Euphorikanin A, a Diterpenoid Lactone with a Fused 5/6/7/3 Ring System from Euphorbia kansui

Abstract

Euphorikanin A (1), an unprecedented diterpenoid lactone which possesses a novel 5/6/7/3-fused tetracyclic ring skeleton, was isolated from the roots of Euphorbia kansui. The chemical structure and absolute stereochemistry were elucidated on the basis of extensive spectroscopic methods and single-crystal X-ray diffraction analysis. Compound 1 exhibited moderate cytotoxicity against two human tumor cell lines HeLa and NCI-446. A proposed biosynthetic pathway of compound 1 is also described.

Euphorbia Diterpenes: An Update of Isolation, Structure, Pharmacological Activities and Structure–Activity Relationship

“…Most of the studied species contained both polycyclic and macrocyclic diterpenes and included E. lathyris [ 31 ], E. stracheyi [ 32 ], E. royleana [ 33 ], E. antiquorum [ 34 ], E. kansuensis [ 35 , 36 ], E. prolifera [ 37 ], E. peplus [ 38 ], E. aellenii [ 39 ], E. pilosa [ 40 ], E. saudiarabica [ 28 ], E. marginata [ 41 ], E. neriifolia [ 42 ], E. resinifera [ 43 ], E. pekinensis [ 44 ], E. hylonoma [ 45 ], E. milii [ 46 ], E. wallichii [ 47 ], and E. ebracteolata [ 48 ]. While others contained only macrocyclic diterpenes like E. esula [ 49 ], E. helioscopia [ 50 ], E. yinshanica [ 51 ], E. grandicornis [ 52 ], and E. kansui [ 53 ]. Of this, E. esula [ 49 ] had the highest number of isolated diterpenes ( n = 44), of which the majority were jatrophane and lathyrane diterpenes, followed by E. royleana [ 33 ] ( n = 36).…”

Natural Products Research in China From 2015 to 2016

“…Dryopteris championii (Hainan, China) produced (±)-drychampones A–C ((±)- 700 , (±)- 701 , and (±)- 702 ), three novel meroterpenoids constructed by a 11/6/6 ring system and a pyronone moiety (Chen et al, 2016d ). Euphorikanin A ( 703 ), characterized by an unusual 5/6/7/3-fused tetracyclic ring skeleton, was obtained from the roots of Euphorbia kansui (Fei et al, 2016 ). Guajavadimer A ( 704 ), a dimeric meroterpenoid featuring two caryophyllenes, one benzylphlorogulcinol, as well as one flavonone-fused complicated stereochemical skeleton, was isolated from the leaves of Psidium guajava (Li et al, 2016a ).…”

Isolation, Characterization, and Possible Anti‐Alzheimer's Disease Activities of Bisabolane‐Type Sesquiterpenoid Derivatives and Phenolics from the Rhizomes of Curcuma longa

“…During our search for pharmacologically active substances from plants, much attention has been given to natural vegetable foods, such as natural spices, because they may be potentially beneficial for human health. From the ethanol extract of the rhizomes of C. longa , one new bisabolane‐type sesquiterpenoid 1 , as well as four known bisabolane‐type sesquiterpenoid derivatives 2–5 and seven phenolics 6–12 , was isolated ( Figure ).…”