Calicheamicin
Appearance
Calicheamicin is an antibiotic derived from organism [Micromonospora echinospora]. It was isolatied originally from a rock collected in [Waco, Texas] by a hiking [Scripps Institute] chemist.
It is highly toxic and has found pharmacological use as a conjugate in antibody cancer therapeutics (e.g. [Gemtuzumab]).
References
http://www.scripps.edu/newsandviews/e_20010226/nicolaou3.html J Antibiot (Tokyo). 1989 Jul;42(7):1070-87.