RCM-based synthesis of a variety of beta-C-glycosides and their in vitro anti-solid tumor activity.

The synthesis of a number of biologically relevant C-glycosides has been carried out through the use of an esterification-ring-closing metathesis (RCM) strategy. The required acid precursors were readily prepared via a number of standard chemical transformations followed by dehydrative coupling of these acids with several olefin alcohols 1 to yield the precursor esters 3 in excellent yield. Methylenation of the esters 3 was followed by RCM and in situ hydroboration-oxidation of the formed glycals to furnish the protected beta-C-glycosides 6 in good overall yield.

The beta- and gamma-CH2 of B27-WT's Leu11 and Ile18 side chains play a direct role in calpain inhibition.

Uncontrolled activation of calpain has been linked to tissue damage after neuronal and cardiac ischemias, traumatic spine and brain injuries, and multiple sclerosis and Alzheimer's disease. In vivo, the activity of calpain is regulated by its endogenous inhibitor calpastatin. The pathological role of calpain has been attributed to an imbalance between the activities of the protease and its inhibitor.

Mutation of the highly conserved tryptophan in the serpin breach region alters the inhibitory mechanism of plasminogen activator inhibitor-1.

We have demonstrated that interactions within the conserved serpin breach region play a direct role in the critical step of the serpin reaction in which the acyl-enzyme intermediate must first be exposed to hydrolyzing water and aqueous deacylation. Substitution of the breach tryptophan in PAI-1 (Trp175), a residue found in virtually all known serpins, with phenylalanine altered the kinetics of the reaction mechanism and impeded the ability of PAI-1 to spontaneously become latent without compromising the inherent rate of cleaved loop insertion or partitioning between the final inhibited serpin-proteinase complex and hydrolyzed serpin. Kinetic dissection of the PAI-1 inhibitory mechanism using multiple target proteinases made possible the identification of a single rate-limiting intermediate step coupled to the molecular interactions within the breach region.

Structural determinants of the calpain inhibitory activity of calpastatin peptide B27-WT.

Calpastatin is the natural specific inhibitor of calpain. Recent research has linked uncontrolled calpain activation to tissue damage after neuronal and cardiac ischemias, traumatic spine and brain injuries, as well as Alzheimer's disease and cataract formation. An imbalance between the activities of calpain and calpastatin is believed to be responsible for the pathological role of calpain.