Preliminary results of 2-D separation of test dye mixture using high-performance thin-layer chromatography (HPTLC) and pressurized planar electrochromatography (PPEC) are demonstrated. The advantage of 2-D HPTLC/PPEC separation is based on different separation selectivities obtained in both HPTLC and PPEC systems. HPTLC RP18 W plates of 5x20 cm from Merck were used in the investigations. In the first dimension, a HPTLC process was performed using 5 cm length of the plate and in the second dimension PPEC separation was obtained applying plate of 20 cm length. PPEC process followed prewetting the chromatographic plate with sample zones on it, which were partly separated after first dimensional (HPTLC) separation. In the experiments, the modified version of PPEC device for 20 cm long chromatographic plate and the reservoir for prewetting the adsorbent layer were applied.
Because chemical and pharmacological studies of Eleutherococcus species growing in Asia showed their biological activity depends on glycosides known as eleutherosides, we used TLC to search for eleutherosides in ethanol extracts of the roots of E. senticosus, E. setchuensis, E. sesiliflorus, E. henryi, E. gracilistylus, and E. divaricatus cultivated in Poland. Eleutherosides B, E, and E 1 were identified in all the roots investigated and isofraxidin was identified in the roots of E. senticosus. Satisfactory separation of the eleutherosides from other components of the extracts was achieved by use of two mobile phases in two-step elution. The identity of the resolved compounds was confirmed by comparing their R F values and UV spectra with those of standards.
A bioautographic assay based on thin layer chromatography was developed for phosphoenolpyruvate (PEP) detecting as a known but rarely studied inhibitor of phosphoglucose isomerase (PGI). The protocol with NADP + /NBT/PMS (b-nicotinamide adenine dinucleotide phosphate/nitrotetrazolium blue chloride/phenazine methosulfate) staining was capable of detecting Mycobacterium tuberculosis H 37 Ra PGI inhibition using PEP. According to this method, visibly brighter spots (zones) against purple background are observed in the area of inhibition of the above-mentioned enzyme activity. The detection limit for PEP as an inhibitor of Mycobacterium tuberculosis H 37 Ra PGI was 226 mg per spot/zone. Noteworthy is that we are the first authors to have successfully used a bioautographic assay to detect Mycobacterium tuberculosis H 37 Ra PGI inhibition by PEP.
In the paper the results of the tryptophan determination in human plasma samples prepared with the novel Solvent Front Position Extraction (SFPE) technique are presented. The SFPE procedure is used for preparation of real biological sample for the first time. The results obtained using SFPE are compared with those using the classical sample preparation procedure. Under the optimal conditions, tryptophan and its internal standard were separated from other plasma compounds (matrix) as a small common zone/spot on a chromatographic plate using semiautomatic device equipped with moving pipet, which distributed developing solvent on the adsorbent layer. Tryptophan and the internal standard were evenly distributed within the small common zone from that the both substances were extracted and the solution obtained was transferred to quantitation with LC–MS and MS techniques. The determination results are satisfactory, the percentage values of relative error and RSD relative standard deviation do not exceed 5%. The procedure is characterized by simplicity, high analysis throughput, very good sample purification and seems to be easy applicable to other biological samples with these advantages mentioned.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.