ABSTRACT
Greenhouse gases such as CO2 strongly contribute to the rising temperatures of our planet, but as long as our society is dependent on fossil fuels, this trend will even increase in the near future. Therefore, CO2 capture and subsequent utilization constitute an approach for decarbonization and CO2 mitigation, and for this purpose, amine scrubbing remains the industrially most established process. In this article, we describe the CO2 capture-ability of pyrrolizidine-based diamines, a scaffold with remarkably good properties to fulfill this challenge. We observed fast equimolar CO2-uptake, as well as high stability of these compounds during multiple capture and release-cycles. In addition, the amines could be utilized for direct air capture. Finally, we demonstrate the utility of the pyrrolizidine absorbents in the reduction of CO2 and for the formation of oxazolidinones.
ABSTRACT
Chemical cell-surface engineering is a tool for modifying and altering cellular functions. Herein, we report the introduction of an antibiotic phenotype to the green alga Chlamydomonas reinhardtii by chemically modifying its cell surface. Flow cytometry and confocal microscopy studies demonstrated that a hybrid of the antibiotic vancomycin and a 4-hydroxyproline oligomer binds reversibly to the cell wall without affecting the viability or motility of the cells. The modified cells were used to inhibit bacterial growth of Gram-positive Bacillus subtilis cultures. Delivery of the antibiotic from the microalgae to the bacterial cells was verified by microscopy. Our studies provide compelling evidence that 1)â chemical surface engineering constitutes a useful tool for the introduction of new, previously unknown functionality, and 2)â living microalgae can serve as new platforms for drug delivery.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Bacillus subtilis/drug effects , Chlamydomonas reinhardtii/chemistry , Drug Carriers/chemistry , Hydroxyproline/administration & dosage , Vancomycin/administration & dosage , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Bacillus subtilis/growth & development , Cell Engineering/methods , Cell Movement/drug effects , Cell Survival/drug effects , Chlamydomonas reinhardtii/cytology , Chlamydomonas reinhardtii/drug effects , Hydroxyproline/chemistry , Hydroxyproline/pharmacology , Surface Properties , Vancomycin/analogs & derivatives , Vancomycin/pharmacologyABSTRACT
The pharmacologically interesting indole alkaloids (-)-mitragynine, (+)-paynantheine and (+)-speciogynine were synthesised in nine steps from 4-methoxytryptamine by a route featuring (i) an enantioselective thiourea-catalysed Pictet-Spengler reaction, providing the tetrahydro-ß-carboline ring and (ii) a Pd-catalysed Tsuji-Trost allylic alkylation, closing the D-ring.
