Optimization of extraction procedure and determination by high performance liquid chromatography of flavonols and phenolic acids from Hypericum Perforatum L.

Hypericum perforatum is a medicinal plant which has been known in traditional medicine as an antiinflammatory and healing agent. Nowadays the use of Hypericum extracts is concerned mainly with antidepressive applications. In the present work, HPLC – RP- C18 column chromatography with photodiode array detection was applied for the determination of the derivatives of cinnamic and benzoic acid (e.g., caffeic, chlorogenic, ferulic, sinapic, gallic acids) (Fig.1.) and flavonols - quercetine derivatives (quercetine, rhamnetine, quercitrin, mirycetine, keampferol and rutin) in Hypericum Perforatum. Phenolic compounds were extracted from the sample matrix with ethanol and ethanolwater mixture in different ratios solvent (3:7; 8:2; v/v) at 30°C and 60°C in water-bath shaker and by ultrasonic extraction and then analyzed before and after acid and basic hydrolysis. The total amount of studied flavonols and phenolic acids were compared with the total flavonoids content (TFC) and with total polyphenols content (TPC). UV-Vis spectrometry was used to investigate methods for qualitative and quantitative determination of these compounds

The influence of pH and selected cations on the spectrofluorometric determination of oxytetracycline hydrochloride

The spectrofluorometric method for the oxytetracycline hydrochloride in pure and in veterinary products Tetrox and Oxymed 50 determination is described. The influence of pH solution and presence selected cations on fluorescence intensity were studied too. It was ascertained that the highest fluorescence intensity take place at pH=9. Moreover, the quenching of fluorescence intensity was observed at presence Ca2+, Al3+ and Fe3+ in contrast to Mg2+ which caused increasing of intensity. The obtained recovery (97.23±0.12% for Tetrox and 95.21±0.10% for Oxymed 50) values meet the European Pharmacopoeia requirement. Moreover, the relative standard deviation (RSD) was below 0.23% confirmed high precise of the method. The statistical test (t-Student and F-Snedecor) used for comparison spectrofluorometric and chromatographic methods pointed that they are comparable in respect of precision but not of accuracy

Hexakis(1H-imidazole-κN 3)cobalt(III) tris­(hexa­fluoridophosphate) hexa­hydrate

In the crystal structure of the title compound, [Co(C3H4N2)6](PF6)3·6H2O, the CoIII atom lies on a special position with site-symmetry and the P atom is located on a special position with site symmetry . The CoIII atom has an almost ideal octa­hedral coordination formed by the N atoms of six imidazole ligands. The water mol­ecules form hydrogen-bonded helical chains propagating in [001] by O—H⋯O inter­actions with a distance of 2.913 (2) Å. They simultaneously inter­act as hydrogen-bond acceptors and donors with the cations and anions, respectively, resulting in the formation of a three-dimensional assembly. Weak C—H⋯F inter­actions further stabilize the crystal structure

From binary to multinary copper based nitrides - unlocking the potential of new applications

This review summarizes the current knowledge on the chemistry of binary copper(I) nitride, Cu3N and its multinary derivatives containing either main group or transition metal elements. For many years, research in this area was focused on the development of copper nitride prepared in the form of thin films. Successful deposition of these materials has been achieved mainly by employing physical methods, which have provided materials suitable for potential application in optical data storage. However, for the last decade, attention has also been devoted to expanding the available options by which Cu3N can be synthesized and deposited. Consequently, the focus has switched to the development of chemical synthetic methods towards the fabrication of this semiconductor and to broadening the range of related compounds that might be discovered. Simultaneously, the formulation of novel techniques and the successful preparation of new nanostructured functional materials has resulted in the rapid evolution of new and relevant applications; e.g. catalytic and electrochemical. The overview presented here concentrates on the chemical methods that have been devised to synthesise both bulk samples and thin films of Cu3N. Our article also shows how these approaches have been developed to achieve significant progress in the creation of multinary copper based nitrides and in identifying their potential applications. It provides a concise history of previous copper nitride research and sets the context for the most current advances. These will no doubt provide the springboard for future research areas that will impact both transition metal nitride chemistry and materials science more generally

Influence of two pt(iv) complexes on viability, apoptosis and cell cycle of B16 mouse melanoma tumors

Several platinum(IV) complexes are showing considerable promise in initial trials, producing reactive intermediates that then interact with DNA. Aim: To perform in vitro study of two new platinum(IV) complexes cytotoxic effect on B16 mouse melanoma cells. Methods: PtCl₄ (dbtp)₂ and PtCl₂ (6mp)₂ complexes were prepared. PtCl₄ (dbtp)₂ was created as modification of PtCl₄ (dmtp) test previously.Apoptosis and necrosis were examined using flow cytometry, upon Annexin V/PI staining. Results: LC₁₀,LC₅₀ andLC₉₀ parameters established for PtCl₄ (dbtp)₂ were as following: 2.6, 17.0, 58.0 μmol/L. However LC₁₀ andLC₅₀ established for PtCl₂ (6mp)₂ were 1.2 and 14.0μmol/l respectively. The both complexes induced apoptosis. PtCl₂ (6mp)₂ induced cell cycle arrest in G0/G1, while PtCl₄ (dbtp)₂ — in S-phase. Conclusions: PtCl₄ (dbtp)₂ appeared to be more cytotoxic against B16 cells than PtCl₂ (6mp)₂ . Apoptosis was the main mechanism of cell loss in cultures incubated with both tested complexes

Re‐evaluation of phosphoric acid–phosphates – di‐, tri‐ and polyphosphates (E 338–341, E 343, E 450–452) as food additives and the safety of proposed extension of use

The Panel on Food Additives and Flavourings added to Food (FAF) provided a scientific opinion re‐evaluating the safety of phosphates (E 338–341, E 343, E 450–452) as food additives. The Panel considered that adequate exposure and toxicity data were available. Phosphates are authorised food additives in the EU in accordance with Annex II and III to Regulation (EC) No 1333/2008. Exposure to phosphates from the whole diet was estimated using mainly analytical data. The values ranged from 251 mg P/person per day in infants to 1,625 mg P/person per day for adults, and the high exposure (95th percentile) from 331 mg P/person per day in infants to 2,728 mg P/person per day for adults. Phosphate is essential for all living organisms, is absorbed at 80–90% as free orthophosphate excreted via the kidney. The Panel considered phosphates to be of low acute oral toxicity and there is no concern with respect to genotoxicity and carcinogenicity. No effects were reported in developmental toxicity studies. The Panel derived a group acceptable daily intake (ADI) for phosphates expressed as phosphorus of 40 mg/kg body weight (bw) per day and concluded that this ADI is protective for the human population. The Panel noted that in the estimated exposure scenario based on analytical data exposure estimates exceeded the proposed ADI for infants, toddlers and other children at the mean level, and for infants, toddlers, children and adolescents at the 95th percentile. The Panel also noted that phosphates exposure by food supplements exceeds the proposed ADI. The Panel concluded that the available data did not give rise to safety concerns in infants below 16 weeks of age consuming formula and food for medical purposes

Facile preparation of copper nitride powders and nanostructured films

The simple fluorinated precursor, copper(II) trifluoroacetate, Cu(CF3COO)2 can be effectively utilised in the synthesis of Copper(I) nitride, Cu3N, powders and films by combinations of wet processing and gas-solid (ammonolysis) techniques. The resulting materials were characterized by powder X-ray diffraction (PXD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), diffuse reflectance UV-visible spectroscopy (DRUV-Vis), Raman spectroscopy, infrared spectroscopy (IR), thermogravimetric-differential thermal analysis-mass spectrometry (TG-DTA-MS) and nitrogen adsorption (BET) analysis. Moreover, variable temperature IR (VT-IR) studies of the solid phase were performed in situ during ammonolysis. Single-phase Cu3N powders composed of sub-micron scale platelets can be produced over relatively short reaction times. Materials prepared in this way are stoichiometric narrow band gap semiconductors. The same trifluoroacetate precursor was used to prepare nanostructured nitride films by dip coating. The surface microstructure was investigated and evaluated relative to films deposited by spin coating and nebulisation using soluble carboxylate precursors