Liquid chromatographic investigation of spontaneous oscillatory in vitro chiral conversion and spontaneous oscillatory condensation of simple carboxylic acids in aqueous and nonaqueous media

Oscillatory reactions are a narrow reaction type among the entity of chemical reactions and those involving purely organic compounds make a small contribution to an overall number of all known oscillatory reactions. The most abundant type is purely inorganic and mixed inorganic-organic oxidation-reduction reactions, basically because monitoring them is relatively easy (e.g., with use of potentiometric measurements). Investigation of the organic reactions can be more demanding, and then chromatography is an analytical technique of choice. In this paper, we provide an overview of chromatographic evidence with oscillatory reactions discovered in our laboratory in the course of the last several years that involve the low-molecular-weight carboxylic acids (profen drugs, amino acids, and hydroxy acids). The investigated processes comprise the oscillatory chiral conversion and the oscillatory condensation, spontaneously running in the aqueous and nonaqueous abiotic media, and they were traced with use of TLC and HPLC coupled with different detector types

Uric acid in the surface waters of Spitsbergen and its role in the dissolution processes which affect carbonate rocks

Using High Performance Liquid Chromatography, concentrations of uric acid in the surface waters of two non−glaciated catchments (Fugle and Dynamisk) on Spitsbergen were measured. Measurements of specific conductivity enabled us to perform tests on the dissolution of the carbonate rocks present in both catchments in both natural and aqueous solutions of uric acid. Samples of calcium urate were made and its water solubility deter− mined. Given a knowledge of concentrations of uric acid, calcium ions and calcium urate solubility product, an estimate of the role of uric acid in the dissolution of carbonate rocks was possible. Uric acid increases the dissolution of carbonate rocks by c. 12.5% in case of the Fugle catchment and 7% in Dynamisk

Investigation of spontaneous non-linear peptidization dynamics and mechanism with selected [alpha]-amino acid pairs

The goal of this study was to provide experimental evidence on the dynamics and mechanism of spontaneous oscillatory peptidization in an abiotic system with three a-amino acid pairs (L-Met-L-Ser, L-His-L-Thr, and L-Cys-L-Phg), and to discuss these data in the context of an earlier established theoretical model. For each individual a-amino acid in a monocomponent and binary system, the dynamics of peptidization was traced with aid of the high performance liquid chromatograph with the evaporative light scattering detector. As an auxiliary technique, mass spectrometry (MS) was employed to scrutinize structures of the resulting peptides. With L-Met-L-Ser and L-His-L-Thr, the dynamics of one amino acid (L-Met and L-Thr, respectively) dominated over that of its counterpart. With LCys- L-Phg, no such predominance of the dynamics of one a-amino acid over that of its counterpart was observed. Mass spectrometric results confirmed the formation of heteropeptides with each investigated a-amino acid pair. With L-Met-L-Ser, L-His- L-Thr, and L-Cys-L-Phg, synchronization of the oscillatory behavior in the binary systems was observed, witnessing to mutual cross-catalysis of the two counterparts, assumed by case 4 of the theoretical model

Qualitative Evaluation of Composition of the Volatile Fraction in Commercial Samples of Cistus incanus L.

The present research is focused on identification of volatile components of different commercial products containing raw herbs of Cistus incanus L. The dried herbal material was hydrodistilled, and the obtained essential oils were analyzed by means of gas chromatography with mass spectrometric detection. Alternatively, the headspace analysis of the volatile sample components was also performed. It was found out that the investigated samples of the C. incanus L. species show a wide variation in terms of quality and quantity of the respective essential oils, which might result in their variable biological activity also. In conclusion, a postulate for standardization of chemical composition of the raw plant material used in therapeutic preparations is formulated

Determination of metaldehyde in different commercial pesticide formulations using green analytical procedure and gas chromatography flame ionization detection

Metaldehyde is a molluscicide allowed for use in the control of slugs and snails in agriculture and horticulture in many countries. A simple, fast, and precise gas chromatography method was developed and single-laboratory validated for determination of metaldehyde in different formulations of plant protection products. The proposed method involves extraction of active substance from samples by sonication with acetone and analysis using gas chromatography-flame ionization detection (GC-FID). The suggested analytical procedure is accurate, precise, and repeatable. Moreover, it is environmentally friendly and useful for laboratories as it uses a no time- and no solvent-consuming reference chromatography technique for quality control of commercially available pesticide formulations. Advantages of the proposed method are consistent with the ideas of sustainable development, which are in accordance with the principles of Green Analytical Chemistry. Analysis of real samples of commercial pesticide formulations confirmed that the proposed method is fit for its purpose

Fatal case of poisoning with a new cathinone derivative: α-propylaminopentiophenone (N-PP)

Purpose: Similar to synthetic cannabinoids, synthetic cathinone derivatives are the most popular compounds among novel psychoactive substances. Along with a growing number of new cathinones, the number of consumers wishing to enrich their experience with these compounds is also growing, and the same can be said about the growing numbers of poisonings. The reason for overdosing is a lack of consumer awareness regarding composition of the product, with which they experiment, and even more, regarding concentration of psychoactive substances contained in the taken product. In this paper, we report a case of the purposeful intake of a high dose of powder containing a novel cathinone derivative, α-propylaminopentiophenone, which resulted in the deadly poisoning of a woman. Methods: Aiming to identify this psychoactive substance causing the fatality, the postmortem specimens collected from the autopsy was analyzed by means of high-performance liquid chromatography coupled with mass spectrometry, and the analysis of a powder material found with the victim was additionally analyzed by means of gas chromatography with mass spectrometric detection. Results: In the course of analysis performed on the specimens originating from autopsy (blood, eyeball fluid, liver, kidney and brain), high concentrations of α-propylaminopentiophenone were established, which was responsible for the death of a young woman. The same psychoactive compound was also identified in the powder material. Conclusions: To the best of the authors' knowledge, this is the first case reported in the literature on fatal poisoning with α-propyloaminopentiophenone

The influence of heavy water as a solvent on the spontaneous oscillatory reactions of [alpha]-amino acids

In our earlier investigations, we have discovered that a-amino acids dissolved in water or aqueous-organic solvents undergo spontaneous oscillatory chiral inversion and oscillatory peptidization in parallel, and the dynamics of these processes strongly depends on the chemical structure of a given amino acid, physicochemical characteristics of a solvent used, ambient temperature, etc. The aim of this study was to perform a preliminary reconnaissance on the possible impact of D2O on the dynamics of spontaneous behavior of the selected test aamino acids (L-Phe, L-His, L-Pro and L-Cys) stored at 25 ± 0.5 C for the period of 1 week. As the measuring techniques, turbidimetry in continuous registration mode and mass spectrometry were employed. For the sake of comparison, the analogous results were presented for the discussed a-amino acids dissolved in the aqueous organic solvents and originally published elsewhere. Based on a comparison of the turbidimetric fingerprints, the dynamics of the turbidity changes in heavy water have proved rather moderate. Mass spectrometric results provided a confirmatory evidence witnessing to rather negligible peptide yields in heavy water. Thus, turbidimetric and mass spectrometric data have served as complementary proofs of a considerable hampering of spontaneous peptidization of a-amino acids in D2O

Circadian rhythm of spontaneous non-linear peptidization with proteinogenic amino acids in abiotic solutions versus homochirality

In this short communication, we report on three striking phenomena of the circadian rhythm. One was observed with the non-linear concentration changes of the monomeric L-Cys and the non-linear yields of the L-Cys derived peptides, when undergoing spontaneous non-linear peptidization. The other one was observed with the binary L-Phe-L-Pro system, and the third one with L-Ser, D-Ser, and DL-Ser. So far, no analogous reports have been released on the circadian rhythm of the spontaneous non-linear peptidization of proteinogenic amino acids in a sterile abiotic environment (70% aqueous acetonitrile, or 70% aqueous methanol solutions). At the moment, we cannot find any rational explanation of this phenomenon, yet it seems highly probable that its origin is analogous to or even of a primordial nature for the circadian rhythm phenomena abundantly found in biological samples by other researchers. An experimentally established lack of the circadian rhythm with peptidization of the non-proteinogenic amino acid (DSer) can encourage us to revisit a still unsolved question of homochirality preconditions

Turbidity patterns of spontaneous peptidization in an aqueous abiotic system and possible secondary peptide structures

The non-linear dynamics of spontaneous peptidization running in 10 monocomponent and binary abiotic liquid systems of L- and D-Ala and L- and D-Phe is investigated with use of turbidimetry with continuous registration, high-performance liquid chromatography with light scattering detection (HPLC-ELSD), mass spectrometry (MS), and spectroscopy of far UV circular dichroism (CD). The turbidity patterns represent a sum of the light scattering effects caused by insoluble peptides of unknown yields, structures, and molecular weights. The auxiliary analytical techniques confirm the non-linear nature of peptidization (HPLC-ELSD) and spontaneous formation of the homo- and heteropeptides (MS). CD spectroscopy seems to confirm the presence of the secondary α-helix structures. The similarity of turbidity patterns is revealed with the monocomponent (L or D) and binary (L-L or D-D) systems of equichiral α-amino acids, and dissimilarity of patterns is observed with the binary systems of inequichiral α-amino acids (L-D). The tentative conclusion is drawn that the peptides assembled of equichiral α-amino acid units are able to assume the secondary (right- or left-handed α-helix) structures, which in a certain way could foster the similarity of turbidity patterns, and the peptides built of inequichiral α-amino acid units cannot ensure an efficient enough stringing of monomer molecules into equichiral heptades to form complete segments of an α-helix. This randomness of the α-amino acids arrangement in the inequichiral peptide molecules most probably manifests itself as a lack of similarity among the respective turbidity pattern

Identification and characterization of new designer drug 4-fluoro-PV9 and [alfa]-PHP in the seized materials

In this study, we present identification and physicochemical characterization of new cathinone derivatives, 4-fluoro-PV9 and already known a-PHP in seized materials. Although the disclosure of a-PHP from an illegal product had been reported and characterized to some extent, the data on a-PHP are also presented together with those of 4-fluoro-PV9. The data of characterization for the two compounds were obtained by high-performance liquid chromatography (HPLC)–mass spectrometry and HPLC– diode array detection, electrospray ionization/ion trap mass spectrometry in MS2 and MS3 modes, gas chromatography– mass spectrometry, thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and nuclear magnetic resonance spectroscopy. To our knowledge, this is the first report for identification and detailed characterization of 4-fluoro-PV9 circulated on the illegal drug market