Glutathione salts of O,O-diorganyl dithiophosphoric acids: Synthesis and study as redox modulating and antiproliferative compounds

© 2017 Elsevier Inc. Reactions of glutathione (GSH) with O,O-diorganyl dithiophosphoric acids (DTPA) were studied to develop bioactive derivatives of GSH. Effective coupling reaction of GSH with DTPA was proposed to produce the ammonium dithiophosphates (GSH–DTPA) between the NH2 group in γ-glutamyl residue of GSH and the SH group in DTPA. A series of the GSH–DTPA salts based on O-alkyl or O-monoterpenyl substituted DTPA were synthesized. Enhanced radical scavenging activity of the GSH–DTPA over GSH was established with the use of DPPH assay and improved fluorescent assay which utilizes Co/H2O2 Fenton-like reaction. Similarly to GSH, the dithiophosphates induced both pro- and antioxidant effects in vitro attributed to different cellular availability of the compounds. Whereas extracellularly applied GSH greatly stimulated proliferation of cancer cells (PC-3, vinblastine-resistant MCF-7 cells), the GSH–DTPA exhibited antiproliferative activity, which was pronounced for the O-menthyl and O-isopinocampheolyl substituted compounds 3d and 3e (IC50 ≥ 1 μM). Our results show that the GSH–DTPA are promising redox modulating and antiproliferative compounds. The approach proposed can be extended to modification and improvement of bioactivity of various natural and synthetic peptides

Reactions of O,O-dialkyldithiophosphoric acids with non-activated α-olefins

Electrophilic addition reactions of O,O-dialkyldithiophosphoric acids to non-activated α-olefins proceeding in accordance with the Markovnikov's rule were studied. In the absence of a catalyst these reactions occur very slowly to give the products in low yields, while Lewis acid as a catalyst can greatly accelerate the reaction and increase the conversion in the Ad E-processes. A similar acceleration of the addition processes and an increase in the reaction product yield occur at the action of ultrasound on the reaction medium. © 2012 Pleiades Publishing, Ltd.

Reactions of 2,4-diaryl 1,3,2,4-dithiadiphosphetane-2,4- disulfides with disilylated resorcinols

© 2016 Taylor & Francis Bis(trimethylsilyl) esters of bisaryldithiophosphonic acids were obtained in 70–81% yields by the reactions of 2,4-diaryl 1,3,2,4-dithiadiphospheta ne-2,4-disulfides with 1,3-bis(trimethylsilyloxy)benzene and 2-methyl 1,3-bis(trimethylsilyloxy)benzene

Improving upset forgingtube billettechnology to avoid the clamp defect on semi-axle housingforging

© Published under licence by IOP Publishing Ltd. Upset forging with heating on the limited site is simulated. Advantage of type-setting conversion formation method application with a punch in the form of a cone is confirmed

Research of influence of geometrical parameters of a stamp engraving of setting transitions at setting of semi finished pipe products to receiving defect-free products

The cause of a pipe clip during the setting of the pipe is determined on the basis of modeling. The method, which excludes the formation of a defect in a semi finished product by changing the configuration of the setting transition, is developed

Reactions of 2,4-diaryl 1,3,2,4-dithiadiphosphetane-2,4-disulfides with disilylated resorcinols

© 2016 Taylor and Francis.Bis(trimethylsilyl) esters of bisaryldithiophosphonic acids were obtained in 70-81% yields by the reactions of 2,4-diaryl 1,3,2,4-dithiadiphospheta ne-2,4-disulfides with 1,3-bis(trimethylsilyloxy)benzene and 2-methyl 1,3-bis(trimethylsilyloxy)benzene

The kabachnik-fields and pudovik reactions on the basis of E,Z-citral and its imines and (R,S)-citronellal

The Kabachnik-Fields reaction of E,Z-citral with diethyl phosphite in the presence of isobutylamine has been found to form α-aminophosphonates. The Pudovik reactions of diethyl phosphite with prenyl imines prepared on the basis of E,Z-citral with isobutylamine also allowed us to obtain the same α-aminophosphonates. We have managed to synthesize α- aminophosphonates by the reaction of O,O-dialkyl trimethylsilyl phosphites with prenyl imines in the presence of water or diethylamine. α- Aminophosphonates were also synthesized by the reaction of diethyl phosphite with (R,S)-citronellal in the presence of alkylamines. α-Aminophosphonates obtained showed bacteriostatic activity against Staphylococcus aureus and Bacillus cereus. © 2012 Wiley Periodicals, Inc