Structural Elucidation of Three 9,11-Seco Tetracyclic Triterpenoids Enables the Structural Revision of Euphorol J

Abstract

Compounds 1–3, the rare examples of 9,11-seco euphane or lanostane triterpenoids featuring an enol-hemiacetal functionality, were isolated from Euphorbia stracheyi. Their structures were elucidated by a combination of spectroscopic, computational, chemical, and single-crystal X-ray diffraction means, which enables the structure of previously published euphorol J to be revised as 1. 1–3 showed significant cytotoxicities on the breast cancer cell line MDA-MB-468 with IC50 values in the range of 2.9–3.9 μM.

Bioactive substances inhibiting COX-2 and cancer cells isolated from the fibrous roots of Alangium chinense (Lour.) Harms

“…Quantum chemical Gaussian calculation was conducted according to a previous report with slight modification. 55 The relative configuration of compound 14 in mol 2 format in Spartan was opened, and the conformation searched for at the molecular force field level of MMFF to obtain the dominant conformation of each compound. Then, under density functional theory (DFT), at B3LYP/6-31G(d) level, these conformations were put into an optimization and vibration analysis calculation, and no virtual frequency was checked after optimization.…”

Glochodpurnoid B from Glochidion puberum Induces Endoplasmic Reticulum Stress-Mediated Apoptosis in Colorectal Cancer Cells

“…Especially, some triterpenoids from Glochidion possessed antitumor-promoting and cytotoxic activities [ 13 , 14 ]. In our continued efforts toward discovering structurally diverse and bioactive triterpenoids from Euphorbiaceae plants [ 15 , 16 , 17 ], two new oleanane derivatives, glochidpurnoids A ( 1 ) and B ( 2 ), along with 17 known analogues were obtained from the stems and twigs of G. puberum . All their cytotoxicity was measured using MTT assay, and six compounds showed pronounced anti-CRC activities against HCT-116 cells.…”