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Designing a new drug has recently become a very important topic that many researches are concerned with. This work relates to a newly synthesized betulin and betulone derivatives which have anticancer activity. Thin-layer chromatography was applied to evaluate the lipophilicity of these triterpenes in order to find the correlation between theoretically and experimentally calculated values of lipophilicity and the structure of compounds investigated. Moreover, the relationships between lipophilicity and pharmacokinetic parameters or anticancer activity were carried out. The similarity analysis was also done for the purpose to divide the compounds investigated into groups pointing which of these can meet the criteria for medicine substances. The cluster analysis showed the differences in the compounds grouping in relation which the values of lipophilicity are considered, i.e., calculated by computer software or obtained experimentally by use of TLC. Analysis clearly shows that those theoretically calculated values of lipophilicity are strongly connected to the structure of the compounds.

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This paper describes a new methodology for lane detection in Thin-Layer Chromatography images. An approach based on the continuous wavelet transform is used to enhance the relevant lane information contained in the intensity profile obtained from image data projection. Lane detection proceeds in three phases: the first obtains a set of candidate lanes, which are validated or removed in the second phase; in the third phase, lane limits are calculated, and subtle lanes are recovered. The superior performance of the new solution was confirmed by a comparison with three other methodologies previously described in the literature.

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In the present investigation, 5-fluorouracil loaded microspheres of Eudragit (RS 100, RL 100 and RSPO) and ethylcellulose were prepared. “O/O solvent evaporation” technique was used for preparation of microspheres using (methanol + acetone)/liquid paraffin system. Magnesium stearate was used as the droplet stabilizer and n-hexane was added to harden the microspheres. The prepared microspheres were characterized for their micromeretic properties and entrapment efficiency; as well by Fourier transform infrared spectroscopy (FTIR) and thin layer chromatography (TLC). Photomicrographs were taken to study the shape of microspheres. The best fit release kinetics was achieved with Higuchi plot. Mean particle size, entrapment efficiency and production yields were highly influenced by the type of polymer and polymer concentration. It is concluded from the present investigation that various Eudragit and Ethylcellulose are promising controlled release carriers for 5-FU(AU)

En la presente investigación, se han preparado microesferas de Eudragit (RS 100, RL 100 y RSPO) y etilcelulosa cargadas con 5-fluorouracilo. Se ha utilizado la técnica de “evaporación del disolvente o/o” para preparar las microesferas utilizando el sistema de (metanol + acetona)/ parafina líquida. Se ha utilizado estearato de magnesio como estabilizador de gotículas y se ha añadido n-hexano para endurecer las microesferas. Las microesferas preparadas se caracterizan por sus propiedades micromeríticas y su eficaz compresión, así como a través de la espectroscopia infrarroja transformada de Fourier (FTIR, por sus siglas en inglés) y la cromatografía en capa fina. Se han tomado microfotografías para estudiar la forma de las microesferas. La mejor cinética de liberación se ha alcanzado con el modelo de Higuchi. El tamaño de la partícula principal, la eficacia de compresión y los rendimientos de producción han sido fuertemente influenciados por el tipo de polímero y su concentración. Tras la presente investigación, se ha determinado que el Eudragit y la Etilcelulosa tienen carreras muy prometedoras en la liberación controlada para el 5-FU(AU)

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Thin-layer chromatography (TLC) and liquid chromatography (LC) methods were developed for the qualitative and quantitative determination of agrimoniin, pedunculagin, ellagic acid, gallic acid, and catechin in selected herbal medicinal products from Rosaceae: Anserinae herba, Tormentillae rhizoma, Alchemillae herba, Agrimoniae herba, and Fragariae folium. Unmodified silica gel (TLC Si60, HPTLC LiChrospher Si60) and silica gel chemically modified with octadecyl or aminopropyl groups (HPTLC RP18W and HPTLC NH2) were used for TLC. The best resolution and selectivity were achieved with the following mobile phases: diisopropyl ether-acetone-formic acid-water (40 + 30 + 20 + 10, v/v/v/v), tetrahydrofuran-acetonitrile-water (30 + 10 + 60, v/v/v), and acetone-formic acid (60 + 40, v/v). Concentrations of the studied herbal drugs were determined by using a Chromolith Performance RP-18e column with acetonitrile-water-formic acid as the mobile phase. Determinations of linearity, range, detection and quantitation limits, accuracy, precision, and robustness showed that the HPLC method was sufficiently precise for estimation of the tannins and related polyphenols mentioned above. Investigations of suitable solvent selection, sample extraction procedure, and short-time stability of analytes at storage temperatures of 4 and 20 degrees C were also performed. The percentage of agrimoniin in pharmaceutical products was between 0.57 and 3.23%.

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A sensitive, selective, precise, and stability-indicating thin-layer chromatographic (TLC) method was developed and validated for the determination of tenatoprazole both as a bulk drug and in formulation. The method uses TLC aluminum plates precoated with Silica Gel 60F-254 as the stationary phase and the solvent system toluene-ethyl acetate-methanol (6 + 4 + 1, v/v/v). This system gave compact spots for tenatoprazole (Rf value of 0.34 +/- 0.02). Tenatoprazole was subjected to acid and alkali hydrolysis, oxidation, and photodegradation. The peaks of the degradation products were well-resolved from that of the pure drug and had significantly different Rf values. Densitometric analysis of tenatoprazole was performed in the absorbance mode at 306 nm. The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 100-1500 ng/spot. The mean values of the correlation coefficient, slope, and intercept were 0.9989 +/- 1.42, 10.27 +/- 0.965, and 4894.2 +/- 1.24, respectively. The method was validated for precision, robustness, and recovery. The limit of detection and limit of quantitation were 50 and 100 ng/spot, respectively. Statistical analysis showed that the method is repeatable and selective for estimation of tenatoprazole. Because the method can separate the drug from its degradation products, it can be used to monitor stability.

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A sensitive and accurate High-Performance TLC (HPTLC) method has been developed to determine the quantity of 6-gingerol in rhizomes of Zingiber officinale (family: Zingiberaceae), commonly known as ginger. Methanol extracts of rhizomes from three different sources were used for HPTLC, n-hexane, and diethyl ether (40:60 v/v) as the mobile phase. The Rf of 6-gingerol was found to be 0.40. The calibration plot was linear in the range of 250-1200 ng of 6-gingerol and the correlation coefficient of 0.9997 was indicative of good linear dependence of peak area on concentration. The mean quantity of 6-gingerol was found to be 60.44+/-2.53 mg/g of ginger extract. The method permits reliable quantification of 6-gingerol and good resolution and separation of 6-gingerol from other constituents of ginger. To study the accuracy and precision of the method, recovery studies were performed by the method of standard addition. Recovery values from 99.79 to 99.84% showed the excellent reliability and reproducibility of the method. The proposed HPTLC method for quantitative monitoring of 6-gingerol in ginger can be used for routine quality testing of ginger extracts.

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A stability-indicating forced-degradation study of valdecoxib was conducted using high performance thin layer chromatography (HPTLC). It was used to analyze valdecoxib as bulk drug and as tablets. Undegraded valdecoxib was eluted with a retardation factor, Rf, of 0.56. Valdecoxib was forcibly degraded by exposure to alkali, acid, oxidation, and light, the greatest degradation occurring under basic conditions. Base-degraded valdecoxib gave an additional peak with an Rf value of 0.76. The calibration curve was linear in the range of 0.2-1 microg/microL with a correlation coefficient of 0.9952. Complete validation was carried out for precision (inter-day, intra-day, repeatability), accuracy, and robustness. All the data were analyzed statistically. This HPTLC procedure shows the reliability needed for use as a stability-indicating method. It can quantify valdecoxib in bulk and in tablets and also resolves the degraded peak of valdecoxib. This method is also useful for studying the degradation pattern and degradation mechanism of valdecoxib.

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A sensitive, rapid, simple, and accurate high performance thin layer chromatographic method has been developed to standardize the bark of Grewia tiliaefolia Vahl. (Family: Tiliaceae) using betulin as an analytical marker. Chloroform extracts of bark from five different sources were used for HPTLC on silica gel with toluene-ethyl acetate, 90 + 10 v/v, as mobile phase. Under these conditions, the Rf of betulin was 0.22. The calibration plot was linear in the range of 1000 ng to 1800 ng of betulin and the correlation coefficient, 0.999, was indicative of good linear dependence of peak area on concentration. The mean assay of betulin was 2.596 +/- 0.594 mg g(-1) of bark. The method permits reliable quantification of betulin and good resolution and separation of betulin from other constituents of Grewia tiliaefolia. Recovery values from 96.09 to 98.87% showed that the reliability and reproducibility of the method were excellent. The proposed HPTLC method for quantitative monitoring of betulin in Grewia tiliaefolia can be used for routine quality testing.

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The selected essential oil components (menthol, (+)bomeol, geraniol, linalool, carvone, camphor, (IR)-(-)fenchone) were separated by adsorption thin-layer chromatography using benzene as mobile phase. Investigated terpenes were characterized by selected topological indexes based on the adjacency and distance matrix. From among all the topological indexes counted only Si(o) index (the sum of the distance between the oxygen atom and all the remaining atoms in graph) as well as cluster Randic indexes (4chi(c), and 4chi(v)c) allow for estimation of the chromatograms obtained. With the fact mentioned above, there exists the possibility of prediction of relative situation on a chromatogram of the terpenes investigated. For the rest of topological indexes that possibility was not stated.

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Silica gel, aluminium oxide, diatomaceous earth, polyamide, cyano, diol and amino plates have been tested for their capacity to separate the color pigments of six chili powders of different origin by both adsorption and reversed-phase thin-layer chromatography. The plates were evaluated at 340 and 440 nm wavelengths. Best separation of color pigments was obtained on impregnated diatomaceous earth layer using acetone-water 17:3 v/v eluent. It was found that the pigment composition of chili powders showed marked differences. Principal component analysis employed for the classification of the chili powders according to their pigment composition indicated that these differences can be used for the determination of the similarity or dissimilarity of the chili powders.

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The effect of the increased natural radiation background (within some areas in Komi Republic) and man-caused radioactive contamination in the Chernobyl NPP accident zone on the composition of liver phospholipids in Microtus oeconomus inhabiting these areas was studied. The significant changes in the liver lipid composition in rodents inhabiting both the Chernobyl accident zone and the areas with the increased natural radiation background were found. The maximal changes in the liver phospholipid composition were revealed during the first year after the accident. The reverse dependence between the phosphatidyl choline/phosphatidyl ethanolamine ratio and the ratio between the sum of more readily oxidizable phospholipids and the sum of more poorly oxidizable ones was found. However, the slope of corresponding curves significantly depends on the radioactive state in the area of the population inhabitance. The conclusion about high sensitivity of the lipid composition of hepatocytes in Microtus oeconomus both to the impact of the man-caused radioactive contamination and the increased level of the natural radioactivity was drawn.

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Methods for analysis of narcotics belonging to amphetamine methylene dioxy derivatives (MDD) are reviewed. The characteristics of these agents, their metabolism, and methods used for their detection and identification (TLC, GC, HPLC, GC/MS) are described. Methods for their extraction from biological objects (human urine and hair) are described. Efficacy of MDMA and MDEA from the urine by different extractants is assessed. The data demonstrate different potentialities for detection and identification of amphetamine MDD, including those in biological specimens (human urine and hairs), by numerous chromatographic methods.

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Mycolic acids analysis by thin-layer chromatography (TLC) has been employed by several laboratories worldwide as a method for fast identification of mycobacteria. This method was introduced in Brazil by our laboratory in 1992 as a routine identification technique. Up to the present, 861 strains isolated were identified by mycolic acids TLC and by standard biochemical tests; 61 per cent out of these strains came as clinical samples, 4 per cent isolated from frogs and 35 per cent as environmental samples. Mycobacterium tuberculosis strains identified by classical methods were confirmed by their mycolic acids contents (I, III and IV). The method allowed earlier differentiation of M. avium complex - MAC (mycolic acids I, IV and VI) from M. simiae (acids I, II and IV), both with similar biochemical properties. The methods also permitted to distinguish M. fortuitum (acids I and V) from M. chelonae (acids I and II), and to detect mixed mycobacterial infections cases as M. tuberculosis with MAC and M. fortuitum with MAC. Concluding, four years experience shows that mycolic acids TLC is an easy, reliable, fast and inexpensive method, an important tool to put together conventional mycobacteria identification methods.

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UNLABELLED: An accurate, simple and low-cost image-analysis system has been set up for capturing thin-layer chromatography images, and a software package, TLCQA, has also been developed for both qualitative and quantitative analyses using the acquired image. AVAILABILITY: Available upon request from the authors. CONTACT: bcftchau@poly.edu.hk

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PURPOSE: To compare kinetic modeling of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (F-18 FDG) between untreated primary lung and untreated primary breast cancers by using positron emission tomographic (PET) findings and to correlate these findings with findings of in vitro studies. MATERIALS AND METHODS: Nineteen patients (12 men, seven women; age range, 49-82 years) with untreated primary lung cancer and 17 women with untreated primary breast cancer (age range, 26-65 years) underwent 1-hour dynamic F-18 FDG PET. A three-compartment model was applied to F-18 FDG kinetics in tumors. The standard uptake value normalized for lean body mass (SUVlean) in tumors was measured 50-60 minutes after tracer injection. In vitro, thin-layer chromatography was performed to evaluate the intracellular phosphorylation of tritiated F-18 FDG in human lung cancer and breast cancer cell lines. RESULTS: At PET, lung cancer had a significantly (P < .003) higher rate constant for F-18 FDG phosphorylation (k3) and SUVlean than did breast cancer (0.164 +/- 0.150 [standard deviation] vs 0.043 +/- 0.018 and 8.25 +/- 3.28 vs 3.17 +/- 1.08, respectively). Breast cancer showed a significant correlation between k3 and SUVlean (r = .607, P < .01), although no such correlation was observed in lung cancer. In vitro studies showed phosphorylation of F-18 FDG in breast cancer cells was less complete in hyperglycemia than it was in lung cancer cells. CONCLUSION: A much lower k3 appears to be a rate-limiting factor for F-18 FDG accumulation in breast cancer, while the higher k3 in lung cancer is probably not rate limiting for F-18 FDG accumulation.

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Offers methods for isolation of lidocaine and novocainamide present together in the urine, blood plasma, and saliva. Demonstrates the possibility of identifying these substances in biological fluids by thin-layer and gas liquid chromatography. Proposes methods for measuring lidocaine and novocainamide in biological objects by UV spectrometry (combined polynomial) and gas liquid chromatography. Demonstrates the reliability of the results.

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AIM: The study of lipid fraction spectrum in plasma of patients with chronic calculous cholecystitis (CCC) before and after the operative intervention. MATERIALS AND METHODS: 28 female patients with CCC. Plasma lipids were measured before the operation, 1 and 5 days after it, at the discharge from hospital and in healthy donors. RESULTS: Before the operation blood concentrations of total lipids, triacylglycerins, phosphatidylcholine and phosphatidylethanolamine were elevated. Cholesterol, lisophosphatidylcholine and sphingomyelin, cholesterol/phospholipids ratio were subnormal. The same changes of the lipids persisted 1 and 5 days after the surgery and at discharge. CONCLUSION: Plasma lipids in CCC patients are not corrected early after the surgery and require drug correction.

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The possibility of isolating 4-nitrophenols from objects of biological origin by acetic anhydride is investigated. Extracts from biological material were purified by extraction followed by silica gel thin layer chromatography. A method for identification and measurement of phenol 4-nitro derivatives in extracts of human cadaveric liver and blood is developed.

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