The Reaction of Propiolic Acid Esters with Tertiary Amines. Formation of Betaines

1974 ◽  
Vol 52 (21) ◽  
pp. 3569-3576 ◽  
Author(s):  
A. W. McCulloch ◽  
A. G. McInnes
Keyword(s):  
Aqueous Media ◽  
Chemical Properties ◽  
Tertiary Amines ◽  
Propiolic Acid ◽  
Acid Esters ◽  
And Chemical Properties

Reaction of propiolate esters, H—C≡C—CO2R, with tertiary alkylamines R′3N in highly aqueous media yields betaines of the type trans R′3N+ •CH=CH•CO2−. The spectral and chemical properties of these derivatives are discussed as well as the mechanism of their formation. The major by-product of reaction is the corresponding trans-3-alkoxyacrylate RO—CH=CH—CO2R.

Hydroxycinnamoyl: Coenzyme A Transferase Involved in the Biosynthesis of Kaempferol-3-(p-coumaroyl Triglucoside) in Pisum sativum

1977 ◽  
Vol 32 (9-10) ◽  
pp. 765-768 ◽  
Author(s):  
Marie H. Saylor ◽  
Richard L. Mansell
Keyword(s):  
Coenzyme A ◽  
Chemical Properties ◽  
Acyl Donor ◽  
Coumaric Acid ◽  
Enzyme Preparations ◽  
Naturally Occurring ◽  
Enzymatic Formation ◽  
Derivatives Of ◽  
Acid Esters ◽  
And Chemical Properties

Abstract The major flavonoids of Pisum are derivatives of kaempferol and quercetin, including both tri-glucosides and acylated triglucosides in which the acyl group is p-coumaric acid. Although hydroxy-cinnamic acid esters of flavonoids are common pigments in many plants, neither the enzymes nor the precursors involved in their biosynthesis have been demonstrated. We report here that crude enzyme preparations extracted from peas catalyze the transfer of the p-coumaroyl moiety of p-coumaroyl: Coenzyme A to kaempferol-3-triglucoside forming kaempferol-3-(p-coumaroyl triglucoside) as the acylated product. The reaction product has been vigorously shown to be identical to the naturally occurring kaempferol-3-(p-coumaroyl triglucoside) in both chromatographic and chemical properties. The enzymatic formation of the acylated derivative occurred only minimally when incubated with the cofactors required for carboxyl group activation (ligase) and maximally when incubated with p-coumaroyl : Coenzyme A as the acyl donor.

Solubilization, characterization, and protein coupling analysis to multiwalled carbon nanotubes

2020 ◽  
pp. 095400832095803
Author(s):  
Juliane Glória ◽  
Walter Brito ◽  
Ariamna Gandarilla ◽  
Duniesky Larrude ◽  
Jacqueline Carlos ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Electron Microscopic ◽  
Multiwalled Carbon ◽  
Physical And Chemical ◽  
The Impact ◽  
Microscopic Techniques ◽  
And Chemical Properties

Since their discovery, carbon nanotubes were used for numerous applications in the most diverse knowledge areas. However, the lack of solubility of these molecules in aqueous media compromises their beneficial properties for certain applications. Several methods to solubilize carbon nanotubes are described, however, depending on the intended application, the impact that the solubilization has on the physical and chemical properties needs to be considered. In the present study, a simple methodology is described that utilizes polyvinylpyrrolidone combined with sonication and centrifugation to solubilize multiwalled carbon nanotubes. Proteins were coupled to the surface of the solubilized products and characterized using various spectroscopic and electron microscopic techniques, evaluating the characteristics and integrity of the nanoparticle after the process. It was successfully demonstrated that nanotubes can be solubilized through a simple technique, without compromising their chemical characteristics, which makes them suitable materials for use in biomedical applications, due to their biocompatibility and lack of toxicity, among others.

Synthesis, optical, and chemical properties of a π-extended rhodol derivative and its derivatives with selectivity and sensitivity for sensing Hg2+in aqueous media

RSC Advances ◽  
2016 ◽  
Vol 6 (88) ◽  
pp. 85165-85172 ◽  
Author(s):  
Lijuan Liang ◽  
Liancheng Zhao ◽  
Xianshun Zeng
Keyword(s):  
Aqueous Media ◽  
Chemical Properties ◽  
And Chemical Properties

A π-extended rhodol dye with optical signaling being controlled by two spirorings has been developed. A Hg2+-selective chemodosimeter based on this rhodol dye has been synthesized and evaluated.

scholarly journals Graphene Oxide/L-phenylalanine/polymethacrylamide Nanocomposite as an Efficient Fluorescent Nanosensor for Heavy Metals Detection in Aqueous Media

2021 ◽  
Author(s):  
Mehdi Barzegarzadeh ◽  
Mohammad Sadegh Amini-Fazl ◽  
Seyed Yasin Yazdi-Amirkhiz
Keyword(s):  
Heavy Metals ◽  
Graphene Oxide ◽  
Chain Transfer ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Selective Detection ◽  
Reversible Addition ◽  
Raft Agent ◽  
Ft Ir ◽  
And Chemical Properties

Abstract The application and fabrication of grapheme-based nanomaterials have, caught great attention in the field of sensors in recent years. In this study, a graphene oxide (GO)-based heavy metals nanosensor was prepared via the surface reversible addition-fragmentation chain transfer (RAFT) method. First, GO was prepared from graphene and was modified with L-phenylalanine (LP). Then a RAFT agent was attached chemically into the surface of GO-LP. Next, GO-LP/polymethacrylamide (GO-LP/PMAM) was prepared via the polymerization of methacrylamide (MAM) monomers on the surface of the GO. The surface morphology and chemical properties of the prepared materials were examined by FT-IR, SEM, TGA, UV and PL techniques. The results of PL indicated that the PL intensity of GO-LP/PMAM compared to GO and GO-LP spectra in the water was stronger. Finally, the modified GO was employed as an excellent nanosensor for the selective detection of Cu (II) ions in the range of 0.25-2 mM (correlation coefficient R2 0.9903). Absence any obvious alteration in the fluorescence intensity after the addition of other metal ions indicated the great selectivity for Cu (II). Based on the experimental results, the surface-functionalized GO with RAFT strategy could be successfully employed as a promising nanosensor for selective detecting of Cu (II) ions.

ChemInform Abstract: SYNTHESIS AND CHEMICAL PROPERTIES OF SOME CARBORANYLPHOSPHONOUS ACID ESTERS

1976 ◽  
Vol 7 (12) ◽  
pp. no-no
Author(s):  
N. N. GODOVIKOV ◽  
A. N. DEGTYAREV ◽  
V. I. BREGADZE ◽  
M. I. KABACHNIK
Keyword(s):  
Chemical Properties ◽  
Acid Esters ◽  
And Chemical Properties

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

The microstructure of a TiB2/Ti-47 Al composite material

1989 ◽  
Vol 47 ◽  
pp. 674-675
Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz
Keyword(s):  
Composite Material ◽  
Ion Beam ◽  
Chemical Properties ◽  
Intermetallic Alloys ◽  
Transmission Electron ◽  
Diamond Polishing ◽  
Al Composite ◽  
The Matrix ◽  
Argon Ion ◽  
And Chemical Properties

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

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