Exploring the interaction between “site-markers,aspirin and esterase-like activity” ternary systems on the human serum albumin: direct evidence for modulation of catalytic activity of the protein in different inhibition modes

Albumin which is the most abundant drug carrier protein in plasma controls the distribution aspect of drug pharmacokinetics. The aim of this study has been to elucidate the concurrent binding behavior of indomethacin/ibuprofen/heme to HSA under the effect of aspirin-mediated protein acetylation and also to explore the esterase-like catalytic property of the unmodified/modified proteins, as binary or ternary systems, by using various spectroscopic and molecular docking techniques. We found that aspirin-based modification of HSA affects the protein conformation as well as ligand binding at sites I–III. Decrease in pNPA-mediated esterase activity of HSA in different reversible inhibition modes, upon the protein–ligand interactions, was also documented, an issue that may receive considerable attention for computational prodrug design in near future.     

Structures of CoII and ZnII complexes of the proton‐transfer compound derived from pyrazine‐2,3‐dicarboxylic acid and piperazine

The reaction of the proton‐transfer compound piperazine‐1,4‐diium pyrazine‐2,3‐dicarboxylate 4.5‐hydrate, C₄H₁₂N₂²⁺·C₆H₂N₂O₄²⁻·4.5H₂O or (pipzH₂)(pyzdc)·4.5H₂O (pyzdcH₂ is pyrazine‐2,3‐dicarboxylic acid and pipz is piperazine), (I), with Zn(NO₃)₂·6H₂O and CoCl₂·6H₂O results in the formation of bis(piperazine‐1,4‐diium) bis(μ‐pyrazine‐2,3‐dicarboxylato)‐κ³N¹,O²:O³;κ³O³:N¹,O²‐bis[aqua(pyrazine‐2,3‐dicarboxylato‐κ²N¹,O²)zinc(II)] decahydrate, (C₄H₁₂N₂)₂[Zn₂(C₆H₂N₂O₄)₄(H₂O)₂]·10H₂O or (pipzH₂)₂[Zn(pyzdc)₂(H₂O)]₂·10H₂O, (II), and catena‐poly[piperazine‐1,4‐diium [cobalt(II)‐bis(μ‐pyrazine‐2,3‐dicarboxylato)‐κ³N¹,O²:O³;κ³O³:N¹,O²] hexahydrate], {(C₄H₁₂N₂)[Co(C₆H₂N₂O₄)₂]·6H₂O}_n or {(pipzH₂)[Co(pyzdc)₂]·6H₂O}_n, (III), respectively. In (I), pyzdcH₂ is doubly deprotonated on reaction with piperazine as a base. Compound (II) crystallizes as a dimer, whereas compound (III) exists as a one‐dimensional coordination polymer. In (II), two pyzdc²⁻ groups chelate to each of the two Zn^II atoms through a ring N atom and an O atom of the 2‐carboxylate group. In one ligand, the adjacent 3‐carboxylate group bridges to a neighbouring metal atom. A water molecule ligates in the sixth coordination site. The structure of (II) can be described as a commensurate superlattice due to an ordering in the hydrogen‐bonded network. In (III), no water is coordinated to the metal atom and the coordination sphere is comprised of two N,O‐chelates plus two bridging O atoms. A large number of hydrogen bonds are observed in all three compounds. These interactions, as well as π–π and C=O...π stacking interactions, play important structural roles.     

Eine neue Darstellungsmethode für Trithiopyrophosphonate; Reaktionsmechanismus

Zusammenfassung Es wird über die Synthese der bisher unbekannten Trithiopyrophosphonate (C₆H₅)(RO)P(S)–S–P(S)(RO)(C₆H₅) aus der entsprechenden thiophosphonigen Säure mit Morpholinosulfenylchlorid berichtet. In Anwesenheit von Triäthylamin bilden sich die bisher nicht beschriebenen S-Morpholino-dithiophosphonate, die dem angenommenen Reaktionsmechanismus nach mit Chlorwasserstoff und thiophosphoniger Säure die Trithiopyrophosphonate liefern. Als Vertreter der Schwefelchloride der Thiophosphonsäuren, die sich bei der Umsetzung von S-Morpholino-dithiophosphonate mit HCl bilden, konnte (C₆H₅)(C₂H₅O)P(S)–SCl isoliert werden.

---

A new synthetic route to trithiophosphonates; Reaction mechanism

The synthesis of the unknown trithiopyrophosphonates, (C₆H₅)(RO)P(S)–S–P(S)(RO)(C₆H₅), which are formed by the interaction between the corresponding thiophosphonic acid and morpholinosulfenyl chloride, is reported.In the presence of triethylamine the reaction leads to the S-morpholinodithiophosphonates which, corresponding to the assumed reaction mechanism, gives, with hydrogen chloride and thiophosphonic acid the trithiopyrophosphonates.Among the sulfenylchlorides of the thiophosphonic acids which arise by the interaction of S-morpholinodithiophosphonates with hydrogen chloride, only (C₆H₅)(C₂H₅O)P(S)–SCl could be isolated.

     

Composes heteroorganiques—XLVII: Les arylsulphonamides de l'acide ethane-ethoxy-thiophosphonique

The synthesis, structure and properties of arylsulphonamides of éthane-éthoxy-thiophosphonic acid 1–6 are described. The compounds exist mainly in the amidothione form. In CCI₄ an equilibrium between monomers and molecules associated through hydrogen bonding is present. Thermodynamic functions of the equilibrium reaction have been determined and the results suggest that the associated molecules are cyclic dimers. The pK-values of 1–6 obey a combination of the Ismajlow-Hammett equations.     

The automated determination of volatile organic contaminants in ambient air and/or soil gas by gas chromatography with selective detectors

Two systems have been developed which are suitable for the determination of sub parts per billion levels of organic contaminants in ambient air and soil gas. Gas samples are passed through an adsorbent where the contaminants are trapped. Following thermal desorption the contaminants are quantitated by capillary GC employing photoionizations electrolytic conductivity, and electron capture detection. The performance of the systems is described in detail.     

Über heteroorganische Verbindungen, 35. Mitt.: O,O-Dialkyl-thiophosphoryl-sulfensäureester

Zusammenfassung Es wird über die bisher unbekannte Verbindungsgruppe: O,O-Dialkyl-thiophosphoryl-sulfensäureester und ihre Darstellungsmöglichkeiten berichtet.

---

O,O-Dialkyl sulfenylthiophosphates, a new group of compounds, are described and the methods for their preparation discussed.

---

---

34. Mitt.:L. Almasi undL. Paskucz, Mh. Chem.99, 187 (1968).     

Densities and Excess Molar Volumes of Binary and Ternary Mixtures Containing Acetonitrile + Acetophenone + 1,2-Pentanediol: Experimental Data,Correlation and Prediction by PFP Theory and ERAS Model

Densities were determined experimentally over the entire range of composition at 298.15 K for the ternary system acetonitrile (1) + acetophenone (2) + 1,2-pentanediol (3) and for the three corresponding binary systems. Excess molar volumes were calculated for the binary and the ternary systems. These results were fitted to variable-degree polynomials. Further, the Prigogine-Flory-Patterson (PFP) theory and Extended Real Associated Solution (ERAS) model were applied to V_m^EV_{m}^{\mathrm{E}} for the binary mixtures of acetonitrile + acetophenone, acetonitrile + 1,2-pentanediol and acetophenone + 1,2-pentanediol, and the findings compared with the experimental results.     

Controlled Cu content of electrodeposited CoCu nanowires through pulse features and investigations of microstructures and magnetic properties

CoCu alloy nanowire arrays embedded in anodic alumina template were fabricated by ac pulse electrodeposition. Different off-times between pulses in an electrolyte with constant concentration of Co⁺² and Cu⁺² and acidity of 4 were employed. The effect of deposition parameters on the alloy contents, microstructures and magnetic properties of Co_xCu_1−x nanowires were studied. It is shown that Co content decreased by increasing the off-time between pulses in a wide range (x = 0.53-0.07). These results are in consistence with saturation magnetization, which was reduced with increase in the off-time between pulses. It was also found that by optimizing the off-times, it is possible to fabricate CoCu nanowires with mixed phase of hcp Co, fcc Cu and fcc CoCu crystal phase.