Synthesis and evaluation of Zn(II) dithiocarbamate complexes as potential antibacterial, antibiofilm, and antitumor agents

Abstract

Four complexes having the formula [Zn(L)₂] [L1 = (C₁₈H₂₀NS₂^–), N-(4-isopropyl-benzyl)-(benzyl)-dithiocarbamate], [L2 = (C₁₀H₁₂NS₂^–), N-(benzyl)-(ethyl)-dithiocarbamate], [L3 = (C₁₉H₂₂ONS₂^–), N-(4-isopropyl-benzyl)-(4-methoxy-benzyl)-dithiocarbamate], and [L4 = (C₁₆H₁₆NS₂^–), N-(benzyl)-(4-methyl-benzyl)-dithiocarbamate] have been contemplated, synthesized, and characterized by elemental analysis and IR, ¹H, ¹³C NMR and UV–visible absorption spectra. All Zn(II) complexes have similar geometry and coordination number. Complex A2 (with ligand L2) crystallizes in triclinic system with space group P-1 having distorted square pyramidal geometry which was stabilized by weak C–H···π and C–H···S intramolecular interactions. The antibacterial, antibiofilm, and antitumor activities of the complexes have been screened and A2 and A3 showed their prominence. Interestingly, both A2 and A3 showed more killing potential against multi-drug resistant gram-positive isolates with MIC indices of 16 μg mL⁻¹ and 16 μg mL⁻¹, respectively, against both MRSA and MSSA, while the antitumor agent A3 showed its prominence with GI₅₀ and LC₅₀ 41.15 and 133.73 µg mL⁻¹, respectively.

Graphical Abstract

Keywords:

• Dithiocarbamate
• transition metal complexes
• bacterial biofilm
• minimum inhibitory concentration
• antitumor
• drug resistance

Acknowledgements

We are thankful to Department of Chemistry, Institute of Sciences, Banaras Hindu University Varanasi for their Instrumentals facilities. We are also thankful to Prof. N. Singh, Department of Chemistry, Institute of Sciences, BHU Varanasi for his fruitful suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We sincerely acknowledge the DST-PURSE grant sanctioned to Department of Microbiology, IMS, BHU. VKM, AKS are also acknowledging University Grant Commission (UGC), New Delhi for Senior Research Fellow Ref. No: 22/12/2013 (II) EU-V and 22/06/2014 (i) EU-V, respectively, and SY acknowledges Council of Scientific and Industrial Research, New Delhi for financial assistance in the form of Junior research fellow ref. no. [1121630870 vide 18/12/2016 (ii) EU-V].