Showing papers by "Nariman F. Salakhutdinov published in 2012"

A new synthetic varacin analogue, 8-(trifluoromethyl)-1,2,3,4,5-benzopentathiepin-6-amine hydrochloride (TC-2153), decreased hereditary catalepsy and increased the BDNF gene expression in the hippocampus in mice

Abstract: Rationale The creation of effective psychotropic drugs is the key problem of psychopharmacology. Natural compounds and their synthetic analogues attract particular attention.

Synthesis of aurones based on usninic acid

Abstract: (+)-Usninic acid was brominated at the acetyl group located on the aromatic ring. Aurones were synthesized based on the intramolecular cyclization of monobrominated (+)-usninic acid.

The Meerwein–Ponndorf–Verley type reaction in a mixture of supercritical isopropanol/CO2 in a continuous flow reactor in the presence of alumina

Abstract: a b s t r a c t A system for efficient reduction of aromatic and aliphatic aldehydes to respective alcohols by the Meerwein-Ponndorf-Verley reaction at a contact time of less than 4 min and temperature below 473 K has been developed. The system comprises a continuous flow reactor, mixed supercritical isopropanol/CO2 solvent and alumina as a catalyst. Reduction of p-nitobenzealdehyde at 425 K yields p-nitrobenzyl alcohol; at 465 K the main reaction product is p-toluidine. ,-Unsaturated monoter- penic aldehyde myrtenal was reduced into corresponding ,-unsaturated alcohol myrtenol. At higher temperatures, reduction of myrtenol to saturated alcohol myrtanol becomes possible. © 2011 Elsevier B.V. All rights reserved.

Influence of Usnic Acid and its Derivatives on the Activity of Mammalian Poly(ADP-ribose)polymerase 1 and DNA Polymerase β

Abstract: The influence of a number of usnic acid derivatives on auto(polyADP-ribosyl)ation catalyzed by PARP1 and DNA synthesis catalyzed by DNA polymerase β was studied. The derivatives of usnic acid containing aromatic substituents were shown to be moderate inhibitors of PARP1. The presence of both usnic acid tricyclic structure and aromatic substituent at any position of the molecule is a key factor for the inhibitory action. In the case of DNA polymerase β, no relationship between the structure and inhibitory properties has been found with the only exception. Derivatives with modified ring A showed mild activation of DNA synthesis catalyzed by DNA polymerase β.

Secondary metabolites of the lichen Cladonia stellaris

Abstract: The composition of slightly polar extracts of the lichen Cladonia stellaris (Opiz.) was studied. The major metabolites of the CHCl3 and Me2CO extracts were isolated. Lichen acids 6 and 7 in addition to 3–5, derivatives of olivetolcarboxylic acid (7), were isolated for the first time from the lichen C. stellaris. The CHCl3 extract was tested for antagonist activity against pathogens of the principal agricultural diseases.

Cyclization of citronellal in a supercritical solvent in a flow reactor in the presence of Al 2 O 3

Abstract: The reactivity of citronellal under supercritical solvent conditions in a flow reactor in the presence of Al2O3 is examined. It is shown that at 160°C, the main transformation product of citronellal is isopulegol, and when the temperature is increased to 190°C, they are monoterpenes with a para-menthane framework and myrcene.

Chiral schiff bases synthesized from terpenes of pinane series in asymmetric metall complex oxidation of sulfides

Abstract: The absolute configuration of α-hydroxyaldehyde obtained from verbenol epoxide in the presence of clay was determined. Two new Schiff bases were synthesized from the aldehyde obtained. The compounds can be used as ligands in the asymmetric vanadium-catalyzed oxidation of sulfides to sulfoxides. The structure of initial sulfides significantly affects the value of the enantiomeric excess in the obtained sulfoxides: the highest enantiomeric excess is observed in the oxidation of thioanisole.

Preparation and nitration of allobetulin seco -derivatives

Abstract: 2-Nitro-derivatives of allobetulone were prepared by reaction of allobetulin with nitric acid 2β-Aminoallobetulin was synthesized by reduction of 2-nitrobetulone with LiAlH4 The corresponding allobetulin seco-derivatives were obtained via oxidation by H2O2 in the presence of K2CO3 of 2-nitroallobetulone and cleavage of 2,2-dinitroallobetulone by K2CO3 in H2O:THF

Reaction of several resveratrol glycoside derivatives with hypochlorites in various media

Abstract: The reactions of pterostilbenoside (trans-3,5-dimethoxystilben-4′-O-β-D-glucoside) and Ar–O–Tr derivatives of resveratroloside (3,5-dihydroxystilben-4′-O-β-D-glucoside) and pinostilbenoside (3-methoxy-5-hydroxystilben-4′-O-β-D-glucoside) with NaOCl and t-BuOCl in the presence of the stable nitroxyl radical TEMPO were studied in various media. It was found that the principal product of pterostilbenoside transformation was its 2,6-dichloroderivative, a part of which was oxidized to form 2,6-dichloropterostilbene glucuronide. Trityl ethers of resveratroloside and pinostilbenoside reacted with the hypochlorites to form mixtures of products.

Transformations of acetophenone and its derivatives in supercritical fluid isopropanol/CO2 in a continuous flow reactor in the presence of alumina

Abstract: Acetophenone and its derivatives undergo various transformations in binary supercritical solvent isopropanol/CO2 in a flow reactor in the presence of granulated Al2O3. Depending on the reaction temperature, respective secondary alcohols, or isopropyl ethers, or substituted styrenes are formed at contact times of ∼4 min. Selectivity for the reaction products attains 96% at high conversion of initial compounds. It was shown that the nature of a substituent in ketone aromatic ring exerts primary effect both on the conversion of initial compounds and on stability of intermediates under reaction conditions, and thus affects the end product distribution.

Oxidation of α-pinene by atmospheric oxygen in the supercritical CO2—ethyl acetate system in the presence of Co(II) complexes

Abstract: The reactivity of monoterpene α-pinene in a flow reactor in the presence of cobalt catalyst in a complex supercritical solvent consisting of CO2 and ethyl acetate is studied over the temperature range of 190–320°C and a pressure range of 110–125 atm. It was found that the main isomerization products include compounds with bicyclo[2.2.1]heptane and p-menthane backbones; the reaction is accompanied by partial racemization. The formation of oxidation products is observed in the presence of air, with epoxydation rather than allylic oxidation being the predominant process at the first stage. The oxidized products (campholenic aldehyde, verbenone, pinocamphone) are shown to be formed with a high enantioselectivity; the formation of acetoxylation products is observed at temperatures above 200°C.

Synthesis of new chiral Schiff bases from (+)-2-carene

Abstract: New chiral Schiff bases were synthesized through tricyclic 2-azetidinones as key intermediate products which were obtained by reaction of (+)-2-carene with chlorosulfonyl isocyanate.

Synthesis of ethers of (+)-usninic acid pyrazole derivatives

Abstract: The reduction of usninic acid pyrazole derivatives by complex boron hydrides under various conditions was studied. New ether derivatives containing added alcohols were obtained upon reduction of the carbonyl. The reaction occurred presumably through a quinonemethide intermediate.

Chiral Schiff Bases Synthesized from Terpenes of Pinane Series in Asymmetric Metal Complex Oxidation of Sulfides.

Abstract: Novel Schiff bases (I) are prepared and tested as chiral ligands in the asymmetric vanadium-catalyzed oxidation of sulfides to sulfoxides.

Reaction of isocembrol and alcohols on clay

Abstract: Isocembrol (1) is a diterpene component of Pinus sibirica gum and a representative of a broad group of cembranoids. It incorporates a 14-membered ring, a tertiary alcohol, and three trans-double bonds in the ring. The principal sources of cembranoids are coniferous plants, tobacco, and marine invertebrates, especially corals. Cyclic alcohol 1 was first isolated from the neutral part of P. sibirica Mayr gum [1] and was described under the name thunbergol as the principal component of the neutral part of Pseudotsuga menziessi Mirb. Franco gum [2]. Compound 1 was also detected in marine corals [3], tobacco leaves [4], and propolis [5]. We improved the method for isolating 1 from P. sibirica gum. The previously reported method [1] was used as a prototype. According to that method, gum is saponified by NaOH solution (1%). Neutral unsaponified substances are extracted by Et2O and fractionated by vacuum distillation. The residual after distillation is chromatographed twice successively over basic Al2O3 (1:15 and 1:50 ratios). Compound 1 is isolated in 1.9% yield of the neutral fraction and 0.5% of the total gum mass. We proposed isolating 1 from the neutral part of the gum by extraction with nonpolar solvents (hexane, petroleum ether) and successive purification of the target product by column chromatography. This method has several advantages over the known methods. The solvents and gum extraction method are selected such that the resulting mixture containing 1 is fluid and easily subjected to either chromatography or vacuum distillation. The yield of target product using the proposed method was 2.9–3.8% of the total gum mass and 18–22% of the hexane-extract mass. This was significantly greater than the yield of known methods. The spectral characteristics of isolated 1 agreed with those published [6]. The properties of 1 are insufficiently studied despite its relative availability. Isomerization of 1 in formic acid that leads to the formation of biand tricyclic compounds [7], epoxidation by per-acids [8], and hydroxylation [9] were studied. Epoxidation of 1 by t-BuOOH in the presence of VO(acac)2 was performed efficiently [10]. Further transformations of the resulting epoxy derivative were studied. Oxidation of 1 by pyridinium chlorochromate produced conjugated enones [11]. Herein results of a study of the reactions of 1 with allyl and methyl alcohols on K-10 clay are reported. Adding 1 to an allyl alcohol–clay system gave an intermolecular product, the allyl ether of isocembrol 2, as the principal product. The reaction was conducted without solvent. Adding CH2Cl2 to the system increased significantly the amount of isomerization products. Thus, adding 1 to a CH2Cl2–allyl alcohol–clay system gave 3 as the principal product (Scheme 1). Compound 3 was formed as a result of intramolecular cyclization and subsequent reaction with allyl alcohol. Furthermore, a mixture of cembrenes was formed.

Synthesis of Betulin Derivatives: N’{N-[3-OXO-20(29)-Lupen-28-OYL]-9-Aminononanoyl}3-Amino-3-Phenylpropionic Acid

Abstract: A method for synthesizing N’-{N-[3-oxo-20(29)-lupen-28-oyl]-9-aminononanoyl}-3-amino-3-phenylpropionic acid, a compound that exhibited immunostimulating and antiviral activities, by adding the methyl ester of N-(9-aminononanoyl)-3-amino-3-phenylpropionic acid to betulonic acid was described

Glycyrrhetinic acid and its derivatives as inhibitors of poly(ADP-ribose)polymerases 1 and 2, apurinic/apyrimidinic endonuclease 1 and DNA polymerase β

Abstract: Novosibirsk Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences 8, Akademika Lavrentieva Ave., Novosibirsk, Russian Federation, 630090 1N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences| 9, Akademika Lavrentieva Ave., Novosibirsk, Russian Federation, 630090 2UMR7242, University of Strasbourg, CNRS, ESBS Cedex Illkirch Cedex, France, 67412