Phenolic Glycosides with antiproteasomal activity from Centaurea urvillei DC. subsp. urvillei.

A new flavanone glycoside, naringenin-7-O-β-D-glucuronopyranoside, and a new flavonol glycoside, 6-hydroxykaempferol-7-O-β-D-glucuronopyranoside were isolated together with 12 known compounds, 5 flavone glycoside; hispidulin-7-O-β-D-glucuronopyranoside, apigenin-7-O-β-D-methylglucuronopyranoside, hispidulin-7-O-β-D-methylglucuronopyranoside, hispidulin-7-O-β-D-glucopyranoside, apigenin-7-O-β-D-glucopyranoside, a flavonol; kaempferol, two flavone; apigenin, and luteolin, a flavanone glycoside; eriodictyol-7-O-β-D-glucuronopyranoside, and three phenol glycoside; arbutin, salidroside, and 3,5-dihydroxyphenethyl alcohol-3-O-β-D-glucopyranoside from Centaurea urvillei subsp. urvillei. The structure elucidation of the new compounds was achieved by a combination of one- ((1)H and (13)C) and two-dimensional NMR techniques (G-COSY, G-HMQC, and G-HMBC) and LC-ESI-MS.

Differential regulation of CFTRDeltaF508 degradation by ubiquitin ligases gp78 and Hrd1.

The most common mutation associated with cystic fibrosis is the deletion of phenylalanine 508 of cystic fibrosis transmembrane conductance regulator (CFTRDeltaF508). This mutation renders otherwise functional protein susceptible to ER-associated degradation (ERAD) and prevents CFTR from exiting the ER and trafficking to the plasma membrane. In this study, we demonstrate that RNAi-mediated silencing of gp78, an established ubiquitin ligase (E3) involved in ERAD, leads to accumulation of CFTRDeltaF508 protein in cells.

Studies of the kinetics and thermochemistry of the forward and reverse reaction Cl + C6H6 = HCl + C6H5.

The laser flash photolysis resonance fluorescence technique was used to monitor atomic Cl kinetics. Loss of Cl following photolysis of CCl4 and NaCl was used to determine k(Cl + C6H6) = 6.4 x 10(-12) exp(-18.