Difluorocarbene-based cyanodifluoromethylation of alkenes induced by a dual-functional Cu-catalyst

2021 ◽  
Author(s):  
Min Zhang ◽  
Jin-Hong Lin ◽  
Chuan-Ming Jin ◽  
Ji-Chang Xiao
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Nitrile Group ◽  
Dual Role ◽  
Cu Complex ◽  
Dual Functional ◽  
Cu Catalyst

Described herein is a Cu-catalyzed difluorocarbene-based cyanodifluoromethylation of alkenes. BrCF2CO2Et and NH4HCO3 serve as a carbon source and a nitrogen source of the nitrile group, respectively. The Cu-complex plays a dual role.

Difluorocarbene-Based Cyanation of Aryl Iodides

Synlett ◽  
2020 ◽  
Vol 31 (07) ◽  
pp. 713-717 ◽  
Author(s):  
Yin-Xiang Zhang ◽  
Xuan Xiao ◽  
Zhi-Hong Fu ◽  
Jin-Hong Lin ◽  
Yu Guo ◽  
...  
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Nitrile Group ◽  
Air Atmosphere ◽  
Aryl Iodides ◽  
Wide Range ◽  
Conventional Methods ◽  
Shelf Stable

A large number of efficient cyanation methods have been developed because of the wide range of applications of nitriles, but conventional methods usually suffer from the need for a toxic cyanation reagent. Although difluorocarbene chemistry has received increasing attention, the use of difluorocarbene as a sources of the nitrile carbon for nitrile groups remains largely unexplored. We describe a difluorocarbene-based cyanation of aryl iodides promoted by a cheap copper source, Cu(NO3)2·2.5H2O, under an air atmosphere. Ph3P+CF2CO2 –, an easily available and shelf-stable difluorocarbene reagent, and NaNH2 are used as the carbon source and the nitrogen source for the nitrile group, respectively. The cyanation protocol is attractive because no toxic reagent is used and performing the reactions under an air atmosphere is operationally convenient.

Studies on the Biological Characteristics of Termitomyces Albuminosus Hypha

2013 ◽  
Vol 709 ◽  
pp. 810-813 ◽  
Author(s):  
Xiong Ya ◽  
Min Jie Li
Keyword(s):  
Growth Factors ◽  
Carbon Source ◽  
Nitrogen Source ◽  
Biological Characteristics ◽  
Edible Fungi ◽  
Growth Environment ◽  
Wild Edible Fungi ◽  
Development And Utilization

Termitomyces albuminosus is a kind of local distinctive wild edible fungi in southwest of China. It is delicious, rich in nutrition and has high development and utilization value, but owing to the restrictions of growth environment, it can not be cultivated artificially. This article mainly studied on the biological characteristics of Termitomyces albuminosus Hypha, and found out the optimal carbon source, nitrogen source, growth factors and the C/N ratio that are suitable for the growth of Hypha of Termitomyces albuminosus .

scholarly journals Monomethylamine as a Nitrogen Source for a Nonmethylotrophic Bacterium, Agrobacterium tumefaciens

2010 ◽  
Vol 76 (12) ◽  
pp. 4102-4104 ◽  
Author(s):  
Yin Chen ◽  
Kathryn L. McAleer ◽  
J. Colin Murrell
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Carbon Source ◽  
Nitrogen Source ◽  
Sole Nitrogen Source ◽  
Key Enzymes ◽  
Genes Encoding

ABSTRACT Monomethylamine can be used by nonmethylotrophs as a sole nitrogen source but not as a carbon source; however, little is known about the genes and enzymes involved. The γ-glutamylmethylamide/N-methylglutamate pathway for monomethylamine utilization by methylotrophs has recently been resolved. We have identified genes encoding key enzymes of this pathway in nonmethylotrophs (e.g., Agrobacterium tumefaciens) and demonstrated that this pathway is also involved in the utilization of monomethylamine as a nitrogen source by nonmethylotrophs.

scholarly journals Mutants affecting histidine utilization inAspergillus nidulans

1975 ◽  
Vol 25 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Meryl Polkinghorne ◽  
M. J. Hynes
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Sole Carbon Source ◽  
Nitrogen Sources ◽  
Limiting Factor ◽  
Sole Nitrogen Source ◽  
Wild Type ◽  
Exogenous Substrate ◽  
Growth Properties ◽  
Type Strains

SUMMARYWild-type strains ofAspergillus nidulansgrow poorly onL-histidine as a sole nitrogen source. The synthesis of the enzyme histidase (EC. 4.3.1.3) appears to be a limiting factor in the growth of the wild type, as strains carrying the mutantareA102 allele have elevated histidase levels and grow strongly on histidine as a sole nitrogen source.L-Histidine is an extremely weak sole carbon source for all strains.Ammonium repression has an important role in the regulation of histidase synthesis and the relief of ammonium repression is dependent on the availability of a good carbon source. The level of histidase synthesis does not respond to the addition of exogenous substrate.Mutants carrying lesions in thesarA orsarB loci (suppressor ofareA102) have been isolated. The growth properties of these mutants on histidine as a sole nitrogen source correlate with the levels of histidase synthesized. Mutation at thesarA andsarB loci also reduces the utilization of a number of other nitrogen sources. The data suggest that these two genes may code for regulatory products involved in nitrogen catabolism. No histidase structural gene mutants were identified and possible explanations of this are discussed.

scholarly journals Production of Feruloyl Esterase from Aspergillus niger by Solid-State Fermentation on Different Carbon Sources

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Shiyi Ou ◽  
Jing Zhang ◽  
Yong Wang ◽  
Ning Zhang
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Wheat Bran ◽  
Cell Walls ◽  
Carbon Sources ◽  
Feruloyl Esterase ◽  
Plant Cell Walls ◽  
Optimal Conditions ◽  
Carbon And Nitrogen ◽  
Maize Bran

A mixture of wheat bran with maize bran as a carbon source and addition of (NH4)SO4 as nitrogen source was found to significantly increase production of feruloyl esterase (FAE) enzyme compared with wheat bran as a sole carbon and nitrogen source. The optimal conditions in conical flasks were carbon source (30 g) to water 1 : 1, maize bran to wheat bran 1 : 2, (NH4)SO4 1.2 g and MgSO4 70 mg. Under these conditions, FAE activity was 7.68 mU/g. The FAE activity on the mixed carbon sources showed, high activity against the plant cell walls contained in the cultures.

scholarly journals A β-d-fructofuranosidase from Claviceps purpurea

1972 ◽  
Vol 129 (2) ◽  
pp. 263-272 ◽  
Author(s):  
A. G. Dickerson
Keyword(s):  
Carbon Source ◽  
Dual Role ◽  
Claviceps Purpurea ◽  
Time Transfer ◽  
Main Carbon Source ◽  
Main Carbon

Evidence suggests that sucrose is the main carbon source for growth of Claviceps spp. in the parasitic condition. The sucrose acts as substrate for an active β-fructofuranosidase, produced by the fungus, which in the first instance converts the disaccharide into glucose and an oligofructoside. In this way, 50% of the glucose, supplied as sucrose, is made available to the parasite for assimilation. Subsequent action of the enzyme on both sucrose and the oligofructoside leads to the release of more glucose and the formation of additional oligosaccharides. The structures of the main oligosaccharides formed have been elucidated and the interactions of each compound studied. In experiments with purified enzyme in vitro the interaction of the oligosaccharides is rapid but in culture they are assimilated only slowly; in each case some free fructose is liberated. Free fructose is not assimilated in the presence of glucose and, further, inhibits growth at concentrations which might be expected to occur in the parasitic condition. A dual role has been suggested for the enzyme, with sucrose as substrate, in which glucose is made available to the growing parasite, while at the same time transfer of the fructose to form oligosaccharides prevents it from accumulating at inhibitory concentrations. Ultimately, when glucose becomes limiting, the fungus will adapt to fructose assimilation.

scholarly journals KAJIAN PENGARUH PENINGKATAN KONSENTRASI EKSTRAK KHAMIR PADA MEDIA HESTRIN DAN SCHRAMM TERHADAP PEROLEHAN SELULOSA OLEH Acetobacter liquefaciens SRC-4

2014 ◽  
Vol 5 (2) ◽  
Author(s):  
Ermina Sari
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Vitamin B1 ◽  
Vitamin B2 ◽  
Static Culture

SRC-4 starin is one of bacteria sellulose producing strains. It was obtained from the rottencoconut meat from Semplak, Bogor. The objective of this study is to obtain the optimumcomposition of modified HS medium to produce cellulose, by increasing yeast extractconcentration and also combination of carbon and vitamin sources. The production of celluloseby SRC-4 was done by 18 treatments on static culture. The increasing of yeast extractconcentration, combination of carbon and vitamin sources gave significant effect to theproduction of cellulose. The highest yield of cellulose was produced at the treatment consist of1.0 % yeat extract (as nitrogen source), 1 % glucose + 1 % glycerol (as carbon source) and0.164 ppm vitamin B1 + 0.020 ppm vitamin B2 (as vitamin source).

Nitrogen-doped carbon dot mediated fluorescence on–off assay for highly sensitive detection of I− and Br− ions

2018 ◽  
Vol 42 (17) ◽  
pp. 14332-14339 ◽  
Author(s):  
Nan Zhou ◽  
Xingwei Zhang ◽  
Yanping Shi ◽  
Zeliang Li ◽  
Zhibiao Feng
Keyword(s):  
Quantum Dots ◽  
Citric Acid ◽  
Carbon Source ◽  
Nitrogen Source ◽  
Carbon Quantum Dots ◽  
Sensitive Detection ◽  
Nitrogen Doped ◽  
Highly Sensitive ◽  
Highly Sensitive Detection ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon quantum dots (CDs) were synthesized in ethanol media by using citric acid (CA) as the carbon source and ethanediamine (EDA) as the nitrogen source.

Utilization of chymotrypsin as a sole carbon and (or) nitrogen source by Escherichia coli

1992 ◽  
Vol 38 (4) ◽  
pp. 290-295 ◽  
Author(s):  
Arthur S. Brecher ◽  
Timothy A. Moehlman ◽  
William D. Hann
Keyword(s):  
Escherichia Coli ◽  
Carbon Source ◽  
Nitrogen Source ◽  
Degradation Products ◽  
Defined Medium ◽  
Host Protein ◽  
Mammalian Host ◽  
Sole Nitrogen Source ◽  
E Coli ◽  
Nitrogen Nutrients

α-Chymotrypsin serves as a sole carbon source, sole nitrogen source, and as sole carbon plus nitrogen source for wild-type Escherichia coli in a totally defined medium. Hence, a mammalian host for E. coli may supply the necessary carbon and nitrogen nutrients for the microorganism. Growth is most rapid when chymotrypsin is a sole nitrogen source,and least rapid with chymotrypsin as a carbon source. The approximate doubling times for E. coli utilizing chymotrypsin as a nitrogen source, carbon plus nitrogen source, and carbon source are 1.6, 4.6, and 11.3 h, respectively. The activity of the residual enzyme in the culture supernates falls off asymptotically over the course of time, as followed by cleavage of glutaryl-L-phenylalanine-p-nitroanilide. Chymotrypsin hydrolyzes succinyl-L-ala-L-ala-L-ala-p-nitroanilide, the elastase substrate, to some extent. Peptidases do not appear to be secreted that hydrolyze such model substrates as benzoyl-DL-arginine-p-nitroanilide, the tryptic and cathepsin B substrate, L-leucine-p-nitroanilide, the leucine aminopeptidase substrate, or L-lysine-p-nitroanilide, the aminopeptidase B substrate. Growth of E. coli is generally directly related to the loss of chymotryptic activity in the medium. Hence, autolysis of chymotrypsin, i.e., self-degradation, is an important factor for the availability of degradation products of the enzyme to the bacterium for growth purposes. Accordingly, the degradation of a host protein by autolysis presents an opportunity for E. coli to survive during periods of host nutritional crisis by utilization of the degradation peptides that are produced during autolysis. Key words: chymotrypsin, Escherichia coli, growth, nutrition, peptide source.

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