Related Experiment Video
Updated: Jul 8, 2026
09:10
An Efficient and Rapid HPLC-QQQ-MS Method for the Quantitation of Tropane Alkaloids in Medicinal Plants
Published on: June 12, 2026
Antimitotic quinoid triterpenes from Maytenus chuchuhuasca
Hiroshi Morita1, Yusuke Hirasawa, Akihiro Muto
1Faculty of Pharmaceutical Sciences, Hoshi University, Ebara 2-4-41 Shinagawa-ku, Tokyo 142-8501, Japan. moritah@hoshi.ac.jp
Bioorganic & Medicinal Chemistry Letters
|January 1, 2008
Abstract:
Four cytotoxic quinoid triterpenes, tingenone (1), 22 beta-hydroxytingenone (2), pristimerin (3), and celastrol (4), isolated from Maytenus chuchuhuasca, potently inhibit the polymerization of tubulin.
Related Concept Videos
01:29Cholinergic Antagonists: Chemistry and Structure-Activity Relationship
Cholinergic antagonists bind to cholinergic receptors and limit the effects of acetylcholine and other cholinergic agonists. Based on the specific cholinergic receptor affinity, these antagonists are classified as muscarinic or nicotinic. Anticholinergics interrupt parasympathetic innervations while sympathetic innervations remain uninterrupted. Muscarinic antagonists are also called 'muscarinic antagonists', 'antimuscarinics', or 'parasympatholytics'. Nicotinic antagonists are called...
01:24Cholinergic Antagonists: Pharmacokinetics
Cholinergic antagonists—such as antimuscarinics—are available in oral, topical, ocular, parenteral, and inhalational formulations. Most antimuscarinics are oral formulations, while scopolamine is available as a topical patch, and ipratropium and tiotropium are available as inhalation aerosols or powders. Atropine, tropicamide, and cyclopentolate are topically instilled in the eye. Most antimuscarinics are lipid-soluble and readily absorbed from the gastrointestinal tract and the conjunctiva.