Synthesis, characterization and biological evaluation of dipicolylamine sulfonamide derivatized platinum complexes as potential anticancer agents

Nadini Thushara; Taniya Darshani; Sameera R Samarakoon; Inoka C Perera; Frank R Fronczek; W M C Sameera; Theshini Perera

doi:10.1039/d1ra00842k

Synthesis, characterization and biological evaluation of dipicolylamine sulfonamide derivatized platinum complexes as potential anticancer agents

RSC Adv. 2021 May 14;11(29):17658-17668. doi: 10.1039/d1ra00842k. eCollection 2021 May 13.

Authors

Nadini Thushara¹, Taniya Darshani¹, Sameera R Samarakoon², Inoka C Perera³, Frank R Fronczek⁴, W M C Sameera⁵, Theshini Perera¹

Affiliations

¹ Department of Chemistry, University of Sri Jayewardenepura Sri Lanka theshi@sjp.ac.lk.
² Institute of Biochemistry, Molecular Biology and Biotechnology, University of Colombo Sri Lanka.
³ Department of Zoology and Environment Sciences, University of Colombo Sri Lanka.
⁴ Department of Chemistry, Louisiana State University Baton Rouge LA USA.
⁵ Institute of Low Temperature Science, Hokkaido University N19-W8, Kita-ku Sapporo Hokkaido 060-0819 Japan.

Abstract

Three new Pt complexes, [PtCl₂(N(SO₂(2-nap))dpa)], [PtCl₂(N(SO₂(1-nap))dpa)] and [PtCl₂(N(SO₂pip)dpa)], containing a rare 8-membered ring were synthesized in good yield and high purity by utilizing the ligands N(SO₂(2-nap))dpa, N(SO₂(1-nap))dpa and N(SO₂pip)dpa, which contain a dipicolylamine moiety. Structural studies of all three complexes confirmed that the ligands are bound in a bidentate mode via Pt-N_(pyridyl) bonds forming a rare 8-membered ring. The intense fluorescence displayed by the ligands is quenched upon coordination to Pt. According to time dependent density functional theory (TDDFT) calculations, the key excitations of N(SO₂(2-nap))dpa and [PtCl₂(N(SO₂(1-nap))dpa)] involve the 2-nap-ligand-centered π → π* excitations. While all six compounds have shown antiproliferative activity against human breast cancer cells (MCF-7), the N(SO₂pip)dpa and N(SO₂(2-nap))dpa ligands and [PtCl₂((NSO₂pip)dpa)] complex have shown significantly high cytotoxicity, directing them to be further investigated as potential anti-cancer drug leads.