Thiazole, isatin and phthalimide derivatives tested in vivo against cancer models: a literature review of the last six years.

BACKGROUND: Cancer is a disease characterized by the abnormal multiplication of cells and is the second leading cause of death in the world. The search for new effective and safe anticancer compounds is ongoing due to factors such as low selectivity, high toxicity, and multidrug resistance. Thus, heterocyclic compounds derived from isatin, thiazole and phthalimide that have achieved promising in vitro anticancer activity have been tested in vivo and in clinical trials. OBJECTIVE: This review focused on the compilation of promising data from thiazole, isatin, and phthalimide derivatives, reported in the literature between 2015 and 2022, with in vivo anticancer activity and clinical trials. METHOD: A bibliographic search was carried out in the PUBMED, MEDLINE, ELSEVIER, and CAPES PERIODIC databases, selecting relevant works for each pharmacophoric group with in vivo antitumor activity in the last 6 years. RESULTS: In our study, 68 articles that fit the scope were selected and critically analyzed. These articles were organized considering the type of antitumor activity and their year of publication. Some compounds reported here demonstrated potent antitumor activity against several tumor types. CONCLUSION: This review allowed us to highlight works that reported promising structures for the treatment of various cancer types and also demonstrated that the privileged structures thiazole, isatin and phthalimide are important in the design of new syntheses and molecular optimization of compounds with antitumor activity.

Structural design, synthesis, and anti-Trypanosomatidae profile of new Pyridyl-thiazolidinones.

The present work reports the synthesis of a novel series of pyridine-thiazolidinones with anti-Trypanosoma cruzi and leishmanicidal activities (compounds 10-27), derived from 2 or 4-pyridine thiosemicarbazones (1-9). The in vitro assays were performed with Trypanosoma cruzi trypomastigotes and amastigotes, as well as with Leishmania amazonensis promastigotes and amastigotes. The cytotoxicity profile was evaluated using the cell line RAW 264.7. From the 18 pyridine-thiazolidinones, 5 were able to inhibit trypomastigotes. Overall, all compounds inhibited amastigotes, highlighting compounds 15 (0.60 µM), 18 (0.64 µM), 17 (0.81 µM), and 27 (0.89 µM). Compounds 15 and 18 were able to induce parasite cell death through necrosis induction. Analysis by scanning electron microscopy showed that T. cruzi trypomastigotes treated with compounds 15 and 18 induced morphological changes such as shortening, retraction and curvature of the parasite body and leakage of internal content. Regarding the antiparasitic evaluation against Leishmania amazonensis, only compound 27 had a higher selectivity compared to Miltefosine against the amastigote form (IC50 = 5.70 µM). Our results showed that compound 27 presented an antiparasitic activity for both Trypanosoma cruzi and Leishmania amazonensis. After in silico evaluation, it was suggested that the new pyridine-thiazolidinones had an appropriate drug-likeness profile. Our results pointed out a new chemical frame with an anti-Trypanosomatidae profile. The pyridine-thiazolidinones presented here for the first time could be used as a starting point for the development of new antiparasitic agents.

Synthesis, ADMET Prediction, and Antitumor Profile of Phenoxyhydrazine- 1,3-thiazoles Derivatives.

BACKGROUND: Cancer is one of the most important barriers to increasing life expectancy in all countries in the 21st century. Investigations of new anti-cancer drugs with low side effects are an urgent demand for medicinal chemists. Considering the known antitumor and immunomodulatory activity of thiazoles, this work presents the synthesis and antineoplastic activity of new thiazoles. METHODS: The 22 new compounds (2a-v) were synthesized from different thiosemicarbazones and 2-bromoacetophenone. The compounds were evaluated on: MOLT-4, HL-60, HL-60/MX1, MM1S, SKMEL-28, DU145, MCF-7, and T47d. RESULTS: Compound 2b induced cellular viability on MOLT-4 (37.1%), DU145 (41.5%), and HL- 60/MX1 (58.8%) cells. On MOLT-4 cells, compound 2b exhibited an IC50 of 8.03 µM, and against DU145 cells, an IC50 of 6.04µM. Besides, at IC50 and fold of IC50, 20% to 30% of dead cells were found, most due to necrosis/late apoptosis. Most compounds no showed cytotoxicity against fibroblast cells L929 at the concentrations tested. The compound did not alter the cell cycle of DU145 cells when compared to the negative control. Therefore, compound 2b stands out against DU145 and MOLT-4 cells. CONCLUSION: Our study reinforced the importance of 1,3-thiazoles nuclei in antitumor activity. In addition, derivative 2b stands out against DU145 and MOLT-4 cells and could be a starting point for developing new antineoplastic agents.

Identification of Novel Zika Virus Inhibitors: A Screening using Thiosemicarbazones and Thiazoles Templates.

BACKGROUND: Zika virus (ZIKV) remains an important cause of congenital infection, fetal microcephaly, and Guillain-Barré syndrome in the population. In 2016, WHO declared a cluster of microcephaly cases and other neurological disorders reported as a global public health emergency in Brazil. There is still no specific treatment for Zika virus fever, only palliative care. Therefore, there is a need for new therapies against this disease. According to the literature, thiosemicarbazone, phthalimide and thiazole are privileged structures with several biological activities, including antiviral activity against various viruses. OBJECTIVE: Based on this, this work presents an antiviral screening using previously synthesized compounds derived from thiosemicarbazone, phthalimide, and thiazole as new hits active against ZIKV. METHODS: After synthesis and characterization, all compounds were submitted to Cytotoxicity by MTT and Antiviral activity against ZIKV assays. RESULTS: Compounds 63, 64, 65, and 73 exhibited major reductions in the ZIKV title from this evaluation. Compounds 63 (99.74%), 64 (99.77%), 65 (99.92%), and 73 (99.21%) showed a higher inhibition than the standard 6MMPr (98.74%) at the CC20 dose. These results revealed new chemical entities with anti-ZIKV activity. CONCLUSION: These derivatives are promising candidates for further assays. In addition, the current approach brings a new privileged scaffolding, which may drive future drug discovery for ZIKV.

Synthesis, anticancer activity and mechanism of action of new phthalimido-1,3-thiazole derivatives.

In this work, 22 new compounds were obtained and evaluated for their cytotoxic activity on peripheral blood mononuclear cells (PBMC) and eight different tumor cell lines. All compounds displayed IC50 values above 100 µM when assayed against PBMCs. The cytotoxic assays in tumor cell lines revealed that sub-series of phthalimido-bis-1,3-thiazoles (5a-f) exhibited the best anti-tumor activity profile, presenting viability values below 59 %. As a result, the IC50 value was calculated for compounds 5a-f and 4c, and compounds 5b and 5e were selected for further assays due to their best IC50s. Considering the results presented by the sub-series 5a-f, the importance of the 1,3-thiazole ring in improving the anti-tumor activity was pointed out. Together, the results highlighted the anti-tumor activity of phthalimido-bis-1,3-thiazole derivatives.

Tannic acid as a precipitating agent of human plasma proteins.

The search for plasma proteins precipitation methods has been increasing due to the plasma protein therapeutic needs in world-wide. Thus, this work evaluates the tannic acid (TA) ability to precipitate proteins from human plasma. In this study, TA-plasma protein complexes were studied at different pH conditions, tannin/plasma ratio and reaction mixing time. The complexes formed from combinations of TA and plasma proteins were analyzed by gel electrophoresis, protein quantification, particle size, charge, mass spectrometry, microscopic image, and circular dichroism. It was possible to verify the precipitate formation in all tested pH values, with high precipitation at pH 5. The native PAGE analysis showed three mainly bands corresponding independent of the pHs used. It was possible to observe a gradual growing of precipitate protein in the first precipitation process (P1) when increased the TA/plasma ratio. 15 min of incubation was enough to precipitate 72.3% of proteins. Spectroscopic analyzes showed albumin signals and the electron microscopy analysis of IgG-TA confirmed the compact form of a precipitate. According to CD, formation of the IgG-TA complexes does not cause a major structural change of the protein. From the results obtained, it was possible to establish some parameters for plasma proteins precipitation using TA.