Glycosidase-Catalysed Synthesis of Ergot Alkaloid α-Glycosides

Abstract

Glycosides are widely occurring natural compounds. Among them, ergot alkaloids, therapeutically potent substances,¹ have been isolated only as mono-^2-4 and oligofructosides.^4,5 The formation of these metabolic by-products in saprophytic cultures of some Claviceps strains grown in sucrose media is catalysed by invertase present in fungal mycelia.³ The other O-glycosides of ergot alkaloids, obtained either synthetically⁶ using peracetylated glycosyl bromides and Ag₂CO₃ as catalyst, or enzymatically^7-12 have a β-configuration at the sugar anomeric centre. Preparation of some ergot alkaloid α-glycosides needed to complete our studies regarding their potential immunomodulatory and antiviral activities is the subject of this paper.

^aPresent address: Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.

Notes

^aPresent address: Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.