Obtained by growing a penicillin-producing mold in a culture medium contg γ-chlorocrotylmercaptoacetic acid: Ford et al., J. Am. Chem. Soc. 70, 3522 (1948); Ford et al., Antibiot. Chemother. 3, 1149 (1953).
This monograph has been retired and is no longer subject to revision or update.