Strychnos 1990 - 2004 - Crops for the Future
Strychnos 1990 - 2004 - Crops for the Future
Strychnos 1990 - 2004 - Crops for the Future
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Author<br />
Title<br />
Year<br />
Source title<br />
Reference<br />
Wins, P., I. Margineanu, J. Penelle, L. Angenot, T. Grisar and L. Bettendorff<br />
Bisindole alkaloids from <strong>Strychnos</strong> guianensis are effective antagonists of nicotini<br />
2003<br />
Naunyn-Schmiedebergs Archives of Pharmacology<br />
367(3): 253-259<br />
Abstract<br />
Several mono- and bisindole quaternary alkaloids isolated from <strong>the</strong> stem bark of <strong>Strychnos</strong><br />
guianensis have recently been shown to be effective blockers of neuromuscular transmission in mice.<br />
In this study, we used a human clonal cell line (TE671) expressing muscle-type nicotinic<br />
acetylcholine receptors. The agonist carbamylcholine activated a receptor-mediated Rb-86(+) efflux<br />
and this activation was antagonized by <strong>the</strong> indole alkaloids, <strong>the</strong> most active being bisindole<br />
bisquaternary compounds. The most effective antagonist, guiachrysine, had an IC50 around 0.43<br />
muM in <strong>the</strong> presence of 0.5 mM carbamylcholine, compared to 0.16 muM <strong>for</strong> d-tubocurarine, <strong>the</strong><br />
most potent curarizing alkaloid. Guiaflavine and 5',6'-dehydroguiaflavine were slightly less effective.<br />
Monoindole compounds were 10 to 100 times less potent than bisindole alkaloids. Kinetic analysis<br />
showed that <strong>the</strong> inhibition of <strong>the</strong> carbamylcholine-dependent Rb-86(+) efflux by guiaflavine was of<br />
mixed competitive and uncompetitive type. The competitive component (K-I = 0.21 muM) is<br />
presumably due to binding at <strong>the</strong> acetylcholine site, while <strong>the</strong> uncompetitive component (K'(I) = 0.92<br />
m u M ) m a y b e d u e t o o p e n c h a n n e l b l o c k .<br />
Author<br />
Title<br />
Year<br />
Source title<br />
Reference<br />
Zlotos, D. P.<br />
Iso-caracurine v, a novel unexpected decomposition product of caracurine v<br />
2003<br />
Journal of Natural Products<br />
66(1): 119-120<br />
Abstract<br />
The structure of iso-caracurine V (3), an unexpected decomposition product of <strong>the</strong> <strong>Strychnos</strong><br />
alkaloid caracurine V (1), was determined by NMR spectroscopy. Compound 3, which was probably<br />
previously regarded as bisnortoxiferine I (2), is a one-sided ring closed product of 2.