Classical and advanced chemical sciences
A series of new hydrazone derivatives were synthesized using dicyclopropyl ketone as starting material. Unexpected reaction of salicylaldehyde with (dicyclopropylmethylene)hydrazine yielded the appropriate bis(salicylaldehyde azine). Treatment of the (dicyclopropylmethylene)hydrazine with the appropriate coupling agents gave the corresponding imides, imidazolones, oxazolones, quinazolinones and triazoles, respectively. The synthesized compounds were characterized using IR, 1H-NMR, 13C-NMR and mass spectral data. These newly formed products were tested for their antibacterial and antifungal activities and most of the compounds showed high activity compared with Ciprofloxacin as positive controls. In addition, the compounds were also, examined for their anticancer activities against breast cancer cell line (MCF7) compared with cisplatin as a positive control. The novel synthesized compounds showed satisfactory activity against (MCF7) with mean IC50 values ranging from 21.5 to 100 μM.
Keywords: Hydrazones; Dicyclopropyl ketone; Anticancer activity; Antibacterial activity
New thiazolidinones and γ- lactams were prepared from mixtures of Schiff base (imine) and thioglycolic acid or phenylsuccinic anhydride, respectively, in moderate yields (52-71 %). The structures of these new thiazolidinones and γ-lactams were established on the basis of the IR, 1H-NMR,13C-NMR, 13C-NMR DEPT and mass spectral data.
Keywords: thiazolidinones; five-membered γ- lactams; imines
[Bmim]OH mediated new synthesis of 3-(1H-indol-3-yl)acrylonitrile derivatives 6 have been developed by the reaction of diethyl phthalate (1) with ethyl cyanoacetic acid hydrazide (2) to form 3-(1,4-dioxo-3,4-dihydrophthalazin-(1H)-yl)-3-oxopropanenitrile (3). Then compound 3 reacted with indole-3-aldehyde (4) by Knoevenagel condensation to form compound 2-(1,4-dioxo-1,2,3,4-tetrahydrophthalazine-2-carbonyl)-3-(1H-indol-3-yl)acrylonitriles (5). Compounds 5 undergo alkylation with alkylating agents to form 6 with good yields. Compounds 6 could also be synthesized by alkylation of 4 followed by condensation with 3.
Keywords: Ionic liquid, [Bmim]OH and green synthesis
Materials and environmental chemistry
This work reports on the development of a bacteria-based inhibition biosensor array for detection of different types of pollutions, i.e. heavy metal ions (Zn2+), pesticides (DDVP) and petro-chemicals (pentane), in water. The biosensor chip for preliminary identification of the above water pollutants is based on three types of bacteria (Escherichia coli, Shewanella oneidensis and Methylosinus trichosporium OB3b) immobilized on screen-printed gold electrode surface via poly L-lysine which provides strong adhesion of bacterial monolayer to the electrode without losses of biological function. A series of optical measurements and DC electrochemical measurements were carried out on these three types of bacteria species immobilized on modified screen printed gold electrodes as well as on the bacteria in solution samples. The principle of electrochemical detection of pollutants is based on the facts that live bacteria adsorbed (or immobilized) on the electrode surface appeared to be insulating and thus reducing the electrochemical current, while the bacteria damaged by pollutants are less insulating. The results obtained demonstrated different effects of the three different types of analytes studied, e.g. Zn2+, DDVP, and pentane, on the three bacteria used. The findings are encouraging for application of a pattern recognition approach for identification pollutants which may lead to development of a novel, simple, and cost-effective bio-sensing array for preliminary detection of environmental pollutants in water.
Keywords: Water pollution, inhibition biosensor, bacteria-based biosensor, immobilized bacteria, electrochemical sensor, sensor array, pattern recognition
Chemical and biological aspects of life
Essential oil from Calotropis gigantea (L) leaves was extracted by hydrodistillation method followed of solvent extraction and characterized by GC-FID and GC-MS techniques. The chemical profiling estimated the presence of 42 components, representing 82.5 % of the total oil composition. Phytol (17.94 %), phenylacetaldehyde (9.16 %), 4-methyl-1-heptanol (4.98 %), benzyl alcohol (4.10 %), 4-vinyl guaiacol (3.87 %), 4-methyl-3-penten-1-ol (3.83%), Gentanol (2.93 %), 2-hexyn-1-ol (2.86 %) and phenethyl alcohol (2.52 %) were found to be the major constituents. Further, biological activities of the extracted oil were studied on the fungal (Candida albicans) and bacterial (Escherichia Coli, Pseudomonas aeruginosa and Staphylococcus aureus) pathogens. 100 μl essential oil extracted from leaf shows effective antimicrobial activity against selective bacterial and fungal pathogens. Among bacterial pathogens, leaf oil showed highest antimicrobial activity against Pseudomonas aeruginosa followed by Escherichia coli and Staphylococcus aureus.
Keywords: Calotropis gigantea, Essential oil; Phytol; Antimicrobial activity.
Prosopis farcta is a widespread weed in the Near East and its an invasive plant of southwestern parts of the USA. Despite being sufficiently studied in the past, some of its activities were not published. In this research, we studied the antifungal and anti-termite activities of four extracts of the plant aerial parts: aqueous, ethanolic, ethyl acetate and hexane. In addition, since the published reports of total phenolic content (TPC) are not consistent, we tested this as well. We also tested the potential of the aqueous extract of Carya illinoinensis as possible weed biocontrol against P. farcta. The n-Hexane extract had the highest antifungal and anti-termite activities. TPC was found around 13.9 mg of gallic acid equivalent for 1 g of dry ethanolic extract (highest). The attempts to use an aqueous extract of C. illinoinensis for weed biocontrol of P. farcta achieved very limited success
Keywords: Prosopis farcta, antifungal, anti-termite, total phenolic content, flavonoids, biocontrol