Synthesis and properties of synthetic analogs of natural humic acids

A new procedure was suggested for preparing analogs of natural humic acids using as precursor a nitrogen-containing amphoteric polyelectrolyte prepared by condensation of pyrocatechol with hexamethylenetetramine. The physicochemical and spectral properties of the product were examined.     

New synthetic routes to furocoumarins and their analogs: a review

Many furocoumarins and their analogs possess a prominent photobiological activity. Some of them are successfully used as drugs in phototherapy of skin diseases. Fries rearrangement of acyloxyheteroarenes, condensation of acylhydroxyheteroarenes with alpha-carbonyl compounds under base catalysis and transformations of dihydrofurocoumarinones are new trends in synthesis of furocoumarins and their analogs.     

Influence of cycloartanes from plants of the genusAstragalus and their synthetic analogs on the contractive function of the myocardium and the activity of Na,K-ATPase

An evaluation has been mde of the cardiotonic activities of cycloartane methylsteroids isolated from plants of the genusAstragalus and their synthetic analogs. It has been established that the compounds investigated exhibit a positive inotropic effect expressed to different degrees. The mechanism of the realization of the positive inotropic action of cycloartane glycosides differs from that of cardiosteroid drugs. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 510–514, July–August, 1994.     

Structural analogs of tetrapyrrole macrocycles and their biological properties

The review summarizes data on the synthesis and properties of analogs of ABBB-and ABAB-type tetrapyrrole macrocycles and their metal complexes. The structural features of these compounds are discussed. Data on aromaticity and biological properties are considered. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 663–679, April, 2007.     

Diol lipids XV. Isolation of a neutral diol plasmalogen from the lipids of starfish

Chemistry of Natural Compounds -     

Influence of cycloartanes from plants of the genusAstragalus and their synthetic analogs on the contractive function of the myocardium and the activity of Na,K-ATPase

An evaluation has been mde of the cardiotonic activities of cycloartane methylsteroids isolated from plants of the genusAstragalus and their synthetic analogs. It has been established that the compounds investigated exhibit a positive inotropic effect expressed to different degrees. The mechanism of the realization of the positive inotropic action of cycloartane glycosides differs from that of cardiosteroid drugs.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 510–514, July–August, 1994.     

Protonation of lipids impacts the supramolecular and biological properties of their self-assembly

We assessed in this work how a chemical structure difference could influence a supramolecular organization and then its biological properties. In our case study, we considered two amphiphilic lipidic gene vectors. The chemical difference was situated on their hydrophilic part which was either a pure neutral thiourea head or a mixture of three thiourea function derivatives, thiourea, iminothiol, and charged iminothiol. This small difference was obtained thanks to the last chemical deprotection conditions of the polar head hydroxyl groups. Light, neutron, and X-ray scattering techniques have been used to investigate the spatial structure of the liposomes and lipoplexes formed by the lipids. The chemical structure difference impacts the supramolecular assemblies of the lipids and with DNA as shown by fluorescence correlation spectroscopy (FCS), X-ray, and neutron scattering. Hence the structures formed were found to be highly different in terms of liposomes to DNA ratio and size and polydispersity of the aggregates. Finally, the transfection and internalization results proved that the differences in the structure of the lipid aggregates fully affect the biological properties of the lipopolythiourea compounds. The lipid containing three functions is a better gene transfection agent than the lipid which only contains one thiourea moiety. As a conclusion, we showed that the conditions of the last chemical step can influence the lipidic supramolecular structure which in turn strongly impacts their biological properties.     

Synthesis and acid-base properties of phosphorylated diazacycloalkanes and their cyclic analogs

Novel cyclopendant organophosphorus complexing agents,viz. 1,5-bis(2-diphenylphosphorylmethyl (or ethyl))-1,5-diazacyclooctane (1, 2) and l-methyl-4-(2-diphenylphosphorylethyl) piperazine (3), were synthesized on the basis of 1,5-diazacyclooctane and piperazine. The protonation constants of the compounds synthesized and some of their analogs were determined by potentiometric titration in 70 % aqueous ethanol and in nitromethane. The nitrogen atoms of the ring are the protonation sites in all of the systems studied. The regularities of the variation of protonation constants have been explained by the formation of intramolecular hydrogen bonds. The conformational possibilities of the formation of H-bonds in the cations of the ligands have been examined by molecular mechanics.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2007–2012, November, 1994.The authors are grateful to T. V. Timofeeva and N. I. Raevskii for the help in coping with the MMX 88 calculation program and for the discussion of the results.This study was carried out with the financial support of the International Science Foundation (Grant No. MJN 000).     

Synthesis of new analogs of valinomycin and their properties. I

Conclusions 1. The synthesis of five valinomycin analogs differing by the configurations of the amino-acid and hydroxy-acid residues and also by the volumes of the radicals of the hydroxy-acid residues has been effected.2. The stability constants of the complexes of these analogs with potassium ions in ethanol solution have been determined.3. The antimicrobial activities of the compounds obtained have been studied and a correlation has been found between the degree of activity and stability of the complexes with K⁺.M. M. Shemyakin Institute of the Chemistry of Natural Compounds, Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 233–240, March–April, 1974.     

Sesquiterpene lactones from plants of the family Asteraceae in the Kazakhstan flora and their biological activity

The results are generalized of the results of a study of 109 species of plants of the family Compositae (Asteraceae) growing on the territory of Kazakhstan. The promising nature is shown of the search for biologically active sesquiterpene -lactones among them. Fourteen new compounds of this series belonging to the germacranolides, eudesmanolides, guaianolides, and pseudogermanolides have been isolated and characterized by various methods. The results are given of biological tests of the lactones isolated and their derivatives. The artifeedant, antitumoral, antiviral, and growth-regulating activities of the sesquiterpene lactones are reported.Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 29–36 January–February, 1995. Original article submitted October 7, 1994.     

A peculiarity of the composition of the free fatty acids in the seed lipids of plants of the family Labiatae

The composition of the free fatty acids of nine species of the family Labiatae has been studied and it has been established that the combined free fatty acids are more diverse in composition and are richer in saturated components than the acids bound in the corresponding triacylglycerols.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 443–446, July–August, 1981. Original article submitted January 20, 1981.     

Synthetic and modified isoflavonoids XIV. Mannich bases and their salts in a series of synthetic isoflavone analogs

Mannich bases and their hydrochlorides have been obtained from 1,3-benzodioxolane, 1,4-benzodioxane, and 1,5-benzodioxepane analogs of pseudobaptigenin. The PMR spectra of the compounds obtained are given and are discussed.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 625–629, September–October, 1994.     

Synthetic and modified isoflavonoids XIV. Mannich bases and their salts in a series of synthetic isoflavone analogs

New 2,6-dialkyl-substituted isoflavone analogues of the natural isoflavone pseudobaptigenin have been synthesized. Their structures have been confirmed by IR and PMR spectroscopies.Taras Shevchenko University, KIEN. Karakalpak Division. Academy of Sciences of the Republic of Uzbekistan. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 674–677, September–October, 1993.     

Stereoselective synthesis of natural (2E,4E)-dienamides and their synthetic analogs

A procedure has been developed for stereoselective synthesis of a number of naturally occurring (2E,4E)-dienamides and their analogs via palladium-catalyzed reaction of (1E)-1-iodoalk-1-enes with acrylamides.     

Synthesis and study of the properties of the homologous series of polyallylcarbosilane dendrimers and their nonfunctional analogs

A synthetic route combining the preparation of functional and nonfunctional carbosilane dendrimers has been developed. Using this route, two representative homologous series of carbosilane dendrimers have been prepared. The use of nonfunctional dendrimer derivatives ensures the possibility of performing long-term experiments both in solution and in the bulk. The intrinsic viscosity and the density of the specimens studied do not depend on the generation number. The obtained dendrimers of later generations were studied by atomic force microscopy and light scattering.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2484–2493, November, 2004.