Natural Products Chemistry and Pharmacognosy Commons^™

A V-To-F Substitution In Sk2 Channels Causes Ca2+ Hypersensitivity And Improves Locomotion In A C. Elegans Als Model, Young-Woo Nam, Sabia N. Baskoylu, Dimitris Gazgalis, Razan Orfali, Meng Cui, Anne C. Hart, Miao Zhang

Pharmacy Faculty Articles and Research

Small-conductance Ca2+-activated K+ (SK) channels mediate medium afterhyperpolarization in the neurons and play a key role in the regulation of neuronal excitability. SK channels are potential drug targets for ataxia and Amyotrophic Lateral Sclerosis (ALS). SK channels are activated exclusively by the Ca2+-bound calmodulin. Previously, we identified an intrinsically disordered fragment that is essential for the mechanical coupling between Ca2+/calmodulin binding and channel opening. Here, we report that substitution of a valine to phenylalanine (V407F) in the intrinsically disordered fragment caused a ~6 fold increase in the Ca2+ sensitivity of SK2-a channels. This substitution resulted in a novel interaction between …

Countercurrent Chromatography Fractions Of Plant Extracts With Anti-Tuberculosis Activity, Douglas Armstrong, Nathan C. Krause, Drew Frey, J. Brent Friesen, Baojie Wan, Jordan Gunn, Scott Franzblau

Faculty Scholarship – Chemistry

Samples of numerous plant species were received from the southwestern part of the USA, from Richard Spjut, and plant samples were collected here in Illinois. All were extracted with typical solvents, giving crude residues, some of which were subjected to chromatographic methods. Some of the crude residues and some of the fractions were tested for anti-tuberculosis activity and/or antibacterial activity.

In a general way, bioactive natural products are dealt with very well by Liang & Fang. More specifically, the southwestern part of the United States has a large variety of indigenous plants many of which have not been investigated for …

Piperlongumine (Piplartine) And Analogues: Antiproliferative Microtubule-Destabilising Agents, Mary J. Meegan, Seema M. Nathwani, Brendan Twamley, Daniela M. Zisterer, Niamh O'Boyle

Articles

Piperlongumine (piplartine, 1) is a small molecule alkaloid that is receiving intense interest due to its antiproliferative and anticancer activities. We investigated the effects of 1 on tubulin and microtubules. Using both an isolated tubulin assay, and a combination of sedimentation and Western blotting, we demonstrated that 1 is a tubulin-destabilising agent. This result was confirmed by immunofluorescence and confocal microscopy, which showed that microtubules in MCF-7 breast cancer cells were depolymerised when treated with 1. We synthesised a number of analogues of 1 to explore structure-activity relationships. Compound 13 had the best cytotoxic profile of this series, …

The Nonpsychoactive Cannabinoid Cannabidiol Inhibits 5-Hydroxytryptamine3a Receptor-Mediated Currents In Xenopus Laevis Oocytes, Keun-Hang Susan Yang, Sehamuddin Galadari, Dmytro Isaev, Georg Petroianu, Toni S. Shippenberg, Murat Oz

Mathematics, Physics, and Computer Science Faculty Articles and Research

The effect of the plant-derived nonpsychotropic cannabinoid, cannabidiol (CBD), on the function of hydroxytryptamine (5-HT)3A receptors expressed in Xenopus laevis oocytes was investigated using two-electrode voltage-clamp techniques. CBD reversibly inhibited 5-HT (1 μM)-evoked currents in a concentration-dependent manner (IC50 = 0.6 μM). CBD (1 μM) did not alter specific binding of the 5-HT3A antagonist [3H]3-(5-methyl-1H-imidazol-4-yl)-1-(1-methylindol-3-yl)propan-1-one (GR65630), in oocytes expressing 5-HT3A receptors. In the presence of 1 μM CBD, the maximal 5-HT-induced currents were also inhibited. The EC50 values were 1.2 and 1.4 μM, in the absence and presence of CBD, indicating that CBD acts as a noncompetitive antagonist of 5-HT3 …