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.

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.