نتایج جستجو برای: hydroxylamines

تعداد نتایج: 1000  

Journal: :Zeitschrift fur Naturforschung. Teil B, Chemie, Biochemie, Biophysik, Biologie und verwandte Gebiete 1971
K Borgert E Wecker K Koschel

If cells are exposed to a mixture of hydroxylamine inactivated and infectious viruses the total rate of viral RNA-replication is lower than if the cells are infected with the same number of infectious viruses alone. This inhibitory influence of inactivated viruses depends on the ratio of infectious: inactivated viruses in the inoculum. One lethal hit by hydroxylamine suffices to produce the eff...

Journal: :Journal of bacteriology 1948
R Novak P W Wilson

Recent studies have provided several types of evidence supporting the view that ammonia is the key intermediate in nitrogen fixation by Azotobacter. An alternative hypothesis based on hydroxylamine depends almost entirely on the detection of traces of oximes in cultures fixing nitrogen. Although the two hypotheses are not mutually exclusive (Burris and Wilson, 1945), hydroxylamine remains an im...

2015
Cheng-Liang Zhu Jun-Shan Tian Zhen-Yuan Gu Guo-Wen Xing Hao Xu

An iron-catalyzed enantioselective and diastereoselective intramolecular olefin aminochlorination reaction is reported (ee up to 92%, dr up to 15 : 1). In this reaction, a functionalized hydroxylamine and chloride ion are utilized as nitrogen and chlorine sources, respectively. This new method tolerates a range of synthetically valuable internal olefins that are all incompatible with existing a...

2012
Alan Armstrong Alexandra Ferguson

tert-Butyl cinnamates are aziridinated with high trans-selectivity by an N-N ylide generated in situ from N-methylmorpholine and O-diphenylphosphinyl hydroxylamine. The resulting N-unfunctionalised aziridines are shown to be versatile synthetic building blocks that undergo highly selective ring-opening reactions with a wide range of nucleophiles.

Journal: :Chemical communications 2006
Gennady S Ananchenko Michaela Pojarova Konstantin A Udachin Donald M Leek Antony W Coleman John A Ripmeester

In an ethanol/water mixture, the nitroxyl radical TEMPO abstracts a hydrogen atom from a phenolic OH group of the amphiphilic para-hexanoylcalix[4]arene, and the hydroxylamine TEMPOH formed yields a stable inclusion complex with another molecule of the calixarene.

Journal: :Journal of virology 1971
K Borgert K Koschel H Täuber E Wecker

Evidence is presented that poliovirus particles with a single lethal hit by hydroxylamine do not induce in host cells either inhibition of cellular protein synthesis or viral ribonucleic acid (RNA) replication. The RNA of these viruses is not replicated even if the cells are simultaneously infected with both active and inactivated viruses. The damaged viral RNA seems to have lost both its templ...

Journal: :Acta pharmaceutica 2006
Hayam H Sayed Ahmed H Shamroukh Aymn E Rashad

4,6-Diamino-1H-pyrimidine-2-thione (1) was used for the preparation of pyrimidine derivatives 2-5. Compound 5 was cyclized to produce pyrimido[2,1-b][1,3]thiazine derivative 6 which was condensed with p-chlorobenzaldehyde to give compound 7. The latter compound was reacted with hydroxylamine to give isoxazolo[4,5-d]thiazino[2,3-a]pyrimidine 8. Compound 8b was treated with 2-chloroethyl methyl e...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2006
Abbas Afkhami Tayyebeh Madrakian Abbas Maleki

A simple, precise and accurate method is proposed for rapid determination of trace amounts of hydroxylamine based on the reaction of hydroxylamine with iodate in acidic media. The reaction of neutral red by the produced nitrite ion was used to monitor the reaction spectrophotometrically at 525 nm by a fixed time method. Hydroxylamine in the range of 0.0400-1.200 microg mL(-1) could be determine...

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