Myrcaulones A-C, Unusual Rearranged Triketone-Terpene Adducts from Myrciaria cauliflora.
J Nat Prod
; 83(8): 2410-2415, 2020 08 28.
Article
in En
| MEDLINE
| ID: mdl-32706260
ABSTRACT
Three rearranged triketone-terpene adducts, myrcaulones A-C (1-3), were isolated from the leaves of Myrciaria cauliflora. Myrcaulones A (1) and B (2) feature a new carbon skeleton with an unprecedented spiro[bicyclo[3.1.1]heptane-2,2'-cyclopenta[b]pyran] core. Myrcaulone C (3) possesses an unusual cyclobuta[6,7]cyclonona[1,2-b]cyclopenta[e]pyran backbone. Their structures with absolute configurations were elucidated by NMR spectroscopy, X-ray diffraction, and electronic circular dichroism calculations. A plausible biogenetic pathway for myrcaulones A-C involving the rearrangement of a triketone unit is also proposed. In addition, myrcaulones A (1) and B (2) exhibited inhibitory effects against tumor necrosis factor-α and nitric oxide generation induced by lipopolysaccharide in RAW 264.7 macrophages.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Terpenes
/
Myrtaceae
/
Ketones
Language:
En
Journal:
J Nat Prod
Year:
2020
Document type:
Article