time t=0 min. to 80% methanol and 20% phosphoric acid (0.15%) at time t=15 min., at a constant mobile phase flow rate of 1.2 mL/min. Detection was performed using a DAD detector in the 190-450 nm wavelength range. The content of monitored flavonoids was calculated from peaks at a wavelength of 277 nm, in which both flavonoids have their absorption maxima. The static digestive model was used to simulate the digestive phase from the oral cavity to the corresponding intestinal phase. RESULTS: The content of diosmin and hesperidin (mg per table) for a prescription drug: Detralex: 480 mg, 26 mg. The content of diosmin and hesperidin (mg per tablet) for OTC drugs: Venostop: 502 mg, 48 mg, Diosminol: 520 mg, 50 mg, Devenal: 496 mg, 49 mg, Diohes: 493 mg, 46 mg. Digestion did not affect the solubility of all tested drugs. The active substances could not be determined in the non-alkalized sample. After alkalization, part of the insoluble matter was visibly dissolved and converted to a yellow flavonoid complex. Neither diosmin nor hesperidin could be identified afterwards. CONCLUSIONS: Our experimental results show that the contents of both listed active substances, diosmin and hesperidin, met the declared amounts in all tested medicaments. Digestion simulation showed identical behaviour in prescription and OTC venotonics. The active substances could not be determined in the non-alkalized sample. Digestion did not affect the solubility of the tested drugs.
Members of Hymenochaetaceae fungi are among well-known macromycetes with various medicinal properties. The aim of this study was to investigate the biological activities of Phellinus tuberculosus and Fuscoporia ferruginosa collected in Iran. The antimicrobial, antioxidant, and cytotoxic activities of the two species were examined, and their phenolic and polysaccharide contents were quantified. Compounds were characterized by HPLC-DAD chromatography and LC-ESI-MS/MS spectroscopy. According to our results, the antibacterial and antioxidant effects of P. tuberculosus extracts were stronger than F. ferruginosa. Also, the effect of hydroalcoholic extracts was higher than the aqueous extract. Gram-positive bacteria were more sensitive to all extracts, especially Streptococcus mutans with a MIC of 0.7 mg/mL and MBC of 6.25 mg/mL. HPLC-DAD analyses detected gallic acid, caffeic acid, and syringic acid in both fungi. The LC-ESI-MS/MS confirmed the detected compounds in HPLC-DAD and showed the presence of several phenolic compounds such as phellifuropyranone, phelligridin, and hispidin, besides others. This study showed that F. ferruginosa and P. tuberculosus are potent medicinal fungi with antibacterial and antioxidant properties, with no toxic effect on normal HDF cells, and possess various bioactive compounds including styrylpyrone-type phenols with well-known bioactivities.
- MeSH
- antibakteriální látky * chemie izolace a purifikace farmakologie MeSH
- antioxidancia * chemie izolace a purifikace farmakologie MeSH
- Basidiomycota * chemie metabolismus MeSH
- chromatografie kapalinová MeSH
- grampozitivní bakterie účinky léků MeSH
- Phellinus chemie MeSH
- tandemová hmotnostní spektrometrie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Írán MeSH
Salicylaldehyde isonicotinoyl hydrazone (SIH) is an iron-chelating aromatic hydrazone with promising pharmacological properties. However, it suffers from relatively short biological half-life. Hence, two novel derivates of SIH, HAP-INH and HPP-INH were synthesized in order to overcome this pharmacokinetic drawback. The aim of the present study was to employ HPLC-DAD and HPLC-MS/MS methods to investigate the identity of the putative impurities of these newly prepared substances, which are being formed in aqueous environment. At first, it was shown that their retention times as well as UV spectra did not correspond to any expected synthetic precursor, by-product or degradation product. HPLC-DAD analysis confirmed purity of peaks and revealed close but not identical UV spectra of putative impurities and corresponding hydrazones. The subsequent HPLC-MS/MS analyses using ESI and the ion trap mass analyzer showed the identical molecular ions (in both modes) as well as their fragmentation, which implicated presence of geometric isomers. This suggestion was further supported by the NMR analyses. Since the Z/E isomers can have different biological activities, results of this study might be of great importance for further development of the aroylhydrazones as novel drug candidates as well as from the theoretical point of view.
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
Di-2-pyridylketone isonicotinoyl hydrazone (PKIH) and di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT) novel iron chelators which possess marked anti-cancer activity in vivo. However, further progress in the development of these drug candidates requires precise and convenient methods for their qualitative and quantitative analysis. The aim of this study was to develop and validate HPLC methods suitable for the purity and stability evaluation of Dp44mT and PKIH and subsequently to employ these methods in stress tests addressing their chemical stability. The chromatographic analyses of both chelators were accomplished via HPLC using a Discovery HSF5 column (25 cm x 4 mm; 5 microm). For separation of Dp44mT and its synthetic precursors, the mobile phase was composed of a mixture of 2 mM EDTA and acetonitrile in a ratio 60:40 (v/v). A desirable separation of PKIH from its synthetic precursors was achieved with a mixture of 0.01 M phosphate buffer (pH 3.0), methanol and acetonitrile in a ratio of 65:21:14 (v/v/v) with the addition of EDTA (2 mM). In order to confirm the utility of these HPLC methods for measuring these drugs and their stability, Dp44mT and PKIH were subjected to chemical stress tests. These experiments showed that Dp44mT was relatively stable against hydrolytic degradation, but quite sensitive to oxidation. On the other hand, PKIH was slightly sensitive to acid-catalyzed hydrolysis, but it was relatively stable under other tested conditions. Furthermore, these studies confirmed the utility of these methods not only for appropriate evaluation of purity but also stability. The analytical methods developed and validated in this study, as well as the basic data on the chemical stability, should further support the development of both these novel anti-cancer chelators as promising drug candidates.
BACKGROUND: A novel supported liquid extraction approach using small polymeric nanofibrous discs was demonstrated and applied to the analysis of real river water. Nanofibrous discs were tested to extract model mixture of 9 common water contaminants 4-nitrophenol, various chlorophenols, bisphenol A, permethrin, and fenoxycarb featuring a wide range of log P values (1.9-6.5). Polyacrylonitrile, polyhydroxybutyrate, and polylactic acid nanofibers were selected as adsorptive materials. One-step desorption was performed directly in HPLC vials, to avoid time-consuming evaporation and reconstitution steps. The discs were allowed to sediment to the bottom of the vial before injection into the chromatographic system. RESULTS: Various parameters affecting the extraction efficiency including 1-octanol volume, extraction time, ionic strength, and sample volume were investigated and optimized. Wetting the nanofiber discs with 1-octanol resulted in up to 20-fold increase in enrichment factor when compared to non-wetted polymer counterparts. The highest enrichment factors were observed for analytes with a log P range of 3.3-4.5. Our developed method showed good linearity in the range 20-200 μg/L for all analytes tested. Satisfactory repeatability with RSD <13 % were achieved covering all steps including disc preparation, wetting, extraction/elution, and chromatography analysis, and recoveries ranged from 58.93 to 121.43 %. SIGNIFICANCE: This work represents novel simple supported liquid extraction approach using impregnated polymer nanofiber discs. Using only 50 μL 1-octanol, we reduced the organic solvent compared to other extraction methods. There was no need for any plastic cartridge to hold the sorbent and direct in-vial desorption reduced the unnecessary, time-consuming steps and simplified the sample preparation protocol.
- Publikační typ
- časopisecké články MeSH
- MeSH
- jedy analýza MeSH
- léčivé přípravky analýza MeSH
- lidé MeSH
- nežádoucí účinky léčiv MeSH
- otrava diagnóza MeSH
- referenční standardy MeSH
- spektrální analýza metody normy MeSH
- toxikologie metody normy MeSH
- vysokoúčinná kapalinová chromatografie metody normy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
