Synthesis and SAR of thioester and thiol inhibitors of IMP-1 metallo-beta-lactamase.

Potent thioester and thiol inhibitors of IMP-1 metallo-beta-lactamase have been synthesized employing a solid-phase Mitsunobu reaction as the key step.     

Synthesis and study of the fungicidal activity of amine salts of glycyrrhizic acid

Amine and triphenyl phosphine salts of glycyrrhizic acid have been synthesized by the reaction of glycyrrhizic acid with amines and triphenyl phosphine in absolute methanol, and their antimicrobial and fungicidal activities have been investigated.     

Synthesis and glucose-6-phosphatase inhibitory activity of (thiouriedo)alkanoic acid esters

A series of (3-pyridin-2-yl-thiouriedo)alkanoic acid esters (5a-j) have been synthesized by the reaction of pyridin-2-yl-dithiocarbamic acid methyl ester (2) and amino acid esters (4). Most of the synthesized compounds have been evaluated against glucose-6-phosphatase enzyme but only four compounds (5g-j) displayed significant inhibitory activity of the enzyme.     

Syntheses of four D- and L-hexoses via diastereoselective and enantioselective dihydroxylation reactions

An expeditious approach to various protected hexoses has been developed by the use of the Sharpless catalytic asymmetric dihydroxylation reaction. Applying the Sharpless catalytic asymmetric dihydroxylation reaction on vinylfuran, diols with high enantioexcess are produced. The resulting diols can be stereoselectively transformed into either protected D- or L-mannose in five steps and approximately 39% yield from furfural. Similarly, both D- and L-talose and gulose have been synthesized in 19% overall yields, respectively. Using a modified strategy, both protected D- and L-gulo- and allo-sugar-delta-lactones were synthesized in eight steps and approximately 20%, overall yield from furfural.     

Cyclization under mild conditions of anthraniloyl- and N-methyl-anthraniloyl dipeptides

Anthraniloyl- and N-methyl-anthraniloyl dipeptides containing C-terminal L and D proline residues have been synthesized and subjected to cyclization reaction under mild conditions. The influence of substituents and of the chirality of the residues on the output of the reaction is discussed.     

Synthesis of New N-Benzoyl-N'-Triazine Thiourea Derivatives and Their Antibacterial Activity

Russian Journal of Bioorganic Chemistry - A series of new N-benzoyl-N'-triazine thiourea derivatives have been synthesized via the reaction of...     

Synthesis and CNS Activity of Some Fluorine Containing 3-Indolylglyoxamides and Tryptamines

A number of new 5-/6-fluoro-2-substitutedaryl-3-indolylglyoxamides and their corresponding tryptamines have been synthesized. 5-/6-Fluoro-2-arylindoles, prepared by Fischer indole synthesis on treatment with oxalyl chloride and subsequent reaction with secondary amines, gave 5-/6-fluoro-2-aryl-3-indolylglyoxamides. The indolylglyoxamides were reduced with lithium aluminium hydride to yield corresponding tryptamines. All the synthesized compounds have been characterized by IR, PMR and ¹⁹F NMR spectral studies. CNS activity of some representative compounds has also been evaluated.     

Synthesis of novel spiropyrrolizidines as potent antimicrobial agents for human and plant pathogens

A series of novel dispirooxindolopyrrolizidine derivatives have been synthesized through 1,3-dipolar cycloaddition reaction of azomethine ylide generated from proline and isatin with the dipolarophile (E)-2-arylidine-1-keto carbazoles. The synthesized cycloadducts were evaluated for antimicrobial activities. Compounds 7d and 7e showed relatively good antibacterial and antifungal activities.     

A Study of Plant Coumarins. 18. Conjugates of Coumarins with Lupane Triterpenoids and 1,2,3-Triazoles: Synthesis and Anti-Inflammatory Activity

Russian Journal of Bioorganic Chemistry - In the reaction of coumarin peuruthenicin with α,ω-dibromoalkanes, the corresponding 7-(ω-bromoalkyloxy)coumarins have been synthesized. The...     

Synthesis of novel analogues of (+)-varitriol via olefin cross-metathesis reaction

Novel analogues of (+)-varitriol have been synthesized via olefin cross-metathesis reaction using Grubb's catalyst. Newly synthesized compounds were screened for cytotoxicity and they showed mild activity against RAW264.7 and HT29 cell lines.     

Synthesis,Antimicrobial and Antitumor Properties of 5-Thiophen-2-ylmethylen-2-Thioxothiazolidin-4-one Derivatives

Russian Journal of Bioorganic Chemistry - By the reaction of thiophen-2-carbaldehyde with rhodanine derivatives, 5-thiophen-2-ylmethylene-2-thioxothiazolidin-4-ones have been synthesized. The...     

A new class of acyclic nucleoside phosphonates: synthesis and biological activity of 9-[[(phosphonomethyl)aziridin-1-yl]methyl]guanine (PMAMG) and analogues

A new class of acyclic nucleoside phosphonates PMAMG, PMAMA, PMAMC, and PMAMT (compounds 1, 2, 3 and 4) have been synthesized and tested in vitro against a wide variety of viruses, fungi and bacteria. PMAMG (1) was synthesized by the alkylation reaction of acetylguanine with the phosphonate side-chain, diisopropyl [[2-(bromomethyl)aziridin-1-yl]]methylphosphonate (9), followed by deesterification reaction in the presence of TMSBr. In similar way, PMAMA, PMAMC, and PMAMT were prepared.     

3-substituted BINOL Schiff bases and their reductive products for catalytic asymmetric addition of diethylzinc to aldehydes

Three new chiral 3-substituted BINOL Schiff bases and their reductive 3-arylaminomethyl BINOL products have been synthesized and used for the asymmetric addition reaction of diethylzinc to aldehydes in the presence of titanium tetraisopropoxide. The reaction provided optically active secondary alcohols in high yield (86-100%) and good enantioselectivity (up to 92% ee).     

Biaryls and heterobiaryls as alpha-glucosidase and protein tyrosine phosphatase inhibitors

Various 6-aryl-4-substituted-2H-pyran-2-one-3-carbonitriles (1a-d) have been synthesized as precursor for the synthesis of 3,4-dihydro-1H-isothiochroman (2a) and benzocycloalkanes (2b-e). Highly functionalized 9-thiaphenanthrene (3b) and phenanthrene (3a) have also been obtained from the reaction of 1c with thiochroman-4-one and 1-tetralone separately. Similarly 4 has been obtained by the ring transformation of 1d by 4-trifluoromethylacetophenone. Most of the synthesized compounds were evaluated for alpha-glucosidase and protein tyrosine phosphatase inhibitory activities. Some of the compounds, 2a, 3a and b and 4 displayed better alpha-glucosidase inhibitory activity compared to standard drug acarbose.     

One set system for the synthesis and purification of glycosaminoglycan oligosaccharides reconstructed using a hyaluronidase‐immobilized column

Using the transglycosylation reaction as a reverse reaction for the hydrolysis of hyaluronidase, new artificial oligosaccharides may be synthesized by reconstructing natural glycosaminoglycans (GAGs) according to preliminary planned arrangements. However, as some problems have been associated with the method, including the low yields of reaction products and complicated processes of separation and purification, improvements in this method were investigated. Transglycosylation reactions were carried out using bovine testicular hyaluronidase‐immobilized resin packed in a column. For the transglycosylation reaction, pyridylaminated (PA) GAG hexasaccharides, which were the minimum size for hydrolysis sensitivity and the transglycosylation reaction, were used as acceptors, whereas large size GAGs were used as donors. The reaction mixture was pooled after incubation in the hyaluronidase‐immobilized resin column and was then introduced into continuously joined HPLC columns constructed from three steps: the first step of ion‐exchange HPLC for concentrating newly synthesized GAG oligosaccharides as reaction products, the second step of reverse phase HPLC for separating PA oligosaccharides from non‐PA oligosaccharides, and the third step of size fractionation HPLC for fractionating newly synthesized oligosaccharides. Newly synthesized oligosaccharides were obtained by one complete cycle of the transglycosylation reaction and separation. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 189–196, 2014.     

Synthesis of alkenyl acyclonucleosides derivatives of 5-halogenouracil as antiviral and antitumoral agents.

Alkenyl acyclonucleosides derivatives of 5-halogenouracil have been synthesized via Michael addition reaction. These compounds were treated by allylbromide, propargylbromide or ethylbromoacetate to give the corresponding N-1,N-3-disubstituted 5-halogenouracil.     

Synthesis of nucleoside-based antiviral drugs in ionic liquids

Nucleoside-based antiviral drugs have been synthesized using imidazolium-based ionic liquids as reaction medium. The ionic liquids were proved to be better solvents for all the nucleoside in terms of solubility and reaction medium as compared to conventional molecular solvents.     

Investigation into an efficient synthesis of 2,3-dehydro-N-acetyl neuraminic acid leads to three decarboxylated sialic acid dimers

Sialic acid, an important carbohydrate found incorporated on the cell surface of many organisms, has been modified for use in a wide range of biological and pharmaceutical applications. We hypothesized that 4,7,8,9-tetra-O-acetyl-2-deoxy-2,3-dehydro-N-acetyl neuraminic acid methyl ester (4) could be efficiently synthesized in a one-pot reaction by heating peracetylated sialic acid (2) in pyridine and acetic anhydride to induce beta-elimination. When reduced to practice, this reaction produced only modest yields of 4. Six compounds, including three new decarboxylated sialic acid dimers, were also found to have been synthesized in the reaction. In an effort to better understand the chemistry and the mechanisms of this reaction, all of the side products were isolated and fully characterized.     

A New and Convenient Approach for the Synthesis of Ribo- and 2′-Deoxyribo-β-L-Furanonucleosides Starting From β-L-Xylofuranonucleosides

Abstract

Ribo- and 2′-deoxyribo-β-L-furanosyladenine have been synthesized. Although these compounds have been already reported in the literature, it seemed to us that a more convenient approach for their synthesis deserved to be developed. Intramolecular substitution as well as Mitsunobu reaction were used to invert the configuration of carbon 3′ of starting β-L-xylofuranosyl intermediates.     

Studies of the mechanism of the periodic acid-Schiff histochemical reaction for glycogen using infrared spectroscopy and model chemical compounds.

It has been proposed in the literature that Schiffs reagent reacts with aldehydes to form one of the following types of compounds: alkylsulfonic acids, N-sulfinic acid derivatives, or Schiff bases. Model compounds whose structures are consistent with those proposed in the literature have been synthesized and subjected to infrared analysis. Also, actual products of Schiff reagent reactions with various aldehydes have been isolated and examined using infrared spectroscopy. Comparison of the spectra of the model compounds with those of Schiff-aldehyde reaction products yielded the following conclusions: 1. The reaction of simple organic aldehydes with Schiff's reagent produces an alkylsulfonate-type reaction product. 2. The reaction of periodate-oxidized glycogen with Schiff's reagent probably involves the formation of an alklsulfonate-type compound. 3. The product of the Schiff-aldehyde reaction exists as neither an N-sulfinic acid nor a Schiff base derivative of the fuchsin molecule.