Alstrostines in Rubiaceae: Alstrostine A from Chassalia curviflora var. ophioxyloides and a novel derivative, rudgeifoline from Rudgea cornifolia

摘要

Monoterpenoid indole alkaloids have frequently been isolated from the species-rich Psychotria alliance (Rubiaceae), a complex group including several tribes and genera. In our aim of understanding the chemical diversification within this remarkably heterogeneous group, members of two genera of the tribe Palicoureeae have been studied. Alstrostine A was isolated from Chassalia curviflora var. ophioxyloides, and a novel derivative, rudgeifoline from Rudgea cornifolia, respectively. Alstrostines, an unusual class of alkaloids comprising one tryptamine and two iridoid units, have recently been discovered in Alstonia rostrata (Apocynaceae). The presence of alstrostines in two rubiaceous species is remarkable but not unexpected as both families share similar biosynthetic pathways and are capable of synthesizing related alkaloids