Ultra-low flow liquid chromatography assay with ultraviolet (UV) detection for piperine quantitation in human plasma.

A robust and sensitive ultra-low flow liquid chromatography (UFLC) method that can reproducibly, at reasonable cost, detect low concentrations of piperine from human plasma is necessary. Piperine in plasma was separated and quantified by a gradient method using ultraviolet detection at a maximal absorbance wavelength of 340 nm. An aliquot was injected onto a reversed-phase column Waters SymmetryShield, 2.

Characterization of S-thiolation on secreted proteins from E. coli by mass spectrometry.

S-thiolation is a reversible post-translational modification in which thiol metabolites of low molecular masses are linked to protein sulfhydryl groups through disulfide bonds. This modification is commonly observed in recombinant proteins secreted from E. coli cells.

Synthesis of orthogonally reactive FK506 derivatives via olefin cross metathesis.

Chemical inducers of dimerization (CIDs) are employed in a wide range of biological applications to control protein localization, modulate protein-protein interactions and improve drug lifetimes. These bifunctional chemical probes are assembled from two synthetic modules, which each provide affinity for a distinct protein target. FK506 and its derivatives are often employed as modules in the syntheses of these bifunctional constructs, owing to the abundance and favorable distribution of their target, FK506-binding protein (FKBP).