Synthesis and antitumor activity of mono and digold(i) alkynyl complexes with oligo(ethylene glycol)methylether

Abstract

Preparation and characterization of a series of oligo(ethylene glycol)methylether functionalized alkynyl gold(I) complexes capped with AuPPh₃ (1a–1d) or dppfAu₂ (dppf, 1,1′-bis(diphenyphosphino)ferrocene) (2a–2d) have been accomplished. The structures of 1b and 1c were established by X-ray crystallography. Their in vitro antitumor activities were measured by the CCK8 method against A549 and HeLa cells. The studies indicated that the cytotoxic activity in vitro was fine-tuned by modification of both the gold(I) centers and the oligo(ethylene glycol)methylether ancillary ligands. Compared to the dppfAu₂ series, the AuPPh₃ series showed better cytotoxicity. Especially, complex 4-(OCH₂CH₂OCH₂CH₂OCH₃)C₆H₄CCAuPPh₃ (1d) displayed strong anticancer activity toward both cancer cells due to the strong inhibition of thioredoxin reductase (TrxR).