An enhanced preparation and purification of the major antioxidants baicalein and wogonin from Scutellariae radix

A simple, rapid and improved method was developed to isolate high-purity baicalein and wogonin from Scutellariae radix. The method involves endogenous baicalinase-catalysed hydrolysis (EBCH), partition, automated low-pressure preparative chromatography (LPPC) and recrystallisation without multiple and tedious column chromatography. This process was optimised for large scale production of baicalein and wogonin with high yields, low costs and process automation. The transformation ratio of baicalin and wogonoside reached 98.21% and 96.60% after EBCH, leading to an increase of 5.41-fold in baicalein and 3.89-fold in wogonin, compared to a raw sample without hydrolysis. The purity of final products was more than 98% after one-step LPPC and recrystallisation. The experimental results show that EBCH–LPPC is an effective method for preparing high purity antioxidants.