Catalysis mediated by iron complexes is emerging as an eco-friendly and inexpensive option in comparison to traditional metal catalysis. The epoxidation of alkenes constitutes an attractive application of iron(III) catalysis, in which terminal olefins are challenging substrates. Herein, we describe our study on the design of biomimetic non-heme ligands for the in situ generation of iron(III) complexes and their evaluation as potential catalysts in epoxidation of terminal olefins.
View Article and Find Full Text PDFTwo new functionalized 4,4'-disubstituted 2,2'-bipyridines that were end-capped with cyanoacrylic acid or cyanoacrylic acid ester anchoring groups, which might allow their efficient functionalization on TiO2 or other metal-oxide semiconductor surfaces, have been synthesized and characterized by electrochemical, photophysical, and spectroscopic measurements. The electrochemical and photophysical properties of these 4,4'-disubstituted 2,2'-bipyridines with extended π systems, in particular their LUMO energies, make them promising candidates to build up inorganic-organic hybrid photosensitizers for the sensitization of metal-oxide semiconductors (e.g.
View Article and Find Full Text PDFContext: T(4)-binding globulin (TBG) is the main transport protein for T(4) in blood and a member of the superfamily of serine proteinase inhibitors. So far, 14 mutations leading to familial complete TBG deficiency have been reported. Eleven of these are caused by mutations leading to truncation of the molecule, and three are caused by single amino acid substitutions.
View Article and Find Full Text PDFBackground: Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism and chronic anovulation. The genetic background of the insulin resistance frequently associated with PCOS is unclear.
Objectives: To examine the influe nce of the Pro12Ala polymorphism of the peroxisome proliferator activated receptor gamma (PPARgamma), which is thought to play a role in the regulation of insulin sensitivity, on endocrine and metabolic parameters in PCOS patients.
We present an unusual variant of T(4)-binding globulin (TBG) found in a family from Allentown, Pennsylvania (TBG-AT). The heterozygous proposita presented serum total T(4) and TBG levels ranging from low to normal. TBG gene sequencing revealed a C-to-T substitution in codon -2 (CAC to TAC) leading to the substitution of the normal histidine by a tyrosine within the signal peptide.
View Article and Find Full Text PDFThyroxine-binding globulin (TBG) and corticosteroid-binding globulin are unique among non-inhibitory members of the superfamily of serine-proteinase inhibitors (serpins) in undergoing a dramatic increase in stability [stressed-to-relaxed (S-->R) transition] after proteolytic cleavage within their exposed reactive-site-loop (RSL) equivalent. This structural rearrangement involves the insertion of the cleaved loop as a new strand into the beta-sheet A and is accompanied by a decrease in hormone binding. To define the mechanism that leads to disruption of hormone binding of TBG after proteolytic cleavage, the effect of partial loop deletions and replacements by the alpha(1)-proteinase inhibitor homologues of TBG were evaluated.
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