1. a Laboratoire des Sciences Analytiques , CNRS, University of Lyon 1 , Bat. CPE 308D, 69622 , Villeurbanne , Cedex , France
2. b Brunel Institute for Bioengineering , Brunel University , Uxbridge , UK
3. c Beijing Research Center for Separation & Purification Technology of Natural Products , Beijing Institute of New Technology Applications , Beijing , P.R. China