13456-08-1Relevant articles and documents
Unravelling the antitumoral potential of novel bis(thiosemicarbazonato) Zn(II) complexes: structural and cellular studies
Palma, Elisa,Botelho, Hugo M.,Morais, Goreti Ribeiro,Rodrigues, Inês,Santos, Isabel Cordeiro,Campello, Maria Paula Cabral,Raposinho, Paula,Belchior, Ana,Gomes, Susana Sousa,Araújo, Maria Fátima,Correia, Isabel,Ribeiro, Nadia,Gama, Sofia,Mendes, Filipa,Paulo, António
, p. 71 - 89 (2019)
The development of pharmacologically active compounds based on bis(thiosemicarbazones) (BTSC) and on their coordination to metal centers constitutes a promising field of research. We have recently explored this class of ligands and their Cu(II) complexes for the design of cancer theranostics agents with enhanced uptake by tumoral cells. In the present work, we expand our focus to aliphatic and aromatic BTSC Zn(II) complexes bearing piperidine/morpholine pendant arms. The new complexes ZnL1–ZnL4 were characterized by a variety of analytical techniques, which included single-crystal X-ray crystallography for ZnL2 and ZnL3. Taking advantage of the fluorescent properties of the aromatic complexes, we investigated their cellular uptake kinetics and subcellular localization. Furthermore, we tried to elucidate the mechanism of action of the cytotoxic effect observed in human cancer cell line models. The results show that the aliphatic complexes (ZnL1 and ZnL2) have a symmetrical structure, while the aromatic counterparts (ZnL3 and ZnL4) have an asymmetrical nature. The cytotoxic activity was higher for the aromatic BTSC complexes, as well as the cellular uptake, evaluated by measurement of intracellular Zn accumulation. Among the most active complexes, ZnL3 presented the fastest uptake kinetics and lysosomal localization assessed by live-cell microscopy. Detailed studies of its impact on cellular production of reactive oxygen species and impairment of lysosomal membrane integrity reinforced the influence of the pendant piperidine in the biological performance of aromatic BTSC Zn(II) complexes.
Biophysical characterization and antineoplastic activity of new bis(thiosemicarbazonato) Cu(II) complexes
Palma, Elisa,Mendes, Filipa,Morais, Goreti Ribeiro,Rodrigues, Inês,Santos, Isabel Cordeiro,Campello, Maria Paula C.,Raposinho, Paula,Correia, Isabel,Gama, Sofia,Belo, Dulce,Alves, Vítor,Abrunhosa, Antero J.,Santos, Isabel,Paulo, António
, p. 68 - 79 (2017)
Aiming to explore alternative mechanisms of cellular uptake and cytotoxicity, we have studied a new family of copper(II) complexes (CuL1-CuL4) with bis(thiosemicarbazone) (BTSC) ligands containing pendant protonable cyclic amines (morpholine and piperidine). Herein, we report on the synthesis and characterization of these new complexes, as well as on their biological performance (cytotoxic activity, cellular uptake, protein and DNA binding), in comparison with the parental CuIIATSM (ATSM = diacetyl-bis(N4-methylthiosemicarbazonate) complex without pendant cyclic amines. The new compounds have been characterized by a range of analytical techniques including ESI-MS, IR spectroscopy, cyclic voltammetry, reverse-phase HPLC and X-ray spectroscopy. In vitro cytotoxicity studies revealed that the copper complexes are cytotoxic, unlike the corresponding ligands, with a similar potency to that of CuATSM. Unlike CuATSM, the new complexes were able to circumvent cisplatin cross-resistance. The presence of the protonable cyclic amines did not lead to an enhancement of the interaction of the complexes with human serum albumin or calf thymus DNA. However, CuL1–CuL4 showed a remarkably augmented cellular uptake compared with CuATSM, as proved by uptake, internalization and externalization studies that were performed using the radioactive congeners 64CuL1-64CuL4. The enhanced cellular uptake of CuL1-CuL4 indicates that this new family of CuIIBTSC complexes deserves to be further evaluated in the design of metallodrugs for cancer theranostics.
Anticoccidial activity of dithiosemicarbazones
Winkelmann,Wagner,Wirth
, p. 950 - 967 (2007/10/05)
Dithiosemicarbazones (di-TSC) with one or two basic substituents were found to be highly active against a variety of Eimeria species (coccidia) in chicks after both prophylactic and therapeutic application. As to the structure-activity relation, it could be shown that the necessary prerequisites of activity were a di-TSC structure in which at least one radical of the TSC part of the molecule carried a basic function, and the C=S group in TSC being freely enolizable, i.e., both nitrogen atoms next to the C=S group carrying another hydrogen atom. If the C=S groups were replaced by C=O or C=NH to form either disemicarbazones or diguanylhydrazones, the compounds obtained were ineffective. The limitation of action to di-TSC with basic substituents of a small volume suggested that the basic radical was of great importance for the absorption of the compound by the mucosa and penetration into the coccidia. The activity against coccidia was clearly attributable to the whole molecule, since the parts resulting from degradation (possibly by hydrolysis), e.g., α,β-dicarbonyl compounds and their derivatives, such as dihydrazones or thiosemicarbazides with basic substituents, or isothiocyanates with basic substituents, were completely ineffective.
