Probing protein aggregation through spectroscopic insights and multimodal approaches: A comprehensive review for counteracting neurodegenerative disorders.

Aberrant accumulation of protein misfolding can cause aggregation and fibrillation and is one of the primary characteristic features of neurodegenerative diseases. Because they are disordered, misfolded, and aggregated proteins pose a significant setback in drug designing. The structural study of intermediate steps in these kinds of aggregated proteins will allow us to determine the conformational changes as well as the probable pathways encompassing various neurodegenerative disorders. The analysis of protein aggregates involved in neurodegenerative diseases relies on a diverse toolkit of biophysical techniques, encompassing both morphological and non-morphological methods. Additionally, Thioflavin T (ThT) assays and Circular Dichroism (CD) spectroscopy facilitate investigations into aggregation kinetics and secondary structure alterations. The collective application of these biophysical techniques empowers researchers to comprehensively unravel the intricate nature of protein aggregates associated with neurodegeneration. Furthermore, the topics covered in this review have summed up a handful of well-established techniques used for the structural analysis of protein aggregation. This multifaceted approach advances our fundamental understanding of the underlying mechanisms driving neurodegenerative diseases and informs potential therapeutic strategies.

Synthesis and Anticancer Evaluation of Novel Indole Based Arylsulfonylhydrazides against Human Breast Cancer Cells.

A series of novel indole based sulfonohydrazide derivatives (5a-k) containing morpholine heterocyclic ring were synthesized through multistep chemical reactions. The target compounds (5a-k) were prepared by the reaction of substituted phenyl sulfonylhydrazides (2a-k) with morpholine derivative of indole 3-carboxaldehyde. All the target compounds were screened for their anticancer activity in vitro against the estrogen receptor-positive breast cancer line MCF-7 and triple-negative breast cancer cell line, MDA-MB-468. It was found that among all the evaluated compounds, the chemotype 4-chloro-N'-((1-(2-morpholinoethyl)-1H-indol-3-yl)methylene)benzenesulfonohydrazide (5f) showed promising inhibition of both MCF-7 and MDA-MB-468 cancer cells with the respective IC50 values of 13.2 µM and 8.2 µM. Compound 5f was found to be nontoxic against HEK 293 noncancerous cells in the studied concentration range, therefore indicating that such chemotypes inhibit the proliferation of cancerous cells selectively and significantly.

Design and Development of Small-Molecule Arylaldoxime/5-Nitroimidazole Hybrids as Potent Inhibitors of MARK4: A Promising Approach for Target-Based Cancer Therapy.

Microtubule affinity-regulating kinase 4 (MARK4), a member of the serine/threonine kinase family, is an emerging therapeutic target in anticancer drug discovery paradigm due to its involvement in regulation of microtubule dynamics, cell cycle regulation, and cancer progression. Therefore, to identify the novel chemical architecture for the design and development of novel MARK4 inhibitors with concomitant radical scavenging property, a series of small-molecule arylaldoxime/5-nitroimidazole conjugates were designed and synthesized via multistep chemical reactions following the pharmacophoric hybridization approach. Compound 4h was identified as a promising MARK4 inhibitor with high selectivity toward MARK4 inhibition as compared to the panel of screened 30 kinases pertaining to the serine/threonine family, which was validated by molecular docking and fluorescence binding studies. The comprehensive cell-based examination divulged the promising apoptotic, antiproliferative, and antioxidant potential for the chemotype 4h. The compound 4h was endowed with the K a value of 3.6 × 103 M-1 for human serum albumin, which reflects its remarkable transportation and delivery properties to the target site via blood. The present study impedes that in the future, such compounds may stand as optimized pharmacological lead candidates in drug discovery for targeting cancer via MARK4 inhibition with a remarkable anticancer profile.

Discovery of 4-(2-(dimethylamino)ethoxy)benzohydrazide derivatives as prospective microtubule affinity regulating kinase 4 inhibitors.

Microtubule affinity regulating kinase 4 (MARK4) is a Ser/Thr kinase, considered as a potential drug target for cancer, diabetes and neurodegenerative diseases. Due to its significant role in the development and progression of cancer, different in-house libraries of synthesized small molecules were screened to identify potential MARK4 inhibitors. A small library of hydrazone compounds showed a considerable binding affinity to MARK4. The selected compounds were further scrutinized using an enzyme inhibition assay and finally two hydrazone derivatives (H4 and H19) were selected that show excellent inhibition (nM range). These compounds have a strong binding affinity for MARK4 and moderate binding with human serum albumin. Anticancer studies were performed on MCF-7 and A549 cells, suggesting H4 and H19 selectively inhibit the growth of cancer cells. The IC50 value of compound H4 and H19 was found to be 27.39 µM and 34.37 µM for MCF-7 cells, while for A549 cells it was 45.24 µM and 61.50 µM, respectively. These compounds inhibited the colonogenic potential of cancer cells and induced apoptosis. Overall findings reflect that hydrazones/hydrazone derivatives could be exploited as potential lead molecules for developing effective anticancer therapies via targeting MARK4.

Identification of α-Mangostin as a Potential Inhibitor of Microtubule Affinity Regulating Kinase 4.

Microtubule affinity regulating kinase 4 (MARK4) is a potential drug target for neuronal disorders and several types of cancers. Filtration of naturally occurring compound libraries using high-throughput screening and enzyme assay suggest α-mangostin is a potential inhibitor of MARK4. Structure-based docking and 100 ns molecular dynamics simulation revealed that the binding of α-mangostin stabilizes the MARK4 structure. Enzyme inhibition and binding studies showed that α-mangostin inhibited MARK4 in the submicromolar range with IC50 = 1.47 µM and binding constant (Ka) 5.2 × 107 M-1. Cell-based studies suggested that α-mangostin inhibited the cell viability (MCF-7 and HepG2), induced apoptosis, arrested the cell cycle in the G0/G1 phase, and reduced tau-phosphorylation. This study implicates MARK4 as a new target of α-mangostin, adding an additional lead molecule to the anticancer repertoire.

Design and development of Isatin-triazole hydrazones as potential inhibitors of microtubule affinity-regulating kinase 4 for the therapeutic management of cell proliferation and metastasis.

Microtubule affinity-regulating kinase 4 (MARK4) is a potential drug target as the same is found to be over expressed in several types of cancers. In search of effective MARK4 inhibitors, we have synthesized and characterized Isatin-triazole hydrazones (9a-i) and evaluated their inhibitory potential. Of all the compounds, 9g showed better binding affinity and enzyme inhibition potential in sub micromolar range. Human serum albumin (HSA) binding assay suggested an easy transportation of 9g in blood stream due to its binding affinity. In vitro anticancer studies performed on MCF-7, MDA-MB-435s and HepG2 cells using 9g showed inhibition of cell proliferation and cell migration. Further, 9g induces apoptosis in these cancerous cells, with IC50 values of 6.22, 9.94 and 8.14 µM, respectively. Putatively, 9g seems to cause oxidative stress resulting in apoptosis. Functional assay of 9g with a panel of 26 kinases showed MARK4 specific profile. In conclusion, 9g seems to possess an effective inhibitory potential towards MARK4 adding an additional repertoire to anticancer therapeutics.

Thienopyrimidine-Chalcone Hybrid Molecules Inhibit Fas-Activated Serine/Threonine Kinase: An Approach To Ameliorate Antiproliferation in Human Breast Cancer Cells.

Apoptotic evasion by cancerous cells being one of the striking hallmarks of cancer has turned into a new arena of drug discovery. A large number of pathways reported that govern the apoptotic evasion have been reported. Fas-activated serine/threonine kinase (FASTK) is a member of Ser/Thr kinase family, and it has been implicated in the apoptotic evasion and, hence, the development of cancer. Keeping this in view, a series of novel thienopyrimidine-based chalcones have been synthesized and evaluated to modulate the FASTK mediated apoptotic evasion. Initial screening was done by enzyme inhibition assay and binding studies, which showed that out of 15 synthesized compounds, 3 thienopyrimidine-based chalcone derivatives possess considerably high binding affinity and enzyme inhibitory potential (nM range) for FASTK. Cell proliferation assessment of selected compounds was performed on HEK-293 and MCF-7 cells. For MCF-7 cells, compounds 2, 10, and 12 show IC50 values of 20.22 ± 1.50, 6.52 ± 0.82, and 8.20 ± 0.61 µM, respectively. Annexin-V and PI staining suggested that these molecules induce apoptosis in MCF-7 cells, arrest the cell cycle in the G0/G1 phase, and subsequently inhibit cell migration presumably by inhibiting FASTK and reactive oxygen species production. In conclusion, we have successfully designed, synthesized, and characterized thienopyrimidine-based chalcones that inhibit FASTK and induce apoptosis. These compounds may be exploited as potential anticancer agents.