Anabasine and cytisine derivatives as reversible cholinesterase inhibitors

A number of analogs of acetyl--methylcholine, containing residues of the alkaloids anabasine and cytisine as cyclic ammonium groupings, have been synthesized. The structures of the substances obtained have been confirmed by their IR and PMR spectra and the result of elementary analysis. The kientic parameters of the interaction of the compounds synthesized with acetylcholinesterase (ACE) of human blood erythrocytes and with butylcholinesterase (BuCE) of horse blood serum have been investigated. All the substances synthesized proved to be reversible inhibitors of ACE and BuCE.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 97–100, January–February, 1988.     

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 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.     

Synthetic analogs of natural flavolignans IX. Synthesis of 3-amino-substituted analogs of hydnocarpin

New 3-amino-substituted chromones with 1,3-benzodioxan and 1,4-benzodioxan nuclei in position 2 have been synthesized. The structures of the compounds obtained have been confirmed by their PMR spectra.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 178–181, March–April, 1999.     

Synthesis of lupinine esters and their interaction with cholinesterases

A number of lupinine esters of carboxylic acids and their hydrochlorides and methiodides have been synthesized. It has been shown that these compounds are reversible inhibitors of human blood erythrocyte acetylcholinesterase and horse blood serum butyryl cholinesterase. Noncompetitive inhibitors of these enzymes 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 Prirodnykh Soedinenii, No. 1, pp. 75–79, January–February, 1990.     

Stereochemistry of the products of the hydrogenation of leucomisin

4-H(4-Me)-3-hetarylcoumarins modified by 1,3-benzodioxolane and 1,4-benzodioxane residues have been synthesized. The structures of the compounds obtained have been confirmed by PMR.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 230–233, March–April, 1994.     

Synthesis and properties of peptide fragments of the S-region of the surface protein of the heptatitis B virus

A peptide fragment with the 140–146 sequence of the main component of the surrace protein of the hepatitis B virus (HBsAG) and a number of its structural analogues have been synthesized by the classical method in solution. Conjugates of the peptides synthesized with bovine serum albumin and with a synthetic polypeptide analogue of polytuftsin have been obtained. The ability of the preparations to bind antibodies from the blood sera of hepatitis B patients has been studied. The possibility has been shown of their use for revealing antibodies to the heptatitis B virus in solid-phase enzyme-mediated immunoassay.Leningrad State University. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 406–413, May–August, 1992.     

Phytoecdysteroids of plants of the genusSilene XVI. 5α-sileneoside E FromSilene brahuica

Derivatives of derrusnin and also its benzodioxane and benzodioxepane analogs have been synthesized. The structures of the compounds obtained have been confirmed by spectral studies.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 226–230, March–April, 1994.     

Reaction of vinyloxyalkylamines with mercaptoacetic acid

N-[2(3)-Hydroxyalkylj-4-thiazolidinones have been synthesized by the reaction of 2(3)-vinyloxyalkylamines with mercaptoacetic acid in 24–69 % yield. The structure of the compounds obtained was supported by (R and¹H NMR spectroscopic data.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 677–679, March, 1996.     

Synthesis,luminescence, and spectral characteristics of 7-diethylamino-3-(2-arylethenyl)coumarins

By condensation of 7-diethylamino-3-formylcoumarin with aromatic compounds containing an active methyl or methylene group, a number of previously unreported 7-diethylamino-3-(2-arylethenyl)coumarins have been obtained. The reaction conditions depend on the activity of the methyl (or methylene) component. The spectral and luminescent properties of the synthesized compounds have been investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, 1171–1175, September, 1992.     

Study of the conformational states of amino-alcohol derivatives of some alkaloids and bases and their protonated forms and quaternary salts

Summary 1. Salsoline, salsolidine, ephedrine, pseudoephedrine, tetrahydroquinoline, and decahydroquinoline have been condensed with ethylene oxide and the corresponding amino alcohols have been obtained.2. The conformational states and spatial structures of the compounds synthesized and their protonated forms and methiodides have been studied by IR and PMR spectroscopy. It has been shown that because of the rapid conversion of the saturated parts of the molecules of the bases and inversion processes, several stable spatial forms of the N-derivatives with quarternized nitrogen atoms exist in solutions.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 486–492, July–August, 1974.     

Preparation of new amino derivatives of the lactone tanachin and their antimicrobial activity

Several amino derivatives have been obtained from the sesquiterpene lactone tanachin by means of the Michael reaction, and their structures have been confirmed by spectral methods. The antimicrobial activities of the compounds synthesized relative to some strains of microorganisms are considered.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 24–28, January–February, 1996. Original article submitted October 21, 1994.     

Synthesis of 1H-[1]benzothiopyrano[3,4-d]imidazol-4-ones

By the condensation of 3,4-diaminothiocoumarins containing primary or secondary amino groups in position 4, with formic and acetic acids (or acetic anhydrides), a number of 1H-[1]benzothiopyrano[3,4-d]imidazol-4-ones and their 2-methyl derivatives have been synthesized; the latter have also been obtained from the corresponding 3-monoacetylamino-4-aminothiocoumarins. By the acetylation of 3-4-diaminothiocoumarins with tertiary amino groups in positions 4 their 3-diacetyl derivative has been obtained, and these, under the action of bases, have been converted into 3-N-acetyl derivatives. The structures of the compounds synthesized have been confirmed by IR, PMR, and mass spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 479–483, April, 1980.     

Synthesis and study of internally complex compounds of o-methoxythiophenol with metals

Conclusion Internally complex compounds of o-methoxythiophenol with a number of divalent metals have been obtained and some of their properties have been studied. The stabilities of the chelates synthesized have been evaluated by potentiometric titration at 25 °.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2050–2051, November, 1966.     

Synthesis and pharmacology of some diisoquinoline alkaloids

A number of tetrahydrodiisoquinoline alkaloids has been synthesized by various routes. Some connections between the chemical structures of the compounds obtained and their pharmacological effects have been found.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 343–350, May–June, 1979.     

Nitro-substituted porphyrazines

This nitration of tetra (tert-butyl)porphyrazine and its metal complexes with different nitrating agents has given their mono-, di-, tri-, and tetra-nistro-derivatives; the metal complexes have also been obtained by the metallation of the corresponding metal—free nitroporphyrazines. The structure of the synthesized compounds has been confirmed by electron and mass spectra, and by PMR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 30–35, January, 1994.     

Protection of the carboxy group in the form of the 2-cyanoethyl ester in synthesis of peptides

With the aim of studying the suitability of the 2-cyano group for the protection of carboxylic functions in peptide synthesis, we have obtained the 2-cyanoethyl esters of a number of amino acids and have studied their behavior under the conditions of peptide synthesis. The synthesis of the pentapeptide leucine-enkaphalin has been performed with the use of 2-cyanoethyl protection for C-terminal carboxy groups throughout. The physicochemical characteristics of the compounds synthesized are given.All-Union Scientific-Research Institute of Molecular Biology Kol'tsovo, Novosibirsk oblast Vector Scientific Industrial Association of the USSR Minmedbioprom, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 412–416, May–June, 1988.     

Characteristic and spectroscopic properties of the Schiff-base model compounds

Two series of conjugated aromatic imines (Schiff-base model compounds) with different central groups and various side-group substitutions have been synthesized and characterized by elemental analysis, differential scanning calorimetry (DSC) technique, hydrogen nuclear magnetic resonance (¹H NMR), Fourier transform infrared (FTIR) and ultra-violet and visible light (UV–vis) spectroscopy measurements. The UV–vis absorption of solutions of these compounds in dimethylacetamid (DMA), chloroform and methanol was investigated in the optical range from 240 to 450 nm, where two distinct absorption bands: at 250–280 and 315–360 nm with the different level of absorption have been observed. The influence of compound molecular structure and polarity of solvent on the absorption spectra and the possible optical transitions have been discussed. Structure of diamines in the azomethine models fundamentally affected their spectroscopic properties and conjugation of π-electrons.     

Synthesis and study of some derivatives of cinchoninic acid

2-(4-Phenylquinolin-2-yl)cinchoninic and 2-(quinoxalin-2-yl)-5,6-benzocinchoninic acids have been synthesized. They have been subjected to decarboxylation and their chlorides and esters, amides, and anilides have been prepared. The spectral characteristics of the Cu(I) complexes of the derivatives synthesized have been obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1536–1537, November, 1973.     

Synthesis of 2-(5-halogeno-2-f uryl)-2,3-dihydroperimidines

By boiling naphthylene-1,8-diamine with 5-halogeno- and 5-nitrofurfural in benzene or xylene, 90–95% yields of the corresponding 2-(5-halogeno-2-furyl)- and 2-(5-nitro-2-furyl)-2, 3-dihydroperimidines have been obtained. The dehydrogenation of 2-(5-bromo-2-furyl)-2, 3-dihydroperimidine with palladium on carbon has given 2-(5-bromo-2-furyl)perimidine. The compounds obtained have been characterized by their UV and IR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1001–1003, July, 1973.