Heliojatrones A and B, Two Jatrophane-Derived Diterpenoids with a 5/10 Fused-Ring Skeleton from Euphorbia helioscopia: Structural Elucidation and Biomimetic Conversion

Abstract

Heliojatrones A and B (1 and 2), two jatrophane-derived diterpenoids with an unprecedented trans-bicyclo[8.3.0]tridecane core, were isolated from the whole plants of Euphorbia helioscopia. Their structures and absolute configurations were unequivocally determined by a combination of spectroscopic data, electronic circular dichroism calculations, biomimetic conversion, and X-ray diffraction analyses. Their plausible biosynthetic pathways were also proposed. Compounds 1 and 2 were biomimetically synthesized from 3 and 4 through a photochemical rearrangement reaction of β,γ-unsaturated ketone, respectively. Compound 2 showed significant P-glycoprotein inhibitory activity compared with the positive control (cyclosporine A).

Jatrophane and rearranged jatrophane-type diterpenes: biogenesis, structure, isolation, biological activity and SARs (1984–2019)

“…Compound 7 (IC 50 = 0.58 ± 0.05 lM) showed a remarkable P-gp inhibitory activity in a concentration-dependent manner similar to P-gp inhibitory activity of CsA (0.84 ± 0.03 lM) while weak P-gp inhibitory activities were observed for 329 (12.03 ± 4.14 lM). Therefore compound 7 can be considered as a new structural template for the development of potential MDR reversal agents (Mai et al 2018a). Li et al (2018) isolated euphornin (208) from E. helioscopia in a large amount.…”

Macrocyclic Diterpenoids from Euphorbia helioscopia and Their Potential Anti-inflammatory Activity

“…Euphorbia helioscopia L., a well-known medicinal herb widely distributed in Europe, Asia, and North Africa, has been used for many years by local populations as a folk medicine due to its various biological activities . Previous phytochemical investigations have revealed that the metabolites of this plant are characterized by multiesterified jatrophane diterpenes and their derivatives. , Recently, heliojatrones A and B, two jatrophane-derived diterpenes bearing an unprecedented densely functionalized bicyclo[8.3.0]­tridecane framework, were discovered from this plant and are the sole examples of diterpenes possessing a 5/10 fused ring system . In an ongoing project to discover structurally unique and biologically significant metabolites from medicinal plants, E. helioscopia was selected for investigation.…”

“…7d,10 Recently, heliojatrones A and B, two jatrophane-derived diterpenes bearing an unprecedented densely functionalized bicyclo[8.3.0]tridecane framework, were discovered from this plant and are the sole examples of diterpenes possessing a 5/10 fused ring system. 11 In an ongoing project to discover structurally unique and biologically significant metabolites from medicinal plants, E. helioscopia was selected for investigation. Based on the analysis of HPLC-UV- MS data, a fraction with most of the peaks showing characteristic UV maximum absorption bands at 220−280 nm as well as mass-to-charge ratios of approximately m/z 500− 600 was selected from the crude extract of E. helioscopia as a diterpene-rich fraction.…”

Euphopias A–C: Three Rearranged Jatrophane Diterpenoids with Tricyclo[8.3.0.02,7]tridecane and Tetracyclo[11.3.0.02,10.03,7]hexadecane Cores from Euphorbia helioscopia

“…Diterpenes from the plants of the genus Euphorbia have broad biological activities (e.g., antiproliferation, antimicrobial, and anti-inflammatory activity) and fascinating structural diversity and have drawn extensive attention from the researchers of natural product chemistry, pharmacology, and synthetic chemistry. − Recently, a series of rearranged diterpenes with diverse structures have been discovered from the genus Euphorbia . − In our present study on the plants of the Euphorbia genus, three novel jatrophane diterpenoid derivatives possessing two types of rearranged skeletons with tricyclo­[8.3.0.0 2,7 ]­tridecane ( 1 and 2 ) and tetracyclo­[11.3.0.0 2,10 .0 3,7 ]­hexadecane ( 3 ) cores were obtained and identified from the whole plants of E. helioscopia (Figure ). In consideration of the medicinal use of E. helioscopia for the treatment of inflammation-linked diseases, such as bacillary dysentery, asthma, and osteomyelitis, the inhibitory effects of compounds 1 – 3 on the NLRP3 inflammasome were tested in this research.…”