Aziridinylketones and their cyclic anils. 12

We have measured the PMR spectra of 5, 7-diaryl-1, 4-diazabicyclo[4. ].O]hept-4-enes. We have studied the structure of the 5-(4-nitrophenyl)-7-phenyl derivative by x-ray diffraction. We show that the six-membered heterocycle has the half-chair form. The 6-H and 7-H protons of the aziridine ring are trans, while the 7-aryl is exo relative to the six-membered ring. Introduction of substituents into the aromatic ring has practically no effect on the geometry of the bicycle.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1117–1124, August, 1994.For Communication 11, see [1].     

5-[5-R-furfurylidene]-2,2-dimethyl-1,3-dioxane-4,6-diones 5. Nucleophilic replacement of halogen in the furan ring

Halogen in positions 3 and 5 of the furan ring in ftirfurylidenedioxanediones is readily replaced by dithiocarbonate, dithiocarbatnate, dithiophosphate, thiocyanate, and azide anions, and by thiourea, and secondary and tertiary amines. The conformation of the initial halogen derivative is retained in the substitution products.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 327–334, March, 1994.     

Effect of infection byVerticillium dahliae on the lipid complex of cotton seeds from varieties with contrasting resistance

The yields and fatty acid compositions of the free lipids and lipids weakly and strongly bound to proteins from seeds of cottonplant varieties resistant and susceptible to verticillium wilt have been determined and the changes in these indices in the seeds of the infected plants have been measured. It has been established that the seeds of healthy plants of the two varieties are similar in the qualitative compositions of the lipids and fatty acids but differ with respect the amounts of lipids in them bound with protein in different ways and with respect to the amounts of the individual fatty acids. The observed changes in the lipid and fatty-acid compositions depend on the degree of resistance of the variety to wilt.     

Electrohydraulic effect in heterodisperse water-plant systems. II. Chemical nature of the suspended particles

On the basis of the results of acid hydrolysis, chromatographic analysis of the hydrolysates, and a study of IR spectra, it has been established that the suspended particles liberated under the action of electrohydraulic shocks on heterodisperse water—plant systems consist of small fragments of the lignocarbohydrate complex of the plant tissue.     

Some kinetic features of the hydrolysis of protopectin

Some features of the kinetics of the hydrolysis of apple protopectin have been studied on the basis of an analysis of monosaccharide residues of the pectin substances and determinations of characteristic viscosity. It has been shown that the fine regulation of the physicochemical parameters of the hydrolysis of protopectin leads to the formation of pectin substances with different properties.     

Mass spectra of pseudoguaianolides related to carpesiolin

The main directions of fragmentation and the EI of six pseudoguaianolides related to carpesiolin have been studied. It has been established that acylation of the OH group at C-6 suppresses the selective breakdown of the guaiane skeleton, while the simultaneous presence of AcO groups at C-2 and C-4 favors the formation of a number of characteristic ions. The hydrogenation of the exomethylene group has no appreciable influence on direction of fragmentation.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 530–535, July–August, 1993.     

Isolation of phospholipase A2 from the venom of the green toadBufo viridis

Phospholipase A₂ has been isolated fromthe venom of he Central Asian green toad Bufo viridis in the electroophoretically homogeneous state for the first time by biospecific absorption chromatography. The affinity sorbent used was Affi-Gel 10 with covalently bound phosphatidylserine (PDS). The chemical inertness of the bound PDS to the hydrolytic action of phospholipase A2 and its high tendency to form biospecific complexes have been shown. Some biochemical characteristics of the enzyme isolated have been studied: influence of the pH and of the Ca²⁺ concentration and dependence of activity on substrate concentration.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Tashkent State University, fax 462472. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 105–109, January–February, 1994.     

Methylphosphonothionates of N-(β-hydroxypropyl)anabasine — Synthesis,structure, and sensitivity of cholinesterases to them

The synthesis has been effected of alkyl anabasinoprop-2-yl and alkyl piperidinoprop-2-yl methylphosphonothionates. It has been shown by¹H,¹³C and³¹P NMR spectroscopies that the anabasine derivatives exist in solution as four diastereomeric forms. The kinetics of the interaction of the compounds synthesized with two types of cholinesterases has been studied.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, Fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 70–74, January–February, 1994.