1. Henan Key Laboratory of Industrial Microbial Resources and Fermentation Technology School of Biological and Chemical Engineering Nanyang Institute of Technology Nanyang 473004 P. R. China
2. School of Basic Medical Sciences North Sichuan Medical College Nanchong 637007 P. R. China
3. Sichuan Provincial Key Laboratory for Structural Optimization and Application of Functional Molecules College of Chemistry and Life Science Chengdu Normal University Chengdu 611130 P. R. China