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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
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K. Venkateshwarlu G. Chakradar Rao V. M. Reddy Y. Narasimha Reddy 《Journal of the Iranian Chemical Society》2014,11(6):1619-1627
A new series of [4,6 substituted diaryl-1,6-dihydropyrimidin-2-yl-oxymethyl]-amines 5a–o have been synthesized by the Mannich condensation on the respective 4,6-diaryl-3,4-dihydropyrimidine-2(1H)-ones 4, in basic medium using formaldehyde along with three secondary amines, viz., dimethylamine, piperidine and morpholine. The dihydropyrimidinones 4 in turn were synthesized by the cyclocondensation of chalcones 3 with urea. Alternatively, compounds 4 were also prepared directly by one-pot 3-component cyclocondensation reaction starting from acetophenone, benzaldehyde and urea. The structures of all the newly synthesized compounds have been confirmed by their spectral and analytical data. All the O-Mannich bases 5 have been evaluated for their in vitro cytotoxic and antitumor activities, and based on the results, the potent compounds were selected for in vivo activity, as well. Only one compound 5m of the series has been found to be relatively more effective. 相似文献
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Dr. Gangavaram V. M. Sharma Gajulapati Venkateshwarlu Pothula Purushotham Reddy Dr. Ajit C. Kunwar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(36):11428-11438
In α‐peptides, the 8/10 helix is theoretically predicted to be energetically unstable and has not been experimentally observed so far. Based on our earlier studies on ‘helical induction’ and ‘hybrid helices’, we have adopted the ‘end‐capping’ strategy to induce the 8/10 helix in α‐peptides by using short α/β‐peptides. Thus, α‐peptides containing a regular string of α‐amino acids with alternating chirality were end capped by α/β‐peptides with 11/9‐helical motifs at the termini. Extensive NMR spectroscopy studies of these peptides revealed the presence of a hitherto unknown 8/10‐helical pattern; the H‐bonds in the shorter pseudorings were rather weak. The approach of using short helical motifs to induce new mixed helices in α‐peptides could provide avenues for more versatile design strategies. 相似文献
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The condensation of benzene 1,3,5-tricarbonylchloride with cystine-di-Me [H2N-CH(COOMe)-CH2-S-S-CH2-CH(COOMe)-NH2] yielded triply bridged (1,3,5) cyclophane 1, which was shown by detailed spectral studies and molecular orbital calculations to have a D3 symmetry with conformationally identical linkers and a spherical topology. In sharp contrast, the (1,3,5) cyclophane 2 from the rarely studied lanthionine di-Me [H2N-CH(COOMe)-CH2-S-CH2-CH(COOMe)-NH2], showed only a equatorial twofold symmetry. This work highlights the special properties of the -S-S- bridge in cystine, which makes it an exceptional synthon in nature and organic synthesis. 相似文献
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Ranu Bhatt Ranita Basu S. Bhattacharya A. Singh D. K. Aswal S. K. Gupta G. S. Okram V. Ganesan D. Venkateshwarlu C. Surgers M. Navaneethan Y. Hayakawa 《Applied Physics A: Materials Science & Processing》2013,110(2):465-470
Y2O3 nanoparticles and nanorods have been firstly synthesized in bulk Ti-Y films prepared by magnetron sputtering on Si (100) substrates at different temperatures. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS) are used to characterize the structure, morphology, and composition of the as-synthesized nanoparticles and nanorods. The mechanical properties of the sputtered films are investigated using nanoindentation techniques. The results indicate that both the nanoparticles and nanorods have a pure cubic Y2O3 structure resulting from the reaction of Y atoms with the residual O2 in the vacuum chamber, and are free from defects and dislocations with uniform diameters of about 30 nm. The Y2O3 nanoparticles mainly distribute at the grain boundaries of the Ti matrix and the nanorods have lengths ranging from 250 nm to more than 1 μm with the growth direction parallel to the (002) plane. As the growth temperature elevates, the nanoparticles turn to be coarsening while more and longer nanorods are inclined to form. Compared with the Ti film, the TiY films have a remarkable increase in hardness, but do not exhibit expected increase in elastic modulus. Finally, the growth mechanism is also briefly discussed. 相似文献
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Cherukumalli Purna Koteswara Rao Tadiboina Bhaskara Rao Gulipalli Kali Charan Bodige Srinu Gangarapu Kiran Sridhar Gattu 《Russian Journal of General Chemistry》2020,90(10):1981-1989
Russian Journal of General Chemistry - A novel series of bis-isoxazole incorporated benzothiazole derivatives has been designed and synthesized. Molecular structures of the compounds have been... 相似文献
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Synthesis of new β3-amino acid, peptides and conformational analysis are reported from d-ribose, using Wittig olefination and Aza-Michael addition. 相似文献
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Gattu Sridhar Karnekanti Rajender Reddy Gangavaram V. M. Sharma 《Journal of carbohydrate chemistry》2018,37(2):94-101
The study describes the synthesis of new α,α-disubstituted β-amino acid (β2,2-Caa) and attempts the synthesis of peptides from it. The β2,2-Caa was prepared from D-(+)-mannose, using crossed aldol and Cannizzaro reactions. 相似文献