Thioalkyl Groups Research Articles

Benzenesulfonamide based 1,3,4-oxadiazole derivatives: synthesis, pharmacokinetic property prediction, bovine carbonic anhydrase activity and molecular docking studies

Sulphur-containing compounds are highly significant as they can possess a variety of biological activities that make them useful for pharmacological purposes and for the mechanism by which drugs such as antibiotics bind to and disrupt bacterial cell walls. In this study, novel thioalkyl substituted-1,3,4 oxadiazole-bearing sulfonamide compounds have been successfully synthesized and characterized by 1HNMR, 13CNMR, IR and elemental analysis. The effects of different thioalkyl groups on the 1,3,4 oxadiazole group, the IC50 value for Bovine Carbonic Anhydrase (BCA) found by in vitro, density functional theory (DFT) calculations, pharmacokinetics prediction and molecular docking are aimed to reveal the interactions on BCA. Firstly, pharmacokinetic predictions of thioalkyl substituted 1,3,4-oxadiazole compounds were generated to predict their potential hazards. Secondly, the predicted molecular docking data and 2D interaction were analyzed based on the best configuration from DFT optimization. Finally, the inhibition against BCA was analyzed in vitro and compared with the theoretical data. The compound (5o) has the best value such as IC50 = 51.80 µM, HOMO–LUMO (ΔE 4.488 Ev), ΔG −7.69 kcal/mol, Full fitness −2152.72 FF and predicted toxicity results showed no significant results except hepatotoxicity.

Bioinspired Metal‐Organic Frameworks in Mixed Matrix Membranes for Efficient Static/Dynamic Removal of Mercury from Water

AbstractThe mercury removal efficiency of a novel metal‐organic framework (MOF) derived from the amino acid S‐methyl‐L‐cysteine is presented and the process is characterized by single‐crystal X‐ray crystallography. A feasibility study is further presented on the performance of this MOF—and also that of another MOF derived from the amino acid L‐methionine—when used as the sorbent in mixed matrix membranes (MMMs). These MOF‐based MMMs exhibit high efficiency and selectivity—in both static and dynamic regimes—in the removal of Hg2+ from aqueous environments, due to the high density of thioalkyl groups decorating MOF channels. Both MMMs are capable to reduce different concentration of the pollutant to acceptable limits for drinking water (<2 parts per billion). In addition, a novel device, consisting of the recirculation and adsorption of contaminated solutions through the MOF–MMMs, is designed and successfully explored in the selective capture of Hg2+. Thus, filtration of Hg2+ solutions with multiple passes through the permeation cell shows a gradual decrease of the pollutant concentration. These results suggest that MOF‐based MMMs can be implemented in water remediation, helping to reduce either contaminants from accidental unauthorized or deliberate metal industrial dumping and to ensure access for clean and potable freshwater.

High-Performance Metal-Organic Framework-Templated Sorbent for Selective Eu(III) Capture.

A stable porous sorbent M1 was achieved through the specific transformation of flexible thioalkyl groups and metal cluster sites in a zirconium MOF (metal–organic framework; Zr-L) template. The target polymer combines sulfoxide/sulfone and phosphoric acid in a single framework, which was fully characterized by 1H-NMR, PXRD, IR, and elemental analysis. When employed as the heavy metal adsorbent, M1 exhibit a remarkable Eu(III) sorption behavior, achieving both high chemical affinity (Kd = 105) and sorption capacity (the maximum Eu(III) sorption capacity reached 220 mg g–1 at pH = 4.0 and T = 298 K calculated from the Langmuir model). Recyclability and selectivity test of M1 further prove that the sorbent is highly stable and effective for europium enrichment in the aqueous solution. This work takes focus on the introduction of multifunctional groups into a single polymeric framework in a feasible and environmentally friendly way and highlights the sorption efficiency for europium removal from the aqueous solution.

Synthesis and Study of the Properties of Amphiphilic Poly-N-Vinylpyrrolidone with Terminal Thioalkyl Groups

Poly-N-vinylpyrrolidone-based amphiphilic polymers, which can be used as drug carriers, were prepared by radical polymerization with a thiol-type chain transfer agent. The polymers did not contain sequences of hydrophilic and hydrophobic fragments in the main chain. Molecules contained only one hydrophilic and one hydrophobic fragment linked by a covalent bond. This facilitated the self-organization of macromolecules into micelles in aqueous media. The critical micelle concentration and its dependence on the molecular weight of the diblock copolymers and the length of the hydrophobic radical were determined

Conducting nanofibres of solvatofluorochromic cyclohexanetrione-dithiolylidene-based C3 symmetric molecule.

We report a novel set of easily tailorable C3 symmetric molecules with a π-extended core and adorned with different thioalkyl groups, exhibiting solvatofluorochromic and amphoteric redox behaviour. The nearly planar core exhibits intermolecular face-to-face π-stacking, SS and intramolecular SO interactions. Current-sensing atomic force microscopy studies revealed a high conductivity of ∼0.15 mS cm-1 in the undoped J-aggregate nanofibres of the thiopropyl appended gelator.

Aggregation behaviour of amphiphilic cyclodextrins: the nucleation stage by atomistic molecular dynamics simulations.

Amphiphilically modified cyclodextrins may form various supramolecular aggregates. Here we report a theoretical study of the aggregation of a few amphiphilic cyclodextrins carrying hydrophobic thioalkyl groups and hydrophilic ethylene glycol moieties at opposite rims, focusing on the initial nucleation stage in an apolar solvent and in water. The study is based on atomistic molecular dynamics methods with a “bottom up” approach that can provide important information about the initial aggregates of few molecules. The focus is on the interaction pattern of amphiphilic cyclodextrin (aCD), which may interact by mutual inclusion of the substituent groups in the hydrophobic cavity of neighbouring molecules or by dispersion interactions at their lateral surface. We suggest that these aggregates can also form the nucleation stage of larger systems as well as the building blocks of micelles, vesicle, membranes, or generally nanoparticles thus opening new perspectives in the design of aggregates correlating their structures with the pharmaceutical properties.

Synthesis of Tetrachalcogenide-Substituted Phenalenyl Derivatives: Preparation and Solid-State Characterization of Bis(3,4,6,7-tetrathioalkyl-phenalenyl)boron Radicals

We report the synthesis and properties of a series of spiro-bis(3,4,6,7-tetrachalcogenide-substituted-phenalenyl)boron salts and two of the corresponding tetrathioalkyl-substituted spiro-bis(phenalenyl)boron radicals [tetrathiomethyl (10) and tetrathioethyl (11)] in which all of the active positions of the phenalenyl (PLY) nucleus are functionalized. In the solid state, radicals 10 and 11 exist as a weak π-dimers due to the steric congestion of the thioalkyl groups in the superimposed PLY units. As a result, the spins are localized in the isolated (nonsuperimposed) PLY rings, and the structure, magnetic susceptibility measurements, and band structure calculations confirm that these PLY units are unable to undergo strong intermolecular interaction as a result of the orientation of the thioalkyl groups.

ChemInform Abstract: Synthesis, Structure and Some Reactions of 1,2-Bis(2-alkylthio-3-thienyl)perfluorocyclopentene.

The synthesis of 1,2-bis(2-ethylthio-3-thienyl)perfluorocyclopentene is described. Metallation with n-BuLi and subsequent treatment with DMF or CO2 gave the corresponding 5,5′-diformyl and dicarboxy derivatives. The structure of 1,2-bis(2-ethylthio-3-thienyl)perfluorocyclopentene was studied by x-ray structural analysis. It was established that the unit cell contains two crystallographically independent molecules with geometrical and conformational parameters close to one another. The thiophene rings were inclined at an angle of 60° to the plane of the perfluorocyclopentene fragment, the thioalkyl groups were disposed antiparallel to it.

E−Z Isomerization and Aggregation Phenomena of Dithiafulvenes in CHCl3

The physical-chemical properties of several 1,3-dithiafulvene (DTF) derivatives having a donor and acceptor group in the molecule were studied. The synthesis of these compounds produces selectively the E isomer, but when the compound is dissolved in CHCl(3) isomerization to the Z isomer takes place with a rate that depends on the substituents. The interconversion rate is slow on the NMR time scale; therefore, two separated signals are observed, and they are used to measure the rate constant of isomerization. The equilibrium constant is, in all cases, very close to 1, and this is coincident with the fact that theoretical calculations of the energy of the two isomers in the gas phase differ by less than 0.1 kcal/mol. The isomerization reaction is completely reversible, and the E isomer can be obtained in pure form by selective crystallization. The derivatives with thioalkyl groups have a strong tendency to aggregate in CDCl(3). The formation of the aggregates is evidenced from the changes in 1D (1)H NMR and DOSY spectra as a function of concentration. The compounds are highly delocalized, and this is reflected by the low activation energy for the isomerization.

Novel 6-position modified 1-thioalkyl-lincosamines

A general method for the synthesis of 6-position modified lincosamines via stereospecific nucleophilic addition to readily available galactose 6-nitrone has been developed. A new route for the stereospecific installation of thioalkyl groups at the 1-position was also developed. These methods allow access to a variety of new derivatives of antibacterial lincosamides.

Self‐Assembled Organic Nanostructures: Effect of Substituents on the Morphology

Three perylene-3,4;9,10-tetracarboxydiimide (PTCDI) compounds with two dodecyloxy or thiododecyl chains attached at the bay positions of the perylene ring, PTCDIs 1-3, were fabricated into nanoassemblies by a solution injection method. The morphologies of these self-assembled nanostructures were determined by transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), and atomic force microscopy (AFM). PTCDI compound 1, with two dodecyloxy groups, forms long, flexible nanowires with an aspect ratio of over 200, while analogue 3, with two thiododecyl groups, self-assembles into spherical particles. In line with these results, PTCDI 2, with one dodecyloxy group and one thiododecyl group, forms nanorods with an aspect ratio of around 20. Electronic absorption and fluorescence spectroscopy results reveal the formation of H-aggregates in the nanostructures of these PTCDI compounds owing to the pi-pi interaction between the substituted perylene molecules and also suggest a decreasing pi-pi interaction in the order 1>2>3, which corresponds well with the morphology of the corresponding nanoassemblies. On the basis of DFT calculations, the effect of different substituents at the bay positions of the perylene ring on the pi-pi interaction between substituted perylene molecules and the morphology of self-assembled nanostructures is rationalized by the differing degree of twisting of the conjugated perylene system caused by the different substituents and the different bending of the alkoxy and thioalkyl groups with respect to the plane of the naphthalene.

Synthesis, structure, and some reactions of 1,2-bis(2-alkylthio-3-thienyl)perfluorocyclopentene

The synthesis of 1,2-bis(2-ethylthio-3-thienyl)perfluorocyclopentene is described. Metallation with n-BuLi and subsequent treatment with DMF or CO2 gave the corresponding 5,5′-diformyl and dicarboxy derivatives. The structure of 1,2-bis(2-ethylthio-3-thienyl)perfluorocyclopentene was studied by x-ray structural analysis. It was established that the unit cell contains two crystallographically independent molecules with geometrical and conformational parameters close to one another. The thiophene rings were inclined at an angle of 60° to the plane of the perfluorocyclopentene fragment, the thioalkyl groups were disposed antiparallel to it.

Reactivity of oxidized oligothiophenes substituted with methoxy and thioalkyl groups

Abstract α-Oligothiophenes with one to five rings, substituted with β-methoxy groups and terminated with either (2-hydroxyethyl)thio ( 1–5 ) or (2-acetoxyethyl)thio groups ( 1a–5a ) were synthesized. Cyclic voltammetry, coulometry and vis spectroscopy were used to investigate the reactivity of the cation radicals and dications. The cation radicals, even the ‘monothiophene cation radical’ 3-methoxy-2,5-bis(hydroxyethylthio)thiophene ( 1 1+ ), were somewhat stable in acetonitrile. The dications of the acetoxy derivatives 2a–5a were also stable on this time scale. Dications 1a 2+ and 1 2+ – 5 2+ were not stable. The instability of 2 2+ – 5 2+ is attributed to an intramolecular reaction between the terminal hydroxy groups and the oxidized thiophene units. This reaction led to the isolation of an unusual spiro product from a preparative scale oxidation of bithiophene 2 . Several of the cation radicals precipitated on the electrode surface. The unusual shape of the voltammograms which resulted was investigated, and evidence for the formation of two different salts, one fully oxidized and one mixed valence, was obtained.

Synthesis and properties of bi- and ter-tetrathiafulvalenyls

New donors containing two or three TTF rings connecting directly to each other were synthesized and their electronic spectra showed the presence of hydrophobic interaction among the long chains of thioalkyl groups attached to TTF frameworks. Furthermore, their redox potential waves indicates the marked tendency to reducing on-site Coulombic repulsive forces in their dicationic states as increasing the number of incorporated TTF frameworks.

Preparation and properties of glutathion conjugates of 2,4,5,6-tetrachloro-1,3-dicyanobenzene

Preparation and spectroscopic properties of 2,5,6-trichloro-4(S-γ-L-glutamyl-L-cysteinyl-glycine)-1.3-dicyanobenzene ( 2), 2,5-dichloro-4,6-di-(S-γ-L-glutamyl-L-cysteinyl-glycine)-1,3-dicyanobenzene ( 3), and 5-chloro-2,4,6-tri(S-γ-L-glutamyl-L-cysteinyl-glycine)-1,3-dicyanobenzene ( 4), gluthation conjugates of the general fungicide chlorothalonil (2,4,5,6-tetrachloro-1,3-dicyanobenzene, 1) are reported. Optimal conditions for preparation and chromatographic separation of the single conjugates are described. NMR-spectroscopic data allowed unambiguous determination of regioselectivity of conjugation reaction of chlorothalonil with glutathione. UV Spectra of 2–4 revealed significant long-wavelength band shift and enhancement of intensity with increasing number of thioalkyl groups attached to the aromatic ring. The UV band assignement is based on the UV-VIS spectra of the model compounds 5–7. The far-UV CD spectra are dominated by the chiral contribution of the amide chromophores. In a trifluoroethanol/water (70:30) mixture the peptide backbone of conjugate 2 likely adopts an ordered (folded) conformation, whereas peptides 3 and 4 show no significant tendency for forming ordered structures.

Protein Adsorption onto Protein-Covered Silica Gels

Abstract Porous silica beads have been modified with aminoalkyl and thioalkyl groups of different chain lengths. The modified silicas were covered with human 1gG or human HSA. In order to investigate the influence of the underlying surface on the adsorbed protein layer, the adsorption onto and desorption and displacement of proteins from protein-covered surfaces were studied and compared with those for silica surfaces not previously covered with protein. The underlying surface exerted a great influence on the composition of the protein-covered surface.

Synthesis 1-thioglycosides from 1-sulfenates

Thioalkyl and thioaryl groups can be used to protect the anomeric position of sugars and can be activated to yield glycosyl donors I,‘. Thioglycosides can be activated by mercury(I1) sulfate 3, mercury(I1) chloride 4*5, phenyl mercury trifluoromethanesulfonate 6, mercury(II) benzoate 7, mercury01) nitrate *, copper trifluoromethanesulfonate 9, and lead011 perchlorate lo. Generation of glycosyl donors involves the conversion of thioglycosides into glycosyl bromides ‘i-l3 and glycosyl fluorides i4, and activation by use of methyl triflate 15-18, dimethyl(methyltio) sulfonium triflate 19, and nitrosyl tetrafluoroborate 20. Numerous methods are available for the preparation of thioglycosides 21*22, of which the most general is the S,2 reaction of alkali salts of thiophenols or alkanethiols with acetylglycosyl halides . 24 Acetylated alkyl l-thio-D-glucopyranosides can be obtained by reaction of 2,3,4,6-tetra-O-ace@-1-thio-/3-n-glucopyranose with alkyl bromides or iodides Z. In order to prepare 1-thioglycosides with non-participating groups, these compounds were deacylated and subsequently alkylated, usually with benzyl halides. The trichloroacetimidate method has been used to synthesise thio sugars and thioglycosides from sugar derivatives with HO-l unprotected . 26 A disadvantage of this procedure is the use of toxic and malodorous thiols and thiophenols. Carbohydrate sulfenates may be prepared 27 by the reaction of appropriate sugar derivatives with 2nitrobenzenesulfenyl chloride or 2,4-dinitrobenzenesulfenyl chloride in the presence of triethylamine, and we now report a new synthesis of aryl 1-thioglycosides by deoxygenation of monosaccharide sulfenates with triethyl phosphite. Thus, 2,3,4,6-tetra-0-methyl-l-O-(2-nitrophenylsulfenyl)-~-~-glucopyranose (la>, 2,3,4,6-tetra-O-benzyl-1-0-(2-nitrophenylsulfenyl)~-D-glucopyranose (2a), 2,3,4,6-tetra-0-ben~l-l-O-(2-nitrophenylsulfenyl)-~,~-~-galactopyranose (3a,

Halogenotricarbonylrhenium(I) complexes of 2,6-bis(thioalkyl)- and -(thioaryl)-pyridines, their syntheses and solution stereodynamics

Reactions of pentacarbonylhalogenorhenium(I) with 2,6-bis(p-tolylthiomethyl)pyridine (L1) or 2,6-bis(methylthiomethyl)pyridine (L2) afforded complexes of type fac-[ReX(CO)3L](X = Cl, Br or I; L = L1 or L2). These potentially tridentate ligands, L1 and L2, are here acting as bidentate N/S species forming five-membered ring chelate complexes. In an NMR study of both series of complexes, pyramidal inversion of the co-ordinated sulfur atoms was observed together with an intramolecular fluxional process which exchanges co-ordinated and unco-ordinated thioalkyl or thioaryl groups. The two processes have similar activation energies but were separately measurable in certain cases. Two possible mechanisms for the novel intramolecular exchange process are discussed.

First carbohydrate liquid crystals of columnar structure

Abstract S, S-Dialkylacetals of aldoses, tripodal in structure and recently synthesized in large numbers by three groups, do not exhibit thermotropically a smectic, but a columnar hexagonal mesophase (Hx) as we have proved by X-ray diffraction. The molecular organization in this mesophase is comparable with a similar one known for phasmidic molecules. These various multiols, although different in stereo-chemistry, form only one type of hydrogen-bonded disc-shaped multimer. Its mesophase structure is made up of about five molecules placed in columns with a skeleton of hydrogen-bridged sugar parts surrounded by thioalkyl groups in the periphery. Since three 6-deoxy sugar dithioacetals were shown to be non-thermomesomorphic the terminal hydroxyl function is essential for this molecular arrangement which seems not to be true for missing ones in the inner part of a sugar chain, as we have found in one case.

Aspects of the radical polymerization of methylmethacrylate in presence of heminal sulphides

The authors have studied the effect of the heminal sulphides containing two, three and four thioalkyl groups on the polymerization of methylmethacrylate. The presence of three active centres—the CS bond, the H atoms of the heminal carbon atom and the less active protons of the α-CH 2 groups of the alkyl residues—means that the transition from one sulphide to another changes the mechanisms of the influence of the sulphur compound on the polymerization process. On photo-initiation the course of photolytic rupture of the CS bond competes with the chain transfer reactions, which leads to a combination of inhibiting initiating properties.