Acetylcholinesterase inhibitory activity of pyrrolizidine alkaloids from Echium confusum Coincy

Abstract

Four pyrrolizidine alkaloids, namely 7-O-angeloyllycopsamine N-oxide 1, echimidine N-oxide 2, echimidine 3 and 7-O-angeloylretronecine 4, were isolated for the first time from the whole plant ethanolic extract of Echium confusum Coincy, through bioassay-guided approach. Their structures were determined by spectroscopic means. All the isolates compounds showed moderate activities in inhibiting AChE, with IC50 0.276–0.769.

Keywords:

• Boraginaceae
• Echium confusum
• pyrrolizidine alkaloids
• 7-O-angeloyllycopsamine N-oxide
• anti-AChE activity

Acknowledgments

The authors wish to thank Mr. A. Ahedmessaoud and Mr. K. Ballot for botanical investigation and plant collection. The authors wish also to thank the Ministry of Higher Education and Scientific Research of Algeria for financial support [grant number F02220120052].