Synthesis, characterization and antibacterial activity of a curcumin–silver(I) complex

Abstract

The current study reports the synthesis of a curcumin–silver(I) complex and its preliminary tests against four bacterial strains viz. Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Bacillus cereus using agar well diffusion method. The results were compared with curcumin by testing it in parallel with the sample. Curcumin showed zones of inhibition against all tested strains of bacteria. Among all bacterial strains, S. aureus was the most sensitive to curcumin with zone of inhibition of 12.2 mm. However, the curcumin–Ag(I) complex did not show the expected enhanced activity against all bacteria. This is perhaps due to the replacement of curcumin phenolic protons by silver ions which might have suppressed the antibacterial property of curcumin. The current research findings suggest that while synthesizing curcumin–metal complexes, the phenolic heads may either be left unaltered or need to be replaced by better substituents than hydroxy groups. Based on the current findings, biologically enhanced models have been provided as future recommendations.

Keywords:

• Curcumin
• Curcumin-silver(I) complex
• Antibacterial activity

Acknowledgements

The authors thank Universiti Sains Malaysia (USM) for the graduate assistant scheme and RU [grant number 1001/PFARMASI/815071]; PRGS [grant number 1001/PFARMASI/844074] support. Dr Muhammad Adnan Iqbal is thankful to USM for the postdoctoral fellowship from the research [grant number RUI 1001/PKIMIA/811260].

Additional information

Funding

This work was supported by Universiti Sains Malaysia (USM) for the graduate assistant scheme and RU [grant number 1001/PFARMASI/815071]; PRGS [grant number 1001/PFARMASI/844074] support.