1. Department of Medicine and Food, Guizhou Vocational College of Agriculture, Guiyang 550041, People's Republic of China
2. State Key Laboratory of Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550014, People's Republic of China
3. The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academy of Sciences, Guiyang 550014, People's Republic of China