Four new tetracyclic alkaloids with cis-decahydroquinoline motif from Myrioneuron effusum

Abstract

Four new Myrioneuron alkaloids, mysumamides A-D (1-4), along with three known ones were isolated from the twigs and leaves of Myrioneuron effusum. All of these alkaloids possessed the tetracyclic skeleton and contained the decahydroquinoline (cis-DHQ) moiety. Their structures and relative configurations were elucidated on the basis of spectroscopic methods, especially 2D NMR techniques. The absolute configuration of 1 was determined by single-crystal X-ray diffraction. The cytotoxic activities of these compounds were also evaluated in vitro.

Keywords: Alkaloids; Myrionamide (PubChem CID: 25105510); Myrioneuron effusum; Myrionidine (PubChem CID: 25067255); Mysumamides A–D; Rubiaceae; Schoberine (PubChem CID: 7278936).