The Alkaloids of Hunteria eburnea Pichon. III.¹ The Tertiary Bases

Abstract

The isolation of nine tertiary bases from Hunteria ebúrnea Pichón is described. Eburnamine (I), isoeburnamine (II), eburnamonine (III), and eburnamenine (IV) are the first members of a new class of pentacyclic indole alkaloids. A new variant of the yohimbinoid ring skeleton is found in burnamicine (VI). Of the remaining alkaloids the indolines pleiocarpine (V) and pleiocarpamine are known compounds, while burnamine, an indoline with an echitamine type ultraviolet absorption spectrum, and neburnamine, an indole, are new compounds.

The chemistry of mavacurane alkaloids: a rich source of bis-indole alkaloids

“…12 Later on, pleiocarpamine (3) (Scheme 3), was isolated from two species of Apocyanaceae: Pleiocapa Mutica Benth in 1961 by Kump and Hess 13 and from Hunteria eburnea Pichon in 1963 by Taylor and co-workers. 14 In an important report, the structures of C-mavacurine, C-alkaloid Y and C-fluorocurine were revised by Hesse, Taylor, Schmid, Karrer and co-workers in 1996. 15 The E ring is actually closed by only a onecarbon linker (C16 carbon) instead of a two-carbon linker.…”

Bisindole Alkaloids from the Alstonia Species: Recent Isolation, Bioactivity, Biosynthesis, and Synthesis

“…(+)-Pleiocarpamine 32 has been isolated from various species of Alstonia [ 6 , 32 , 36 , 48 , 49 , 50 , 51 ]. The unprecedented (+)-bipleiophylline (not shown) was found to contain two pleiocarpamine 32 units connected by utilizing an aromatic spacer (pyrocatechuic acid).…”

“…Anticancer, cytotoxic against HT-29 cell lines with an ED 50 6.5 µM value (paclitaxel was used as the positive control). [39] Antileishmanial against promastigotes of L. mexicana with an IC 50 78 µM value (amphotericin B was used as the positive control). [39] (+)-Macralstonine 24 was active against the K1 strain of P. falciparum (IC 50 8.92 ± 2.95 µM).…”

“…Species Discussed Herein, Required for Bisindole Synthesis 5.1. The Total Synthesis of (±)-Pleiocarpamine 32 (+)-Pleiocarpamine 32 has been isolated from various species of Alstonia [6,32,36,[48][49][50][51]. The unprecedented (+)-bipleiophylline (not shown) was found to contain two pleiocarpamine 32 units connected by utilizing an aromatic spacer (pyrocatechuic acid).…”

Synthesis of Bisindole Alkaloids from the Apocynaceae Which Contain a Macroline or Sarpagine Unit: A Review

“…(+)-Pleiocarpamine, one unit, has been isolated from many Apocynaceae plants. To date, it has been isolated from Alstonia macrophylla [22], Alstonia angustifolia [131], Pleiocarpa mutica [151], Pleiocarpa pycnantha [152], Pleiocarpa tubicina [151], Kopsia dasyrachis [152], and from Hunteria eburnean Pichon [153] as well as Alstonia muelleriana [73]. The structure was based on examination of the NMR spectra, as well as in depth studies via mass spectrometry [154].…”