Retention Behavior of Anticancer Thiosemicarbazides in Biomimetic Chromatographic Systems and In Silico Calculations.

Chromatographic methods, apart from in silico ones, are commonly used rapid techniques for the evaluation of certain properties of biologically active compounds used for their prediction of pharmacokinetic processes. Thiosemicarbazides are compounds possessing anticancer, antimicrobial, and other valuable biological activities. The aim of the investigation was to estimate the lipophilicity of 1-aryl-4-(phenoxy)acetylthiosemicarbazides, to predict their oral adsorption and the assessment of their % plasma-protein binding (%PPB). RP-HPLC chromatographic techniques with five diversified HPLC systems, including columns with surface-bonded octadecylsilanes (C-18), phosphatidylcholine (immobilized artificial membrane, IAM), cholesterol (Chol), and α1-acid glycoprotein (AGP) and human serum albumin (HSA), were applied. The measured lipophilicity of all investigated compounds was within the range recommended for potential drug candidates. However, some derivatives are strongly bonded to HSA (%PPB ≈ 100%), which may limit some pharmacokinetic processes. HPLC determined lipophilicity descriptors were compared with those obtained by various computational approaches.

Qualitative and Quantitative Evaluation of Rosavin, Salidroside, and p-Tyrosol in Artic Root Products via TLC-Screening, HPLC-DAD, and NMR Spectroscopy.

Artic root is a well-known plant adaptogen with multipotential pharmacological properties. Thin-layer chromatography (TLC)-screening followed by diode-array high-performance liquid chromatography and nuclear magnetic resonance spectroscopy proved to be a reliable and convenient method for the simultaneous determination of the quality of various herbal raw materials and supplements. This combination allowed for comparing and differentiating arctic root samples as well as defining their authenticity. The study provided information on the chemical and biological properties of the seven chosen samples as well as qualitative and quantitative evaluation of the quality markers: rosavin, salidroside, and p-tyrosol. The absence of rosavin, salidroside, and p-tyrosol in three samples was detected using TLC screening and confirmed by HPLC-DAD and NMR. The paper highlighted the importance of quality control and strict regulation for herbal medicine supplements and preparations.

Cholinesterases Inhibition, Anticancer and Antioxidant Activity of Novel Benzoxazole and Naphthoxazole Analogs.

Benzoxazole and naphthoxazole fused systems are found in many biologically active molecules. Novel benzoxazole and naphthoxazole analogs functionalized by the 2,4-dihydroxyphenyl moiety were designed, obtained and evaluated as a broad spectrum of biological potency compounds. Sulfinylbis[(2,4-dihydroxyphenyl)methanethione] or its analogs and 2-aminophenols or 1-amino-2-naphthol were used as starting reagents. 4-(Naphtho[1,2-d][1,3]oxazol-2-yl)benzene-1,3-diol was identified as the most promising compound of the nanomolar activity against AChE (IC50 = 58 nM) of the mixed-type inhibition and of the moderate activity against BChE (IC50 = 981 nM). The higher antiproliferative potency against a panel of human cancer cell lines for naphtho[1,2-d][1,3]oxazoles than for benzoxazoles was found. The activity of the analog with chlorine atom was in the range of 2.18-2.89 µM (IC50) against all studied cells and it is similar to that of cisplatin studied comparatively. Moreover, this compound was not toxic at this concentration to human normal breast cells and keratinocytes. For some compounds it also has proved antioxidant properties at the level of IC50 = 0.214 µM, for the most active compound. The lipophilicity of all compounds, expressed as log p values, is within the range recommended for potential drugs. The biological activity profile of the considered analogs and their lipophilic level justify the search for agents used in AD or in anticancer therapy in this group of compounds.

Cold atmospheric pressure plasma (CAPP) as a new alternative treatment method for onychomycosis caused by Trichophyton verrucosum: in vitro studies.

PURPOSE: Anthropophilic dermatophytes as etiological factors of onychomycoses are more common than zoophilic fungi. In the case of the latter, reverse zoonoses are possible, which poses a threat to the persistence of dermatophytes in the environment. Nevertheless, without treatment, both types of tinea unguium may lead to complete nail plate destruction and secondary mixed infections with fungi and bacteria. One of the zoophilic dermatophytes that cause onychomycosis is Trichophyton verrucosum, whose prevalence has been increasing in recent years. Such infections are usually treated with allylamines and/or azoles, but such a conventional treatment of infections caused by T. verrucosum often fails or is discontinued by patients. METHODS: Herein, we reveal the results of our in vitro studies related to direct application of cold atmospheric pressure plasma (CAPP) on Trichophyton verrucosum growth, germination and adherence to nail as a new alternative treatment method of such types of dermatomycoses. RESULTS: Our in vitro studies showed that, while exposure to CAPP for 10 min delays germination of conidia and clearly impairs the fitness of the fungal structures, 15 min is enough to kill all fungal elements exposed to plasma. Moreover, the SEM images revealed that T. verrucosum cultures exposed to CAPP for 10 and 15 min were not able to invade the nail fragments. CONCLUSION: The results revealed that single exposure to CAPP was able to inhibit T. verrucosum growth and infection capacity. Hence, cold atmospheric pressure plasma should be considered as a promising alternative treatment of onychomycoses.

Effect-directed analysis as a method for quality and authenticity estimation of Rhodiola rosea L. preparations.

Adulterations of food and pharmaceutical preparations are the important global problem. On the one hand, fraud practices are becoming more and more sophisticated while on the other, monitoring and uncovering falsifications are insufficient. One of the most common consumer concern is the quality and authenticity of the purchased products, related to the confidence that they have composition and properties in accordance with the manufacturer's declaration on the label. This refers also to pharmaceuticals potentially delivering great health benefits such as Rhodiola rosea L. supplements. The aim of this study was defining authenticity and possible adulterations of two R. rosea preparations basing on their TLC-bioprofiles and the presence of biomarker compounds characteristic for this plant. The effect-directed analysis (EDA), i.e. TLC hyphenated with micro-chemical and biological assays performed directly on TLC plates followed by HPLC-ESI-MS was used for the bioprofiling of antioxidants, antibacterials, and inhibitors of lipase, acetylcholine, α-glucosidase and tyrosinase as well as for the identification of the biomarkers. The results pointed to the possible adulteration of one of the tested products related to the absence of two rosavins, the most important quality markers of R. rosea.

Determination of chlorogenic acid, polyphenols and antioxidants in green coffee by thin-layer chromatography, effect-directed analysis and dot blot - comparison to HPLC and spectrophotometry methods.

The great prevalence of thin-layer chromatography over high-performance liquid chromatography is connected with the possibility of analyzing many samples in parallel. Therefore, the method is often used in screening and/or effect directed analysis to compare composition and chemical/biological properties of many samples in one run. It was already proved, that high performance thin-layer chromatography, in many cases, can replace high-performance liquid chromatography for quantitative analysis. The main aim of the paper is to show that simple thin-layer chromatography can also be used as a quantitative or at least as a semi-quantitative method, even when it concerns effect directed analysis e.g. direct bioautography. Chlorogenic acid content was measured in four methanol extracts of various green coffees and in one extract of black coffee using thin-layer chromatography with ultraviolet detection and thin-layer chromatography with effect directed detection. High-performance liquid chromatography was used as a reference method. Additionally, total contents of polyphenols and antioxidants were estimated using thin-layer chromatography or dot-blot on chromatography plates. These results were compared to spectrophotometric methods. It was proved that thin-layer chromatography can be used as a quantitative (using densitometry) or semi-quantitative method (using other detection methods including effect directed detection) as well as for estimating total antioxidants or polyphenols content.

Retention and Separation Changes of Ternary and Quaternary Alkaloids from Chelidonium majus L. by TLC Under the Influence of External Magnetic Field.

Thin layer techniques proved their usefulness in the analysis of plant extract material. Thanks to their low operation costs, high sample throughput and possibility to gather chromatographic data for the whole sample in a single act, they allowed to find, and in some cases identify, active ingredients often hidden in sophisticated plant extract matrices. It was also proved that the presence of a magnetic field changes the retention of some substances, and moreover changes the separation efficiency of chromatographic systems. In the presented experiment, retention, efficiency and separation abilities of TLC chromatographic systems for mixtures of alkaloids under the influence of magnetic field depending on inductivity of the magnetic field, the saturation of chromatographic chamber and quantity of chromatographed substances were investigated. The results obtained were tested on real plant extracts that revealed the ability of chromatography in a magnetic field for separation of ternary and quaternary alkaloids from Chelidonium majus L. Our experiments proved that the presence of magnetic field induction lines perpendicular to the chromatographic plate plane can influence the width and retention of chromatographed substances, and can be considered as a tool for separation adjustment of plant extracts containing ternary and quaternary alkaloids.

Comparison of TLC and Different Micro TLC Techniques in Analysis of Tropane Alkaloids and Their Derivatives Mixture from Datura Inoxia Mill. Extract.

Planar chromatography is a very useful tool for analysis of wide range of different mixtures. Thanks to its possibility for rapid separation of large number of samples simultaneously, low solvent consumption and ability to analyse rough material allow to receive precise and reliable results in short time and low cost. Miniaturization of planar techniques brings a lot of advantages, such as shortening distance and time of chromatogram development, and further lowering of solvent consumption. Besides, it often allows to improve separation parameters and raise efficiency of chromatographic system. In this paper, ability of analysis of tropane alkaloids mixture from Datura Inoxia Mill. extract using conventional TLC technique with five micro TLC techniques (short distance TLC, HPTLC, UTLC, OPLC and ETLC) in maximally closed chromatographic conditions was compared in order to present abilities of micro TLC techniques in plant material analysis.

Some aspects of TLC in homogenous magnetic fields.

This article consists of two parts. First part is a short review about the role of magnetic phenomena in natural environment, human surroundings, and his activities such as science, engineering, and medicine. The second part of the article presents a set of experiments, their results, and data obtained in a static homogenous magnetic field, generated by a pair of permanent magnets and outside it. Adsorption chromatographic systems were investigated: as chromatographed substances - polyaromatic hydrocarbon (PAH), as stationary phase - silica gel 60, as monocomponent mobile phases - n-hexane, n-heptane, n-octane, and benzene were used and binary mobile phases n-hydrocarbons - benzene. Magnetic field influences retention and efficiency of investigated chromatographic systems. Experimental data analysis (RF, N) allows us to propose some explanations of the differences between experiment results performed in induced magnetic field and outside it, and in consequence on the changes in the interfacial phenomena induced by field presence.