Thiosemicarbazone Complexes of Indium with New Modes of Coordination: X-ray Crystal Structure of {(Me2In)2[NC5H4CMeNNC(S)NC6H5]2}(InMe)

Synthesis of a series of novel In(III) 2,6-diacetylpyridine bis(thiosemicarbazide) complexes: structure, anticancer function and mechanism

The anticancer function and anticancer mechanism of indium (In) complexes still remain mysterious to date. Furthermore, it is greatly challenging to design a multi-functional metal agent that not only kills cancer cells but also inhibits their invasion and metastasis. Thus, to develop novel next-generation anticancer metal agents, we designed and synthesized a series of novel In(iii) 2,6-diacetylpyridine bis(thiosemicarbazide) complexes (C1-C4) for the first time and then investigated their structure-activity relationships with human urinary bladder cancer (T-24) cells. In particular, C4 not only showed higher cytotoxicity to cancer cells and less toxicity toward normal cells relative to cisplatin but also inhibited cell invasion and metastasis of T-24 cells. Interestingly, C4 acted against T-24 cells exhibiting multiple mechanisms: (1) arresting the S-phase of cell cycle via regulation of cytokine kinases, (2) activating the mitochondrial-mediated apoptosis, endoplasmic reticulum-stress-mediated cell death, PERK and c-Jun N-terminal kinase 1 (JNK) cell signaling pathways, and (3) inhibiting the expression of telomerase via the regulation of c-myc and h-TERT proteins. Our results suggested that C4 may be developed as a potential multi-functional and multi-targeting anticancer candidate.

Cu(ii), Ga(iii) and In(iii) complexes of 2-acetylpyridine N(4)-phenylthiosemicarbazone: synthesis, spectral characterization and biological activities

In this paper, synthesis and characterization of metal complexes [Cu2(L)3]ClO4 (1), [Ga(L)2]NO3·2H2O (2) and [In(L)2]NO3·H2O (3) (HL = 2-acetylpyridine N(4)-phenylthiosemicarbazone) was carried out, including elemental analysis, spectral analysis (IR, UV-vis, NMR), and X-ray crystallography. Complex 1 contains one S-bridged binuclear [Cu2(L)3]+ unit, where two Cu atoms display diverse coordination geometries: one being square planar geometry and the other octahedral geometry. Both 2 and 3 are mononuclear complexes, and the metal centers in 2 and 3 are chelated by two NNS tridentate ligands possessing a distorted octahedral geometry. Biological studies show that all the complexes possess a wide spectrum of modest to effective antibacterial activities and remarkable cytotoxicities against HepG2 cells, and 1, in particular, with an IC50 value of 0.19 ± 0.06 μM, is 113-fold and 28-fold more cytotoxic than HL and the antitumor drug mitoxantrone, respectively. In addition, 3 exhibits excellent photoluminescence properties. Upon the addition of 1 equiv of In3+ ions, a remarkable fluorescence intensity of HL and fluorescent color change (from transparent to light-green) could be observed with 365 nm light, indicating that this ligand may be used as a promising colorimetric and fluorescent probe for In3+ detection.

Steric control on the coordination behaviour of carbazole thiosemicarbazones towards [RuH(Cl)(CO)(AsPh3)3]: a combined experimental and theoretical study

We report the steric control on the coordination behaviour of carbazole thiosemicarbazones towards ruthenium(ii) complexes, along with the combined experimental and theoretical investigations.

Synthesis, spectral, catalytic and antimicrobial studies of PPh3/AsPh3 complexes of Ru(II) with dibasic tridentate O, N, S donor ligands

Complexes of the type [Ru(CO)(EPh(3))(B)(L)] (E = P or As; B = PPh(3), AsPh(3), py or pip; L=dianion of the Schiff bases derived from thiosemicarbazone with acetoacetanilide, acetoacet-o-toluidide and o-chloro acetoacetanilide) have been synthesized from the reactions of equimolar amounts of [RuHCl(CO)(EPh(3))(2)(B)] and Schiff bases in benzene. The new complexes have been characterized by analytical and spectral (IR, electronic, NMR) data. The arrangement of PPh(3) groups around ruthenium metal was determined from (31)P NMR spectra. An octahedral structure has been assigned for all the new complexes. All the complexes exhibited catalytic activity for the oxidation of benzyl alcohol and cyclohexanol in presence of N-methylmorpholine-N-oxide as co-oxidant. The complexes also exhibited antibacterial activity against E. coli, Aeromonas hydrophilla and Salmonella typhi. The activity was compared with standard streptomycin.