Synthesis of some bis(2-morpholino-1-methylethyl) esters of carboxylic acids and study of their interaction with the cholinesterases of warm-blooded animals

The bis(2-morpholino-1-methylethyl) esters of glutaric, adipic, azelaic, and sebacic acids have been synthesized, and their dihydrochlorides and dimethiodides have been obtained. The structures of the compounds obtained have been shown by their IR and PMR spectra. The interaction of the compounds synthesized with the acetylcholineresterase (ACE) of human blood erythrocytes and the butyrylcholinesterase (BuCE) of horse blood serum have been investigated. All the bis-esters are reversible competitive inhibitors of ACE and BuCE, while the dimethiodides exhibit specificity of their action with respect to ACE.Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 239–243, March–April, 1998.     

Synthesis of a number of derivatives of alkaloids and of nitrogen-containing heterocycles and their anticholinesterase activities

N-Methyl- and N-phenylcarbamates based on a number of alkaloids and nitrogen-containing heterocycles have been synthesized, and they have proved to be weak irreversible inhibitors of acetylcholinesterase and butyrylcholinesterase. It has been shown that the choline fragments of the above-mentioned carbamates and their -methylcholine analogs are reversible inhibitors of both cholinesterases and make a substantial contribution to the anticholinesterase activity. Selective inhibitors of ACE and BuCE have been found among the compounds synthesized.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 825–831, November–December, 1988.     

Synthesis and physicochemical study of hexafluorocomplexes of tin with mixed alkali metal cations

Conclusions Hexafluorocomplexes of tin with mixed cations of alkali metals with the composition NaMSnF₆ (M=K, Rb, Cs) and crystallizing in the orthorhombic system have been synthesized for the first time from aqueous solutions. The parameters of the unit cells of these substances have been determined.The compounds synthesized are optically positive biaxial crystals; their optical and x-ray diffraction constants are given.In the IR spectra of all the fluorocomplexes synthesized a splitting is observed in the frequency of the stretching vibration (₃) for the octahedral anion SnF₆ ^2–.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1927–1931, September, 1987.     

Carbohydrate compositions of preparations of fungal origin

The fractional composition of the polysaccharides formed by some local strains of basidial fungi (Panus tigrinus, Pleurotus ostreatus, Fomes formentarius, andPhanarechaeta chrysosporium) in a submerged medium on various plant wastes (spent cottonseed pulp and cottonplant stems) has been investigated. Water-soluble polysaccharides, pectin substances, and hemicelluloses have been isolated from the products synthesized by the fungi, and their qualitative and quantitative monosaccharide compositions have been determined.Materials presented at the Second International Symposium of the Chemistry of Natural Compounds (SCNC, Eskiehir, Turkey, October 22–24, 1996).Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 352–357, May–June, 1977.     

Synthesis of a number of derivatives of alkaloids and of nitrogen-containing heterocycles and their anticholinesterase activities

N-Methyl- and N-phenylcarbamates based on a number of alkaloids and nitrogen-containing heterocycles have been synthesized, and they have proved to be weak irreversible inhibitors of acetylcholinesterase and butyrylcholinesterase. It has been shown that the choline fragments of the above-mentioned carbamates and their β-methylcholine analogs are reversible inhibitors of both cholinesterases and make a substantial contribution to the anticholinesterase activity. Selective inhibitors of ACE and BuCE have been found among the compounds synthesized.     

2–Hydroxy–1,3–propylene bis (oxamato)–bridged new NiIICuIINiII trinuclear complexes with an S = 3/2 high-spin ground state: synthesis and magnetism

Four new heterotrinuclear complexes have been synthesized and characterized, namely {[Ni(L)2]2[Cu(pbaOH)]}(ClO4)2, where pbaOH denotes 2–hydroxy–1,3–propylenebis(oxamato) and L = 1,10–phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO2–phen), 2,2–bipyridyl (bpy) and 4,4–dimethyl–2,2–bipyridyl (Me2bpy). The temperature dependence of the magnetic susceptibility of {[Ni(phen)2]2[Cu(pbaOH ]}(ClO4)2·H2O has been studied in the 4–300 K range, giving an exchange integral J = –94 cm– . The MT versus T plot exhibits a minimum at ca. 93 K, characteristic of this type of coupled polymetallic complex with an irregular spin-state structure.     

Development and Validation of an HPTLC–Densitometric Method for Determination of ACE Inhibitors

A high-performance thin layer chromatographic method coupled with densitometric analysis has been developed for measurement of benazepril and cilazapril, both pure and in their commercial dosage forms. The active substances were extracted from tablets with methanol (mean recovery 102%) and chromatographed on silica gel 60 F₂₅₄ HPTLC plates in horizontal chambers with ethyl acetate–acetone–acetic acid–water, 8:2:0.5:0.5 (v/v), as mobile phase. Chromatographic separation of these ACE inhibitors was followed by UV densitometric quantitation at 215 nm. Calibration plots were constructed in the range 0.4 to 2.0 g L^–1 for benazepril (2.0–10.0 g spot^–1) and from 0.5 to 1.5 g L^–1 for cilazapril (4.0–12.0 g spot^–1) with good correlation coefficients (r 0.990). The method was used to determine benazepril and cilazapril in pharmaceutical preparations with satisfactory precision (1.4% < RSD < 5.6%) and accuracy (1.7 < RE < 5.1).     

N-(2,6-Dihalobenzoyl)-N′-pyrimidinylharnstoffe

N-(2,6-Dichlorobenzoyl)- and N-(2,6-difluorobenzoyl)-N-pyrimidinylureas3b–3n have been synthesized by reaction of the corresponding aminopyrimidine derivatives with 2,6-dichlorobenzoyl isocyanate or 2,6-difluorobenzoyl isocyanate. The insecticidal activity of compounds3b–3n has been evaluated.

     

Synthesis of derivatives of N-acetylmuramyl-ℓ-alanyl-d-isoglutamine containing activated disulfide bonds

N-Acetylmuramyl--alanyl-d-isoglutaminyl--S-(2-pyridylthio)cysteine and 1-(N-acetylmuramyl--alanyl-d-isoglutaminamido)-6-[3-(2-pyridylthio)-propionamido]hexane, derivatives of muramyldipeptide each with an activated disulfide bond, have been synthesized. Disulfide conjugates of muramyldipeptide with peptide fragment 136–147 of the heavy chain of the hemagglutinin of influenza virus A/Aichi/2/68 have been obtained.All-Union Scientific-Research Institute of Molecular Biology. Vektor Scientific-Industrial Association, Kol'tsovo, Novosibirsk Oblast. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 387–391, May–June, 1989.     

Synthesis and spectral properties of 2-methyl-5-aryl-1,3,4-oxadiazoles

By heterocyclization of 1-acyl-2-aroylhydrazines under the influence of strong dehydrating substances, a series of 2-methyl-5-aryl-1,3,4-oxadiazoles has been synthesized and their UV, IR, and PMR spectra have been investigated. Through analysis of data on the influence of substituents on the position of the maximum in the electronic absorption spectrum, together with calculated data, it has been shown that the long-wave band of 2-methyl-5-phenyl-1,3,4-oxadiazole is due to an S₀–S₁ transition of the –^* type and that it is a charge transfer band for transfer from the phenyl radical to the oxadiazole ring; the 1,3,4-oxadiazole ring as a substituent has an electron-acceptor character.Institute of Single Crystals, National Academy of Sciences of the Ukraine, Khar'kov 310001. Khar'kov State University, Khar'kov 310077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 816–821, June, 1997.     

Polysaccharides ofEremurus. XXI. Pectin substances of the leaves ofEremurus regelii

The pectin substances have been isolated fromEremurus regelii Vved., their qualitative and quantitative monosaccharide compositions have been determined, and their physicochemical properties have been studied. The partial hydrolysis of the pectin gave a galacturonan. On the basis of the results of periodate-nitric acid oxidation, enzymatic hydrolysis, and methylation it has been shown that in the galacturoman the galacturonic acid residues are linked by -(1 4)-glycosidic bonds.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 172–174, March–April, 1985.     

Stereochemistry of 16-Membered Azo- and Azoxycrown Ethers. Structures of Their Sandwich Potassium Iodide Complexes

16-Membered dibenzoazo- and dibenzoazoxycrown ethers have been synthesized. The Z and E isomers of the azocrown compound have been separated and the geometry of the –N=N– and –-N(O)=N–- groups determined. Potassium iodide complexes of the azo- and azoxycrown ethers were obtained and their structures were determined by the X-ray method. The crystal of the azocrown ether complex is triclinic, space group P¯1, a = 21.071(5), b = 12.112(4), c = 8.757(2) Å = 81.28(2), = 84.66(2), = 107.49(2)°. The azoxycrown ether complex is monoclinic, space group C2/c, a = 15.648(3), b = 19.597(4), c = 14.651(3) Å; = 111.30(3).     

Interaction with cholinesterases and conformational analysis of analogs of acetylcholine containing the alkaloids ephedrine and pseudoephedrine

Acetyl--methylcholine analogs of ephedrine and pseudoephedrine have been synthesized. The kinetics of their interaction with cholinesterases have been studied. To explain the differences in the sensitivity of the enzymes to conformers, a conformational analysis of the compounds synthesized has been made by the NMR method.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 654–658, September–October, 1988.     

Synthesis,spectroscopic and magnetic properties of methoxo- bridged copper(II) complexes with 2-amino-4-methylpyridine as the ligand

Three new methoxo-bridged copper(II) complexes with 2-amino-4- methylpyridine as the ligand have been synthesized and characterized by elemental analyses, FTIR and electronic spectra, and by their magnetic properties. The complexes exhibit strong antiferromagnetic interactions at room temperature. The u.v.-vis spectra exhibits three absorption bands, which can attributed to d–d, L–M and –* transitions. The i.r. spectra indicates Cu2O2 ring vibrations in the 580–530cm–1 range. The magnetic properties of the [Cu2(2-amino-4-methylpyridine)4(O- Me)2](ClO4)2 complex has been investigated in the 5–270K range and a singlet-triplet energy gap (–2J) of 67cm–1 was observed. All complexes in the solid state are e.p.r.-silent and show no triplet spectrum; in fact a weak signal due to a monomeric impurity are observed. Frozen solution e.p.r. spectra suggest that the complexes dissociate when dissolved in DMF or DMSO.     

New liquid crystal derivatives of thiazole

2-(4-Alkoxybenzylidenamino)-4-(4-nitrophenoxy)thiazoles, which possess monotropic mesomorphism of the nematic type over the range 68–160°C, have been synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 546–548, April, 1996.     

Effective synthesis of 7-hydroxyisoflavone O-glucosides

An effective procedure for condensing acetobromoglucose with 2,4-dihydroxy-phenyl benzyl ketones has been developed. The 2-hydroxy-4-(-D-tetra-O-acetylglucopyranosyloxy)phenyl benzyl ketones synthesized with yields of 47–69% have been converted under the action of ethyl orthoformate in pyridine solution into 7-hydroxyisoflavone O-glucosides and these have also been obtained by the glycosylation of 7-hydroxyisoflavone. The advantages and disadvantages of the alternative pathways of the synthesis of 7-hydroxyisoflavone O-glycosides are discussed.T. G. Shevchenko Kiev State University. Khar'kov State Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 511–519, July–August, 1988.     

Transformation of natural compounds

-Piperazinylmethylenedeoxyvasicinones have been synthesized by the interaction of -hydroxymethylenedeoxyvasicinones with various N-substituted piperazines.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 62 70 71. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 331–333, May–June, 1998.     

Unsaponifiable substances of the lipids of the leaves ofHibiscus sp

The unsaponifiable substances of the lipids of the leaves ofHibiscus sp. have been studied. The compositions have been found of seven classes of compounds: hydrocarbons, carotenoids, tocopherols, isoprenols, triterpenols, and phytosterols and their esters.The materials of the paper were presented at the IInd International Symposium on the Chemistry of Natural Compounds (SCNC, Turkey, Eskiehir, October 22–24, 1996).Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, Vol. 33, No. 1, pp. 49–51, January–February, 1997.