Supersensitive Schiff's Aldehyde Reagent. Demonstration of a Free Aldehyde Group In Certain Aldoses

1942 ◽  
Vol 14 (5) ◽  
pp. 405-406 ◽  
Author(s):  
Walter Tobie
Keyword(s):  
Aldehyde Group ◽  
Free Aldehyde

The Maillard Reaction in Fish Products

1950 ◽  
Vol 8a (2) ◽  
pp. 74-81 ◽  
Author(s):  
H. L. A. Tarr
Keyword(s):  
Amino Acids ◽  
Metal Ions ◽  
Maillard Reaction ◽  
Aldehyde Group ◽  
Fish Products ◽  
Free Aldehyde

The brown discolouration which occurs on heating (120 °C., 1 hr.) white flesh of fish was found to be due largely to reactions of the Maillard type. Browning did not occur in leached flesh unless compounds containing a free aldehyde group, or a potential free aldehyde group, were added. Addition of amino acids and substances which did not possess a free aldehyde group did not occasion browning in leached flesh. Discolouration was inhibited by bisulphite and hydroxylamine and slightly by acids, but it was not affected by heating in vacuo, by storing whole fish in ice prior to heating or by addition of metal ions.

The cardiac glycosides of Gomphocarpusf ruticosus R.Br. I. Afroside

1956 ◽  
Vol 9 (4) ◽  
pp. 497 ◽  
Author(s):  
TR Watson ◽  
SE Wright
Keyword(s):  
Simple Structure ◽  
Lactone Ring ◽  
Aldehyde Group ◽  
Hydroxyl Group ◽  
Naturally Occurring ◽  
Ring Junction ◽  
Infra Red ◽  
Free Aldehyde ◽  
Acetyl Group ◽  
Hydrolysis Of

Afroside, C29H42O9, is a new cardiac glycoside which has been obtained from Gomphocarpus fruticosus R.Br. It contains a carbonyl (aldehyde) group at C10, and a secondary hydroxyl group in the nucleus, which has been placed provisionally at position C11. On the basis of the available evidence, afroside appears to consist of a mixture of the isomeric free aldehyde and the 19-11 cyclic hemiacetal forms. Of these substances, the cyclic hemiacetal form is the only one which has been isolated in pure condition (afroside B). Acetylation of afroside produced a triacetate, C35H46O12.H2O, which is identical with that obtained by the acetylation of afroside B. Reduction of afroside with sodium borohydride produces afrosidol, C29H44O9, which shows no evidence for a carbonyl group at C10. Hydrolysis of afroside produces α-anhydroafrogenin, C23H28-30O5.H2O, which forms a monoacetate, C25H32O7.H2O. The infra-red spectra of these compounds show the presence of a saturated γ-lactone ring in the structure of the nucleus, besides the normal Δα-β-γ-lactone ring at C17 (1786, 1755, 1633 cm-1). Acetyl-α-anhydroafrogenin also shows an intense absorption band of simple structure at 1238 cm-1, which indicates an equatorially orientated acetyl group at C3. As all the naturally occurring cardiac aglycones of known structure have a β-orientated hydroxyl group at C3, for the substituent in this position to be equatorial, the A/B ring junction is probably trans. Hydrolysis of afrosidol produces α-anhydroafrogenol, C23H32O5.H2O, which forms a diacetate, C27H36O7.H2O. The infra-red spectrum of α-anhydroafrogenol shows no evidence of the saturated y-lactone ring which is present in the structure of α-anhydroafrogenin.

scholarly journals The chemical nature of the active group in the enzyme glucose dehydrogenase

1933 ◽  
Vol 113 (781) ◽  
pp. 150-160 ◽  
Keyword(s):  
Gluconic Acid ◽  
Glucose Dehydrogenase ◽  
Intermediate Formation ◽  
Aldehyde Group ◽  
Ring Structure ◽  
The Body ◽  
Open Chain ◽  
Body Tissues ◽  
Free Aldehyde ◽  
Oxidation Of Glucose

It has been shown (Harrison, 1931) that an enzyme, glucose dehydrogenase, which brings about the oxidation of glucose, can be extracted from the liver of various animals. The product of this oxidation of glucose has been shown to be d -gluconic acid (Harrison, 1932). It seemed likely that during this conversion of glucose to gluconic acid, the ring structure of glucose would be broken, with the intermediate formation of the open chain form of glucose containing a free aldehyde group. This free aldehyde group of glucose might then be capable of oxidation by another enzyme, the Schardinger enzyme, which appears to bring about the oxidation of any soluble aldehyde. The Schardinger enzyme is widely distributed in the body tissues, and it seemed possible that it might collaborate in this way with glucose dehydrogenase in the oxidation of glucose in the body. On carrying out an experiment to test this, however, it was surprising to find that the addition of the Schardinger enzyme to glucose and glucose dehydrogenase, so far from accelerating the oxidation, brought about a complete, or almost complete, inhibition of the oxidation of glucose by the dehydrogenase. Further experiments described below showed that the inhibition was due to the Schardinger enzyme itself and not to some impurity in the enzyme preparation. It was decided to investigate the inhibition further, for it is well known that the Schardinger (or xanthine) oxidase induces the oxidation of only aldehydes and certain purines. If it could be shown that the inhibition was due to an oxidative destruction of the glucose dehydrogenase by the Schardinger enzyme, it might well throw light on the chemical structure of the dehydrogenase enzyme.

The use of polymer supports in organic synthesis. VII. Polymer-bound 1,3-diols as monoblocking agents of symmetrical dialdehydes

1976 ◽  
Vol 54 (24) ◽  
pp. 3824-3829 ◽  
Author(s):  
Clifford C. Leznoff ◽  
Shafrira Greenberg
Keyword(s):  
Organic Synthesis ◽  
Aldehyde Group ◽  
Polymer Supports ◽  
Styrene Copolymers ◽  
Free Aldehyde

Two different 2% cross-linked divinylbenzene–styrene copolymers incorporating 1,3-diol groups were prepared. The symmetrical dialdehydes terephthalaldehyde and o-phthalaldehyde were attached to these polymers through acetal formation, showing that even hindered o-aromatic dialdehydes can be monoblocked by the use of polymer supports. The free aldehyde group of polymer-bound terephthalaldehyde reacted with Wittig reagents to give 1-p-formylphenyl-4-phenyl-1,3-butadiene and p-formylstilbene. Similarly, polymer-bound o-phthalaldehyde gave o-formylstilbenes. Polymer-bound 1,3- and 1,2-diols did not form acetals of aliphatic dialdehydes and formed ketals of symmetrical diketones in very low yield.

scholarly journals A QUANTITATIVE STUDY OF THE FEULGEN REACTION WITH THE AID OF HISTOCHEMICAL MODEL SYSTEMS

1964 ◽  
Vol 12 (10) ◽  
pp. 752-757 ◽  
Author(s):  
M. J. HARDONK ◽  
P. VAN DUIJN
Keyword(s):  
Absorption Spectra ◽  
Quantitative Study ◽  
Aldehyde Group ◽  
Uv Absorption ◽  
Model Systems ◽  
Feulgen Reaction ◽  
Amino Groups ◽  
Bovine Albumin ◽  
Free Aldehyde ◽  
Quantitative Results

This paper reports some quantitative results with three histochemical model systems. The model systems are DNA-cellulose, deoxyadenylic acid-cellulose and deoxyguanylic acid-cellulose, and DNP-bovine albumin-polyacrylamide. By measuring the UV-absorption of the nucleotide-cellulose after various hydrolysis times, the rates of splitting-off of the purines by HCl were determined. Adenine is found to be split off twice as fast as guanine. The phosphorus/pararosaniline ratio is found to differ considerably from the theoretical value calculated on the assumption that every free aldehyde group reacts with pararosaniline. The differences in the values found for the phosphorus/pararosaniline ratio of the DNA-cellulose and the nucleotide-cellulose can be related to the differences in the absorption spectra of these models, which points to different degrees of substitution at the amino groups of pararosaniline. Addition of protein to DNP in a polyacrylamide film does not alter the phosphorus/pararosaniline ratio.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

scholarly journals Isolation of a Gene Responsible for the Oxidation oftrans-Anethole topara-Anisaldehyde by Pseudomonas putida JYR-1 and Its Expression in Escherichia coli

2012 ◽  
Vol 78 (15) ◽  
pp. 5238-5246 ◽  
Author(s):  
Dongfei Han ◽  
Ji-Young Ryu ◽  
Robert A. Kanaly ◽  
Hor-Gil Hur
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Putida ◽  
Hypothetical Protein ◽  
Aldehyde Group ◽  
Agrobacterium Vitis ◽  
T7 Promoter ◽  
Content Type ◽  
E Coli ◽  
Cell Extracts ◽  
Isoeugenol Monooxygenase

ABSTRACTA plasmid, pTA163, inEscherichia colicontained an approximately 34-kb gene fragment fromPseudomonas putidaJYR-1 that included the genes responsible for the metabolism oftrans-anethole to protocatechuic acid. Three Tn5-disrupted open reading frame 10 (ORF 10) mutants of plasmid pTA163 lost their abilities to catalyzetrans-anethole. Heterologously expressed ORF 10 (1,047 nucleotides [nt]) under a T7 promoter inE. colicatalyzed oxidative cleavage of a propenyl group oftrans-anethole to an aldehyde group, resulting in the production ofpara-anisaldehyde, and this gene was designatedtao(trans-anetholeoxygenase). The deduced amino acid sequence of TAO had the highest identity (34%) to a hypothetical protein ofAgrobacterium vitisS4 and likely contained a flavin-binding site. Preferred incorporation of an oxygen molecule from water intop-anisaldehyde using18O-labeling experiments indicated stereo preference of TAO for hydrolysis of the epoxide group. Interestingly, unlike the narrow substrate range of isoeugenol monooxygenase fromPseudomonas putidaIE27 andPseudomonas nitroreducensJin1, TAO fromP. putidaJYR-1 catalyzed isoeugenol,O-methyl isoeugenol, and isosafrole, all of which contain the 2-propenyl functional group on the aromatic ring structure. Addition of NAD(P)H to the ultrafiltered cell extracts ofE. coli(pTA163) increased the activity of TAO. Due to the relaxed substrate range of TAO, it may be utilized for the production of various fragrance compounds from plant phenylpropanoids in the future.

scholarly journals Paramagnetic solid-state NMR assignment and novel chemical conversion of the aldehyde group to dihydrogen ortho ester and hemiacetal moieties in copper(ii)- and cobalt(ii)-pyridinecarboxaldehyde complexes

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20216-20231
Author(s):  
Ayelén F. Crespi ◽  
Verónica M. Sánchez ◽  
Daniel Vega ◽  
Ana L. Pérez ◽  
Carlos D. Brondino ◽  
...  
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Assignment ◽  
Cobalt Complexes ◽  
Chemical Conversion ◽  
Aldehyde Group ◽  
Ortho Ester ◽  
Complex Chemical ◽  
Chemical Functionalization

The complex chemical functionalization of the aldehyde group was elucidated in copper and cobalt complexes for 4- and 3-pyridinecarboxaldehyde ligands.

Regioisomeric AIE-active luminogens with a substituent aldehyde group for controllable and reversible photochromic behavior and sensitive fluorescence detection of hydrogen sulfite

2021 ◽  
Vol 9 (11) ◽  
pp. 3882-3891
Author(s):  
Hai-Xia Yu ◽  
Junge Zhi ◽  
Jin-Liang Wang
Keyword(s):  
Fluorescence Detection ◽  
Aldehyde Group ◽  
Photochromic Behavior ◽  
Solid States

Three simple AIE-active molecules displayed obvious photoactive behaviors in both solution and solid states and selective sensing of hydrogen sulfite.

scholarly journals Study on microcrystalline cellulose/chitosan blend foam gel material

2020 ◽  
Vol 27 (1) ◽  
pp. 424-432
Author(s):  
Hongkai Zhao ◽  
Kehan Zhang ◽  
Shoupeng Rui ◽  
Peipei Zhao
Keyword(s):  
Microcrystalline Cellulose ◽  
Raw Materials ◽  
Pore Space ◽  
Sodium Dodecyl ◽  
Cost Effective ◽  
High Water ◽  
Aldehyde Group ◽  
Sem Analysis ◽  
Present Contribution ◽  
Bet Analysis

AbstractIn the present contribution, an environmental-friendly and cost-effective adsorbent was reported for soil treatment and desertification control. A novel foam gel material was synthesized here by the physical foaming in the absence of catalyst. By adopting modified microcrystalline cellulose and chitosan as raw materials and sodium dodecyl sulfonate (SDS) as foaming agent, a microcrystalline cellulose/chitosan blend foam gel was synthesized. It is expected to replace polymers derived from petroleum for agricultural applications. In addition, a systematical study was conducted on the adsorbability, water holding capacity and re-expansion performance of foam gel in deionized water and brine under different SDS concentrations (2%–5%) as well as adsorption time. To be specific, the adsorption capacity of foam gel was up to 105g/g in distilled water and 54g/g in brine, indicating a high water absorption performance. As revealed from the results of Fourier transform infrared spectroscopy (FTIR) analysis, both the amino group of chitosan and the aldehyde group modified by cellulose were involved. According to the results of Scanning electron microscope (SEM) analysis, the foam gel was found to exhibit an interconnected pore network with uniform pore space. As suggested by Bet analysis, the macroporous structure was formed in the sample, and the pore size ranged from 0 to 170nm. The mentioned findings demonstrated that the foam gel material of this study refers to a potential environmental absorbent to improve soil and desert environments. It can act as a powerful alternative to conventional petroleum derived polymers.

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