Corrigendum: Dimeric Pimprinine Alkaloids From Soil-Derived Streptomyces sp. NEAU-C99 - Yu, Zhiyin; Jiang, Hao; Wang, Li; Yang, Feng-Xian; Huang, Jian-Ping; Liu, Chongxi; Guo, Xiaowei; Xiang, Wensheng; Huang, Sheng-Xiong (Frontiers in Chemistry, 2020)