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921.
Saloni Kakkar Sanjiv Kumar Siong Meng Lim Kalavathy Ramasamy Vasudevan Mani Syed Adnan Ali Shah Balasubramanian Narasimhan 《Chemistry Central journal》2018,12(1):130
Background
In view of wide range of biological activities of oxazole, a new series of oxazole analogues was synthesized and its chemical structures were confirmed by spectral data (Proton/Carbon-NMR, IR, MS etc.). The synthesized oxazole derivatives were screened for their antimicrobial and antiproliferative activities.Results and discussion
The antimicrobial activity was performed against selected fungal and bacterial strains using tube dilution method. The antiproliferative potential was evaluated against human colorectal carcinoma (HCT116) and oestrogen- positive human breast carcinoma (MCF7) cancer cell lines using Sulforhodamine B assay and, results were compared to standard drugs, 5-fluorouracil and tamoxifen, respectively.Conclusion
The performed antimicrobial activity indicated that compounds 3, 5, 6, 8 and 14 showed promising activity against selected microbial species. Antiproliferative screening found compound 14 to be the most potent compound against HCT116 (IC50?=?71.8 µM), whereas Compound 6 was the most potent against MCF7 (IC50?=?74.1 µM). Further, the molecular docking study has been carried to find out the interaction between active oxazole compounds with CDK8 (HCT116) and ER-α (MCF7) proteins indicated that compound 14 and 6 showed good dock score with better potency within the ATP binding pocket and may be used as a lead for rational drug designing of the anticancer molecule.
922.
Rehana Saeed Syed Muhammad Saqib Nadeem 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(6):1143-1150
The kinetics of the electron transfer reaction of methylene green and titanium trichloride was investigated in different solvents by spectrophotometry at different temperatures. The the reaction rate was determined by monitoring the absorbance as a function of time at λmax 655 nm. The reaction is pseudo-first order, dependent only on the concentration of titanium trichloride at a fixed concentration of methylene green. 相似文献
923.
Amjad Hussain Achyut Adhikari Syed Abdulmajid Ayatollahi Atta-ur-Rahman 《Natural product research》2016,30(13):1511-1516
A new adduct of abietane-type diterpene, salvialeriicone (1), was isolated from Salvia leriifolia Benth., along with a new chemical entity nor-abietane diterpene, 2-isopropyl-8,8-dimethyl-7,8-dihydrophenanthrene-1,4,5(6H)-trione (2). Their structures were determined using mass spectrometry, and 1D- and 2D-NMR spectroscopy. 相似文献
924.
Shukor MY Masdor N Baharom NA Jamal JA Abdullah MP Shamaan NA Syed MA 《Applied biochemistry and biotechnology》2008,144(3):283-291
A heavy-metal assay has been developed using bromelain, a protease. The enzyme is assayed using casein as a substrate with
Coomassie dye to track completion of hydrolysis of casein. In the absence of inhibitors, casein is hydrolysed to completion,
and the solution is brown. In the presence of metal ions such as Hg2+ and Cu2+, the hydrolysis of casein is inhibited, and the solution remains blue. Exclusion of sulfhydryl protective agent and ethylenediaminetetraacetic
in the original assay improved sensitivity to heavy metals several fold. The assay is sensitive to Hg2+ and Cu2+, exhibiting a dose–response curve with an IC50 of 0.15 mg l−1 for Hg2+ and a one-phase binding curve with an IC50 of 0.23 mg l−1 for Cu2+. The IC50 value for Hg2+ is found to be lower to several other assays such as immobilized urease and papain assay, whilst the IC50 value for Cu2+ is lower than immobilized urease, 15-min Microtox™, and rainbow trout. 相似文献
925.
Shukor MY Rahman MF Shamaan NA Lee CH Karim MI Syed MA 《Applied biochemistry and biotechnology》2008,144(3):293-300
Molybdenum-reducing activity in the heterotrophic bacteria is a phenomenon that has been reported for more than 100 years.
In the presence of molybdenum in the growth media, bacterial colonies turn to blue. The enzyme(s) responsible for the reduction
of molybdenum to molybdenum blue in these bacteria has never been purified. In our quest to purify the molybdenum-reducing
enzyme, we have devised a better substrate for the enzyme activity using laboratory-prepared phosphomolybdate instead of the
commercial 12-phosphomolybdate we developed previously. Using laboratory-prepared phosphomolybdate, the highest activity is
given by 10:4-phosphomolybdate. The apparent Michaelis constant, K
m for the laboratory-prepared 10:4-phosphomolybdate is 2.56 ± 0.25 mM (arbitrary concentration), whereas the apparent V
max is 99.4 ± 2.85 nmol Mo-blue min−1 mg−1 protein. The apparent Michaelis constant or K
m for NADH as the electron donor is 1.38 ± 0.09 mM, whereas the apparent V
max is 102.6 ± 1.73 nmol Mo-blue min−1 mg−1 protein. The apparent K
m and V
max for another electron donor, NADPH, is 1.43 ± 0.10 mM and 57.16 ± 1.01 nmol Mo-blue min−1 mg−1 protein, respectively, using the same batch of molybdenum-reducing enzyme. The apparent V
max obtained for NADH and 10:4-phosphomolybdate is approximately 13 times better than 12-phoshomolybdate using the same batch
of enzyme, and hence, the laboratory-prepared phosphomolybdate is a much better substrate than 12-phoshomolybdate. In addition,
10:4-phosphomolybdate can be routinely prepared from phosphate and molybdate, two common chemicals in the laboratory. 相似文献
926.
Cold water fish gelatin films: Effects of cross-linking on thermal, mechanical, barrier, and biodegradation properties 总被引:1,自引:0,他引:1
Bor-Sen Chiou Roberto J. Avena-Bustillos Haani Jafri Syed H. Imam William J. Orts 《European Polymer Journal》2008,44(11):3748-3753
Gelatin was extracted from Alaska pollock (Theragra chalcogramma) and Alaska pink salmon (Oncorhynchus gorbuscha) skins and cast into films. The fish gelatin films’ tensile, thermal, water vapor permeability, oxygen permeability, and biodegradation properties were compared to those of bovine and porcine gelatin films. In addition, fish gelatin films were cross-linked with glutaraldehyde. Pollock and salmon gelatin films had comparable tensile properties, but had lower tensile strength and percent elongation than mammalian gelatin films. The lower strength and elongation might have been due to lower structural gelatin levels present in fish gelatin films. The addition of cross-linkers had little effect on tensile properties and melting temperatures of fish gelatin films. Pollock gelatin films had the lowest water vapor and oxygen permeability values, whereas mammalian gelatin films had the highest permeability values. Cross-linking resulted in lower water vapor permeability for salmon gelatin films and higher oxygen permeability for pollock gelatin films. However, all fish gelatin films had better water vapor and oxygen barrier properties than mammalian gelatin films. Also, fish gelatin films degraded faster than mammalian gelatin films. 相似文献
927.
Ansari R Kazi TG Jamali MK Arain MB Sherazi ST Jalbani N Afridi HI 《Journal of AOAC International》2008,91(2):400-407
A simple and fast procedure is proposed for the extraction of iron (Fe), copper (Cu), and nickel (Ni) in 16 varieties of sunflower seed oil samples using an ultrasonic bath. The experimental parameters of the ultrasonic-assisted extraction (UAE) method were optimized to improve the sensitivity and detect the metals at trace levels in minimum time. Conventional wet acid digestion method was used for comparative purposes. The optimum recovery of all 3 metals was obtained by UAE for 7 min, while the separation of aqueous and organic phases after extraction using centrifugation (UAE-2) required 3 min, as compared to the conventional equilibration method (UAE-1) that required 90 min. The respective recoveries of Cu, Fe, and Ni obtained with UAE-2 were in the range of 95.8-97.5, 93.5-98.3, and 95.6-98.2%, respectively, for different varieties of sunflower oil samples. Accuracy was determined by the standard addition method. Under the optimum operating conditions, the limits of detection obtained from the standard addition curves were 21.7, 20.4, and 35.6 ng/mL for Fe, Cu, and Ni, respectively. The fact that all varieties of sunflower oil contain significant amounts of Fe, Cu, and Ni indicates the deterioration of sunflower oil quality immediately after extraction from seeds, which poses a threat to oil quality and human health. 相似文献
928.
Guoquan Suo Yan Cheng Jiaqi Zhang Syed Musab Ahmed Xiaojiang Hou Yanling Yang Xiaohui Ye Li Zhang 《Materials Today Chemistry》2022
Potassium-ion batteries (PIBs) have gained considerable attention in the past decade because of the rich potassium reserves in our planet. However, the development of anode materials is still a major challenge because of the hard reaction kinetics and poor cycling stability in the insertion/extraction process. Herein, we report interconnected MnCO3 nanostructures anchored on carbon fibers (MnCO3/CF) composites as anode for PIBs. The MnCO3/CF can be directly used as anode on PIBs, avoiding the addition of polyvinylidene fluoride (PVDF) binders and the complicated slurry coating onto copper process. The nanosized MnCO3 nanostructures are interconnected with each other, which can provide short ions diffusion length during the charge/discharge process. The MnCO3 nanostructures are firmly anchored on the surface of CF through C–Mn bonds, ensuring cycling stability. Also, the CF with good electronic conductivity guarantees fast electrons transportation in MnCO3/CF system. Benefiting from the advantageous features mentioned earlier, the MnCO3/CF anode behaves enhanced potassium storage performance compared with that of pure MnCO3 anode. The MnCO3/CF anode delivers a high capacity of 462 mAh/g at 50 mA/g after 100 cycles, whereas the capacity of pure MnCO3 anode is only 134 mAh/g at 50 mA/g after 80 cycles. This work demonstrates the prospect of metal carbonate as anode materials for PIBs and provides a useful strategy to design advanced anode materials for PIBs. 相似文献
929.
Jamila Javid Aziz-ur-Rehman Muhammad A. Abbasi Sabahat Z. Siddiqui Javed Iqbal Naeem A. Virk Shahid Rasool Hira A. Ali Muhammad Ashraf Wardah Shahid Safdar Hussain Syed A. Ali Shah 《Journal of heterocyclic chemistry》2021,58(1):93-110
A comparative microwave assisted and conventional synthetic strategies were applied to synthesize heterocyclic 1,3,4-oxadiazole analogues as active anti-enzymatic agents. Green synthesis of compound 1 was achieved by stirring 4-methoxybenzenesulfonyl chloride ( a ) and ethyl piperidine-4-carboxylate ( b ). Compound 1 was converted into respective hydrazide ( 2 ) by hydrazine and then into 1,3,4-oxadiazole ( 3 ) by CS2 on reflux. The electrophiles, N-alkyl/aralkyl/aryl-2-bromopropanamides ( 6a–p ) were synthesized and converted to N-alkyl/aralkyl/aryl-2-propanamide derivatives ( 7a–p ) by reaction with 3 under green chemistry. Microwave assisted method was found to be effective relative to conventional method. 13C-NMR, 1H-NMR and IR techniques were availed to corroborate structures of synthesized compounds and then subjected to screening against lipoxygenase (LOX), α-glucosidase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. A number of compounds presented better potential against these enzymes. The most active compounds against LOX and α-glucosidase enzymes were subjected to molecular docking study to explore their interactions with the active sites of the enzymes. 相似文献
930.
The pooling layer is at the heart of every convolutional neural network (CNN) contributing to the invariance of data variation. This paper proposes a pooling method based on Zeckendorf’s number series. The maximum pooling layers are replaced with Z pooling layer, which capture texels from input images, convolution layers, etc. It is shown that Z pooling properties are better adapted to segmentation tasks than other pooling functions. The method was evaluated on a traditional image segmentation task and on a dense labeling task carried out with a series of deep learning architectures in which the usual maximum pooling layers were altered to use the proposed pooling mechanism. Not only does it arbitrarily increase the receptive field in a parameterless fashion but it can better tolerate rotations since the pooling layers are independent of the geometric arrangement or sizes of the image regions. Different combinations of pooling operations produce images capable of emphasizing low/high frequencies, extract ultrametric contours, etc. 相似文献