A series of new 4-(1,3,4-thiadiazol-2-yl)-containing polysubstituted pyrroles 3 a-k has been synthesized by a preparative convenient method from ethyl 5-chloro-4-formyl-1H-pyrrole-3-carboxylates 1 a-e, which were selectively transformed into the corresponding polysubstituted pyrrole-4-carboxylic acids 2 а-е using sodium hypochlorite as an oxidizer. Further, they were transformed into the target compounds with a high yield using the cyclocondensation with N-mono- or N,N-disubstituted thiosemicarbazides in the boiling phosphorus trichloroxide. As seen from the screening of antimicrobial activity, the synthesized compounds exhibit the inhibiting and bactericide activity against some bacteria and fungi. The highest activity has been established for the compounds 3 a, c, e-h, j against the strain Klebsiella pneumoniae (МІС=31.25 µg/mL). The calculated HOMO energy level proves that the compound 3 с is the most reactive ligand for the interaction with a protein receptor. The molecular docking data show that the compound 3 h has the highest affinity to the ThiM Klebsiella pneumoniae kinase.

Novel 2,4-disulfonylsubstituted 5-aminothiazoles were synthesized and their anticancer activity was assessed at a high dose (10 μM) against NCI 60 cancer cell lines. Compounds 24 and 25 showed the antiproliferative activity with mean growth inhibition about 66.0%. Replacing 4-hydroxypiperidine 24 with the more hydrophilic N-methyl piperazine 25 increased the number of sensitive cell lines while replacing these hydrophilic groups with lipophilic ones abolished the anticancer activity. The COMPARE analysis showed that the tested compounds had a moderate positive correlation with alkylating agents (CCNU and methyl CCNU) and with a purine nucleotide biosynthesis inhibitor analog (L-cysteine). The results indicate that the above mechanisms of antitumor action of standard compounds are not the main ones for the tested compounds due to the lack of a high correlation. The results of this study allow us to consider compounds 24 and 25 as a basis for their further functionalization to obtain more active compounds.

Rhodanines are recognized as privileged heterocycles in medicinal chemistry. The main achievements include the development of drug-like molecules with numerous biological activities as well as approved drugs. The Furan nucleus is considered one of the promising heterocyclic cores in medicinal chemistry that showed numerous ranges of activity. The combination of several heterocycles in a one molecule commonly provides much more interest in the enhanced activity profile of its analogs than their parent separate constituents. Such conjugates are promising objects for modern medicinal chemistry. In this review paper recent advances in the synthesis and biological activities rhodanine-furan conjugates which its application in the different field of drug discovery.

New analogues of pulmonarin B were synthesized from (3,5-dibromo-4-hydroxyphenyl)acetic acid derivatives, and their antibacterial and antibiofilm activities against E. coli, S. aureus, and P. aeruginosa were evaluated. The antibacterial activity of synthesized ammonium salts against the methicillin-resistant strain of S. aureus 222 depends on the length of the alkyl chain. Bisquaternary ammonium salt 5 demonstrated better activity against S. aureus 222, E. coli 311, and P. aeruginosa 449 compared to mono-alkylated derivatives. Analogues of pulmonarin B 5 and 4d reduced S. aureus 222 biofilm formation by 74.5% and 89.4%, respectively. In addition,
compound 4c turned out to be the most active against the biofilm formation of P. aeruginosa 449 (biomass decreased by 39.8%).

A crucial direction in the progress of modern medical chemistry is the development and improvement of theoretical investigation methods of drugs mechanisms of action, predicting their activity, and virtual design of new drugs. This review describes the history of targeted search for biologically active compounds, current in silico approaches and tools used in the rational design of potential drugs, in particular the main computational strategies used in modern drug design are presented and outlines the main methodologies for implementing these strategies.

On the base of 3-formylpicolinic acid by two successive heterocyclizations (the formation of a pyrone fragment by the cyclization of chloroacetone with the carboxyl and formyl groups; and the construction of the thiazole cycle through the bromination of the acetyl fragment and following interaction with thioamides), 6-(2-(phenyl/thiophen-2-yl)thiazole-4-yl)-8H-pyrano[3,4-b]pyridin-8-ones were obtained; and then the pyrone fragment was converted to pyridone by the action of ammonia under high pressure. When such 6-(2-R-thiazol-4-yl)-1,7-naphthyridin-8(7H)-ones reacted with triflic anhydride, O-sulfonylation of the pyridone fragment occurred, after that triflate group was easily substituted by secondary cyclic aliphatic amines. Thus, a number of new 8-amino-6-(2-R-thiazol-4-yl)-1,7-naphthyridines – previously inaccessible heterocyclic derivatives with promising biological activity – were obtained.

The 4-bromomethyl-substituted thiazolium salts and corresponding thiazoles obtained through the condensation of 1,3-dibromoacetone with thioamide derivatives were utilised as efficient alkylating reagents for a series of thiophenols and heterylthiols. As a result, a small library of 4-thiomethyl-functionalised 1,3-thiazoles was synthesised in high yields, and their structures were characterised by ¹H, ¹³C NMR, LC-MS and IR spectra. Antioxidant activity of obtained compounds was studied in vitro using the DPPH test. The synthesised compounds showed high absorption level of DPPH radicals in the 70-98% range. For the most active derivatives 7e,m,p,t IC50 values were determined, which were in the range 191-417 µM (for ascorbic acid (reference) IC⁵⁰ value was 29 µM). Obtained radical scavenging activity screening data suggest in-depth study of the antioxidant potential for these types of heterocyclic compounds.

Condensed bicyclic systems with thiadiazole core being annelated to other five-membered heterocycles such as 1,3-thiazole, imidazole or 1,2,4-triazole occupy prominent place in medicinal chemistry because of their broad spectrum of pharmacological activities. The combination of several heterocycles into a bicyclic system commonly provides much more interest in the enhanced activity profile of its analogs than their parent separate constituents. In this review, we summarized the literature data about the main approaches for obtaining and possible directions of structural modification of the most common 1,3,4-thiadiazole containing [5+5] annelated heterosystems as promising objects for modern medicinal chemistry.

In the present work, we presented an efficient synthesis and anticancer activity evaluation of some new 3-R-6-(5-arylfuran-2-yl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles. We have shown that the proposed synthetic protocols provided the possibility to design triazolothiadiazoles diversity with a considerable chemical novelty. The structures of target substances were confirmed by using 1H NMR spectroscopy, mass spectrometry and elemental analysis. The synthesized compounds were selected by the National Cancer Institute Developmental Therapeutic Program for the in vitro cell line screening. Among all the substances tested, three compounds exhibited significant cytotoxic activity.

The paper proposes an improved design of a shock absorber used in drilling deep oil and gas and geothermal wells with polycrystalline diamond compact (PDC) bits. The proposed innovations successfully combat the dangerous phenomenon of self-excited vibrations, which can lead to malfunctions such as stick-slip and whirling of the drilling tool. Most conventional drill shock absorbers are designed to only absorb longitudinal vibrations, which was sufficient when using roller cutter bits for the drilling process. However, the design features of PDC bits and the phenomenon of interaction of their cutters with interlayered rocks during deep drilling impose new requirements on the properties of the drill shock absorber. To protect the downhole tool from abnormal torque values and torque oscillations, it is proposed to equip the shock absorber with a special torque transmission unit in the form of a fourteen-thread self-releasing screw pair. This unit is capable of transforming increases in external torque into increases in the force that loads the elastic element of the shock absorber. The numerical and analytical models of the mechanism of transferring external axial load and torque to the elastic element of the drill shock absorber are constructed. The distribution of contact pressures on the interacting surfaces of the screw pair and the distribution of equivalent stresses in the screw pair parts are analysed. The strength of the proposed drill shock absorber assembly was evaluated using the Huber-von Mises energy criterion. The dependence of the load transmitted to the elastic element of the shock absorber on changes in the external torque and external axial force is investigated. In general, it is determined that the external load is distributed evenly between all turns of the screw pair, and the limit state of the parts of the proposed assembly is not reached even under high-torque operating load. The obtained analytical dependencies will allow to effectively determine the required strength and stiffness of the elastic element of the drill shock absorber at the design stage. The obtained analytical results were verified using a finite element model.