Amides derived from common hydroxycinnamic acids — including 4‐hydroxycinnamic acid, 3‐methoxy‐4‐hydroxycinnamic 3,4‐dihydroxycinnamic 3,4‐dimethoxycinnamic and 3,4,5‐trimethoxycinnamic acid along with various free aminobenzoic acids, such as 5‐hydroxy‐2‐aminobenzoic a key component of the avenanthramide family, have been rapidly synthesized using an innovative, environmentally friendly synthetic methodology. This approach, grounded in traditional chemistry, utilizes mixed anhydrides to...

A peptidomics approach was developed to identify transglutaminase‐susceptible Q residues within a pepsin–trypsin gliadin digest. Based on tagging with monodansylcadaverine fluorescent probe, six α/β‐, γ‐gliadin, and low molecular weight glutenin peptides were identified by nanospray tandem mass spectrometry. In functioning as an acyl acceptor, tissue transglutaminase able form complexes the glutamine‐rich peptides, whereas lowering pH, deamidated at same residues, which previously...

Abstract Green solvents like ethyl acetate and acetone convert hydroxycinnamic acids into natural unnatural derivatives such as amides, esters, other valuable synthetic intermediates. Employing protection‐activation a system based on an alkyl chloroformate N ‐methyl morpholine, emerges excellent solvent for coupling O ‐carbonate‐protected mixed anhydrides in acylation reactions of C‐protected amino acids, amines, catalyzed alcohols. This results high yields ‐protected phenolic amides esters....

N-protected α-amino acids are readily coupled with α-aminoacyl esters by polystyryl diphenylphosphine-iodine complex in very high yields and without detectable racemization. Protecting groups of general use for both amine carboxyl functions, as well the common side-chain-function protecting groups, tolerated under our experimental conditions. The workup is easy since only byproduct formed a polymer-linked phosphine oxide that simply filtered off to achieve coupling product.

Coatings of graphene nanoplatelets (GNPs) were deposited on a low density polyethylene (LDPE) substrate by micromechanical method based rubbing graphite platelets against the surface polymer. Transmission electron microscopy measurements reveal that coatings composed containing 13–30 layers. Thermal gravimetric analysis shows investigated GNP LDPE (GNP/LDPE) samples are thermally stable up to 250 °C. Optical spectra these samples, compared those pristine in ultraviolet-visible-near-infrared...

Abstract The general synthesis of a new class non‐natural diamino acids, 2‐amino‐3‐[(2′‐aminoalkyl)thio]propanoic acids or S ‐(aminoalkyl)cysteines, is reported. Under the conditions devised, enantiopure N ‐Boc‐protected β‐iodoamines, readily generated from proteinogenic α‐amino are treated with L ‐cysteine ethyl ester hydrochloride, using Cs 2 CO 3 as base. ‐alkylation products, obtained in high yields (96–98 %) and without any detectable traces accompanying byproducts, hydrolysed to yield...

A novel enantioselective route to monoprotected 2-substituted-1,3-dicarbonyl compounds has been developed via acylation of silylenol ethers with chiral ortho esters derived from diethyl or di-isopropyl (R,R)-tartrates; good yields and stereoselectivity can be achieved starting cyclic enolsilanes.

Abstract Background Celiac disease is a widely prevalent enteropathy caused by intolerance to gliadin, one of the gluten proteins. We developed two methods for analysis gliadin levels. Both use flow cytometry and rat antibodies against 16‐residue peptide gliadin. The common α‐, β‐, γ‐, ω‐gliadins. Methods In one‐site assay, antigen (gliadin standard or food extract) was adsorbed on 3‐μm latex particles. Sensitized particles were then incubated, in this order, with anti‐gliadin anti‐rat...

Abstract Ketones are reported to be conveniently converted into their α-tolylsulfinylated derivatives. This new procedure is based on the reaction of corresponding trimethylsilyl enol ethers with p-toluenesulfinyl p-tolylsulfone in presence tris(dimethylamino)sulfur trimethylsilyldifluoride (TAS-F). Considering that β-ketosulfoxides key intermediates for preparation α,β-unsaturated ketones, this turns out rather broad synthetic relevance.

Abstract A novel procedure for reduction and simultaneous protection of phenol groups hydroxycinnamic acids to the related alcohols has been developed. During formation mixed anhydrides from an alkyl chloroformate, was protected as carbonate, were reduced with aqueous solution sodium borohydride. Free phenols obtained by deprotection under mild conditions 30% aq. NH 4 OH in methanol. O ‐protected phenolic can be converted standard methods into orthogonal derivatives. This rapid efficient...

Abstract Hydroxycinnamic acids such as p ‐coumaric, ferulic, sinapic and caffeic were protected carbonates activated mixed carbonic anhydrides in water at RT by adding a base isobutyl chloroformate. These used for amine C ‐protected α‐amino acid acylation to give O ‐carbonate phenolic amides. Acylation of free was performed acetone‐water high yields producing the N ‐hydroxycinnamoyl‐α‐amino acids. Pure derivatives obtained many cases directly crystallization. Free compounds rapidly carbonate...

The stereoselectivity of the Lewis acid induced acylation open-chain silyl enoi ethers by chiral orthoesters is strongly affected CC bond configuration: both Z and E enol are acylated in good isolated yields, but isomers give rise to a 1 : ratio diastereoisomeric monoprotected 1,3-diketones, while excellent stereoselectivities obtained with enols.

Abstract Aldehydes and methyl ketones readily afford 5,6-dihydro-1,4-dithiins that can be converted by n-butyllithium into their corresponding sulfur stabilized carbanions. Coupling of the latter with alkyl halides leads to species having a cis-configurated, disubstituted double bond tied up sulfur-containing ring which is known susceptible selective removal.

Abstract A new high yielding coupling reaction of C-2 monosubstituted 5,6-dihydro-1,4-dithiins with aldehydes is reported. In this way allylic alcohols having the cis-substituted double bond tied up by a sulfur-containing ring can be readily prepared. Subsequent stereoselective sulfur removal then affords cis-configurated bond.