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DEPARTMENT OF HEALTH & HUMAN SERVICES Public Health Service 



National Institutes of Health 

 National Cancer Institute 

 Bethesda. Maryland 20892 



JAN i 8 1994 



The Honorable Gerry Studds 



Chairman, Subcommittee on Environment and Natural Resources 



Committee on Merchant Marine and Fisheries 



House of Representatives 



Washington, DC 20515 



Dear Mr. Studds: 



Thank you for the opportunity to testify at the November 9 hearing on drug discovery and 

 development from natural sources. As I stated at the hearing, the National Cancer Institute 

 (NCI) is committed to bringing cancer and AIDS patients new diagnostic procedures and 

 treatments to help eradicate, slow, or prevent the progress of their disease. The exploration 

 of plant species and other natural products as sources of valuable pharmaceutical agents is 

 considered by NCI to be a high priority for active investigation. At the same time, we 

 recognize that the preservation of natural resources within the host country is critical to 

 preserving both the resource and financial interest of the country of origin. 



At the hearing you asked whether NCI was exploring a compound derived from the root of a 

 cucumber-like plant from China, as a potential anti-HTV agent. At the time I could tell you 

 that, while NCI had received quandties of "Compound Q" for screening, I did not know the 

 outcome of those tests. Please allow me to take this opportunity to update you on the status 

 of our research with this agent. 



Compound Q, also known as trichosanthin, is a protein isolated from the plant Trichosanthes 

 kirilowii . Several scientific papers have been published on this substance, covering a variety 

 of subjects, including its possible utility as an anti-HIV agent and its other biological 

 properties. 



Since 1987, a number of samples of trichosanthin, as well as extracts of the plant itself, were 

 obtained by NCI from a variety of sources in the U.S. and China. These materials were 

 tested in the standard anti-HIV screen used to detect substances worthy of further 

 development. None of these samples has demonstrated activity in this screen, and NCI has 

 no plans at present to pursue trichosanthin as an anti-HIV agent. This decision is, of course, 

 subject to further review and consideration by NCI based on additional scientific information, 

 either preclinical or clinical, that may become available in the future. 



