Lyoluminescence of luminol induced by -irradiated NaCl has been studied in aqueous amines. The emission spectra of lyoluminescence are recorded on 400 ASA Kodak film using a Fuess spectrograph. A broad continuous emission band appears in the visible region from 390 to 500 nm. The emission band showed two peaks centered at 430 and 470 nm. The 430 nm peak is more intense in secondary amines while the 470 nm band is more intense in primary amines. The mechanism of light emission is based on the comparative study of lyoluminescence, fluorescence and chemiluminescence of luminol in aqueous amines. 相似文献
A new synthetic strategy has been devised to access a variety of polyhydroxylated piperidines belonging to the azasugar class of glycosidase inhibitors. The key precursor (3aR, 7aR)-5-benzyl-2,2-dimethyl-7-methylenehexahydro[1,3]dioxo[4,5-c]pyridine is obtained by photoinduced electron transfer (PET) cyclization of the corresponding alpha-trimethylsilylmethylamine radical cation to the tethered acetylene functionality. The new molecules have been evaluated for inhibitory properties for certain beta-glycosidases and have been found to be moderate to weak inhibitors of the enzymes under study. 相似文献
The process of phenol biodegradation by the yeast Candida tropicalis NCIM 3556 in aqueous medium was studied by 1H, 13C, and DOSY NMR techniques. Samples at regular intervals were centrifuged to separate the cells, and 1H spectral data were collected at 400 MHz. Though a gradual decrease in the concentration of phenol was observed, after an incubation period of ~8 h, formation of any intermediate products could not be detected. Experiments carried out with uniformly 13C-labeled phenol also failed to detect formation of any carboxylic acid intermediates during degradation. The studies indicated that the phenol was completely degraded to carbon dioxide and water in approximately 20 h. Self-diffusion coefficient measurements showed that the lifetime of phenol in the bound form is too small to impart any change in its diffusion behavior and the intermediates formed are converted to carbon dioxide and water at a very fast rate. 相似文献
Quorum sensing (QS) is the communication between bacterial cells governed by their population density and regulated by the genes controlling virulence factors and biofilm formation. Multiple mechanisms of biofilms are resistive to antimicrobial chemotherapy; therefore novel strategies are required to overcome its limitations. Here, we report the effect of various copper oxide nanostructures (CuO-NSs) on quorum sensing inhibition. The two-dimensional CuO-NSs such as interlaced nanodiscs, nanodiscs and leaf-shaped nanosheets are prepared via a simple chemical method. The Quorum sensing inhibition (QSI) activity of all the CuO-NS are examined using reporter strain Chromobacterium violaceum CV026 and Escherichia coli pSB1142. We found that the CuO-interlaced nanodisc structures exhibit better QSI activity than nanodiscs and leaf-shaped sheets. The interlaced nanodisc structures are inhibited various long-chain N-acyl homoserine lactones (AHLs) mediated QS individually and confirmed by other QS-associated phenomena for Pseudomonas aeruginosa, including biofilm inhibition, inhibition of virulence factors such as pyocyanin, protease production and swarming motility. Thus QSI activity of CuO-NSs is solely dependent on specific shape offering large surface area and more active sites. The CuO-NS is effective quorum sensing inhibitors, which has potential clinical applications in the management of P. aeruginosa associated infections.
We have developed a simple method for the chemoselective aromatization of tetrahydro-β-carboline with selective nondeallylation O-allyl groups in the presence of iodine (100 mol %) in dimethyl sulfoxide/H2O2. A convergent approach toward the oxidative aromatization with selective deallylation (deprotection) of O-allyl-tetrahydro-β-carboline using iodine in dimethyl sulfoxide/HCl has been described. The present protocol contains cheap catalyst, easy work up, normal reaction conditions, and high selectivity. 相似文献
Chemistry of Natural Compounds - (3E,7Z)-Tetradecadienyl acetate, the major sex pheromone component of the potato pest Symmetrischema tangolias (Gyen), was stereoselectively synthesized from the... 相似文献