Pb (II) and Hg (II) thiosemicarbazones for inhibiting the broad‐spectrum pathogen Cladosporium sphaerospermum ASU18 (MK387875) and altering its antioxidant system. (28th June 2022)

• Record Type: Journal Article
• Authors: Ibrahim, Ahmed B. M.; Mahmoud, Ghada Abd‐Elmonsef; Cordes, David B.; Slawin, Alexandra M. Z.
• Is Part Of: Applied organometallic chemistry. Volume 36:Number 8(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-28
• Subjects: catalase -- heavy metals -- NNS ligands -- pathogen -- superoxide dismutase; Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.6798
• Languages: English
• ISSNs: 0268-2605

Abstract

Abstract : Pb (II) and Hg (II) ions were reacted in aqueous solution with two tridentate thiosemicarbazones, resulting in four complexes {[Pb(L 1 )2 ] 1, [Pb(L 2 )2 ] 2, [Hg(L 1 )2 ] 3, and [Hg(L 2 )2 ] 4 ; HL 1 = 4‐(4‐nitrophenyl)‐1‐[(pyridin‐2‐yl)methylene]thiosemicarbazide and HL 2 = 4‐(2‐chlorophenyl)‐1‐[(pyridin‐2‐yl)methylene]thiosemicarbazide}. The solid‐state structures of complexes 2 and 3 were determined by X‐ray crystallography, which also confirmed the monobasic tridentate NNS nature of the ligands, and the octahedral coordination geometry around the metal centers. Complexes 1–4 exhibited high antifungal activity against the pathogen Cladosporium sphaerospermum ; all four complexes give rise to a reduction in the fungal dry mass and sugar consumption. Complexes 2 and 4 that inhibited C. sphaerospermum growth at the concentration of 1.8 mM are more efficient inhibitors than the free ligand and metal ions. Further, the complexes gave varied values of the fungal total antioxidants (TA), superoxide dismutase (SOD), and catalase (CAT) activities dependent on their concentrations. Abstract : New thiosemicarbazone complexes with Pb (II) and Hg (II) ions were isolated and structurally characterized. The complexes affected the antioxidant system of Cladosporium sphaerospermum leading to a reduction in the fungal dry mass and sugar consumption, and varied values of the fungal total antioxidants, soluble proteins, and SOD and CAT activities.