1,4-Naphthoquinone Motif in the Synthesis of New Thiopyrano[2,3-d]thiazoles as Potential Biologically Active Compounds.

A series of 11-substituted 3,5,10,11-tetrahydro-2H-benzo[6,7]thiochromeno[2,3-d][1,3]thiazole-2,5,10-triones were obtained via hetero-Diels-Alder reaction of 5-alkyl/arylallylidene/-4-thioxo-2-thiazolidinones and 1,4-naphthoquinones. The structures of newly synthesized compounds were established by spectral data and a single-crystal X-ray diffraction analysis. According to U.S. NCI protocols, compounds 3.5 and 3.6 were screened for their anticancer activity; 11-Phenethyl-3,11-dihydro-2H-benzo[6,7]thiochromeno[2,3-d]thiazole-2,5,10-trione (3.6) showed pronounced cytotoxic effect on leukemia (Jurkat, THP-1), epidermoid (KB3-1, KBC-1), and colon (HCT116wt, HCT116 p53-/-) cell lines. The cytotoxic action of 3.6 on p53-deficient colon carcinoma cells was two times weaker than on HCT116wt, and it may be an interesting feature of the mechanism action.

Actual prospects of using some types of larch growing in Kazakhstan in medicine.

Local plants can save natural resources and be used as a source of biologically active compounds, which can be high-quality, effective, and safe ingredients for pharmacological or chemical industries. Therefore, this study aimed to investigate the properties of two medicinal plants - the fine-scaled larch (Lárix Kaémpferi) and Siberian larch (Lárix Sibirica), which are growing in the Republic of Kazakhstan. We compared the two types of larches according to botanical affiliation and species description. We studied the alcoholic extracts from Lárix Kaémpferi and Lárix Sibirica to determine their physical and chemical properties. The data on the chemical composition of extractive compounds were generalized and systematized. The authenticity of Lárix Kaémpferi and Lárix Sibirica was established by external, anatomical, and diagnostic signs in microscopic examination and qualitative reactions. Specific indicators and their norms for raw materials were identified. This is the standard for both types of larch and determines their quality. We experimented with grinding fineness for studied materials and tested the impurities and moisture content of raw materials, total ash, and ash insoluble in a 10% hydrochloric acid solution. Determination of heavy metals and radionuclides was also considered. The quality specifications were developed based on the standardization of fine-scaled larch and Siberian larch.

Chemical Composition and Antimicrobial Activity of Subcritical CO2 Extract of Lepidium latifolium L. (Brassicaceae).

The genus Lepidium L. from Brassicaceae Burnett. family covers over 150 species with an almost cosmopolitan spread. In Kazakhstan, 21 species are described, of which four species are characterized by medicinal properties (L. crassifolium Waldst. et Kit., L. perfoliatum L., L. ruderale L., and L. latifolium L.), used in folk medicine as means of antibacterial, irritant, laxative, antitumor, analgesic, and anthelmintic action. Methods. Raw materials were collected from Almaty region (Republic of Kazakhstan). Lepidium latifolium L. herb's carbon dioxide extract (CO2 extract) was obtained by subcritical carbon dioxide extraction. A gas chromatograph with a mass spectrometric detector was used to determine the component composition of the extract. Antimicrobial activity was determined by two methods: the micromethod of serial dilution and the disc-diffusion method. Four microbial test strains were used: Staphylococcus aureus ATCC 6538-P, Escherichia coli ATCC 8739, Klebsiella pneumonia ATCC 10031, and Candida albicans ATCC 10231. Results. The technology of carbon dioxide extraction has undoubted advantages over traditional methods of extraction: it has a controlled selectivity in relation to groups of biologically active substances, allows deep extraction, and maximizes the release of rich complexes of compounds contained in plants. In this study, firstly, the CO2 extract was obtained under subcritical conditions from the aerial part of L. latifolium L., and the composition was determined. Hexane was the best solvent for CO2 extract, and 40 components were identified. Screening of antimicrobial activity of the L. latifolium's CO2 extract showed the essential activity of all clinically significant strains tested: Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Candida albicans. Conclusions. This research showed that the CO2 extract of the raw material of Lepidium latifolium L. contains biologically active compounds exhibiting an essential antimicrobial effect, and therefore it is possible to recommend for the development of various drugs for use in medical practice.

Corrigendum to "Phytochemical and Antioxidant Studies on a Rare Rheum cordatum Losinsk: Species from Kazakhstan".

[This corrects the article DOI: 10.1155/2019/5465463.].

Phytochemical and Antioxidant Studies on a Rare Rheum cordatum Losinsk. Species from Kazakhstan.

An optimisation of extraction towards an increased antioxidant capacity and the study on the extracts' composition by HPLC-ESI-Q-TOF-MS were performed on different organs of a rarely studied plant: Rheum cordatum Losinsk (Polygonaceae) growing in Kazakhstan. More than 20 compounds from anthraquinones and phenolics were identified in an optimised method. The plant was proven to contain a wide variety of phenolic compounds (catechins, flavonoids, and their glucosides and phenolic acids) in contrast to the anthraquinone composition, which was mainly represented by emodin and its analogues. The results of the studies could determine the plant as a rich source of pharmacologically precious polyphenols. It was evidenced that the extracting solvents, the time of collection, and the organs tested affected both the chemical content and the antioxidant potential of the extracts. Ethanol : water (50 : 50 v/v) was selected as the most beneficial extractant for all metabolites, and based on the principal component analysis of raw data, the radical scavenging potential of the plant was strictly related to the presence of epicatechin gallate (ECG), kaempferol glucoside, and epigallocatechin gallate (EGCG) occurring in this extract at the concentration of 1.69-5%, 0.16-0.47%, and 0.001-2.93%, respectively.