Carbonylation

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Straightforward routes to fused tetrahydroindolizinones by two routes A and B, starting either from 2-formylbenzoic acid and esters or from β-hydroxy lactones via acyl iminium ions, are described. A plausible mechanism and limitations are given. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Background: Glucosinolates from brassica plants are hydrolyzed by internal or salivary myrosinase to produce isothiocyanates. Glucoraphanin, a major glucosinolate in broccoli, is hydrolyzed to sulforaphane (SFN), which exhibits antitumor and detoxification activities. Regarding the influence of broccoli and its constituents on the skin, a few studies have reported anti-inflammatory and antioxidant effects. Recently, advanced glycation end products (AGEs)
and carbonyl proteins have been reported to accelerate skin aging.

Objective: We evaluated the effects of broccoli seed extract (BSE) and glucosinolates on protein glycation and carbonylation in vitro.

Methods: To evaluate the effects of BSE and its constituents, protein glycation and carbonylation were induced by mixing fructose with bovine serum albumin (BSA) and then measuring production of AGEs, fructosamine, and carbonyl proteins (CP). Production of CP after mixing fatty acids with BSA was also assessed. Furthermore, the effect of BSE and its constituents on CP production by human fibroblasts (TIG103) was examined.

Results: BSE suppressed the production of AGEs, fructosamine, and CP after mixing fructose and BSA. BSE also suppressed production of CP when oxidized linoleic acid was mixed with BSA. Isothiocyanates, including SFN and iberin, suppressed fructose-based CP production, but
SFN had no effect on CP production stimulated by oxidized linoleic acid. In contrast, glucosinolates from BSE did not suppress fructose-based CP production, but suppressed CP
production due to oxidized linoleic acid. Among the glucosinolates in BSE, glucoberteroin showed the strongest suppression of CP production. CP production in fibroblasts was also suppressed by glucosinolates, including glucoiberin and glucoberteroin.

Conclusions: BSE demonstrated anti-glycation and anti-carbonylation effects on protein reactions with fructose and oxidized fatty acids. Isothiocyanates suppressed protein
carbonylation induced by fructose, but not those induced by oxidized lipids. On the other hand, glucosinolates (precursors of isothiocyanates) did not suppress protein carbonylation induced by fructose, but suppressed carbonylation due to oxidized lipids. Moreover, glucoberteroin and glucoiberin suppressed CP production in a cell-based assay. These results suggest that glucosinolates in BSE could suppress protein carbonylation leading to aging of the skin.

Keywords: Broccoli; glucosinolate; sulforaphane; carbonylation; glycation; glucoberteroin; glucoiberin

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate), a structurally well defined O-containing transition metal complex, is reported to be an efficient catalyst for alkoxycarbonylation and aminocarbonylation reactions under milder operating conditions. The system tolerated the carbonylative coupling of various aryl halides with phenol/alcohol and amines, providing good to excellent yields of desired products under optimized reaction conditions. Copyright © 2009 John Wiley & Sons, Ltd.

A series of trans-and cis-methylpalladium carbamate complexes PdMe(OCONRR′)L 2 (L = tertiary phosphine; R, R′= H, alkyl, and phenyl) was prepared by the reaction of dimethylpalladium complexes with primary or secondary amine and carbon dioxide. When diphenylamine ...

Reactive oxygen and nitrogen species may cause various types of chemical modifications on specific proteins, Such modifications if irreversible are often associated with permanent loss of function and may lead to the elimination or to the accumulation of the damaged proteins. Reversible modifications, particularly at the cysteine residues, may have a dual role of protection from cysteine irreversible oxidation and modulation of protein function (redox regulation). Here we will review the techniques available for identifying proteins based on their redox state. In particular, we will focus on protein carbonylation, tyrosine nitration and thiol-disulfide chemistry of cysteines, with special emphasis on glutathionylation, because these are the fields where the tools of proteome analysis have been applied.