Selective extraction of cordycepin from Cordyceps militaris - optimisation, kinetics and equilibrium studies

Cordycepin was separated successfully from Cordyceps militaris using extraction with a mixture of ethanol and water. Optimum temperature, composition of ethanol in water, solvent/solid ratio and pH of solvent were determined by a central composite design (CCD) with respect to extraction yield. The highest yield for cordycepin (96%) was predicted by the regression model and validated by comparison with the experimental results, showing good agreement. The RP-HPLC method was applied to analyse cordycepin from Cordyceps militaris extracts, and 100% purity of cordycepin was achieved. The extraction characteristics were investigated in terms of equilibrium and kinetics. The second-order kinetics correlates well with the experimental data.