Valeria Belikova, Vitaly Panchuk, Evgeny Legin, Anastasia Melenteva, Dmitry Kirsanov, Andrey Legin Continuous monitoring of water quality at aeration plant with potentiometric sensor array, Sensors and Actuators B: Chemical, 282, 2019, 854-860. DOI: 10.1016/j.snb.2018.11.153

Abstract

The potential of multisensor array in continuous on-line monitoring of processed water quality at aeration plant is explored. The responses of 23 potentiometric sensors were continuously registered every seven seconds through the 26 days of experiment in a special container having connection with outlet water line of the aeration plant. Using chemometric tools it is shown that potentiometric “electronic tongue” is capable of evaluation of two important parameters of water quality: ammonium nitrogen and nitrate nitrogen. Unlike traditional sampling-based analysis the results of multisensor are available immediately in a real-time mode. Moreover, the achieved precision is sufficient to monitor possible alarm events. The employment of topological data analysis allowed for exploration of the very large dataset (295,828 measurements) accumulated through the long period of continuous measurements with sensors and for judgment on stability of water quality.

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Oliver Hegen, Jens Braese, Alexey Y. Timoshkin, Manfred Scheer, Bidentate Phosphanyl- and Arsanylboranes, Chem. Eur. J., 2018. DOI:10.1002/chem.201804772

Abstract

A new class of neutral bidentate ligands with pnictogenyl-functional sites has been obtained. The reaction of tmeda⋅(BH₂ I)₂ (1, tmeda=tetramethylethylendiamine) with different phosphanides yields the corresponding bidentate phosphanylboranes tmeda⋅(BH₂ PH₂ )₂ (2 a), tmeda⋅(BH₂ PPh₂ )₂ (2 b), and tmeda⋅(BH₂ tBuPH)₂ (2 c). This reaction strategy could be further extended to synthesize the first bidentate arsanylborane tmeda⋅(BH₂ AsPh₂ )₂ (3). Depending on the substituents on the phosphorus, these compounds form different Au^I complexes, to build either polymeric tmeda⋅(BH₂ PH₂ AuCl)₂ (4 a), or monomeric tmeda⋅(BH₂ PPh₂ AuCl)₂ (4 b) products. These compounds form also neutral oligomeric group 13/15 chain-like molecules by coordination to a boron moiety such as tmeda⋅(BH₂ PH₂ BH₃ )₂ (5 a) and tmeda⋅(BH₂AsPh₂ BH₃ )₂ (5 b). DFT calculations provide insight into the differences between the syntheses of mono- and bidentate pnictogenylboranes.

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Reutskaya, E.; Osipyan, A.; Sapegin, A.; Novikov, A.; Krasavin, M. Rethinking Hydrolytic Imidazoline Ring Expansion: A Common Approach to the Preparation of Medium-Sized Rings via Side Chain Insertion into [1.4]Oxa- and [1.4]Thiazepinone Scaffold. J. Org. Chem. 2019, In press. DOI: 10.1021/acs.joc.8b02805

Abstract

The previously reported ring-expansion strategy involving hydrolytically prone imidazoline rings was thought to include the formation of a hydrated imidazoline intermediate. In this work, we accessed the latter via the addition of a 2-aminoethyl side chain onto a lactam moiety. This led to an efficient three-atom ring expansion of diarene-fused [1.4]oxazepines and [1.4]thiazepines and led us to propose to term this common approach the hydrated imidazoline ring expansion (HIRE) reaction. The strategy was extended to the insertion of longer (containing up to five atoms) side chains, and thus, larger (11- to 12-membered) diarene-fused rings were obtained via the homo-HIRE and homo²-HIRE reactions, respectively. This underscores the utility of the HIRE reaction for the preparation of medium-sized rings, an important class of chemical tools for interrogation of various biological targets.

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Krasavin, M.; Shetnev, A.; Sharonova, T.; Baykov, S.; Kalinin, S.; Nocentini, A.; Sharoyko, V.; Poli, G.; Tuccinardi, T.; Presnukhina, S.; Tennikova, T. B.; Supuran, C. T. Continued exploration of 1,2,4-oxadiazole periphery for carbonic anhydrase-targeting primary arene sulfonamides: discovery of subnanomolar inhibitors of membrane-bound hCA IX isoform that selectively kill cancer cells in hypoxic environment. Eur. J. Med. Chem. 2019, accepted. DOI: 10.1016/j.ejmech.2018.12.049

Abstract

An expanded set of diversely substituted 1,2,4-oxadiazole-containing primary aromatic sulfonamides was synthesized and tested for inhibition of human carbonic anhydrase I, II, IX and XII isoforms. The initial biochemical profiling revealed a significantly more potent inhibition of cancer-related, membrane-bound isoform hCA IX (reaching into submicromolar range), on top of potent inhibition of hCA XII that is another cancer target. The observed structure-activity relationships have been rationalized by molecular modeling. Comparative single-concentration profiling of the carbonic anhydrase inhibitors synthesized for antiproliferative effects against normal (ARPE-19) and cancer (PANC-1) cell lines under chemically induced hypoxia conditions revealed several candidate compounds selectively targeting cancer cells. More in-depth characterization of these leads revealed two structurally related compounds that showed promising selective cytotoxicity against pancreatic cancer (PANC-1) and melanoma (SK-MEL-2) cell lines.