Biocatalytic synthesis of asymmetric water-soluble indirubin derivatives /

A method for the synthesis of asymmetric carboxy-substituted indirubins is presented. It employs indole-5-carboxylic acid or indole-6-carboxylic acid and 2-indolinone derivatives as substrates for bacterial monooxygenase-driven enzymatic bioconversion in different bacterial hosts. This bioconversion system achieved the highest titer of monocarboxyindirubin production of up to 327 mg L−1 for 5-bromoindirubin-6′-carboxylic acid during the 16-h incubation period. The purified monocarboxyindirubins exhibited high solubility in water, up to three orders of magnitude higher than that of indirubin. In addition, several monocarboxyindirubins, namely 1-methylindirubin-5′-carboxylic acid, possess potent antiproliferative activity against different cancer cell lines. Therefore, the synthesis method for monocarboxyindirubins described herein is an efficient and environmentally friendly bioconversion system and the synthesized monocarboxyindirubins show great promise due to their high water solubility and potential antiproliferative activity

Real-time observation of ion exchange dynamics during surface treatment of all-inorganic perovskite quantum dots with Zn-halogenide complexes for color tuning and enhanced quantum efficiency

All-inorganic lead perovskite quantum dots (QDs), due to their distinctive optical properties, have become one of the “hottest” topics in materials science; therefore, the development of new QD synthesis methods or their emission color adjustment is of great interest. Within this study, we present the simple preparation of QDs employing a novel ultrasound-induced hot-injection method, which significantly reduces the QD synthesis time from several hours to merely 15-20 minutes. Moreover, the post-synthesis treatment of perovskite QDs in solutions using zinc halogenide complexes could increase the QD emission intensity and, at the same time, boost their quantum efficiency. This behavior is due to the zinc halogenide complex's ability to remove or significantly reduce the number of surface electron traps in perovskite QDs. Finally, the experiment that shows the ability to instantly adjust the desired emission color of perovskite QDs by variation of the amount of added zinc halogenide complex is presented. The instantly obtained perovskite QD colors cover virtually the full range of the visible spectrum. The zinc halogenide modified perovskite QDs exhibit up to 10-15% higher QEs than those prepared by an individual synthesis