Synthesis and Structural Revision of a Natural Tetrasaccharide from Starfish Asterias rollestoni Bell.
Chemistry
; 30(30): e202400946, 2024 May 28.
Article
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| MEDLINE
| ID: mdl-38516955
ABSTRACT
Starfish provide important saponins with diverse bioactivities as the secondary metabolites, among which 2-O-glycosylated glycosides are commonly found. Preparation of those 1,2-trans 2-O-glycosylated glycosides usually relies on 2-O-acyl participation requiring the selective installation and cleavage of 2-O-acyl groups. A convergent synthesis using 2-O-glycosylated oligosaccharide donors would be more straightforward but also pose greater challenges. Herein, we report a convergent synthesis of a distinctive tetrasaccharide isolated from starfish Asterias rollestoni Bell. Dual 2-(diphenylphosphinoyl)acetyl (DPPA) groups at O3 and O4 on galactose moiety led to high ß-selectivities (ß/α=12/1 or ß only) in the challenging [2+2] glycosylation, giving the desired tetrasaccharides in >90 % yields from the 2-O-glycosylated disaccharide donors. These synthetic studies have also unambiguously revised the structure of these natural tetrasaccharides. This work would facilitate further studies on new inhibitors of α-glucosidase as hypoglycemic drugs.
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Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Oligosacáridos
Idioma:
En
Revista:
Chemistry
Asunto de la revista:
QUIMICA
Año:
2024
Tipo del documento:
Article