Related Experiment Video
Updated: Oct 12, 2025

Measuring Fast Calcium Fluxes in Cardiomyocytes
Published on: November 29, 2011
Rhynchines A-E: Cav3.1 Calcium Channel Blockers from Uncaria rhynchophylla
Hao-Feng Zhou1,2, Wen-Yan Li1, Li-Yan Peng1
1State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China.
Abstract:
Rhynchines A-E (1-5), five new indole alkaloids with an unprecedented skeleton, were isolated from Uncaria rhynchophylla. The new skeleton was characterized by an indole moiety and a 2-oxa-8-azatricyclo[6,5,01,5,01,8]tridecane core, forming a unique 6/5/7/5/5 ring system. Their structures were determined by nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, infrared spectroscopy, and calculated electronic circular dichroism (ECD) and were confirmed by X-ray crystallography. Interestingly, 1 and 2 showed strong inhibitory activities against the Cav3.1 calcium channel with IC50 values of 6.86 and 10.41 μM.
Related Concept Videos
Antihypertensive Drugs: Action of Calcium Channel Blockers
Antianginal Drugs: Calcium Channel Blockers and Ranolazine
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Antiepileptic Drugs: Calcium Channel Blockers
Calcium channel blockers exert their antiepileptic effects by targeting T-type calcium channels, which are integral to transmitting nerve signals in the central nervous system. These channels allow the passage of calcium ions, which are vital for neuronal communication. By inhibiting T-type calcium channels, calcium channel blockers effectively reduce the release of neurotransmitters and...

