Crotonianoids A−C (1−3), three unusual tigliane diterpenoids, were isolated from the seeds of Croton tiglium. Compound 1 is a 13,14:13,15-diseco-tigliane featuring a unique spiro [bicyclo[5.3.0]decane-2,5′-2′(3′H,4′H)-furanone] core; 2 is a 13,15-seco-tigliane incorporating a rare peroxide bridge between C-13 and C-15; and 3 is the first example of a phorbol ester with a 10R-configuration. Their structures were determined by spectroscopic, computational, and X-ray diffraction methods. Compounds 1 and 2 markedly inhibited the growth and survival of prostate cancer cell C4−2B at micromolar concentrations and induced cell apoptosis. Mechanistic study revealed that 1 and 2 could suppress androgen receptor (AR) signaling pathway by promoting the degradation of AR protein.

This work describes a base-mediated borylsilylation of benzylic ammonium salts to synthesize geminal silylboronates bearing benzylic proton under mild reaction conditions. Deaminative silylation of aryl ammonium salts was also achieved in the presence of LiO t Bu. This strategy which is featured with high efficiency, mild reaction conditions, and good functional group tolerance provides efficient routes for late-stage functionalization of amines.

Phytochemical investigation on the 95 EtOH extract of the Traditional Chinese Medicine (TCM) Euphorbia royleana (Ba-wang-bian in Chinese) led to the isolation of 11 diterpenoids (1−11) and two triterpenoids (12 and 13). Among them, compounds 1 and 2 were new ingol and ingenane diterpenoids, respectively. Their structures were elucidated by a combination of spectroscopic analyses (1D and 2D NMR, HRMS, ECD, UV, and IR data) and chemical methods. Compounds 12 and 13 exhibited moderate cytotoxicities in vitro against human lung cancer cell line A549 with IC50 values of 14.8 and 27.1 M, respectively.

Three new halimane furanoditerpenoids (1–3) and three new clerodane furanoditerpenoids (4–6), along with seven known terpenoids including four pimarane diterpenoids (7–10) and three norisoprenoids (11–13) were isolated from the 95% EtOH extracts of the plants of Croton cnidophyllus. The 2D structures including absolute configuration of new furanoditerpenoids (1–6) were elucidated by analysis of their HRMS and NMR data as well as comparison of experimental and calculated ECD curves. Bioassay revealed that two compounds (8 and 9) possessed certain inhibitory effects against NO production stimulated by LPS, with IC50 values of 19.00 ± 1.76 and 21.61 ± 1.11 μM, respectively. Graphical Abstract