Berberis alkaloids. XXVI. An investigation of the alkaloids ofBerberis amurensis

In addition to alkaloids isolated previously, young shoots of Berberis amurensis Rupr. have yielded berberrubine, oxyacanthine, and pseudopalmatine, and the new amorphous base amurenine. It's structure has been established on the basis of spectral characteristics and chemical transformations.     

Calculation of the concentration fields of solid and fluid phases in the flow of a chemically active fluid through a porous medium

The flow of a chemically active fluid through a porous medium is considered. Under certain assumptions, an analytical solution is obtained which describes the distribution of the concentration of the chemically active component and the variation of the solidphase porosity. On the basis of the results obtained, the optimization of the hydrochloric acid treatment of wells is considered.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 78–81, March–April, 1985.     

Profile of spectral-line intensity along a negative glow

The longitudinal profile of the spectral-line intensity has been measured in a plasma of a negative glow in helium, neon, and mixtures of these gases. Under the conditions of a normal glow discharge, the intensities of several spectral lines fall off exponentially toward the anode. The decay of the line intensity was used to evaluate the effective cross section for attenuation of the electron beam from the cathode dark space. There is a discussion of the mechanism for the change in the profile of the line intensity in the discharge gap at the transition on a normal glow discharge to an anomalous discharge.     

Synthesis of ether-amines of propane-1,2-diol and their biological activity

An account is given of various routes for the synthesis of ether-amines of propane-1,2-diol from glycerol derivatives. It has been established that this series of compounds exhibits pharmacological activity and also a stimulating or inhibiting effect on the germinating capacity and the energy of germination of the seeds of agricultural crops. A definite relationship has been revealed between the structure and biological activity of ether-amines of propane-1,2-diol. Ether-amines of propanediol and unsymmetrical 1,3-diaminopropan-2-ols, and also their sulfur-containing analogs, containing residues of primary amines or hydrazine are convenient synthons for passing to heterocyclic systems: derivatives of 1,3-ozazolidine, 1,3-thiazolidine, and 3-methyl-5-pyrazolone. The possibility of obtaining new polycyclic systems by diene synthesis from 1,3-oxazolidine and 1,3-thiazolidine derivatives including furfural residues and also from 1,3,4-thiadiazole derivatives, using cyano and thiocyano derivatives of glycerol and thiosemicarbazide is discussed.Tadzhik State University (TGU), Dushanbe. Translated from Khimiya Prirodnykh Soedinenii, No. 5 pp. 649–654, September–October, 1997.     

Approximation of Dirichlet polynomials in cases of sparse exponents

Let \(0< \lambda \kappa \uparrow \infty ,\sum\nolimits_{\kappa = 1}^\infty {\lambda _\kappa ^{ - 1}< \infty } \) , and let γ be an analytic arc. For the Dirichlet polynomial \(P(z) = \sum\nolimits_1^n {a_k e^{\lambda _k .z} } \) , in angle \(E - \pi /2 + \varphi _0< \arg [ - (z - \alpha )]< \pi /2 + \varphi _0 ,0< \varphi _0< \pi /2,\operatorname{Re} \alpha< \beta = \mathop {\max }\limits_{t \in \gamma } \operatorname{Re} t\) we obtain the estimate $|P(z)|< A\mathop {\max }\limits_{t \in \gamma } |P(t)|$ where A depends only on angle E and {λ_k}. When γ is a segment, an estimate was obtained by L. Schwartz.     

Cyclosieversigenin 3-O-β-D-glucopyranoside fromAstragalus kuhitangi

Cyclosieversigenin, cyclosieversigenin 3-O-β-D-xylopyranoside, cyclosieversioside F, astragaloside VII, and, for the first time in native form, cyclosieversigenin 6-O-β-D-glucopyranoside have been isolated from the roots ofAstragalus kuhitangi (Nevski) Sirj. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 751–755, November–December, 1998.