Derivatisation of buforin IIb, a cationic henicosapeptide, to afford its complexation to platinum(ii) resulting in a novel platinum(ii)-buforin IIb conjugate with anti-cancer activity.

Herein we report the synthesis of buforin IIb, its novel malonate derivative malBuf and its Pt(ii) complex cis-[Pt(NH3)2(malBuf-2H)]. We decided to harness the cell targeting, cell-penetrating and anti-proliferative effects of buforin IIb to help target a cytotoxic dose of a Pt DNA binding species, {Pt(NH3)2} to cancer cells whilst also delivering a peptide with potent anti-cancer properties. Preliminary in vitro data shows cis-[Pt(NH3)2(malBuf-2H)] to be more cytotoxic against the cisplatin resistant ovarian cancer cell line (A2780cisR) relative to buforin IIb, cisplatin and cis-[Pt(NH3)2(malonate)].

Ruthenium(III) readily abstracts NO from L-arginine, the physiological precursor to NO, in the presence of H2O2. A remarkably simple model system for NO synthases.

Reaction of [Ru(Hedta)Cl]- with H2O2 in the presence of arginine, produces NO, in the form of an Ru(II)-(NO+) complex and citrulline which is a remarkably simple model system for the physiological NO synthase reaction.