排序方式: 共有63条查询结果,搜索用时 15 毫秒
1.
Prakasham RS Rao ChS Rao RS Rajesham S Sarma PN 《Applied biochemistry and biotechnology》2005,120(2):133-144
Optimization of alkaline protease production parameters by Bacillus sp. was investigated using Taguchi methodology. The pH of the medium was observed to be the most significant factor among
all selected optimization parameters at an individual level. The combinatorial influence of least significant factors, inoculum
level and salt solution concentration (at the individual level), resulted in an interacting severity index of 76%, suggesting
their interactive role in the regulation of protease production in this microbial species. Protease production could be improved
more than 100% with Taguchi’s optimized conditions of the medium composition by this microorganism. 相似文献
2.
Rhodium Enalcarbenoids: Direct Synthesis of Indoles by Rhodium(II)‐Catalyzed [4+2] Benzannulation of Pyrroles
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Sudam Ganpat Dawande Vinaykumar Kanchupalli Jagadeesh Kalepu Haribabu Chennamsetti Bapurao Sudam Lad Dr. Sreenivas Katukojvala 《Angewandte Chemie (International ed. in English)》2014,53(16):4076-4080
Disclosed herein is the design of an unprecedented electrophilic rhodium enalcarbenoid which results from rhodium(II)‐catalyzed decomposition of a new class of enaldiazo compounds. The synthetic utility of these enalcarbenoids has been successfully demonstrated in the first transition‐metal‐catalyzed [4+2] benzannulation of pyrroles, thus leading to substituted indoles. The new benzannulation has been applied to the efficient synthesis of the natural product leiocarpone as well as a potent adipocyte fatty‐acid binding protein inhibitor. 相似文献
3.
Devanga K. Sreenivas 《Tetrahedron》2010,66(51):9650-9654
A simple route for the synthesis of quinocarbazoles in good yields via palladium-mediated intramolecular arylation involving ortho C-H activation is reported. 相似文献
4.
We herein report a serendipitously observed acid mediated rearrangement of monoethylene ketal of 2-methyl-2-(3-methylbut-2-en-1-yl)cyclohex-4-ene-1,3-diones to Dihydrobenzopyran and demonstrated the application of this methodology in the construction of core carbon scaffolds of dimethoxyajacareubin, cariphenone-A and crotamadine. 相似文献
5.
A new, efficient, and diastereoselective one-pot synthesis of cis-fused pyrano and furano chromenylaminoanthraquinones through hetero Diels–Alder reaction of 1-aminoanthraquinone and salicylaldehydes with electron-rich alkenes such as 3,4-dihydro-2H-pyran, 2,3-dihydrofuran, and ethyl vinyl ether under mild conditions is reported. 相似文献
6.
[1+1+3] Annulation of Diazoenals and Vinyl Azides: Direct Synthesis of Functionalized 1‐Pyrrolines through Olefination
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Vinaykumar Kanchupalli Dr. Sreenivas Katukojvala 《Angewandte Chemie (International ed. in English)》2018,57(19):5433-5437
A dirhodium carboxylate catalyzed [1+1+3] annulation reaction of diazoenals and vinyl azides that gives synthetically important enal‐functionalized 1‐pyrroline derivatives was developed. The reaction involves a novel rhodium‐catalyzed olefination of diazoenals with vinyl azides via electrophilic enal carbenoids, resulting in a new class of enal acrylates. The annulation reaction was used for the direct synthesis of valuable deuterated 1‐pyrrolines. Structural diversification of the enal‐functionalized 1‐pyrrolines resulted in the biologically important pyrrolidine‐fused oxaziridine, amino acid derivatives, and a 6‐azabicyclo[3.2.1]octane motif present in polycyclic alkaloids. 相似文献
7.
Variable‐Temperature Powder X‐ray Diffraction of Aromatic Carboxylic Acid and Carboxamide Cocrystals
L. Sreenivas Reddy Prashant M. Bhatt Rahul Banerjee Ashwini Nangia Prof. Dr. Gert J. Kruger Prof. Dr. 《化学:亚洲杂志》2007,2(4):505-513
The effect of temperature on the cocrystallization of benzoic acid (BA), pentafluorobenzoic acid (FBA), benzamide (BAm), and pentafluorobenzamide (FBAm) is examined in the solid state. BA and FBA formed a 1:1 complex 1 at ambient temperature by grinding with a mortar and pestle. Grinding FBA and BAm together resulted in partial conversion into the 1:1 adduct 2 at 28 °C and complete transformation into the product cocrystal at 78 °C. Further heating (80–100 °C) and then cooling to room temperature gave a different powder pattern from that of 2 . BAm and FBAm hardly reacted at ambient temperature, but they afforded the 1:1 cocrystal 3 by melt cocrystallization at 110–115 °C. Both BA+FBAm ( 4 ) and BA+BAm ( 5 ) reacted to give new crystalline phases upon heating, but the structures of these products could not be determined owing to a lack of diffraction‐quality single crystals. The stronger COOH and CONH2 hydrogen‐bonding groups of FBA and FBAm yielded the equimolar cocrystal 6 at room temperature, and heating of these solids to 90–100 °C gave a new crystalline phase. The X‐ray crystal structures of 1 , 2 , 3 , and 6 are sustained by the acid–acid/amide–amide homosynthons or acid–amide heterosynthon, with additional stabilization from phenyl–perfluorophenyl stacking in 1 and 3 . The temperature required for complete transformation into the cocrystal was monitored by in situ variable‐temperature powder X‐ray diffraction (VT‐PXRD), and formation of the cocrystal was confirmed by matching the experimental peak profile with the simulated diffraction pattern. The reactivity of H‐bonding groups and the temperature for cocrystallization are in good agreement with the donor and acceptor strengths of the COOH and CONH2 groups. It was necessary to determine the exact temperature range for quantitative cocrystallization in each case because excessive heating caused undesirable phase transitions. 相似文献
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9.
Saeed Dehghanpour Rhett Kempe Sreenivas Balireddi Lida Fotouhi Farzaneh Tabasia Fresia Mojahed Samaneh Salek 《无机化学与普通化学杂志》2006,632(14):2321-2325
A novel ligand, N,N′‐Bis‐[3‐(2‐nitrophenyl)‐allylidene]‐ethane‐1,2‐diamine (nca2en), and their corresponding copper(I) complexes, [Cu(ncaen)2]ClO4 ( 1 ), and [Cu(nca2en)(PPh3)2]BPh4 ( 2 ), have been synthesized and characterized by CHN analyses, 1H and 13C‐NMR, IR, and UV‐Vis spectroscopy. The crystal and molecular structures of [Cu(ncaen)2]ClO4 ( 1 ), and [Cu(nca2en)(PPh3)2]BPh4 ( 2 ), were determined by X‐ray crystallography from single‐crystal data. The coordination polyhedron about the copper(I) atom in the two complexes is best described as a distorted tetrahedron. A quasireversible redox behavior is observed for complex 1 and 2 (E1/2 = 0.55 and 0.95 V, respectively). 相似文献
10.
Sharmila Kameyanda Poonacha Madhyastha Harishkumar Madhyastha Radha Remya Varadarajan Suchetha Kumari Nalilu Shilpa Sharathraj Shetty Praveen Kumar Shetty Revanasiddappa Bistuvalli Chandrashekharappa Mahendra Gowdru Sreenivas Satheesh Kumar Bhandary Bavabeedu 《Molecules (Basel, Switzerland)》2021,26(24)
Oroxylum indicum, of the Bignoniaceae family, has various ethnomedical uses such as an astringent, anti-inflammatory, anti-bronchitis, anti-helminthic and anti-microbial, including anticancer properties. The druggability of OI stem bark extract was determined by its molecular docking interactions with PARP and Caspase-3, two proteins involved in cell survival and death. Note that 50 µg/mL of Oroxylum indicum extract (OIE) showed a significant (p < 0.05%) toxicity to HSC-3 cells. MTT aided cell viability and proliferation assay demonstrated that 50 µg/mL of OIE displayed significant (p < 0.5%) reduction in cell number at 4 h of incubation time. Cell elongation and spindle formation was noticed when HSC-3 cells were treated with 50 µg/mL of OIE. OIE initiated DNA breakage and apoptosis in HSC-3 cells, as evident from DNA ladder assay and calcein/EB staining. Apoptosis potential of OIE is confirmed by flow cytometer and triple-staining (live cell/apoptosis/necrosis) assay. Caspase-3/7 fluorescence quenching (LANCE) assay demonstrated that 50 µg/mL of OIE significantly enhanced the RFU of caspases-3/7, indicating that the apoptosis potential of OIE is probably through the activation of caspases. Immuno-cytochemistry of HSC-3 cells treated with 50 µg/mL of OIE showed a significant reduction in mitochondrial bodies as well as a reduction in RFU in 60 min of incubation time. Immunoblotting studies clearly showed that treatment of HSC-3 cells with OI extract caused caspase-3 activation and PARP deactivation, resulting in apoptotic cell death. Overall, our data indicate that OIE is an effective apoptotic agent for human squamous carcinoma cells and it could be a future cancer chemotherapeutic target. 相似文献