Fig. 4. Key 1H–1H in Pimarane, abietane, and labdane diterpenoids from Euphorbia pekinensis Rupr. and their anti-tumor activities

Fig. 4. Key 1H–1H COSY (red bold lines) and HMBC (blue→) correlation of compounds 11 (a), 12 (b), 13 (c), and 15 (d). (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)Published as part of Chen, Yan-Yan, Zeng, Xiao-Tao, Xu, Ding-Qiao, Yue, Shi-Jun, Fu, Rui-Jia, Yang, Xue, Liu, Zhao-Xi & Tang, Yu-Ping, 2022, Pimarane, abietane, and labdane diterpenoids from Euphorbia pekinensis Rupr. and their anti-tumor activities, pp. 1-8 in Phytochemistry (113113) 197 on page 5, DOI: 10.1016/j.phytochem.2022.113113, http://zenodo.org/record/823523