525 EAST 68th STREET, NEW YORK. NY. 10021 THE NEW YORK HOSPITAL-CORNELL MEDICAL CENTER DEPARTMENT OF PHARMACOLOGY (212) 472-6030 DEPARTMENT OF MEDICINE DIVISION OF CLINICAL PHARMACOLOGY Fouket ELLER ONES —."® INOV $1920 Qe of sane SES Ww November 4, 1980 Joshua Lederberg, Ph.D. President Rockefeller University NY, NY 10021 Dear Dr. Lederberg: Thank you for the copy of the article from the Times on hydrazine toxicity. I find it fascinating that, in addition to hydrazines being present as industrial chemicals, fungi including the common edible mush- room have phenylhydrazines present in amide linkage as a natural product. The fungi also apparently contain the enzyme to hydrolize this amide bond (Archives Biochem and Biophysics, 1979, 192:235-240; J Amer Chem Soc 1961, 83:503-504). I appreciate your continued interest and encourage- ment. Best personal wishes. Sincerely yours, Marcus M. Reidenberg, M.D. Professor of Pharmacology and Medicine Head, Division of Clinical Pharmacology MMR/jc