A Novel Alkaloid from Melodinus henryi

Abstract

The isolation and structure elucidation of a novel alkaloid, namely of the 14-O-ethyl-substituted (3a,14a,16a)-2,7-secoeburnamine derivative 1 from the leaf of Melodinus henryi is reported. Ten known alkaloids were also isolated. Their structures were determined spectroscopically. The isolates were evaluated for their cytotoxicity.

Phytochemical and Pharmacological Properties of the Genus Melodinus – A Review

“…14, 15-Seco-3-oxokopsinal (16) originated a further oxidation of bond C (14)-C (15) of venalstonine was identified by comparison of their spectral and physical properties from M. guillauminii [14]. 10, 22 -Dioxokopsane was a known alkaloids but was isolated obtained from this genus for the first time [35]. …”

“…Fig 6) Five pair of epimers, 87-96, were isolated from nine Melodinus species. Four eburnamine-type alkaloids including two new ones, melodinines F-G (97, 98), together with O-methylepivincanol (100), (-)-eburnamenine (101) were isolated from M. henryi [35,48]. Δ14-Isoeburnamine (105) and (+)-isoeburnamine (106) were obtained from M. celastroides, M. henryi, M. oblongus and M. henryi [30,40,42,52].…”

“…Five indole alkaloids, Δ14-vincamenine N4-oxide (99), meloyunine (109), 14β-hydroxymeloyunine (110) and its epimer (111), and 16,19-epoxy-Δ14-vincanol (113) were described from M. yunnanensis [32]. [26,32,35,43,45,46]. (Table 5( Melodinines A-C (158-160, resp.…”

“…Two known compounds, stemmadenine (166) and its N-oxide (167), were isolated from M. henryi [18,35,48]. [38].…”

“…Other monomeric alkaloids, 204-210 ( Figure 13) (-)-Rhazinilam (204) was a natural compound isolated from M. australis and M. henryi, whose tetracyclic structure possesses an axially chiral phenyl-pyrrole subunit bridged by a ninemembered lactam ring [18,35,48,68]. Melohenine B (205), 14, 15-dehydromelohenine B (206) and…”