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21.
Synthesis and Antioxidant Activity of Amido‐Linked Benzoxazolyl/Benzothiazolyl/Benzimidazolyl‐Pyrazoles and Isoxazoles 下载免费PDF全文
Suram Durgamma Putta Ramachandra Reddy Venkatapuram Padmavathi Adivireddy Padmaja 《Journal of heterocyclic chemistry》2016,53(3):738-747
A new class of amido‐linked bis heterocycles‐benzoxazolyl/benzothiazolyl/benzimidazolyl‐pyrazoles and isoxazoles were prepared from benzoxazolyl /benzothiazolyl/benzimidazolyl‐cinnamamides and tested for antioxidant activity. 相似文献
22.
Saibabu Polina V. P. Rama Kishore Putta Raghuram Gujjarappa Prasad Pralhad Pujar Chandi C. Malakar 《Journal of heterocyclic chemistry》2021,58(4):1029-1033
An efficient and mild protocol was realized using 1,2-diazoles and related heterocycles with cyclic and acyclic enones in presence of T3P (2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphorinane-2,4,6-trioxide) toward the regioselective formation of N-cycloalkyl heterocycles at room temperature. The developed reaction conditions showcased good selectivity over a wide range of 1,2-diazoles and enones by delivering N-cycloalkyl heterocycles in excellent yields. 相似文献
23.
Ravi Kumar Vuradi Srishailam Avudoddi Venkat Reddy Putta Laxma Reddy Kotha Praveen Kumar Yata Satyanarayana Sirasani 《Journal of fluorescence》2017,27(3):939-952
Three ruthenium(II) polypyridyl complexes, [Ru(phen)2(mip)](ClO4)2 (1) (phen =1,10-Phenanthroline), [Ru(bpy)2(mip)](ClO4)2 (2) (bpy = 2,2’bipyridyl) and [Ru(dmb)2(mip)](ClO4)2 (3) (dmb = 4, 4′-dimethyl 2, 2′-bipyridine), were synthesized with an intercalative ligand mip (2-morpholino-1H-imidazo[4,5-f][1, 10]phenanthroline) and characterized by 1H, 13C–NMR, IR, UV-vis, mass spectra and elemental analysis. pH effect, ion selectivity (cations, anions) and solvent sensitivity of complexes were studied. The interaction of these complexes with DNA was performed using absorption, emission spectroscopy and viscosity measurements. The experimental results indicated that the two complexes interacted with calf thymus DNA (CT-DNA) by intercalative mode. BSA (Bovine Serum Albumin) protein binding of these complexes was studied by UV-visible and fluorescence techniques. The binding capacity of these complexes was explained theoretically by molecular docking method. 相似文献
24.
Sreekanth Tellamekala Mohan Gundluru Murali Sudileti Santhisudha Sarva Chenna Rohini Kumar Putta Suresh Reddy Cirandur 《Monatshefte für Chemie / Chemical Monthly》2020,151(2):251-260
A straightforward and greener approach has been developed for the synthesis of novel aminomethylene bisphosphonates by one-pot reaction of diverse aryl/heteroaryl amines with dialkyl phosphite and triethyl orthoformate using CuO nanoparticles as catalyst under microwave irradiation and solvent-free conditions. This is an ecofriendly synthetic approach for swift access to a library of diverse aminomethylene bisphosphonates. All the synthesized new compounds were evaluated for their antimicrobial activity by disc diffusion method and antioxidant activity by DPPH, H2O2, and NO methods. The title compounds exhibited significant antioxidant and considerable antimicrobial activities. 相似文献
25.
Synthesis of Heteroaryl Thiazolidinones and Azetidinones under Conventional and Ultrasonication Methods 下载免费PDF全文
Putta Ramachandra Reddy Adivireddy Padmaja Venkatapuram Padmavathi 《Journal of heterocyclic chemistry》2015,52(5):1474-1482
A simple and an efficient protocol for the synthesis of differently substituted thiazolidinones was reported under conventional and also under ultrasonication in one‐step and in two‐step methodologies. Heteroaryl Schiff's bases were also exploited to develop heteroaryl azetidinones under both conventional and ultrasound irradiation. 相似文献
26.
Velocity field was measured by laser Doppler velocimetry in isothermal, turbulent bubbly gas-liquid flow through a 26.6 mm inner diameter vertical pipe. The measurements were made about 33 diameters downstream from the pipe entrance, gas injection being just upstream of the entrance. The gas phase radial distribution at the measurement plane exhibited influence of the injection device in that higher gas fraction existed in the central region of the pipe. For comparison, velocity field was also measured in isothermal, turbulent single-phase liquid flow through the same pipe at the same axial plane. Measured were the radial distributions of liquid mean axial and radial velocities, axial and radial turbulent intensities, and axial Reynolds shear stress. The radial distributions of gas bubble mean axial velocity and axial velocity fluctuation intensity were also measured by LDV. A dualsensor fiberoptic probe was used at the same time to measure the radial distributions of gas fraction, bubble mean axial velocity and size slightly downstream of the LDV measurement plane.List of Symbols
an average gas bubble diameter
-
f, f
TP
friction factor, friction factor for gas-liquid flow
-
k
L
liquid turbulent kinetic energy
-
,
gas, liquid mass flow rate
-
R
inner radius of pipe
-
r, {sitR}*
radial coordinate; nondimensional radial coordinate (=r/R)
-
Re
L
liquid Reynolds number
-
U
G
mean axial velocity of gas bubble
-
U
L
mean axial velocity of liquid
-
U
LO
mean axial velocity for flow at the total mass velocity with properties of the liquid phase
-
u
L
+
nondimensional mean axial velocity of liquid in wall coordinate
-
friction velocity
-
axial velocity fluctuation intensity of liquid
-
axial velocity fluctuation intensity of gas bubbles
- VL
mean radial velocity of liquid
-
v
L
radial velocity fluctuation intensity of liquid
- (uv)L
single-point cross-correlation between axial and radial velocity fluctuations of liquid ( axial Reynolds shear stress)
-
T
in
mean liquid temperature at test section inlet
-
x
flow quality
-
y
normal distance from wall
-
y
+
nondimensional normal distance from wall in wall coordinate (=yu/vL)
-
G
gas phase residence time fraction
-
L
rate of dissipation in the liquid
-
L
Kolmogorov length scale in the liquid
-
L
liquid kinematic viscosity
-
L
characteristic turbulence length scale in the liquid
-
G,
L
density of gas, liquid
-
m
gas-liquid mixture density
This work was partly supported by National Science Foundation, Thermal Transport and Thermal Processing Program, Chemical and Thermal Systems Division, under Grant No. CTS-9411898. 相似文献
27.
Aswathanarayana Srinivasa Putta Prabhakar Varma Vijaykumar Hulikal Kittappa M. Mahadevan 《Monatshefte für Chemie / Chemical Monthly》2008,139(2):111-115
Summary. Antimony sulfate was found to be on effective catalyst for the condensation reaction of indoles with carbonyl compounds at
room temperature. This catalyst is inexpensive, easily available and it was also found that this catalyst could be recovered
quantitatively and reused without much loss of catalytic activity. 相似文献
28.
Warmuth MK Liao J Rätsch G Mathieson M Putta S Lemmen C 《Journal of chemical information and computer sciences》2003,43(2):667-673
We investigate the following data mining problem from computer-aided drug design: From a large collection of compounds, find those that bind to a target molecule in as few iterations of biochemical testing as possible. In each iteration a comparatively small batch of compounds is screened for binding activity toward this target. We employed the so-called "active learning paradigm" from Machine Learning for selecting the successive batches. Our main selection strategy is based on the maximum margin hyperplane-generated by "Support Vector Machines". This hyperplane separates the current set of active from the inactive compounds and has the largest possible distance from any labeled compound. We perform a thorough comparative study of various other selection strategies on data sets provided by DuPont Pharmaceuticals and show that the strategies based on the maximum margin hyperplane clearly outperform the simpler ones. 相似文献
29.
Swamy Putta Ramachandrappa Rangegowda Ramalingaiah Hulivana 《Transition Metal Chemistry》1999,24(1):52-58
The kinetics of the RuIII-catalyzed oxidation of urea and substituted ureas namely: methylurea, ethylurea and propylurea, to the corresponding hydrazines by sodium N- bromobenzenesulphonamide or bromamine-B (BAB) in HCl medium has been studied at 303K. The reaction rate shows a first order dependence each upon [BAB], [amide] and [RuIII] and is dependent on [H+]. Addition of halide ions and benzenesulphonamide do not significantly affect the rate. Proton inventory studies were made in H2O-D2O mixtures for urea and methylurea. A Taft linear free energy relationship is observed for the reaction with *=–2.95 and =–0.25, showing that electron-donating groups enhance the rate. An isokinetic relation is observed with =370K, indicating that enthalpy factors control the rate; this result is also confirmed by Exner Criterion which showed a linear plot for the logarithms of rate constants at the highest and lowest temperatures employed. The protonation constant of monobromamine-B has been evaluated and equals 7.5. A mechanism consistent with the observed kinetic data has been proposed. 相似文献