Publications by authors named "L R Ptitsyn"

The crude aqueous ethanol extract of the cones of Alnus glutinosa (L.) Gaertn. (Betulaceae; black alder, European alder) was obtained and further partitioned between water and various organic phases.

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Article Synopsis
  • An ethanol extract from Pyrola rotundifolia stimulates AMPK phosphorylation in C2C12 muscle cells.
  • Bioassay-guided fractionation isolated a compound, 2-methyl-7-hydroxymethyl-1,4-naphthoquinone, which exhibited dose-dependent AMPK activation, particularly at concentrations between 2.5-20 μg/ml.
  • At 10 μg/ml, this compound increased AMPK phosphorylation by about four times, showing similar effectiveness to other natural AMPK activators.
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An aqueous ethanol extract of Bergenia crassifolia rhizomes strongly inhibited human pancreatic lipase activity and increased scavenging of DPPH free radicals in vitro. Chromatographic separation of this extract led to isolation of the hydrolysable tannins (+)-catechin 3,5-di-O-gallate (1) and (+)-catechin 3-O-gallate (2). This is the first report of the isolation of compound 1 from plant material.

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Overexpression of the yeaS gene encoding a protein belonging to the RhtB transporter family conferred upon cells resistance to glycyl-l-leucine, leucine analogues, several amino acids and their analogues. yeaS overexpression promoted leucine and, to a lesser extent, methionine and histidine accumulation by the respective producing strains. Our results indicate that yeaS encodes an exporter of leucine and some other structurally unrelated amino acids.

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The yicM gene of Escherichia coli was found by selection for resistance to 6-mercaptopurine. Translation and transcription initiation sites of yicM were determined. Overexpression of yicM increased resistance of sensitive cells to inosine and guanosine, decreased E.

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