Recently, there has been a worldwide substantial increase in the consumption of new psychoactive substances (NPS), compounds that mimic the structure of illicit drugs, such as amphetamines or ecstasy. The producers try to avoid the law by a slight modification of illicit structures, thereby developing dozens of temporarily legal NPS every year. The current trends in the detection and monitoring of such substances demand a fast and reliable analysis. Molecular spectroscopy represents a highly effective tool for the identification of NPS and chiroptical methods can provide further information on their 3D structure, which is the key for the determination of their biological activity. We present the first systematic study of NPS, specifically butylone, combining chiroptical and vibrational spectroscopies with ab initio calculations. According to density functional theory calculations, 6 stable lowest energy conformers of butylone were found and their molecular structure was described. For each conformer, the relative abundance based on the Boltzmann distribution was estimated, their population weighted spectra predicted and compared to the experimental results. Very good agreement between the experimental and the simulated spectra was achieved, which allowed not only the assignment of the absolute configuration, but also a precise description of the molecular structure.

Purpose The growing availability of new psychoactive substances with unknown toxicity is alarming all over the world. The simplicity of acquiring these drugs of abuse from internet markets has caused an increase in the total number of seizures. We present the first systematic spectroscopic study of methylone and pentylone, which are in the class of synthetic cathinones. Methods High performance liquid chromatography (HPLC) was used for the enantioseparation of methylone and pentylone. The substances were further analysed by the conventional methods of ultraviolet (UV) and infrared (IR) absorption and chiroptical methods, specifically electronic circular dichroism (ECD) and vibrational circular dichroism (VCD). The obtained data were supported with the density functional theory (DFT) calculations using the B3LYP or B3PW91 functional and 6-311++G(d,p) basis sets, including the solvent effects. Results The 3D structure of methylone and pentylone in solution was revealed. Moreover, the chiral separation of both studied substances was achieved and the absolute configuration of the respective enantiomers was determined. Conclusion Vibrational circular dichroism spectroscopy seems to be the best of the methods employed to distinguish structurally similar chiral substances, especially in combination with quantum chemical calculations. According to the structural analysis, 5 and 9 stable conformers of methylone and pentylone, respectively, were revealed in an aqueous solution. Finally, very good agreement between the experimental and simulated spectra was achieved.

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The preparation of inherently chiral rigidified calix[4]arenes with an intact cavity is a synthetic challenge due to the complicated synthesis of starting compounds. Here, we report on a novel strategy...

New psychoactive substances and among them synthetic cathinones represent a significant threat to human health globally. However, within such a large pool of substances derived from a natural compound ((S)-cathinone), substances with important pharmaceutical uses can be identified, as already documented by bupropione. Therefore, this work aimed to find a synthetic pathway for a novel synthetic cathinone, namely 4-isobutylmethcathinone, and describe its spectroscopic properties and biological activity in vitro. Since cathinones comprise a chiral center in their structure, a method for chiral separation of the substance was elaborated using high-performance liquid chromatography on an analytical and preparative scale. Preparative enantioseparation on a polysaccharide column provided a sufficient amount of the drug for the chiroptical studies leading to the determination of the absolute configuration of enantiomers as well as for their subsequent in vitro cytotoxicity study. The cytotoxicity induced by 4-isobutylmethcathinone was determined in human cells derived from the urinary bladder (5637), neuroblastoma (SH-SY5Y), microglia (HMC-3), and hepatocellular carcinoma (Hep G2), in which the IC50 values after 72 h reached an 18–65 µM concentration. This is significantly higher cytotoxicity in comparison with other synthetic cathinones. In the receptor binding studies, a significant difference in the agonistic effect on dopamine and adrenergic receptors of individual enantiomers was observed. The lack of binding affinity towards the serotonin receptors then relates 4-isobutylmethcathinone to the family of monoamine drugs, such as 3,4-methylenedioxymathamphetamine (ecstasy, MDMA).