Phonerilins A-K, cytotoxic ingenane and ingol diterpenoids from Euphorbia neriifolia

A phytochemical study of the aerial parts of Euphorbia neriifolia led to the isolation of six new ingenane-type diterpenoids, phonerilins A-F (1-6), five new ingol-type diterpenoids, phonerilins G-K (7-11), and five known analogues (12-16). Their structures with absolute configurations were elucidated by a combined method. Phonerilin A (1) is the second rearranged ingenane diterpenoid with a unique 6/6/7/ 3-fused ring system. Based on single-crystal X-ray diffraction and NOESY data, the structure of 20-deoxy-16-hydroxyingenol was revised as 20-deoxy-17-hydroxyingenol (12) that is likely the biogenetic pre-cursor of 1. Biological evaluation revealed some isolates exhibited cytotoxic effects against two human tumor cell lines, A549 and HL-60.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

A phytochemical study of the aerial parts of Euphorbia neriifolia led to the isolation of new ingenane-type and ingol-type diterpenoids. The structures and absolute configurations of these compounds were determined, and their biological evaluation revealed cytotoxic effects against human tumor cell lines.