SYNTEX, S.A.

APARTADO 2679 MEXICO, D. F.

CARL DJERASS!
VICEPRESIDENTE
INVESTIGACION

June 10, 1960

Professor Joshua Lederberg
Department of Genetics
Medical School

Stanford University

Palo Alto, California

Dear Joshua:

Some time ago we isolated from a Mexican plant
a new colorless crystalline substance named genipin, and
have recently proved its structure. Genipin has the un-
usual property of turning the skin blue when placed in
contact with some crystals, and we have found that it
also forms blue complexes with amino acids, Recently
some genipin was injected into mice, whereupon they
turned blue and excreted blue urine. It appears that
genipin reacts with amino acids as well as with pro-
teins, and I am wondering whether there may be some use~
ful histochemical applications of this substance,

If you would like to try it for some staining
experiments, I would suggest that you call Dr. Eisenbraun
and ask him to give you some of the material. Dr, Nakano
in my laboratory has been working with it and he could
recrystallize some to give you ave pure specimen,

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ec: Dr, E. J. Eisenbraun

Cables: SYNTEX - 20-60-50 - MEXICO