Classical chemical sciences
The conversion of the 2(3H)-furanone into the oxazinone and pyrimidinone derivatives are studied. A 2-(furan-2-ylmethylene)-4-oxo-4-phenylbutanoyl azide 3 was synthesized to carry out these conversions through its thermolysis in dry benzene and base-catalyzed decomposition of this azide in the presence of different amines. The structures of all compounds were demonstrated from their spectral data and elemental analyses.
Keywords: 2(3H)-furanone, acid hydrazide, acylazide, oxazinone, pyrimidinones
Knoevenagel condensation of pyrazole aldehydes with malononitrile is selectively carried out using ammonium carbonate as a mild, cheap, efficient and selective catalyst, in aqueous media at ambient temperature under sonication. This method is green and providing an expeditious way for Knoevenagel condensation of pyrazole aldehyde.
Keywords: Pyrazole aldehyde, malononitrile, Knoevenagel condensation, ammonium carbonate, aqueous medium
Synthesis of new azetidin-2-ones on the basis of 4-aminophenyl-3-nitrobenzopyran-2-one is reported. By condensation reaction of 4-chloro-3-nitrobenzopyran-2-one 2 and phenylenediamine, 4-(4-aminophenylamino)-3-nitrochromen-2-one 3 is synthesized in high yield. Catalytic condensation of product 3 and benzaldehyde, salicylaldehyde and 3-nitrobenzaldehyde, afforded novel derivatives of 4-[4-(benzylideneamino)phenylamino]-3-nitrobenzopyran-2-one, 4a-4c. In the following series of reactions, by cyclization of the products 4a-4c with acetyl chloride, corresponding substituted azetidinones 5a-5c are synthesized. Structural characterization of the synthesized products is done on the basis of spectrometric data. Compounds of series 4a-4c and 5a-5c are examined for their antibacterial activity against S. aureus, E. coli, and Klebsiella. Antibacterial activity is examined by measuring the inhibition zones around the disks marked with the corresponding product solutions in DMF concentration 2 mg mL-1, 4 mg mL-1, and 6 mg mL-1. Compounds of series 4 have shown moderate antibacterial activity against these microorganisms, whereas compounds of series 5 have shown significant activity. The impact of substitutions in antimicrobial activity is also explored.
Keywords: azetidin-2-one, 3-nitrobenzopyran-2-one; condensation; cyclization; antmicrobial citvity
Chemical and biological aspects of life
Plants belonging to the genus Arum are being used for nutritional and medicinal purposes for many centuries, despite their toxicity. Few subspecies of this genus were widely investigated by modern research, mainly for potential therapeutic goals and drug discovery. Other subspecies were never studied by current research despite the fact that some of them have known and well documented traditional medicinal and other uses. In this review article, we will present the traditional uses of this plant genus and summarize the published results of modern medicinal and other studies of these plants. Special attention will be drawn to effective, natural products that were isolated from these plants. The toxicity of the plants will be discussed extensively.
Keywords: Arum, alkaloids, toxicity, anticancer, antibacterial, volatile amines
The best preservation of tissue structures for a long time has been reached by the embedding of tissues into epoxy resins. The aim of the current research is to show the potential of light microscopic studies on the research of blood vessels of tissues embedded and conservated in epoxide resins. Our results demonstrated that preservation of tissue in epoxide resins proved to be a convenient method for theirs studying under light microscope independently of the age and temperature conditions of the sample storage.
Keywords: Light optical microscopy, epoxy resin, coronary artria disease (CAD), liver, chronic stress
Pycnanthus angolensis (Welw.) Warb. (Family; Myristiceae) leaves were extracted cold with 50 % ethanol and the obtained aqueous crude extract partitioned with ethyl acetate. Furthermore, the ethyl acetate fraction was subjected to silica gel column chromatography and the isolated chemical compounds tested for antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans. The identities of two isolates have been revealed to be 3-ethoxy-3,7-dimethyl-1, 6-octadiene (ethyl linalool) and diethyl phthalate (1,2-benzenedicarboxylic acid diethyl ester) using the MS and IR spectral techniques. Both compounds showed strong bacteriostatic action against E. coli but were inactive against S. aureus and C. albicans.
Keywords: Pycnanthus angolensis; fraction; chromatography; isolates; antimicrobial effect.
Industrial and engineering chemistry, biotechnology
The problems of purification of quarry waters from the ions of heavy metals by the use of electrochemical method are considered and a construction of electrochemical reactor is described allowing to perform the so-called channel electrolysis at a high rate of liquid flow along of the electrodes in the conditions of limiting cathode current density (Jk). Technological schemes of complex processing of quarry waters for separation of useful components and estimation of their economic efficiency are presented.
Keywords: electrochemical processing; quarry waters; copper
Theoretical and computational chemistry
Structural-dynamic processes in macro- and microsystems, including the specifics of formation of direct or reverse rotation of the planets are explained based on the previously proposed method to evaluate the corpuscular-wave mechanism. Equations of dependence of rotational and orbital motions of planets are given, their rotation angles are calculated. Wave principles of direct and reverse rotation of planets are also established.
Keywords: orbital and rotational motion; direct and reverse rotation; planets; rotation angles