Artificial Glucosinolates (GSLs)

Glucosinolates (GSLs) are secondary metabolites produced by plants of the order Brassicales including several agricultural crops of the Brassicaceae such as cauliflower, radish, white and black mustard, broccoli or rocket. They are part of the myrosinase-glucosinolate defense system that protects against herbivores. Chemically, GSLs, such as sinigrin are thioglycosidic thiohydroximate-O-sulfonates with variable, amino acid-derived side chains, which are stored in the vacuole of so-called S-cells by the producing plants. Adjacent myrosin cells contain the enzyme myrosinase in vacuole-derived myrosin bodies. Plant myrosinases hydrolyze the anomeric thioglycosidic S-C-bond of GSLs upon tissue damage under release of glucose and a thiohydroximate-O-sulfonate aglycone. The aglycone undergoes a thio-Lossen rearrangement to form a corresponding isothiocyanate (ITC), which acts as toxic or deterrent defense compound. Interestingly, in the absence of active thioglucosidases, e.g. when myrosinases have been inactivated by cooking of the corresponding vegetables, the remaining GSLs display a remarkable chemical stability and pass the acidic milieu of the stomach without significant degradation. Besides their role in anti-herbivore defenses, ITCs show a broad variety of interesting biological activities in vertebrates and microbes such as chemoprotective and pronounced antibacterial effects.

 

We work on the synthesis, biochemical and biological characterization of novel artificial GSLs  and aim to develope antimicrobial prodrugs and compounds suitable for imaging and drug delivery.

Selected publications:

Synthesis and biochemical evaluation of artificial, fluorescent glucosinolates (GSLs)C. P. Glindemann, A. Backenköhler, M. Strieker, U. Wittstock, P. Klahn*, ChemBioChem 2019, 20, 2341-2345.