Technology transfer and scale up of a potential cancer-preventive plant dynamic extraction of glucoraphanin

Glucosinolates are anionic, hydrophilic beta-thioglucoside N-hydroxysulfates, which are abundant plant secondary metabolites found in cruciferous plants and are of particular interest for their chemoprotective, antioxidant and antibiotic activities. The purification of gluoraphanin (GR), the predominant glucosinolate in broccoli, was achieved using high-speed countercurrent chromatography (HSCCC) with a high salt, highly polar phase system of 1-propanol-acetonitrile-saturated ammonium sulphate-water (1:0.5:1.2:1) on a preparative scale (850mL capacity) Pharma-Tech HSCCC instrument at ca 700 mg glucosinolates per run in about 3 hours. To scale up the production of glucosinolates the technology was transferred from Johns Hopkins to Brunel Institute for Bioengineering (BIB). Within three days a 50 x scale up was achieved with comparable target compound recovery and purity using a MIDI-dynamic extraction centrifuge (928 mL capacity) with run times of 30 min and processing loads of 30 mL of ca 50% w/w viscous solutions (15 g injected). The 34 runs processed 589 g of extract producing a total of 52.6 g of 98% pure GR.