New PNM Mutation in SUP35

A number of [PSI+]-no-more (PNM) mutations, eliminating [PSI+] prion, were previously described in SUP35. In this study, we designed and analyzed a new PNM mutation based on the parallel in-register β-structure of Sup35 prion fibrils suggested by the known experimental data. In such an arrangement, substitution of non-charged residues by charged ones may destabilize the fibril structure. We introduced Q33K/A34K amino acid substitutions into the Sup35 protein, corresponding allele was called sup35-M0. The mutagenized residues were chosen based on ArchCandy in silico prediction of high inhibitory effect on the amyloidogenic potential of Sup35. The experiments confirmed that Sup35-M0 leads to the elimination of [PSI+] with high efficiency. Our data suggested that the elimination of the [PSI+] prion is associated with the decreased aggregation properties of the protein. The new mutation can induce the prion with very low efficiency and is able to propagate only weak [PSI+] prion variants. We also showed that Sup35-M0 protein co-aggregates with the wild-type Sup35 in vivo. Moreover, our data confirmed the utility of the strategy of substitution of non-charged residues by charged ones to design new mutations to inhibit a prion formationRFBR grant 19-04-00173, RFBR grant 17-54-150002, and PRC CNRS grant PRC1524,18-34-00536, RSF grant 18-14-0005

6′-Amino-5,7-dibromo-2-oxo-3′-(trifluoromethyl)-1′<i>H</i>-spiro[indoline-3,4′-pyrano[2,3-<i>c</i>]pyrazole]-5′-carbonitrile

The multicomponent reactions are environmentally benign synthetic methods of building-up of complex molecules and several levels of structural diversity for diverse applications. Spirooxindoles are an important synthetic target possessing extended biological activity and drug discovery applications. In this communication, the multicomponent transformation of 5,7-dibromoisatin, malononitrile, and 5-(trifluoromethyl)-2,4-dihydro-3H-pyrazol-3-one in EtOH at reflux in the presence of sodium acetate was carefully investigated to give 6′-amino-5,7-dibromo-2-oxo-3′-(trifluoromethyl)-1′H-spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-5′-carbonitrile in excellent yield. The structure of the new compound was established by means of elemental analysis, mass and nuclear magnetic resonance, and infrared spectroscopy

1,3-Dimethyl-3&prime;,5-diphenyl-1,5-dihydro-2H,5&prime;H-spiro[furo[2,3-d]pyrimidine-6,4&prime;-isoxazole]-2,4,5&prime;(3H)-trione

Michael addition&ndash;halogenation&ndash;intramolecular ring-closing (MHIRC) reactions are processes in which a halogen atom as a leaving group can attach to substrates or reactants during the reaction, which then undergoes intramolecular ring closure. In this communication the MHIRC transformation of 4-benzylidene-3-phenylisoxazol-5(4H)-one and 1,3-dimethylbarbituric acid in the presence of N-bromosuccinimide and sodium acetate in EtOH at room temperature was carefully investigated to give novel 1,3-dimethyl-3&prime;,5-diphenyl-1,5-dihydro-2H,5&prime;H-spiro[furo[2,3-d]pyrimi- dine-6,4&prime;-isoxazole]-2,4,5&prime;(3H)-trione in a good yield. The structure of the new compound was confirmed by the results of elemental analysis as well as mass, nuclear magnetic resonance, and infrared spectroscopy

5-(1-(4-Hydroxy-6-methyl-2-oxo-2<i>H</i>-pyran-3-yl)-2-oxo-2-phenylethyl)-1,3-dimethylpyrimidine-2,4,6(1<i>H</i>,3<i>H</i>,5<i>H</i>)-trione

Multicomponent reactions have been demonstrated as a promising tool for the creation of diverse molecular structures with enhanced efficiency, reduced waste, and a high atom economy. Arylglyoxal monohydrates with two different carbonyl groups are well known as worthwhile synthons in organic synthesis. 2-Pyrone and pyrimidine-2,4,6-trione are versatile building blocks for the synthesis of key intermediates in synthetic organic chemistry as well as in medicinal chemistry. A simple and efficient tandem Knoevenagel–Michael protocol for the synthesis of the previously unknown 5-(1-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-2-oxo-2-phenylethyl)-1,3-dimet-hylpyrimidine-2,4,6(1H,3H,5H)-trione was elaborated. The suggested method is based on the multicomponent reaction of phenylglyoxal hydrate, 1,3-dimethylbarbituric acid, and 4-hydroxy-6-methyl-2H-pyran-2-one. The structure of the synthesized compound was proven by 1H, 13C-NMR, and IR spectroscopy, mass spectrometry, and elemental analysis. A procedure for predicting the possible types of its biological activity was carried out for the title compound

1,3-Dimethyl-3′,5-diphenyl-1,5-dihydro-2<i>H</i>,5′<i>H</i>-spiro[furo[2,3-<i>d</i>]pyrimidine-6,4′-isoxazole]-2,4,5′(3<i>H</i>)-trione

Michael addition–halogenation–intramolecular ring-closing (MHIRC) reactions are processes in which a halogen atom as a leaving group can attach to substrates or reactants during the reaction, which then undergoes intramolecular ring closure. In this communication the MHIRC transformation of 4-benzylidene-3-phenylisoxazol-5(4H)-one and 1,3-dimethylbarbituric acid in the presence of N-bromosuccinimide and sodium acetate in EtOH at room temperature was carefully investigated to give novel 1,3-dimethyl-3′,5-diphenyl-1,5-dihydro-2H,5′H-spiro[furo[2,3-d]pyrimi- dine-6,4′-isoxazole]-2,4,5′(3H)-trione in a good yield. The structure of the new compound was confirmed by the results of elemental analysis as well as mass, nuclear magnetic resonance, and infrared spectroscopy

4a′-Hydroxy-3′,3′,5,6′,6′,7-hexamethyl-3′,4′,4a′,6′,7′,9a′-hexahydrospiro[indole-3,9′-xanthene]-1′,2,8′(1<i>H</i>,2′<i>H</i>,5′<i>H</i>)-trione

Pseudo-multicomponent reactions (Pseudo-MCRs) have led to a variety of compounds with interesting biological properties, especially desirable in the pharmaceutical industry. The isatin nucleus could be considered a privileged scaffold for the design of biologically active substances. Dimedone is an interesting and versatile molecule for most organic transformations, especially one-pot and multicomponent reactions. Xanthene derivatives are still an attractive research field for both academia investigations and industry. In this investigation, a simple and efficient tandem Knoevenagel–Michael protocol with subsequent cyclization for the synthesis of the previously unknown 4a′-hydroxy-3′,3′,5,6′,6′,7-hexamethyl-3′,4′,4a′,6′,7′,9a′-hexahydrospiro[indole-3,9′-xanthene]-1′,2,8′(1H,2′H,5′H)-trione was elaborated. The suggested method is based on the pseudo-MCR of 5,7-dimethylisatin and dimedone. The structure of the earlier unknown compound was proven using 1H, 13C-NMR, and IR spectroscopy, mass spectrometry, and elemental analysis. To compare the developed protocol with the existing ones, unsubstituted spiro[indole-3,9′-xanthene] was synthesized. Its structure has been proven using two-dimensional (2D) NMR spectroscopy techniques