Flow-Injection Determination of Benzylpenicillin Novocaine Salt in Penicillin Preparations with Spectrophotometric Detection

Working conditions were found for determining the novocaine salt of benzylpenicillin antibiotic as its 4,6-dinitrobenzofuroxan derivative by flow-injection analysis with spectrophotometric detection ( = 510 nm). The best results were obtained for flows of methanol (ethanol) and water with a volume ratio of 30 : 70. The calibration range of the pharmaceutical is 0.28–10 g/mL with a throughput capacity of 30 samples/h. The limit of detection (3, n= 4) is 0.14 g/mL. Amino acids and components of penicillin-containing pharmaceuticals did not interfere with the determination. Procedures for determining benzylpenicillin novocaine salt in medicinal formulations containing benzylpenicillin N,N"-dibenzylethylenediamine, potassium, and sodium salts and some other     

Claisen rearrangement taking place in the mass spectrometer

Conclusions The Claisen rearrangement of bucharaine and of the aldehyde bucharainal takes place under the conditions of mass spectrometry. At low temperatures inversion predominates and at high temperatures the anomalous rearrangement.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 577–583, September–October, 1970.     

Lipophilic extracts in phytotherapy and phytocosmetics: Production and biological properties

This review considers methods of obtaining lipophilic extracts from plant raw material, and their composition, biological properties, and use in phytotherapy and phytocosmetics.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 240 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 437–448, July–August, 1998.     

Tribological properties of polytetrafluoroethylene modified with fullerene black in dry sliding friction

The effect of fullerene black introduced (after extraction of light fullerenes from the black with toluene) into polytetrafluoroethylene F-4 on its wear resistance and antifriction properties in sliding over steel at contact pressures in the range 0.2–2.0 MPa was studied.     

Thermodynamic Properties of Salsoline Salsolinodithiocarbamate

Heat of solution of salsoline salsolinodithiocarbamate (SS) at 1 : 18 000, 1 : 36 000, and 1 : 72 000 dilution (mol per mol H₂O) was determined on a DAK-I-IA calorimeter, and the standard heat of solution at infinite dilution was estimated. The temperature dependence of the heat capacity of SS was studied over the range 173–348 K. The heats of combustion and fusion, and the standard heat of formation of liquid (molten) and crystalline SS were estimated by indirect methods.     

Effect of dose on radiation-induced conductivity in polymers

Numerical simulation of radiation-induced conductivity in polymers upon long-term irradiation on the basis of the generalized Rose-Fowler-Vaisberg model, which allows for both dipolar carrier transport and generation of radiation traps during irradiation, was performed. The unusual properties of radiation-induced conductivity, such as the appearance of a maximum on current transients, the absence of a steady state, and a substantial difference between these curves for the first and subsequent irradiation, are rationalized in terms of the formation of free radicals, the major feature of radiolysis in the chemical aspect. This interpretation does not require the involvement of degradation or crosslinking processes, unlike other interpretations that appear in the literature. With the use of low-density polyethylene as an example, it was shown that radiation-induced conductivity both upon pulse and continuous irradiation can satisfactorily be described with the unified set of parameters of the generalized Rose-Fowler-Vaisberg model.     

Solvability of the general boundary-value problem for the linearized nonstationary system of Navier-Stokes equations

On the bounded cylindrical domain Q_T = x(0,T), ³, one considers the initialboundary-value problem for the system of Navier-Stokes equations in which the boundary conditions are given by an arbitrary matrix differential operator of dimension 3×4. Under certain restrictions on this operator and on the data of the problem one shows the existence of a solution in the spaces W _p ^2l,l (Q_T) for any finite T.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 110, pp. 105–119, 1981.     

Determination of an infinite non-self-adjoint Jacobi matrix from its generalized spectral function

Restoration from the generalized spectral function of the equations $$b_0 y_0 + a_0 y_1 = \lambda y_{0,} a_{n - 1} y_{n - 1} + b_n y_n + a_n y_{n + 1} = \lambda y_{n,} n = 1,2,3,...,$$ wherea _n and b_n are arbitrary complex numbers,a _n≠ 0 (n = o, i, 2,...), λ is a complex parameter, and {P _n (λ)} ₀ ^∞ is the required solution, is investigated. Necessary and sufficient conditions for solvability of the inverse problem are obtained, and the restoration procedure is described.     

Synthesis of benzoates of 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis-(2,5-dimethyl-4-hydroxypiperidino)-2-butyne

1,4-Bis(2,5-dimethyl-4-hydroxypiperidino)-2-butene and 1,4-bis(2,5-dimethyl-4-hydroxypiperidino)-2-butyne (II and III) were obtained by the action of 1,4-dibromo-2-butene and 1,4-dibromo-2-butyne on the form of 2,5-dimethyl-4-piperidol (I). The benzoates (IV and V) were obtained by acylation of II and III with benzoyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 352–353, March, 1971.     

The structure of the phospholipids of the cotton plant and the position specificity of their fatty acids

Summary 1. The structure of the main groups of phospholipids isolated from the seed kernels of the thin-fibered cotton plant of variety S-6029 has been studied.2. The fatty-acid compositions and the position distributions of the fatty acids have been determined, and from the results the possible molecular compositions of the phosphatidylcholines, phosphatidylethanolamines, and phosphatidylinositols have been calculated.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedimenii, No. 1, pp. 22–26, January–February, 1976.