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

## TL;DR

Researchers synthesized new gold complexes with antitumor properties, finding that some were especially effective at killing cancer cells by inhibiting a key enzyme.

## Contribution

The paper introduces novel alkynyl gold(i) complexes with tunable antitumor activity and identifies their mechanism of action via TrxR inhibition.

## Key findings

- AuPPh3 complexes showed better cytotoxicity than dppfAu2 complexes against A549 and HeLa cells.
- Complex 4-(OCH2CH2OCH2CH2OCH3)C6H4CAuPPh3 (1d) strongly inhibited thioredoxin reductase (TrxR).
- Modifications to gold centers and ligands fine-tuned the in vitro antitumor activity.

## 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)C6H4C

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CAuPPh3 (1d) displayed strong anticancer activity toward both cancer cells due to the strong inhibition of thioredoxin reductase (TrxR).

In this paper, novel oligo(ethylene glycol)methylether functionalized alkynyl gold(i) complexes capped with AuPPh3 or dppfAu2 were synthesized. The AuPPh3 series showed better cytotoxicity and were powerful inhibitors of TrxR.