Zhu Dayuan

Recent studies on traditional Chinese medicinal plants

This review will discuss several new drugs which were discovered and developed in recent years from traditional Chinese medicines by the Shanghai Institute of Materia Medica. Huperzine A was isolated from Huperzia serrata, a plant used for the treatment of contusion, strain, haematuria, and swelling in Chinese folk medicine. Pharmacological studies have indicated that huperzine A has powerful and reversible anticholinesterase activity. Y‐maze methods have shown that huperzine A improves learning and retrieval processes, and facilitates memory retention. Huperzine A is used to treat patients with myasthenia gravis and Alzheimers disease in China. Sarmentosin, a cyanogenic glucoside was isolated from the whole plant of Sedum sarmentosium. This plant has long been used to treat hepatitis by folk medicine. Sarmentosin significantly lowers the SGPT level of patients suffering from chronic viral hepatitis, and shows a suppressive effect on cell‐mediated immune responses in mice. The root of Aconitum is well known in traditional Chinese medicine. Many Aconitum alkaloids have been isolated. Most show potent bioactivities, but with severe toxicity. Recently, some alkaloids such as 3‐acetylaconitine, lappaconitine, have shown significant anesthetic activity and exhibit a higher therapeutic index. Guan‐fu base A was isolated from the tuber root of Aconitum coreanum. Guan‐fu base A has antiarrhythmic action and is now in clinical trials. Drug Dev. Res. 39:147–157.

1H nuclear magnetic resonance relaxation investigation of huperzine E binding to acetylcholinesterase

In order to search for better acetylcholinesterase (AchE) inhibitors, the binding properties of AchE with huperizine E, which is a derivative of huperzine A, were investigated with 1H nuclear magnetic resonance (1H NMR) method. The nonselective, selective and double-selective spin-lattice relaxation rates of some protons in huperzine E were acquired in the absence and presence of AchE at a concentration ratio of [ligand]/[protein] = 1: 0.005. The enhancements of selective relaxation rates of these protons were obvious after adding AchE. The molecular motional correlation times of two pairs of protons, H-1a/H-1b and H-2/H-3, in the bound state at T = 298 K were 11.7 and 9.46 ns respectively, while they were 27.7 and 35.2 ps in the free state. All of these show that huperzine E has high binding affinity with AchE.