OPEN Foundation

Day: 28 April 2015

Ibogan, Tacaman, and Cytotoxic Bisindole Alkaloids from Tabernaemontana. Cononusine, an Iboga Alkaloid with Unusual Incorporation of a Pyrrolidone Moiety

April 28, 2015 / Chemistry, Iboga / Ibogaine, Neuroscience, Other subjects, Other substances, Papers, Psychopharmacology, Publications / By / , , , , ,

Abstract

Abstract Image

Six new indole alkaloids, viz., cononusine (1, a rare example of an iboga–pyrrolidone conjugate), ervaluteine (2), vincamajicine (3), tacamonidine (4), 6-oxoibogaine (5), and N4-chloromethylnorfluorocurarine chloride (6), and two new vobasinyl-iboga bisindole alkaloids, ervatensines A (7) and B (8), in addition to other known alkaloids, were isolated from the stem-bark extract of the Malayan Tabernaemontana corymbosa. The structures of these alkaloids were established on the basis of NMR and MS analyses and, in one instance (7), confirmed by X-ray diffraction analysis. Vincamajicine (3) showed appreciable activity in reversing multidrug resistance in vincristine-resistant KB cells (IC50 2.62 μM), while ervatensines A (7) and B (8) and two other known bisindoles displayed pronounced in vitro growth inhibitory activity against human KB cells (IC50 < 2 μM). Compounds 7 and 8 also showed good growth inhibitory activity against A549, MCF-7, MDA-468, HCT-116, and HT-29 cells (IC50 0.70–4.19 μM). Cell cycle and annexin V-FITC apoptosis assays indicated that compounds 7 and 8 inhibited proliferation of HCT-116 and MDA-468 cells, evoking apoptotic and necrotic cell death.

Lim, K. H., Raja, V. J., Bradshaw, T. D., Lim, S. H., Low, Y. Y., & Kam, T. S. (2015). Ibogan, Tacaman, and Cytotoxic Bisindole Alkaloids from Tabernaemontana. Cononusine, an Iboga Alkaloid with Unusual Incorporation of a Pyrrolidone Moiety. Journal of natural products. http://dx.doi.org/10.1021/acs.jnatprod.5b00117

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Intimate insight: MDMA changes how people talk about significant others

April 28, 2015 / MDMA, Papers, Psychology, Publications / By / , , ,

Abstract

Rationale: ±3,4-methylenedioxymethamphetamine (MDMA) is widely believed to increase sociability. The drug alters speech production and fluency, and may influence speech content. Here, we investigated the effect of MDMA on speech content, which may reveal how this drug affects social interactions.

Method: Thirty-five healthy volunteers with prior MDMA experience completed this two-session, within-subjects, double-blind study during which they received 1.5 mg/kg oral MDMA and placebo. Participants completed a five-minute standardized talking task during which they discussed a close personal relationship (e.g. a friend or family member) with a research assistant. The conversations were analyzed for selected content categories (e.g. words pertaining to affect, social interaction, and cognition), using both a standard dictionary method (Pennebaker’s Linguistic Inquiry and Word Count: LIWC) and a machine learning method using random forest classifiers.

Results: Both analytic methods revealed that MDMA altered speech content relative to placebo. Using LIWC scores, the drug increased use of social and sexual words, consistent with reports that MDMA increases willingness to disclose. Using the machine learning algorithm, we found that MDMA increased use of social words and words relating to both positive and negative emotions.

Conclusions: These findings are consistent with reports that MDMA acutely alters speech content, specifically increasing emotional and social content during a brief semistructured dyadic interaction. Studying effects of psychoactive drugs on speech content may offer new insights into drug effects on mental states, and on emotional and psychosocial interaction.

Baggott, M. J., Kirkpatrick, M. G., Bedi, G., & de Wit, H. (2015). Intimate insight: MDMA changes how people talk about significant others. Journal of Psychopharmacology, 0269881115581962. https://dx.doi.org/10.1177/0269881115581962
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30 April - Q&A with Rick Strassman

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