Regioselective glycosylation of novobiocin alters activity.

Glycosylation is a promising approach to overcome antimicrobial drug resistance. In this study, we investigated Koenigs-Knorr and phase transfer glycosylation on novobiocin. While the former only gave a 4'-OH product, the later produced mainly a kinetic controlled 5-OH product, but still achieved the 4'-OH modification and novoise-glycosylated products (with stronger base), as well as a diglycosylated compound.

Selectivity of major isoquinoline alkaloids from Chelidonium majus towards telomeric G-quadruplex: A study using a transition-FRET (t-FRET) assay.

Background: Natural bioproducts are invaluable resources in drug discovery. Isoquinoline alkaloids of Chelidonium majus constitute a structurally diverse family of natural products that are of great interest, one of them being their selectivity for human telomeric G-quadruplex structure and telomerase inhibition.

Methods: The study focuses on the mechanism of telomerase inhibition by stabilization of telomeric G-quadruplex structures by berberine, chelerythrine, chelidonine, sanguinarine and papaverine.

Hiatal hernia with upside-down stomach. Management of acute incarceration: case presentation and review of literature.

Upside-down stomach (UDS) represents the rarest type of hiatal hernia (<5%) and is characterized by herniation of the entire stomach or most gastric portions into the posterior mediastinum. We present here a very rare complication of such a condition which is incarceration of upside-down stomach. A 54 year-old female was admitted to the emergency department presenting signs of acute epigastric pain radiating into thorax.

Why do forward maskers affect auditory intensity discrimination? Evidence from "molecular psychophysics".

Nonsimultaneous maskers can strongly impair performance in an auditory intensity discrimination task. Using methods of molecular psychophysics, we quantified the extent to which (1) a masker-induced impairment of the representation of target intensity (i.e.