Russian Journal of General Chemistry最新文献

The reaction of dicarboxylate ligand, cis-4-cyclohexene-2-dicarboxylic acid (H₂ccdca), with Pb(II) in solvothermal condition resulted in the formation of a new coordination polymer (CP) i. e., [Pb(ccdca)]_n. Single crystal X-ray study reveals that this coordination polymer features a two-dimensional network whereas ccdca^2– anions adopt their carboxylate groups to link with five neighboring Pb centers in µ₁:η¹:η¹ and µ₃:η²:η¹ coordination modes. The ccdca^2– ligands display trans-conformation and link with Pb centers to form an interesting 4,4-connected topological network with point symbol of {4³·6³}. In addition, the photoluminescent spectra indicate that free H₂ccdca ligand and [Pb(ccdca)]_n exhibit the emission maxima at 412 and 512 nm and emit blue and green luminescence at room temperature, respectively. Compound [Pb(ccdca)]_n displays a red-shift of 100 nm in emission by comparison with free H₂ccdca ligand, with enhanced emission band, which is attributed to the chelation of ligand to the Pb(II), increasing rigidity and reducing energy loss via nonradiative decay in the excited state.

New tripodal tricarboxylic acids on the triphenylphosphine oxide platform [2-HO(O)C(CH₂)_nOC₆H₄]₃PO with different linker length (n = 1, 3) have been prepared. Their composition and structure have been determined by elemental analysis, IR and multinuclear (¹H, ¹³C, ³¹P) NMR spectroscopy, and X-ray diffraction analysis. The complexes of the tripodal ligands with La(III) have been prepared; their composition and structure have been investigated by means of elemental analysis and IR spectroscopy.

Phosphorylated derivatives of furanсarbaldehydes and furanylacetic aldehydes containing an ester and tert-butyl groups in the ring were synthesized. Their behavior in the Wittig reaction with resonance-stabilized acylmethylenetriphenylphosphoranes was studied. The resulting furanylalkenes are heterocyclic analogues of trans-chalcones. The compounds obtained by reaction with acetylmethylenetriphenylphosphorane were used as starting substrates for the synthesis of (E)-[2-(1,2,3-selenodiazol-4-yl)ethen-1-yl]furans, heterocyclic analogues of trans-stilbenes. Furanylacetic aldehydes form two isomers in the Wittig reaction, differing in the position of the double bond in the propene fragment. All obtained unsaturated ketones react with hydrazine to form 3,5-disubstituted 4,5-dihydro-1H-pyrazoles.

O-Nitration reactions of betulin and trioxylupane under the action of a nitric acid and acetic anhydride mixture were studied, and effective approaches to the production of mono-, di-, and trinitroesters of the betulin series were developed. A one-stage method for the production of 2,3-seco-28-oxo-19β,28-epoxy-18a-oleane-2,3-dicarboxylic acid from betulin under the action of fuming nitric acid was proposed.

In this study, metal complexes of the corresponding substituted phthalocyanines with magnesium and zinc, aluminum and erbium have been synthesized using the “nitrile” method by heating 4-(2,4,5-trichlorophenoxy)-5-nitrophthalonitrile with acetates and chlorides of some d- and f-metals. The influence of modifications to the peripheral environment of the central phthalocyanine core on spectral and other properties has been investigated. Demetalation of the magnesium complex has yielded the corresponding phthalocyanine ligand, whose acid-base properties have also been studied.

A series of novel aminoacetamides based on isoquinolinium salts was designed by molecular hybridization of the aminoacetamide scaffold and isoquinoline motif. The target compounds were synthesized and their biological activities were evaluated. Some of the target molecules showed excellent antifungal activities against Sclerotinia sclerotiorum. Significantly, 2-{2-[(4-methoxyphenyl)amino]-2-oxoethyl}isoquinolin-2-ium chloride displayed the most potent activity against Sclerotinia sclerotiorum with EC₅₀ = 13.59 μg/mL. Additionally, 2-{2-[(4-methoxyphenyl)amino]-2-oxoethyl}isoquinolin-2-ium chloride, 2-[2-oxo-2-(propylamino)ethyl]isoquinolin-2-ium chloride, 2-[2-(butylamino)-2-oxoethyl]isoquinolin-2-ium chloride and 2-[2-oxo-2-(pentylamino)ethyl]isoquinolin-2-ium chloride showed better acetylcholinesterase inhibition than positive control tacrine.

A series of 2-(pyridin-3-yl)indoles was obtained by reductive desulfurization of pyridothieno[3,2-b]indoles with Raney nickel. It was shown that in the case of chlorine-substituted pyridothienoindoles the reaction was accompanied by dehalogenation.

A method was proposed for the synthesis of new mixed phosphonium-azinium/pyrrolinium salts based on the reactions of nitrogen-containing heterocyclic compounds with 3-bromoalkyltriphenylphosphonium bromides. The structure of the obtained compounds was proven by NMR (¹H, ³¹P, ¹³C) and single crystal X-ray diffraction analysis.

Although pectin and chitosan are popular polymers in the field of drug delivery, their combination serves a vast gap of their unexplored properties and applications for the same. Oral drug route consists of the harsh environment of the alimentary canal where most of the drug carriers get degraded by the digestive enzymes present in the stomach causing early release of drug and thereby, lowering their bioavailability. The current work aims to establish a sustained release formulation of pectin–chitosan composite incorporated with montmorillonite clay for anti-diabetic drug sitagliptin. The prepared composites were assessed for their physical and chemical properties by measuring their mechanical strength, swelling capability, UV transparency and were also characterized by FTIR, SEM, XRD and DSC. An in vitro study conducted in media simulating the physiological conditions of the stomach and intestine showed that approximately 38% of the drug was released in the acidic environment of the stomach, followed by a sustained release pattern in the small intestine. Drug release kinetics study indicated Koresmeyer–Peppas model as best fit indicating diffusion as the driving force behind release of drug from the polymeric matrix. Based on the results obtained, it is anticipated that the prepared composites can act as potential drug carriers for oral administration.

In this study, a series of novel vanillic acid derivatives incorporating 1,3,4-oxadiazole and thioether moieties were synthesized and their structures were confirmed using ¹H NMR, ¹³C NMR, and HRMS techniques. The results of bioactivity determination demonstrated that the target compounds exhibited moderate to good in vitro antibacterial activities against Xanthomonas axonopodis pv. citri (Xac) and Xanthomonas oryzae pv. oryzae (Xoo). Particularly, compound 2-{4-[(4-chlorobenzyl)oxy]-3-methoxyphenyl}-5-(propylthio)-1,3,4-oxadiazole displayed remarkable antibacterial activities against Xac and Xoo with EC₅₀ values of 5.58 and 18.82 μg/mL respectively, surpassing those of bismerthiazol and thiodiazole copper. To the best of our knowledge, this study presents the first report on the synthesis and antibacterial activity evaluation of vanillic acid derivatives incorporating 1,3,4-oxadiazole and thioether moieties.