Synthesis and antibacterial screening of new N-Substituted-9H-β-carboline 6-amine derivatives

β-Carboline is also known as nor-harmane. It is a nitrogen-containing heterocyclic compound formed in plants and animals as Maillard reaction products between amino acids and reducing sugars or aldehydes. These tricyclic nitrogen heterocyclics play a vital role in medicinal chemistry, due to significant biological activities of their derivatives. It is also a key pharmacophore present in a large number of natural tricyclic alkaloids. Current work is reported with the synthesis and antibacterial activity screening of a new series of N-Substituted-9H-β-carboline-6-amine derivatives. The title compounds were synthesized according to the well known Pictet Spengler reaction in three steps by taking 5-Chlorotryptamine and glyoxalic acid as starting materials. This is an acid-catalyzed intramolecular condensation of an iminium ion and an aromatic C-nucleophile which resulted in the formation of 6-Chloro-1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indol-2-ium-1-carboxylate (3). Oxidative decarboxylation and aromatization of compound 3 with iodobenzene diacetate led to the 6-Chloro-β–carboline (4) which were treated with different mono substituted amines gave the title compounds (5 a-J). Structures of the synthesized entities were confirmed spectroscopically (FT-IR, 1H NMR and Mass) and screened for antibacterial activity against various pathogenic bacterial strains ( Streptococcus pyogenes, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) by disc diffusion method. The title compounds showed moderate to good antibacterial activity.

EFFECT OF SURFACTANT ON THE MORPHOLOGY OF ZnO/Al:ZnO NANOSTRUCTURES AND THEIR ETHANOL SENSING APPLICATIONS AT ROOM TEMPERATURE

Zinc oxide (ZnO) and aluminum (Al) doped ZnO nanostructures with and without surfactant have been successfully prepared via sol-gel route. The effect of the surfactant glyoxalic acid and various concentration of Al on the structural property of ZnO was analyzed by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR). The morphology of the samples was recorded using field emission scanning electron microscopy. The uniform distribution of ZnO nanostructures with hexagonal facets is facilitated by the surfactant and the grain growth is further inhibited by the increase in concentration of Al. The ethanol (0–300[Formula: see text]ppm) sensing characteristics of the as-prepared samples were systematically investigated at room temperature. Surfactant-assisted ZnO/Al:ZnO nanostructures show higher sensitivity of 94% at room temperature than ZnO/Al:ZnO nanostructures without surfactant. Faster response at 68[Formula: see text]s and recovery at 50[Formula: see text]s is also achieved by the samples. The surfactant-assisted ZnO nanostructures exhibit sharp selective detection towards ethanol when compared to the samples without surfactant. The enhanced ethanol sensing property may be ascribed to the larger surface area which is due to uniform and smaller crystallite size of the surfactant-assisted sample.

The formation of aldehydes and ketones ozonation by-products and their variation through general water treatment plant in Hamadan, Iran

<div> <p>The effect of pre-ozonation on the formation of four aldehydes (i.e. formaldehyde, acetaldehyde, glyoxal, methyl glyoxal) and two ketones (i.e. pyruvic acid and glioxalic acid) at the Beheshti water treatment plant in Hamadan, Iran were studied. Water samples were taken from the treatment plant at different points of the treatment train during September-January, 2013. The variation of formaldehyde, acetaldehyde, glyoxal, methyl glyoxal, pyruvic acid, and acid glioxalic concentration within treatment process were monitored in September and January. The results indicated that formaldehyde and acetaldehyde were the most abundant aldehyde species in the raw water. After pre-ozonation all of the aldehydes and ketones reached the maximum concentration. On the contrary, results show that the coagulation-filtration process was beneficial to the removal of aldehydes and ketones. Also, the results indicated that the level of aldehydes was increased after post chlorination. The percent increase was 52.3, 34.6, 12.1, 26.8 and 38% for formaldehyde, acetaldehyde, glyoxal, methyl glyoxal and glyoxalic acid, respectively, in September. Therefore, final chlorination led to increase in the formation of aldehydes in the pre-ozonated water. Ketones were not detected in the post-chlorinated water. Moreover, there was no correlation between total organic carbon (TOC) and total aldehyde and total ketone in water samples.&nbsp;</p> </div> <p>&nbsp;</p>