On the Function of Base Formation Suffixes in Jeonnam Dialects

2021 ◽  
Vol 69 ◽  
pp. 29-48
Author(s):  
Bok-Seoung Song
Keyword(s):  
Base Formation

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.

First-principles investigation of the Lewis acid–base adduct formation at the methylammonium lead iodide surface

2018 ◽  
Vol 20 (16) ◽  
pp. 11183-11195 ◽  
Author(s):  
Giacomo Giorgi ◽  
Koichi Yamashita ◽  
Hiroshi Segawa
Keyword(s):  
Lewis Acid ◽  
First Principles ◽  
Adduct Formation ◽  
Lead Iodide ◽  
Acid Base ◽  
Methylammonium Lead Iodide ◽  
Base Formation

Theoretical insights into the mechanism of Lewis acid–base formation at the surface of methylammonium lead iodide (MAPbI3).

Schiff Base Formation upon Complexation of Tris(acetylacetonato)iron with N[(CH2CH2NH2)(CH2CH2OH)(CH2CH2CH2OH)]

2004 ◽  
Vol 630 (13-14) ◽  
pp. 2558-2561 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Christoph Jocher ◽  
Thomas L�gger ◽  
Tania Pape
Keyword(s):  
Schiff Base ◽  
Schiff Base Formation ◽  
Base Formation

scholarly journals Immobilization of Chondroitin Sulfate A onto Monolithic Epoxy Silica Column as a New Chiral Stationary Phase for High-Performance Liquid Chromatographic Enantioseparation

2021 ◽  
Vol 14 (2) ◽  
pp. 98
Author(s):  
Ratih Ratih ◽  
Hermann Wätzig ◽  
Azminah Azminah ◽  
Mufarreh Asmari ◽  
Benjamin Peters ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Chondroitin Sulfate ◽  
High Performance ◽  
Chiral Stationary Phase ◽  
High Performance Liquid Chromatographic ◽  
Schiff Base Formation ◽  
The Individual ◽  
Liquid Chromatographic ◽  
Base Formation ◽  
Chondroitin Sulfate A

Chondroitin sulfate A was covalently immobilized onto a monolithic silica epoxy column involving a Schiff base formation in the presence of ethylenediamine as a spacer and evaluated in terms of its selectivity in enantioseparation. The obtained column was utilized as a chiral stationary phase in enantioseparation of amlodipine and verapamil using a mobile phase consisting of 50 mM phosphate buffer pH 3.5 and UV detection. Sample dilution by organic solvents (preferably 25% v/v acetonitrile-aqueous solution) was applied to achieve baseline enantioresolution (Rs > 3.0) of the individual drug models within 7 min, an excellent linearity (R2 = 0.999) and an interday repeatability of 1.1% to 1.8% RSD. The performance of the immobilized column for quantification of racemate in commercial tablets showed a recovery of 86–98% from tablet matrices. Computational modeling by molecular docking was employed to investigate the feasible complexes between enantiomers and the chiral selector.

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