scholarly journals Ultrastructural cytochemistry of p-N,N-dimethylamino-beta-phenethylamine (DAPA) oxidation reactions.

1976 ◽  
Vol 24 (3) ◽  
pp. 527-539 ◽  
Author(s):  
W A Shannon ◽  
H L Wasserkrug ◽  
R E Plapinger ◽  
A M Seligman
Keyword(s):  
Oxidation Reaction ◽  
Amine Oxidase ◽  
Oxidative Polymerization ◽  
Tetrazolium Salt ◽  
Oxidation Reactions ◽  
Reaction Products ◽  
Schiff’S Base ◽  
Tetrazolium Chloride ◽  
Pig Kidney ◽  
Base Formation

The ultracytochemical localization of amine oxidase (AO) activity is demonstrated with a new substrate, p-N,N-dimethylamino-beta-phenethylamine (DAPA). DAPA was designed to yield a stronger reducing agent on oxidation by monoamine oxidase (MAO) than is obtained from the MAO substrate, tryptamine, upon oxidation. Thus MAO and possibly other oxidase(s) can be demonstrated with DAPA and the tetrazolium salt, 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl) tetrazolium chloride (BSPT). The latter is a nonosmiophilic tetrazolium salt which is reduced to an osmiophilic formazan. In addition, DAPA itself demonstrates AO activity ultracytochemically with and without BSPT. We speculate that either oxidative polymerization of DAPA or Schiff's base formation with protein after aldehyde formation is responsible for the latter reaction, which is made permanent for ultracytochemical localization by osmication at a later step. DAPA oxidation reaction products are demonstrated in guinea pig kidney, specifically in the endoplasmic reticulum, nuclear envelope and mitochondrial outer compartments and cristae. Differences in reaction product characteristics and localization in relation to formaldehyde fixation and the localization of reaction product in mitochondrial cristae, as well as outer compartments, suggest that DAPA oxidation is mediated through one or more MAOs and possible other oxidases.

scholarly journals Ultrastructural cytochemistry of p-N,N-dimethylamino-beta-phenethylamine (DAPA) oxidation reactions. "activation" and inhibition studies.

1976 ◽  
Vol 24 (3) ◽  
pp. 540-555 ◽  
Author(s):  
W A Shannon ◽  
H L Wasserkrug ◽  
A M Seligman
Keyword(s):  
Monoamine Oxidase ◽  
Diamine Oxidase ◽  
Amine Oxidase ◽  
The Other ◽  
Oxidation Reactions ◽  
Fixed Tissue ◽  
Tetrazolium Chloride ◽  
Ultrastructural Cytochemistry ◽  
Inhibition Studies ◽  
Reaction Media

The oxidation of p-N,N-dimethylamino-beta-phenethylamine (DAPA) by amine oxidase(s) (AO), i.e., diamine oxidase (DAO), monoamine oxidase (MAO) and/or possibly other oxidases, has been previously demonstrated. This study reports the results of variations in fixation procedures and the incorporation of a series of possible "activators" and inhibitors into the DAPA oxidase (DAPAO) and DAPAO-BSPT [2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl) tetrazolium chloride] reaction media in an attempt to elucidate the oxidase(s) involved. Results of these studies are indicative of at least two different oxidases acting preferentially on one or the other of the two systems. The presence of MAO, especially in unfixed tissue, and DAO, especially in fixed tissue, is denoted and that of other oxidase(s) is connoted.

Mitochondrial Oxidation of p-N, N-Dimethylamino-β-Phenethylamine (DAPA)

1975 ◽  
Vol 33 ◽  
pp. 458-459
Author(s):  
W. Allen Shannon ◽  
Hannah L. Wasserkrug ◽  
andArnold M. Seligman
Keyword(s):  
Guinea Pig ◽  
Oxidase Activity ◽  
Amine Oxidase ◽  
Histochemical Demonstration ◽  
Guinea Pig Heart ◽  
Pig Kidney ◽  
Cytoplasmic Vacuoles ◽  
Liver And Kidney ◽  
Mitochondrial Oxidation ◽  
Amine Oxidase Activity

The synthesis of a new substrate, p-N,N-dimethylamino-β-phenethylamine (DAPA)3 (Fig. 1) (1,2), and the testing of it as a possible substrate for tissue amine oxidase activity have resulted in the ultracytochemical localization of enzyme oxidase activity referred to as DAPA oxidase (DAPAO). DAPA was designed with the goal of providing an amine that would yield on oxidation a stronger reducing aldehyde than does tryptamine in the histochemical demonstration of monoamine oxidase (MAO) with tetrazolium salts.Ultracytochemical preparations of guinea pig heart, liver and kidney and rat heart and liver were studied. Guinea pig kidney, known to exhibit high levels of MAO, appeared the most reactive of the tissues studied. DAPAO reaction product appears primarily in mitochondrial outer compartments and cristae (Figs. 2-4). Reaction product is also localized in endoplasmic reticulum, cytoplasmic vacuoles and nuclear envelopes (Figs. 2 and 3) and in the sarcoplasmic reticulum of heart.

Green Application of Phase-Transfer Catalysis in Oxidation: A Comprehensive Review

2020 ◽  
Vol 17 (4) ◽  
pp. 405-411
Author(s):  
Chuan-Hui Wang ◽  
Chen-Fu Liu ◽  
Guo-Wu Rao
Keyword(s):  
Organic Chemistry ◽  
Green Chemistry ◽  
Oxidation Reaction ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Important Application ◽  
Oxidation Reactions ◽  
Comprehensive Review ◽  
Phase Transfer Catalysts ◽  
Onium Salts

Oxidation reactions have emerged as one of the most versatile tools in organic chemistry. Various onium salts such as ammonium, phosphonium, arsonium, bismuthonium, tellurium have been used as phase transfer catalysts in many oxidation reactions. Certainly, considerable catalysts have been widely used in Phase-Transfer Catalysis (PTC). This review focuses on the application of PTC in various oxidation reaction. Furthermore, PTC also conforms to the concept of “Green Chemistry”. <p></p> • Oxidation has become one of the most widely used tools in organic chemistry and phase transfer catalysts has been widely used in oxidation. <p></p> • The application of phase transfer catalysts in oxidation reaction will be summarized. <p></p> • Phase transfer catalysts have important application in various oxidation reaction.

scholarly journals Lipid Metabolic Events Underlying the Formation of the Corneocyte Lipid Envelope

2021 ◽  
pp. 1-13
Author(s):  
Philip W. Wertz
Keyword(s):  
Stratum Corneum ◽  
Outer Surface ◽  
Barrier Function ◽  
Skin Surface ◽  
Schiff’S Base ◽  
Cornified Envelope ◽  
Epoxy Alcohol ◽  
Viable Epidermis ◽  
Transglutaminase 1 ◽  
Base Formation

Cornified cells of the stratum corneum have a monolayer of an unusual lipid covalently attached to the outer surface. This is referred to as the corneocyte lipid envelope (CLE). It consists of a monolayer of ω-hydroxyceramides covalently attached to the outer surface of the cornified envelope. The CLE is essential for proper barrier function of the skin and is derived from linoleate-rich acylglucosylceramides synthesized in the viable epidermis. Biosynthesis of acylglucosylceramide and its conversion to the cornified envelope is complex. Acylglucosylceramide in the bounding membrane of the lamellar granule is the precursor of the CLE. The acylglucosylceramide in the limiting membrane of the lamellar granule may be oriented with the glucosyl moiety on the inside. Conversion of the acylglucosylceramide to the CLE requires removal of the glucose by action of a glucocerebrosidase. The ester-linked fatty acid may be removed by an as yet unidentified esterase, and the resulting ω-hydroxyceramide may become ester linked to the outer surface of the cornified envelope through action of transglutaminase 1. Prior to removal of ester-linked fatty acids, linoleate is oxidized to an epoxy alcohol through action of 2 lipoxygenases. This can be further oxidized to an epoxy-enone, which can spontaneously attach to the cornified envelope through Schiff’s base formation. Mutations of genes coding for enzymes involved in biosynthesis of the CLE result in ichthyosis, often accompanied by neurologic dysfunction. The CLE is recognized as essential for barrier function of skin, but many questions about details of this essentiality remain. What are the relative roles of the 2 mechanisms of lipid attachment? What is the orientation of acylglucosylceramide in the bounding membrane of lamellar granules? Some evidence supports a role for CLE as a scaffold upon which intercellular lamellae unfold, but other evidence does not support this role. There is also controversial evidence for a role in stratum corneum cohesion. Evidence is presented to suggest that covalently bound ω-hydroxyceramides serve as a reservoir for free sphingosine that can serve in communicating with the viable epidermis and act as a potent broad-acting antimicrobial at the skin surface. Many questions remain.

Trimetallic PtNiCo branched nanocages as efficient and durable bifunctional electrocatalysts towards oxygen reduction and methanol oxidation reactions

2021 ◽  
Author(s):  
hengrui Ma ◽  
Zhiping Zheng ◽  
Hongsheng Zhao ◽  
Cong Shen ◽  
Hanming Chen ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Methanol Oxidation ◽  
Oxidation Reaction ◽  
Reduction Reaction ◽  
Great Promise ◽  
Methanol Oxidation Reaction ◽  
Oxidation Reactions ◽  
Bifunctional Electrocatalysts ◽  
Composition And Structure

Engineering the composition and structure of Pt-based alloy electrocatalysts has exhibited great promise for enhancing activity and durability in oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). However, it...

Schiff's base formation rater than molecular association between acetone and 3-amino-6-methoxypyridine

1993 ◽  
Vol 31 (7) ◽  
pp. 685-688 ◽  
Author(s):  
John Maguire ◽  
David G. Morris ◽  
David S. Rycroft ◽  
F. S. Ortiz
Keyword(s):  
Molecular Association ◽  
Schiff’S Base ◽  
Base Formation

scholarly journals Phenylmethoxybis(tetrazolium) ion-association complexes with an anionic indium(III) — 4-(2-pyridylazo)resorcinol chelate

2013 ◽  
Vol 11 (2) ◽  
pp. 280-289 ◽  
Author(s):  
Teodora Stefanova ◽  
Kiril Gavazov
Keyword(s):  
Limit Of Detection ◽  
Ion Association ◽  
Molar Absorptivity ◽  
Tetrazolium Salt ◽  
Limit Of Quantification ◽  
Tetrazolium Chloride ◽  
Liquid Liquid Extraction ◽  
Blue Tetrazolium ◽  
Blue Tetrazolium Chloride ◽  
Molar Absorptivity Coefficient

AbstractComplex formation and liquid-liquid extraction were studied in systems containing indium(III), 4-(2-pyridylazo)resorcinol (PAR), phenylmethoxybis(tetrazolium) salt (MBT), water and chloroform. The following MBTs, which differ only by the number of -NO2 groups in their cationic parts, were used: 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis(2,5-diphenyl-2H-tetrazolium chloride) (Blue Tetrazolium chloride, BT), 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis[2-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride] (Nitro Blue Tetrazolium chloride, NBT) and 3,3′-(3,3′-dimetoxy-4,4′-biphenylene)bis[2,5-di(4-nitrophenyl)-2H-tetrazolium chloride] (Tetranitro Blue Tetrazolium chloride, TNBT). The composition of the formed ternary complexes was determined, In:PAR:MBT=1:2:2, and the optimum conditions for their extraction found: pH, shaking time, concentration of the reagents and the sequence of their addition. Some key constants were estimated: constants of extraction (Kex), constants of association (β) and constants of distribution (KD). BT appears to be the best MBT for extraction of the In(III)-PAR species, [In3+(OH)3(PAR)2]4−, (Log Kex=10.9, Log β=9.8, Log KD=1.12, R%=92.7%). Several additional characteristics concerning its application as extraction-spectrophotometric reagent were calculated: limit of detection (LOD = 0.12 µg cm−3), limit of quantification (LOD = 0.40 µg cm−3) and Sandell’s sensitivity (SS =1.58 ng cm−2); Beer’s law is obeyed for In(III) concentrations up to 3.2 µg mL−1 with a molar absorptivity coefficient of 7.3×104 L mol−1 cm−1 at λmax=515 nm.

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