Pro‐toxic 1,2‐Dehydropyrrolizidine Alkaloid Esters, Including Unprecedented 10‐Membered Macrocyclic Diesters, in the Medicinally‐used Alafia cf. caudata and Amphineurion marginatum (Apocynaceae: Apocynoideae: Nerieae and Apocyneae)

摘要: INTRODUCTION: Within the Apocynoideae (Apocynaceae) pro‐toxic dehydropyrrolizidine alkaloids have been reported only in Echiteae. However, attraction of pyrrolizidine alkaloid‐pharmacophagous insects suggested their presence Alafia cf. caudata Stapf (Nerieae: Alafiinae) and Amphineurion marginatum (Roxb.) D.J. Middleton (Apocyneae: Amphineuriinae), both used as medicinal plants. OBJECTIVE: To confirm identify structures. METHODS: Methanol extracts air‐dried roots, stems leaves non‐flowering plants were analysed using HPLC‐ESI(+)MS MS/MS or collision‐induced dissociation MS low and/or high resolution modes. Pyrrolizidine tentatively identified based on mass spectrometry data. Solid phase extraction combined with semi‐preparative HPLC to isolate major alkaloids. Structures elucidated NMR spectroscopy. RESULTS: Monoesters retronecine senecioic, hydroxysenecioic syringic acids roots caudata. Two unprecedented 10‐membered macrocyclic alkaloid diesters isolated from marginatum. detected root leaf material at 0.34 0.01% dry weight (DW), 0.13, 0.02 0.09% DW root, stem CONCLUSIONS: The suggests that medical preparations these pose potential health risks consumers. Dehydropyrrolizidine are evidently more widespread than previously assumed, it would seem rewarding study other members this family for pyrrolizidines, dehydropyrrolizidines dihydropyrrolizines. Copyright © 2016 John Wiley & Sons, Ltd.