Conodurine

Planta Med. 1994 Oct;60(5):455-9.

Isolation of bis-indole alkaloids with antileishmanial and antibacterial activities from Peschiera van heurkii (syn. Tabernaemontana van heurkii).[Pubmed: 7997477]

METHODS AND RESULTS:
Extracts from leaves and stem bark of Peschiera van heurkii (Muell. Arg.) L. Allorge (syn. Tabernaemontana van heurkii Muell. Arg., Apocynaceae) have been assayed for antileishmanial and antibacterial activities. The activities were concentrated in the alkaloid fractions which yielded 20 indole and bisindole alkaloids. The strongest leishmanicidal and antibacterial activities were observed with the dimeric alkaloids Conodurine (1), N-demethylConodurine (= gabunine) (2), and conoduramine (3).
CONCLUSIONS:
Weak toxicity towards macrophage host cells and strong activity against the intracellular amastigote form of Leishmania were observed for compounds 1 and 2. In vivo, 1 was less active than glucantime (= N-methylglucamine antimonate), the drug of reference, while 2 was devoid of activity at 100 mg/kg.

An Acad Bras Cienc. 2008 Sep;80(3):419-26.

Two fast screening methods (GC-MS and TLC-ChEI assay) for rapid evaluation of potential anticholinesterasic indole alkaloids in complex mixtures.[Pubmed: 18797794]

METHODS AND RESULTS:
In this work two fast screening techniques were combined in order to easily identify novel cholinesterase inhibitors (ChEI). Gas chromatography-mass spectrometry (GC-MS) of the less polar alkaloidic fractions obtained from the acid-base extraction of the stalk of T. laeta revealed thirteen monoindole alkaloids, four of them confirmed by co-injection with previously isolated alkaloids. The others were tentatively identified by mass fragmentation analysis. By gas chromatography with flame ionization detection (GC-FID) and using isatin as internal standard, affinisine and voachalotine were determined as major compounds. These fractions and fourteen previously isolated alkaloids, obtained from root bark of T. laeta and T. hystrix were investigated for acetyl (AChE) and butyrylcholinesterase (BuChE) inhibitory activities by the modified Ellman's method in thin layer chromatography(TLC-ChEI).
CONCLUSIONS:
Results showed selective inhibition of the alkaloids heyneanine and Nb-methylvoachalotine for BuChE, and 19-epi-isovoacristine for AChE, whereas olivacine, affinisine, ibogamine, affinine, Conodurine and hystrixnine inhibited both enzymes. In addition to confirming that monoterpenoid indole alkaloids can be novel therapeutic agents for AD, this is the first report of the ChEI activity of olivacine, a pyridocarbazole alkaloid.

Phytochemistry. 2003 Jul;63(5):625-9.

Conodurine, conoduramine, and ervahanine derivatives from Tabernaemontana corymbosa.[Pubmed: 12809725]

METHODS AND RESULTS:
Four bisindole alkaloids, viz., 19'(S)-hydroxyConodurine, conodurinine, 19'(S)-hydroxyconoduramine, and 19'(S)-hydroxyervahanine A, in addition to Conodurine and ervahanine A, were obtained from the leaf and stem-bark extracts of Tabernaemontana corymbosa.
CONCLUSIONS:
The structures of the new alkaloids were determined using NMR and MS analysis.