نتایج جستجو برای: heterocyclic

تعداد نتایج: 9423  

Journal: :Journal of the National Cancer Institute 1999
A E Norrish L R Ferguson M G Knize J S Felton S J Sharpe R T Jackson

BACKGROUND Some epidemiologic studies have described positive associations between prostate cancer risk and meat consumption, but underlying mechanisms have not been identified. Heterocyclic amines are mutagens formed during the cooking of meat. Well-done meat has been associated with increased risks of colorectal and breast cancers in humans. This study examined associations between prostate c...

1995
J. S. Felton M. G. Knize

To investigate a method to reduce the amount of mutagenic/carcinogenic heterocyclic aromatic amines formed during frying of ground beef, we measured both the mutagenic activity in Salmonella strain TA98 and the amount of known heterocyclic amines by solid-phase extraction and HPLC. The beef patties received microwave treatment for various times before frying. Microwave pretreatment for 0, 1, 1....

2005
Xiang-Ping Hu Hui-Lin Chen Zhuo Zheng

The presence of the additional heterocyclic nitrogen atoms in chiral P,N ligands has an important influence on the asymmetric catalysis, and a clear trend was observed in the present research that the enantioselectivity and reactivity were significantly increased by raising the number of heterocyclic nitrogen atoms in these P,N ligands. Through finely tuning the number of heterocyclic nitrogen ...

2013
Pragi Arora Varun Arora H. S. Lamba Deepak Wadhwa

Heterocyclic compounds are of very much interest in our daily life. Heterocyclic compounds have one or more hetero atoms in their structure. They may be cyclic or non cyclic in nature. Heterocyclic compunds have a wide range of application. They are predominantly used as pharmaceuticals, as agrochemicals and as veterinary products. They also find applications as sanitizers, developers, antioxid...

2016
V. Vijayakumar

Heterocyclic compounds are widely prevalent in animal kingdom as well as in plant kingdom and they play various roles in metabolic processes. A large number of heterocyclic compounds are in clinical practice as a drug, while many of them find industrial utility and hence the syntheses of heterocyclic compounds and understanding of the biological importance of specific heterocyclic class will be...

Journal: :Molecules 2011
Nagwa Mohamed Mahrous Hamada Essam Mohamed Sharshira

Some new heterocyclic compounds containing isoxazole, pyrazole and oxadiazole ring systems were prepared from various chalcones. The synthesized compounds have been characterized by elemental analysis and spectral methods. These compounds were screened for their antimicrobial activities.

Journal: :The Journal of organic chemistry 2008
Ian R Morgan Arife Yazici Stephen G Pyne Brian W Skelton

Pyrido- and pyrrolo[2,3-d]oxazoles can be conveniently prepared in high yield from the Ritter reaction of nitriles and in situ generated chiral cyclic N-acyliminium ions. cis-4-Hydroxy-5-acylaminopyrrolidines and cis-5-hydroxy-6-acylaminopiperidines can be readily obtained by acid hydrolysis of these bicyclic heterocyclic compounds, respectively.

Journal: :Molecules 2010
Junko Koyama Izumi Morita Takao Yamori

To search for possible anti-tumor agents or anti-tumor promoters among natural or synthetic products, we used cyclic voltammetry to determine the reduction-oxidation potentials of heterocyclic quinones in phosphate buffer at pH 7.2. We determined the growth inhibitory- and cytotoxic activities of 12 heterocyclic quinone anti-tumor agent candidates against a panel of 39 human cancer cell lines (...

Journal: :The Journal of organic chemistry 2016
Arife Yazici Uta Wille Stephen G Pyne

Novel tricyclic bridged heterocyclic systems can be readily prepared from sequential 1,4- and 1,2-addition reactions of allyl and 3-substituted allylsilanes to indolizidine and quinolizidine α,β-unsaturated N-acyliminium ions. These reactions involve a novel N-assisted, transannular 1,5-hydride shift. Such a mechanism was supported by examining the reaction of a dideuterated indolizidine, α,β-u...

2014
S. Elumalai S. Guhanathan

Functional modification of PVA or introducing reactive functional groups into the polymer chain has been believed to have basic significance while expanding its application. Phosphorous containing nitrogen heterocyclic compounds have been synthesized. The synthesized compounds were characterized using FTIR, NMR spectral studies. Thermo gravimetric analysis (TGA) display that organophosphorous-N...

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