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71.
Guda Mallikarjuna Reddy Jarem Raul Garcia Nemallapudi Bakthavatchala Reddy Grigoriy V. Zyryanov Gutha Yuvaraja 《Journal of heterocyclic chemistry》2019,56(3):845-849
Highly prominent dihydropyridine analogs have been developed and screened for their yields by using different catalysts under eco‐friendly ethanol solvent condition. Triethylamine catalyst was identified as ro bust catalyst for this synthetic path. The key benefits of this procedure are environmentally benign procedure, mild reaction conditions, simplicity of operation, high yields, mild reaction period, and decent substrate generality. 相似文献
72.
Jhillu S. Yadav K. Anantha Lakshmi N. Mallikarjuna Reddy Nipunge Swapnil A. Ramachandra Prasad 《Tetrahedron: Asymmetry》2012,23(15-16):1155-1160
The stereoselective total synthesis of decarestrictine O, a polyketide natural product is described. The synthesis involves MacMillan α-hydroxylation, C1-Wittig olefination, hydrolytic kinetic resolution and ring closing metathesis (RCM) as key steps. Improved efficiency was achieved by using the DIBAL mediated reductive transformation of trans-dimethyl l-tartrate acetonide into ε-hydroxy α,β-unsaturated ester in a single step. 相似文献
73.
Anwar A Gu M Brady S Qamar L Behbakht K Shellman YG Agarwal R Norris DA Horwitz LD Fujita M 《Photochemistry and photobiology》2008,84(2):477-483
UVB exposure of skin results in various biologic responses either through direct or indirect damage to DNA and non-DNA cellular targets via the formation of free radicals, reactive oxygen species (ROS) and inflammation. Bucillamine [N-(2-mercapto-2-methylpropionyl)-l-cysteine] is a cysteine-derived compound that can replenish endogenous glutathione due to its two donatable thiol groups, and functions as an antioxidant. In this study, we investigated the effects of bucillamine on UVB-induced photodamage using the SKH-1 hairless mouse model. We have demonstrated that UVB exposure (two consecutive doses, 230 mJ cm(-2)) on the dorsal skin of SKH-1 mice induced inflammatory responses (edema, erythema, dermal infiltration of leukocytes, dilated blood vessels) and p53 activation as early as 6 h after the last UVB exposure. Bucillamine pretreatment (20 mg kg(-1) of body weight, administered subcutaneously) markedly attenuated UVB-mediated inflammatory responses and p53 activation. We have also demonstrated that the stabilization and upregulation of p53 by UVB correlated with phosphorylation of Ser-15 and Ser-20 residues of p53 protein and that bucillamine pretreatment attenuated this effect. We propose that bucillamine has potential to be effective as a photoprotective agent for the management of pathologic conditions elicited by UV exposure. 相似文献
74.
Synthesis of monophasic ultrafine molybdenum oxide at low temperatures by thermal decomposition of molybdenum acetylacetonate
sol-gel is reported. The sol-gel is obtained through a solvent extraction technique from the organic solvent with the reduction
in oxidation state of molybdenum. The thermal behaviour of the sol-gel is studied from the thermal analysis traces. The structural
changes accompanying the thermal decomposition of the gel and the formation of monophasic molybdenum oxide is also reported
with the help of X-ray diffraction and scanning electron microscopy techniques.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
75.
Mitsuji Yamashita Valluru Krishna ReddyPutta Mallikarjuna Reddy Yukihiro KatoBuchammagari Haritha Kazumitsu SuzukiMasaki Takahashi Tatsuo Oshikawa 《Tetrahedron letters》2003,44(17):3455-3458
An efficient method is described in the synthesis of several novel deoxy phospha sugar pyrimidine nucleosides in racemic form, analogs of normal sugar nucleosides, in high yields by treatment of (±)-2-aminophospholane 1-oxide with several, α-cyano-, -acetyl-, -ethoxycarbonyl-β-ethoxy-N-ethoxycarbonylacrylamides. 相似文献
76.
Gowravaram Sabitha K. Sudhakar N. Mallikarjuna Reddy M. Rajkumar J.S. Yadav 《Tetrahedron letters》2005,46(38):6567-6570
The total synthesis of tarchonanthuslactone (1) has been achieved by two different routes. In the first approach, LiAlH4-LiI reduction and RCM protocols, and in the second approach, Wacker oxidation and LiAlH4-LiI reduction were used as key steps. 相似文献
77.
Guda Mallikarjuna Reddy Jarem Raul Garcia Vemulapati Hanuman Reddy Avula Krishna Kumari Grigory V. Zyryanov Gutha Yuvaraja 《Journal of Saudi Chemical Society》2019,23(3):263-273
An ecofriendly itinerary for the synthesis of pyranopyrazole derivatives having thioether link has been established via reusable, green catalyst, green solvent and multicomponent domino approach. To avoid impurities, usage of toxic solvents, toxic catalyst, simple workup and quantitative yields were strategies of this method. In addition, all the reported compounds were tested for their antioxidant and antibacterial properties. Some compounds displayed higher antioxidant activity than the standard drug (6a and 6j), while some other active compounds showed prominent antibacterial activity (6e and 6n). The results demonstrated that these active compounds may be used to support as a decent stand for further investigation in a way to ascertain innovative antioxidant and antibacterial medicines. 相似文献
78.
Jawalkar SS Adoor SG Sairam M Nadagouda MN Aminabhavi TM 《The journal of physical chemistry. B》2005,109(32):15611-15620
Computer simulations play an important role in designing new polymers as well as in predicting properties of existing polymers. In this paper, the blend compatibility of poly(vinyl alcohol) (PVA) with poly(methyl methacrylate) (PMMA) was studied over the wide range of compositions allowed by the atomistic and mesoscopic simulation methods. The Flory-Huggins interaction parameter, chi, of the blends computed using the atomistic simulation confirmed the blend compatibility for compositions containing >60 wt % of PVA. This observation was further supported by differential scanning calorimetric experiments. Solubility parameters of the polymers obtained from the simulation procedure were in good agreement with those of the literature data. Simulation results were further supported by the spectral and solution property measurements. From the atomistic simulations, chi versus concentration plots were constructed, which showed trends similar to those experimentally measured melting temperature versus concentration. The chi values for the blends, which satisfied the criteria of miscibility of two polymers by the atomistic simulation, agreed quite well with the solubility criteria related to order parameters calculated from the mesoscopic simulation. Kinetics of phase separation was examined via density profiles calculated using the MesoDyn approach for incompatible blends. The length and time scales spanned by these simulations were found to be relevant to the real application scales. The free energy computed in the mesoscopic simulation for blends reached equilibrium, particularly when the simulation was performed at a higher time step, indicating the stability of the blend system at certain compositions. 相似文献
79.
80.
G.R. Dillip K. Mallikarjuna S.J. Dhoble B. Deva Prasad Raju 《Journal of Physics and Chemistry of Solids》2014
A red-emitting phosphor NaSrB5O9:Eu3+ was synthesized by employing a solid-state reaction (SSR) method. The structures of the phosphors were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) and Raman studies. The band at ~282 nm in the excitation spectra indicated the charge transfer band (CTB) of B-O in the host, whereas the CTB of Eu-O was observed at ~275 nm for the NaSrB5O9:Eu3+ (Eu3+=1 at.%) phosphor, which was supported by diffuse reflectance spectroscopy (DRS) measurements. The photoluminescence (PL) measurements exhibited a strong red emission band centered at about 616 nm (5D0→7F2) under an excitation wavelength of 394 nm (7F0→5L6). Upon host excitation at 282 nm, the pristine NaSrB5O9 exhibited a broad UV emission centered at ~362 nm. The energy transfer from host to Eu3+ ions was confirmed from luminescence spectra, excited with a 355 nm Nd:YAG laser. In addition, the asymmetric ratios indicate a higher local symmetry around the Eu3+ ion in the host. The calculated CIE (Commission International de l′Eclairage) coordinates displayed excellent color purity efficiencies (around 99.7%) compared to other luminescent materials. 相似文献