JAN 21 1969

THE LILLY RESEARCH LABORATORIES

ELI LILLY AND COMPANY
INDIANAPOLIS 6G, IND.,U. S.A.

January 14, 1963

Dr. Joshua Lederberg, Chairman
Department of Genetics

School of Medicine

Stanford University

Stanford, California

Dear Dr. Lederberg:

A promise is a promise and I can therefore now report to you our
preliminary results using the E. coli mutants 1577 and B83, re-
quiring thymine which you sent to us early last fall.

At levels where there is little or no growth on thymidylic acid
and good growth on thymine, we find no growth at all with the
adamantyl amidate derivative of thymidylic acid. The same negé-
tive results were obtained with the corresponding adenine series
with an E. coli mutant (&®) requiring adenine. These observations
parallel those at S.I.M.B. with the U-requiring mutant and one
speculates whether this is typical for #. coli only or perhaps
indicates a general difference between bacteria and mammalian
cells.

I have savei 2 sample of the thymidylic phosphoramidate for you
in case your interest in it for bacterial work has not vanished
because of our negative findings.

Iam very pleased with the further results Dr. Aronow has obtained
with the adenylic acid derivatives, since they seem to complete
the picture quite nicely.

My main problem at present is to bring the chemical problems

to solution so that I can make enough of the 6=mercaptopurine
derivative for animal testing and, if favorable, clinical testing.
Being alone in the nucleotide work here renders me homesick

for a good phosphate-inclined colleague who would be Willing

to be a partner and not be ashamed to do medicinel work - with

a possible fundamental bonus.

WaZ1o~)
Dr. Joshua Lederberg
Page 2
January 14, 196%

My best but belated wishes go to you and Mrs. Lederberg for
a good year in 1963.

Sincerely yours,
j '
Kn Ve

Koert Gerzon
Organic Chemical Division

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