Sibiromycin, a glycosylated pyrrolobenzodiazepines (PBDs) compound, is a naturally occurring and potent antitumor antibiotic. It exerts its activity by covalently binding to DNA in the minor groove at the NH2 of guanine.

Pyrrolobenzodiazepines (PBDs) are highly specific DNA alkylating agents known for their exceptional antineoplastic properties, effectively targeting and binding to DNA sequences with a preference order of 5′-Pu-G-Pu>5′-Py-G-Pu>5′-Pu-G-Py>5′-Py-G-Py. Among them, anthramycin, sibiromycin, and tomaymycin demonstrate this sequence-specific action. Notably, sibiromycin exhibits potent cytotoxic capabilities against various cell lines, including L1210 (leukemia), ADJ/PC6 (plasmacytoma), and CH1 (ovarian), with half-maximal inhibitory concentrations (IC50s) ranging from 0.000017 to 0.0029 μM, highlighting its potential as a therapeutic agent.