Ecdysteroids from the underground parts of Rhaponticum acaule (L.) DC.
Phytochemistry
; 180: 112530, 2020 Dec.
Article
in En
| MEDLINE
| ID: mdl-33049649
ABSTRACT
In addition to two known ecdysteroids, 20-hydroxyecdysone and turkesterone, three previously undescribed stigmastane-type ecdysteroids were isolated from the underground parts of Rhaponticum acaule (L.) DC. by chromatographic techniques (CC, VLC, MPLC). The structures of the compounds were established by chemical (acetylation) and spectroscopic methods including UV, IR, HRMS, 1D-NMR 1H-NMR, 13C-NMR, DEPT-135. and 2D-NMR COSY, NOESY, HSQC, HMBC. Two compounds were isolated as an isomeric mixture and each of them was purified and converted to the corresponding acetylated derivative. Based on all of the evidence, the structures of three undescribed stigmastane-type ecdysteroids were established as 2ß,3ß,11α,20ß,22α,24,28-heptahydroxy-6-oxo-stigmast-7-en-25,29-lactone and the cyclic 22,29-hemiacetals 22R and 22S stigmast-7-en-29-al,2ß,3ß,11α,20α,22,28-hexahydroxy-6-oxo, and the trivial names acaulesterone and rhapocasterones A and B are suggested, respectively. The structures and absolute configurations of 20-hydroxyecdysone and cyclic-22,29-hemiacetal-22R-stigmast-7-en-29-al,2ß,3ß,11α,20α,22,28-hexahydroxy-6-oxo were confirmed by X-ray crystal-structure analyses of their acetyl derivatives.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ecdysteroids
/
Leuzea
Language:
En
Journal:
Phytochemistry
Year:
2020
Document type:
Article
Affiliation country:
Libya