Synthesis, characterization, pharmacological evaluation and molecular docking studies of benzothiazole azo derivatives

Discovery of novel third generation P-glycoprotein inhibitors bearing an azo moiety with MDR-reversing effect

P-glycoprotein (P-gp)-caused multidrug resistance (MDR) is a crucial factor in the cancer chemotherapy failure. Herein, a total of twenty two azo-containing WK-X-34 (WK34, a third generation P-gp inhibitor) derivatives were synthesized as novel P-gp inhibitors. Biological evaluation revealed that compound 7i effectively reversed P-gp-mediated MDR in K562/A02 cells, with a higher reversal fold (RF) value than WK34 (142.79 vs. 64.41). Further investigation indicated that 7i dose-dependently inhibited P-gp function, without affecting its expression. CETSA results illustrated that 7i could obviously improve P-gp stability, suggesting its high affinity with P-gp. Molecular docking analysis revealed that 7i fit well into P-gp's binding pocket, thus displaying potent reversal effect on P-gp-mediated tumor MDR Optical properties evaluation confirmed that azo-containing 7i can undergo reversible changes in the cis and trans configurations under the irradiation of 365 nm and 520 nm wavelength of light. Notably, the configuration change of azo might affect the MDR-reversal potency, and cis-7i has a lower RF value than trans-7i (122.70 vs. 142.79), suggesting that development of photoswitchable P-gp inhibitors might be a novel strategy to reduce the systemic toxicity caused by indiscriminate inhibition of P-gp by traditional inhibitors. Collectively, 7i, as a novel P-gp inhibitor, warranted further investigation.

Spectroscopic Studies on Structurally Modified Anthraquinone Azo Hydrazone Tautomer: Theoretical and Experimental Approach

A series of unique four mono-azo substituted anthraquinone analogue were synthesized by using the anthraquinone components in the diazo-coupling technique. The FT-IR, 1H NMR, and HRMS, data were used to confirm the structure of the molecules, and spectroscopic techniques like UV-Vis, and photoluminescence spectroscopy were employed to estimate the photophysical properties of the molecules. The molecular optimized geometry and frontier molecular orbitals were estimated using density functional theory. Further, global chemical reactivity descriptors parameter was theoretically estimated using the value of the highest occupied molecular orbit and lowest unoccupied molecular orbits. The anti-tubercular action of the synthesised dyes were also examined. The results of this biological activity showed that N-isopropyl aniline combined with anthraquinone N-isopropyl aniline had superior anti-tubercular activity when compared to Rifampicin as the standard. As per molecular docking studies, the synthesized compound Q1 showed excellent binding energy (-10.0 kcal/mol) among all compounds against the 3ZXR Protein. These results agreed with our in-vitro anti-TB activity results.

The effect of Azo-dyes on glioblastoma cells in vitro

Despite the multidisciplinary standard treatment of glioblastoma (GB) consisting of maximal surgical resection, followed by radiotherapy (RT) plus concomitant chemotherapy with temozolomide (TMZ), the majority of patients experience tumor progression and almost universal mortality. In recent years, efforts have been made to create new agents for GB treatment, of which azo-dyes proved to be potential candidates, showing antiproliferative effects by inducing apoptosis and by inhibiting different signaling pathways. In this study we evaluated the antiproliferative the effect of six azo-dyes and TMZ on a low passage human GB cell line using MTT assay. We found that all compounds proved antiproliferative properties on GB cells. At equimolar concentrations azo-dyes induced more cytotoxic effect than TMZ. We found that Methyl Orange required the lowest IC₅₀ for 3 days of treatment (26.4684 μM), whilst for 7 days of treatment, two azo dyes proved to have the highest potency: Methyl Orange IC₅₀ = 13.8808 μM and Sudan I IC₅₀ = 12.4829 μM. The highest IC₅₀ was determined for TMZ under both experimental situations. Conclusions: Our research represents a novelty, by offering unique valuable data regarding the azo-dye cyototoxic effects in high grade brain tumors. This study may focus the attention on azo-dye agents that may represent an insufficient exploited source of agents for cancer treatment.

Dihydropyrazole-Carbohydrazide Derivatives with Dual Activity as Antioxidant and Anti-Proliferative Drugs on Breast Cancer Targeting the HDAC6

Breast cancer (BC) is the most frequently diagnosed cancer and is the second-most common cause of death in women worldwide. Because of this, the search for new drugs and targeted therapy to treat BC is an urgent and global need. Histone deacetylase 6 (HDAC6) is a promising anti-BC drug target associated with its development and progression. In the present work, the design and synthesis of a new family of dihydropyrazole-carbohydrazide derivatives (DPCH) derivatives focused on HDAC6 inhibitory activity is presented. Computational chemistry approaches were employed to rationalize the design and evaluate their physicochemical and toxic-biological properties. The new family of nine DPCH was synthesized and characterized. Compounds exhibited optimal physicochemical and toxicobiological properties for potential application as drugs to be used in humans. The in silico studies showed that compounds with –Br, –Cl, and –OH substituents had good affinity with the catalytic domain 2 of HDAC6 like the reference compounds. Nine DPCH derivatives were assayed on MCF-7 and MDA-MB-231 BC cell lines, showing antiproliferative activity with IC₅₀ at μM range. Compound 2b showed, in vitro, an IC₅₀ value of 12 ± 3 µM on human HDAC6. The antioxidant activity of DPCH derivatives showed that all the compounds exhibit antioxidant activity similar to that of ascorbic acid. In conclusion, the DPCH derivatives are promising drugs with therapeutic potential for the epigenetic treatment of BC, with low cytotoxicity towards healthy cells and important antioxidant activity.

Current Perspective of Synthesis of Medicinally Relevant Benzothiazole Based Molecules: Potential for Antimicrobial and Anti-Inflammatory Activities

The therapeutic potential of the majority of the marketed drugs is due to the presence of a heterocyclic nucleus, which constitutes a huge role in the field of medicinal chemistry. These heterocyclic scaffolds could act as a template in order to design potential therapeutic agents against several diseases. Benzothiazole scaffold is one of the influential heteroaromatic rings in the field of medicinal chemistry owing to its extensive pharmacological features. Herein, we have focused on the synthesis of benzothiazole based medicinal molecules, which possess antimicrobial and anti-inflammatory activities. This review covers a systematic description of synthetic routes for biologically relevant benzothiazole derivatives in the last five years. The main aim of this study is to show the diversification of benzothiazole based molecules into their pharmacologically more active derivatives. This review's synthetic protocols include metal-free, metal-catalyzed, and metal precursor azo dyes strategies for the development of benzothiazole derived bioactive compounds. The discussion under the various headings covers synthetic schemes and biological activities of the most potent molecules in the form of minimum inhibitory concentration.

Aspects regarding colour fastness and adsorption studies of a new azo-stilbene dye for acrylic resins

The aim of this study was the colour fastness investigation of the new synthetized direct symmetrical azo-stilbene dye, using two of the film field domain reference tests, namely the wet-scrub and the UV tests. The dye was incorporated in a water-based resin, and then was applied on a PCV foil. The film colour parameters were determined before and after 200 wet-scrub cycles. Further, the dye was mixed with an acrylo-polyurethanic resin and then was applied on an aluminium plate, which was exposed to UV radiation for 414 h. The film colour parameters were recorded periodically. The maxima of the reflectance spectra depend on the UV time exposure. The quality of the film was analysed by the degree of gloss. A second focus was the elimination of the dye's traces from wastewaters (these may be resulted from the industries which apply surface coating methods), using the active carbon powder. The main operational adsorption process parameters influence were investigated. Equilibrium, kinetic and thermodynamic studies were performed. The adsorption process was confirmed by the CIEL*a*b* colour space analysis. All colour studies were investigated using UV-Vis spectroscopy.