Nourseothricin, also known as the streptothricin natural product mixture, was discovered in the early 1940s, generating intense initial interest because of excellent activity against Gram-negative bacteria. Morgan et al. established the activity spectrum of nourseothricin and its main components, streptothricin F (S-F, 1 lysine) and streptothricin D (S-D, 3 lysines), purified to homogeneity, against highly drug-resistant, carbapenem-resistant Enterobacterales...
