Pan,ZH (reprint author),Chinese Acad Sci,Guangxi Inst Bot,Guangxi Key Lab Funct Phytochem Res & Utilizat,Guilin 541006,Peoples R China.
Three new nor-clerodane diterpenoids, crotoeurins A-C (1-3), together with four known ones were isolated from the twigs and leaves of Croton euryphyllus. Among them, crotoeurin A (1) is a new nor-clerodane diterpenoid dimer with a unique cyclobutane ring via a [2+2] cycloaddition. Their structures were elucidated by spectroscopic analyses and the stereochemistry of 1 was confirmed by single-crystal X-ray diffraction analysis. Compounds 1-3 exhibited neurite outgrowth-promoting activity on NGF-mediated PC12 cells at concentration of 10 mu M. (C) 2015 Elsevier Ltd. All rights reserved.
National Natural Science Foundation of China 
; West Light Foundation of the Chinese Academy of Sciences
; Natural Science Foundation of Guangxi [2011GXNSFB018022]
; Foundation of Guangxi Key Laboratory of Functional Phytochemicals Research and Utilization [ZRJJ2014-8]