Selectfluor-mediated tandem cyclization of enaminones with diselenides toward the synthesis of 3-selenylated chromones.

A practical and metal-free approach for the regioselective selenation of chromones employing Selectfluor reagent under mild conditions is described. The developed method is suitable for a wide substrate scope and affords 3-selenylated chromones in good to excellent yield with high selectivity. An ionic mechanism is proposed for this transformation.

[Reversion Mechanism Study of PESV to Multidrug Resistance at Leukemia Stem Cell Level].

Objective: To explore the effect of peptide extract from scorpion venom (PESV) to multidrug resistance (MDR) of leukemic stem cell (LSC) in vivo.

Methods: K562/A02 cells were cultured and collected in the logarithmic phase. K562/A02 stem cells were screened using immunomagnetic beads for reserve.