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1.
Banerjee A Grewer C Ramakrishnan L Jäger J Gameiro A Breitinger HG Gee KR Carpenter BK Hess GP 《The Journal of organic chemistry》2003,68(22):8361-8367
The synthesis and characterization of a new photolabile protecting group (caging group) for carboxylic acids, the 2-(dimethylamino)-5-nitrophenyl (DANP) group, is described. This compound has a major absorption band in the visible wavelength region with a maximum near 400 nm (epsilon400 = 9077 M(-1) cm(-1) at pH 7.4 and 21 degrees C). The caging group is attached through an ester linkage to the carboxyl functionality of beta-alanine, which activates the inhibitory glycine receptor in the mammalian central nervous system. Such caged compounds play an important role in transient kinetic investigations of fast cellular processes. Upon photolysis of DANP-caged beta-alanine, the caging group is released within 5 micros. Quantum yields of 0.03 and 0.002 were obtained in the UV region (308 and 360 nm) and the visible region (450 nm), respectively. Laser-pulse photolysis experiments, using 337 or 360 nm light, were performed with the caged compound equilibrated with HEK 293 cells transiently transfected with cDNA encoding the alpha1 homomeric, wild-type glycine receptor. The experiments demonstrated that neither DANP-caged beta-alanine nor its byproducts inhibit or activate the glycine receptors on the cell surface. Under physiological conditions, the DANP-caged beta-alanine is water-soluble and stable and can be used for transient kinetic measurements. 相似文献
2.
Mondal Imdadul Hoque Rangan Latha Uppaluri Ramagopal V. S. 《Journal of Thermal Analysis and Calorimetry》2021,145(5):2389-2403
Journal of Thermal Analysis and Calorimetry - Drying characteristics of horticultural produce often target studies on the process parameters so as to derive useful data for the development of... 相似文献
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4.
Venkateshwarlu Jetti Ramakanth Pagadala Jyotsna S. Meshram Himani N. Chopde Latha Malladi 《Journal of heterocyclic chemistry》2013,50(Z1):E160-E165
In an attempt to synthesize antibacterial agents effective against gram‐positive and gram‐negative bacteria, the efficient synthesis of novel bis‐azetidinones ( 3a–j ) has been established. Thus, cycloaddition reaction of substituted bis‐imines with chloroacetylchloride under microwave irradiation in the presence of zeolite yielded bis‐azetidinones ( 3a–j ). Structures of the synthesized compounds have been elucidated on the basis of their elemental analysis and spectral data (IR, 1H‐NMR, 13C‐NMR, and mass spectra). The synthesized bis‐azetidinones were screened for their antibacterial activity against five microorganisms: Bacillus subtilis, Proteus vulgaris, Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli. They were found to exhibit good to moderate antibacterial activity. 相似文献
5.
Shwetha U. R Maha Abdallah Alnuwaiser Latha M. S Virupaxappa S. Betageri Shilpa V. A M. Ijaz Khan Kamel Guedri 《印度化学会志》2022,99(9):100606
The present research highlights physical significance of green combination of metal oxide nanomaterials utilizing medicinal plant which has widely analyzed in different medical applications i.e., medicinal science, therapeutics. In this paper, we discussed environmentally benign approach for synthesizing silver doped copper oxide nanoparticles (Ag–CuO NPs) utilizing (ACLE). Scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) were utilized to confirm the size, crystalline structure and surface morphology of the obtained nanomaterials. The monoclinic crystalline structure of the Ag–CuO NPs as produced was revealed by XRD patterns. Morphological analysis disclosed the nano-based spherical configuration of Ag–CuO NPs, as well as their morphology and elemental composition. The anti-diabetic effect of Ag–CuO NPs was further investigated utilizing a yeast cell model and amylase inhibition. Here, a decrease in intracellular glucose and a delay in carbohydrate digestion indicate promising antidiabetic action. Furthermore, the prepared nanomaterial showed anticancer potential against the MCF-7 cancer cell line, with an IC 50 value of 11.21 g/ml. 相似文献
6.
The layered double hydroxides (LDHs) of Li and Al can be synthesized from the four polymorphs of Al(OH)3, namely gibbsite, bayerite, nordstrandite, and doyleite. The crystal structure of this class of compounds depends on the type of the precursor used due to their topotactic reaction mechanism. While the LDHs derived from gibbsite and bayerite yield different crystal structures, the incorporation of Li into nordstrandite was expected to yield new LDH structures different from those derived from gibbsite and bayerite. The structure of nordstrandite derived LDHs were however identical to that derived from the bayerite counterpart. The absence of symmetry in the interlayer of nordstrandite (C1) makes it unsuitable to accommodate the intercalating anions with different molecular symmetries. To make the interlayer gallery suitable for the anions, the metal hydroxide layers of the nordstrandite translate, transforming nordstrandite to bayerite. The bayerite with site symmetries Oh and C2 stabilizes the anions in the interlayer by hydrogen bonding. The transformation of nordstrandite to bayerite, when soaked in lithium salt solution is, therefore, a manifestation of the intercalating anions. 相似文献
7.
P. Pardhasaradhi D. Madhavi Latha P. V. Datta Prasad G. Padmaja Rani P. R. Alapati V. G. K. M. Pisipati 《Journal of Thermal Analysis and Calorimetry》2013,111(2):1483-1490
As a part of the systematic studies on symmetric liquid crystal dimer homologous series, α,ω-bis-(4-n-alkylaniline benzylidene-4′-oxy) alkanes, (referred to as m.OnO.m with m = 3, 4, and 5; and n = 8, 9, and 10), we present in this article the nature of phase transitions across isotropic–nematic and nematic–smectic-A (N–SmA) phases exhibited by the just mentioned compounds. The methods employed are differential scanning calorimetry and dilatometry. The compounds studied were 3.O8O.3, 4.O8O.4, and 5.O8O.5; and 3.O9.03, 5.O9O.5, 3.O10O.3, 4.O10O.4, and 5.O10O.5. Different from the case of their corresponding monomers, all these compounds exhibit a nematic phase only with the exception of 5.O8O.5 which exhibits a SA phase in addition to the nematic phase. The phase transitions viz., isotropic–nematic transitions studied in all these compounds were confirmed to be of first-order nature, whereas the N–SmA transition exhibited by the compound 5.O8O.5 only was found to be of second-order nature. We also report in this article the calculated density jumps, thermal expansion coefficient maxima, and pressure dependence of transition temperatures which are analyzed in the light of the available literature data. 相似文献
8.
Syahmi AR Vijayarathna S Sasidharan S Latha LY Kwan YP Lau YL Shin LN Chen Y 《Molecules (Basel, Switzerland)》2010,15(11):8111-8121
Elaeis guineensis (Arecaceae) is widely used in West African traditional medicine for treating various ailments. An evaluation on the toxicity of extracts of this plant is crucial to support the therapeutic claims. The acute oral toxicity and brine shrimp lethality of a methanolic extract of this plant was tested. Oral administration of crude extract at the highest dose of 5,000 mg/kg resulted in no mortalities or evidence of adverse effects, implying that E. guineensis is nontoxic. Normal behavioral pattern, clinical signs and histology of vital organs confirm this evidence. The E. guineensis extracts screened for toxicity against brine shrimp had 50% lethal concentration (LC??) values of more than 1.0 mg/mL (9.00 and 3.87 mg/mL, at 6 and 24 h, respectively), confirming that the extract was not toxic. Maximum mortalities occurred at 100 mg/mL concentration while the least mortalities happened to be at 0.195 mg/mL concentration. The results of both tests confirm that E. guineensis is nontoxic and hence safe for commercial utilization. 相似文献
9.
K. Madhavi Latha 《Journal of Quantitative Spectroscopy & Radiative Transfer》2006,101(2):367-379
The extent to which airborne particles penetrate into the human respiratory system is determined mainly by their size, with possible health effects. The research over the scientific evidence of the role of airborne particles in adverse health effects has been intensified in recent years. In the present study, seasonal variations of PM10 and its relation with anthropogenic activities have been studied by using the data from UK National Air Quality Archive over Reading, UK. The diurnal variation of PM10 shows a morning peak during 7:00-10:00 LT and an evening peak during 19:00-22:00 LT. The variation between 12:00 and 17:00 LT remains more or less steady for PM10 with the minimum value of ∼16 μg m−3. PM10 and black smoke (BS) concentrations during weekdays were found to be high compared to weekends. A reduction in the concentration of PM10 has been found during the Christmas holidays compared to normal days during December. Seasonal variations of PM10 showed high values during spring compared to other seasons. A linear relationship has been found between PM10 and NOx during March, July, November and December suggesting that most of the PM10 is due to local traffic exhaust emissions. PM10 and SO2 concentrations showed positive correlation with the correlation coefficient of R2=0.65 over the study area. Seasonal variations of SO2 and NOx showed high concentrations during winter and low concentrations during spring. Fraction of BS in PM10 has been found to be 50% during 2004 over the study area. 相似文献
10.
CeO2/zeolite nanocomposite was successfully prepared by the mixing-calcination method. The structural characteristics of photocatalyst were investigated by XRD, SEM, TEM and EDX. Photocatalytic degradation experiments were carried out with varying amounts of the CeO2/zeolite, the ratio of 3:1 (CeO2/zeolite) was exhibited excellent photocatalytic activity towards dye degradation. Synergistic effect of CeO2/zeolite played a key role in photocatalytic degradation. The main reactive oxygen species was determined by trapping experiments. Additionally, the recyclability was tested up to the fourth cycle. The CeO2/zeolite nanocomposite is a promising photocatalyst for removing trace and unprocessed organic contaminants in the industrial dye waste water treatment. The efficiency of CeO2/zeolite nanocomposite offers a potential economical route to degrade organic contaminants and recovering photocatalyst simultaneously. 相似文献