Ecdysteroids and bufadienolides from Helleborus torquatus (Ranunculaceae)

• Published in: Phytochemistry (Oxford) 2001-06, Vol.57 (3), p.401-407
• Main Authors: Meng, Yanhui, Whiting, Pensri, Šik, Vladimir, Rees, Huw H, Dinan, Laurence
• Format: Article
• Language: English
• Subjects: Animals; Bioassay; Biological and medical sciences; Biological Assay; Bufadienolides; Bufanolides - chemistry; Bufanolides - isolation & purification; Bufanolides - pharmacology; Cell Line; Cell Survival - drug effects; Chemical constitution; Chromatography, High Pressure Liquid; Drosophila melanogaster; Ecdysteroid; Ecdysteroids; Fundamental and applied biological sciences. Psychology; Helix (Snails) - enzymology; Hellebortin A (5-[β- d-glucopyranosyloxy]-10, 14, 16-trihydroxy-19-nor-{5β, 10β, 14β, 16β}-bufa-3, 20, 22-trienolide ); Hellebortin B (5-[β- d-glucopyranosyloxy]-3, 4-epoxy-14-hydroxy-19-oxo-bufa-20, 22-dienolide ); Hellebortin C (5-[β- d-glucopyranosyloxy]-3, 4-epoxy-10, 14-dihydroxy-19-nor-bufa-20, 22-dienolide ); Helleborus torquatus; Hydrolases - metabolism; Magnetic Resonance Spectroscopy; Magnoliopsida - chemistry; Models, Molecular; Molecular Conformation; Molecular Structure; Plant physiology and development; Ranunculaceae; Seeds - chemistry; Steroids - chemistry; Steroids - isolation & purification; Steroids - pharmacology
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(01)00070-X

Three bufadienolides, hellebortin A (5-[β- d-glucopyranosyloxy]-10,14,16-trihydroxy-19-nor-{5β,10β,14β,16β}-bufa-3,20,22-trienolide [ 1]), hellebortin B (5-[β- d-glucopyranosyloxy]-3,4-epoxy-14-hydroxy-19-oxo-bufa-20,22-dienolide [ 2]) and hellebortin C (5-[β- d-glucopyranosyloxy]-3,4-epoxy-10,14-dihydroxy-19-nor-bufa-20,22-dienolide [ 3]), together with 20-hydroxyecdysone 3- O-β- d-glucoside ( 4) and 20-hydroxyecdysone ( 5) have been isolated by bioassay- and RIA-directed HPLC analyses of a methanol extract of the seeds of Helleborus torquatus. The structure and relative stereochemistry of the novel bufadienolide hellebortin A ( 1) and the structures of hellebortin B ( 2) and hellebortin C ( 3) were determined unambiguously by comprehensive analyses of their 1D and 2D NMR data. These five compounds are isolated from Helleborus torquatus for the first time. The biological activities of compound 1, 4 and 5 as ecdysteroid agonists and antagonists have been assessed. Three bufadienolides (hellebortins A–C), together with the known ecdysteroids 20-hydroxyecdysone and 20-hydroxyecdysone 3-glucoside have been identified from seeds of Helleborus torquatus.