Ibogan, Tacaman, and Cytotoxic Bisindole Alkaloids
from <i>Tabernaemontana</i>. Cononusine, an Iboga Alkaloid
with Unusual Incorporation of a Pyrrolidone Moiety
Kuan-Hon Lim
Vijay
J. Raja
Tracey
D. Bradshaw
Siew-Huah Lim
Yun-Yee Low
Toh-Seok Kam
10.1021/acs.jnatprod.5b00117.s002
https://acs.figshare.com/articles/dataset/Ibogan_Tacaman_and_Cytotoxic_Bisindole_Alkaloids_from_i_Tabernaemontana_i_Cononusine_an_Iboga_Alkaloid_with_Unusual_Incorporation_of_a_Pyrrolidone_Moiety/2164762
Six new indole alkaloids, viz., cononusine
(<b>1</b>, a rare
example of an iboga–pyrrolidone conjugate), ervaluteine (<b>2</b>), vincamajicine (<b>3</b>), tacamonidine (<b>4</b>), 6-oxoibogaine (<b>5</b>), and <i>N</i><sup>4</sup>-chloromethylnorfluorocurarine chloride (<b>6</b>), and two
new vobasinyl-iboga bisindole alkaloids, ervatensines A (<b>7</b>) and B (<b>8</b>), in addition to other known alkaloids, were
isolated from the stem-bark extract of the Malayan <i>Tabernaemontana
corymbosa</i>. The structures of these alkaloids were established
on the basis of NMR and MS analyses and, in one instance (<b>7</b>), confirmed by X-ray diffraction analysis. Vincamajicine (<b>3</b>) showed appreciable activity in reversing multidrug resistance
in vincristine-resistant KB cells (IC<sub>50</sub> 2.62 μM),
while ervatensines A (<b>7</b>) and B (<b>8</b>) and two
other known bisindoles displayed pronounced in vitro growth inhibitory
activity against human KB cells (IC<sub>50</sub> < 2 μM).
Compounds <b>7</b> and <b>8</b> also showed good growth
inhibitory activity against A549, MCF-7, MDA-468, HCT-116, and HT-29
cells (IC<sub>50</sub> 0.70–4.19 μM). Cell cycle and
annexin V-FITC apoptosis assays indicated that compounds <b>7</b> and <b>8</b> inhibited proliferation of HCT-116 and MDA-468
cells, evoking apoptotic and necrotic cell death.
2015-05-22 00:00:00
Cell cycle
MS analyses
HT
Compounds 7
ervatensine
Unusual Incorporation
HCT
KB cells
Iboga Alkaloid
MDA
compounds 7
Pyrrolidone MoietySix
multidrug resistance
NMR
Cytotoxic Bisindole Alkaloids
IC 50
bisindole
indole alkaloids
Malayan Tabernaemontana corymbosa
2 μ M
cell death
MCF