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Synthesis, in vitro α-amylase inhibitory, and radicals (DPPH & ABTS) scavenging potentials of new N-sulfonohydrazide substituted indazoles

Rafique R, Khan KM, Arshia, Chigurupati S, Wadood A, Rehman AU, et al.

Bioorg Chem, 2020 01;94:103410.
PMID: 31732193 DOI: 10.1016/j.bioorg.2019.103410

Over-expression of α-amylase enzyme causes hyperglycemia which lead to many physiological complications including oxidative stress, one of the most commonly associated problem with diabetes mellitus. Marketed α-amylase inhibitors such as acarbose, voglibose, and miglitol used to treat type-II diabetes mellitus, but also linked to several harmful effects. Therefore, it is essential to explore new and nontoxic antidiabetic agents with additional antioxidant properties. In this connection, a series of new N-sulfonohydrazide substituted indazoles 1-19 were synthesized by multistep reaction scheme and assessed for in vitro α-amylase inhibitory and radical (DPPH and ABTS) scavenging properties. All compounds were fully characterized by different spectroscopic techniques including 1H, 13C NMR, EI-MS, HREI-MS, ESI-MS, and HRESI-MS. Compounds showed promising α-amylase inhibitory activities (IC50 = 1.23 ± 0.06-4.5 ± 0.03 µM) as compared to the standard acarbose (IC50 1.20 ± 0.09 µM). In addition to that all derivatives were found good to moderate scavengers of DPPH (IC50 2.01 ± 0.13-5.3 ± 0.11) and ABTS (IC50 = 2.34 ± 0.07-5.5 ± 0.07 µM) radicals, in comparison with standard ascorbic acid having scavenging activities with IC50 = 1.99 ± 0.09 µM, and IC50 2.03 ± 0.11 µM for DPPH and ABTS radicals. In silico molecular docking study was conducted to rationalize the binding interaction of α-amylase enzyme with ligands. Compounds were observed as mixed type inhibitors in enzyme kinetic characterization.

Matched MeSH terms: Indazoles/chemical synthesis*; Indazoles/chemistry*
Synthesis, α-amylase and α-glucosidase inhibition and molecular docking studies of indazole derivatives

Nawaz M, Taha M, Qureshi F, Ullah N, Selvaraj M, Shahzad S, et al.

J Biomol Struct Dyn, 2022;40(21):10730-10740.
PMID: 34463216 DOI: 10.1080/07391102.2021.1947892

Herein, we report the synthesis and inhibitory potential of indazole (Methyl 1H-indazole-4-carboxylate) derivatives (1-13) against α-amylase and α-glucosidase enzymes. The described derivatives demonstrated good inhibitory potential with IC50 values, ranging between 15.04 ± 0.05 to 76.70 ± 0.06 µM ± SEM for α-amylase and 16.99 ± 0.19 to 77.97 ± 0.19 µM ± SEM for α-glucosidase, respectively. In particular, compounds (8-10 and 12) displayed significant inhibitory activities against both the screened enzymes, with their inhibitory potential comparable to the standard acarbose (12.98 ± 0.03 and 12.79 ± 0.17 µM ± SEM, respectively). Additionally, the influence of different substituents on enzyme inhibition activities was assessed to study the structure activity relationships. Molecular docking simulations were performed to rationalize the binding of derivatives/compounds with enzymes. All the synthesized derivatives (1-13) were characterized with the aid of spectroscopic instruments such as 1H-NMR, 13C-NMR, HR-MS, elemental analysis and FTIR.Communicated by Ramaswamy H. Sarma.

Matched MeSH terms: Indazoles/pharmacology
Binding of an anticancer drug, axitinib to human serum albumin: Fluorescence quenching and molecular docking study

Tayyab S, Izzudin MM, Kabir MZ, Feroz SR, Tee WV, Mohamad SB, et al.

J. Photochem. Photobiol. B, Biol., 2016 Sep;162:386-94.
PMID: 27424099 DOI: 10.1016/j.jphotobiol.2016.06.049

Binding characteristics of a promising anticancer drug, axitinib (AXT) to human serum albumin (HSA), the major transport protein in human blood circulation, were studied using fluorescence, UV-vis absorption and circular dichroism (CD) spectroscopy as well as molecular docking analysis. A gradual decrease in the Stern-Volmer quenching constant with increasing temperature revealed the static mode of the protein fluorescence quenching upon AXT addition, thus confirmed AXT-HSA complex formation. This was also confirmed from alteration in the UV-vis spectrum of HSA upon AXT addition. Fluorescence quenching titration results demonstrated moderately strong binding affinity between AXT and HSA based on the binding constant value (1.08±0.06×10(5)M(-1)), obtained in 10mM sodium phosphate buffer, pH7.4 at 25°C. The sign and magnitude of the enthalpy change (∆H=-8.38kJmol(-1)) as well as the entropy change (∆S=+68.21Jmol(-1)K(-1)) clearly suggested involvement of both hydrophobic interactions and hydrogen bonding in AXT-HSA complex formation. These results were well supported by molecular docking results. Three-dimensional fluorescence spectral results indicated significant microenvironmental changes around Trp and Tyr residues of HSA upon complexation with AXT. AXT binding to the protein produced significant alterations in both secondary and tertiary structures of HSA, as revealed from the far-UV and the near-UV CD spectral results. Competitive drug displacement results obtained with phenylbutazone (site I marker), ketoprofen (site II marker) and hemin (site III marker) along with molecular docking results suggested Sudlow's site I, located in subdomain IIA of HSA, as the preferred binding site of AXT.

Matched MeSH terms: Indazoles/metabolism*; Indazoles/pharmacology
Synthesis and Staphylococcus aureus biofilm inhibitory activity of indolenine-substituted pyrazole and pyrimido[1,2-b]indazole derivatives

Yap CH, Ramle AQ, Lim SK, Rames A, Tay ST, Chin SP, et al.

Bioorg Med Chem, 2023 Nov 15;95:117485.
PMID: 37812886 DOI: 10.1016/j.bmc.2023.117485

Staphylococcus aureus is a highly adaptable opportunistic pathogen that can form biofilms and generate persister cells, leading to life-threatening infections that are difficult to treat with antibiotics alone. Therefore, there is a need for an effective S. aureus biofilm inhibitor to combat this public health threat. In this study, a small library of indolenine-substituted pyrazoles and pyrimido[1,2-b]indazole derivatives were synthesised, of which the hit compound exhibited promising antibiofilm activities against methicillin-susceptible S. aureus (MSSA ATCC 29213) and methicillin-resistant S. aureus (MRSA ATCC 33591) at concentrations significantly lower than the planktonic growth inhibition. The hit compound could prevent biofilm formation and eradicate mature biofilms of MSSA and MRSA, with a minimum biofilm inhibitory concentration (MBIC50) value as low as 1.56 µg/mL and a minimum biofilm eradication concentration (MBEC50) value as low as 6.25 µg/mL. The minimum inhibitory concentration (MIC) values of the hit compound against MSSA and MRSA were 50 µg/mL and 25 µg/mL, respectively, while the minimum bactericidal concentration (MBC) values against MSSA and MRSA were > 100 µg/mL. Preliminary structure-activity relationship analysis reveals that the fused benzene ring and COOH group of the hit compound are crucial for the antibiofilm activity. Additionally, the compound was not cytotoxic to human alveolar A549 cells, thus highlighting its potential as a suitable candidate for further development as a S. aureus biofilm inhibitor.

Matched MeSH terms: Indazoles/pharmacology
Chemical-Induced Inhibition of Blue Light-Mediated Seedling Development Caused by Disruption of Upstream Signal Transduction Involving Cryptochromes in Arabidopsis thaliana

Ong WD, Okubo-Kurihara E, Kurihara Y, Shimada S, Makita Y, Kawashima M, et al.

Plant Cell Physiol, 2017 01 01;58(1):95-105.
PMID: 28011868 DOI: 10.1093/pcp/pcw181

Plants have a remarkable ability to perceive and respond to various wavelengths of light and initiate regulation of different cascades of light signaling and molecular components. While the perception of red light and the mechanisms of its signaling involving phytochromes are largely known, knowledge of the mechanisms of blue light signaling is still limited. Chemical genetics involves the use of diverse small active or synthetic molecules to evaluate biological processes. By combining chemicals and analyzing the effects they have on plant morphology, we identified a chemical, 3-bromo-7-nitroindazole (3B7N), that promotes hypocotyl elongation of wild-type Arabidopsis only under continuous blue light. Further evaluation with loss-of-function mutants confirmed that 3B7N inhibits photomorphogenesis through cryptochrome-mediated light signaling. Microarray analysis demonstrated that the effect of 3B7N treatment on gene expression in cry1cry2 is considerably smaller than that in the wild type, indicating that 3B7N specifically interrupts cryptochrome function in the control of seedling development in a light-dependent manner. We demonstrated that 3B7N directly binds to CRY1 protein using an in vitro binding assay. These results suggest that 3B7N is a novel chemical that directly inhibits plant cryptochrome function by physical binding. The application of 3B7N can be used on other plants to study further the blue light mechanism and the genetic control of cryptochromes in the growth and development of plant species.

Matched MeSH terms: Indazoles/metabolism; Indazoles/pharmacology*; Indazoles/chemistry
Fulltext Novel Azoles as Antiparasitic Remedies against Brain-Eating Amoebae

Anwar A, Mungroo MR, Khan S, Fatima I, Rafique R, Kanwal, et al.

Antibiotics (Basel), 2020 Apr 17;9(4).
PMID: 32316387 DOI: 10.3390/antibiotics9040188

Balamuthia mandrillaris and Naegleriafowleri are opportunistic protozoan pathogens capable of producing infection of the central nervous system with more than 95% mortality rate. Previously, we have synthesized several compounds with antiamoebic properties; however, synthesis of compounds that are analogues of clinically used drugs is a highly desirable approach that can lead to effective drug development against these devastating infections. In this regard, compounds belonging to the azole class possess wide range of antimicrobial properties and used clinically. In this study, six novel benzimidazole, indazole, and tetrazole derivatives were synthesized and tested against brain-eating amoebae. These compounds were tested for their amoebicidal and static properties against N. fowleri and B. mandrillaris. Furthermore, the compounds were conjugated with silver nanoparticles and characterized. The synthetic heterocyclic compounds showed up to 72% and 65% amoebicidal activities against N. fowleri and B. mandrillaris respectively, while expressing up to 75% and 70% amoebistatic activities, respectively. Following conjugation with silver nanoparticles, amoebicidal activities of the drugs increased by up to 46 and 36% versus B. mandrillaris and N. fowleri. Minimal effects were observed when the compounds were evaluated against human cells using cytotoxicity assays. In summary, azole compounds exhibited potent activity against N. fowleri and B. mandrillaris. Moreover, conjugation of the azole compounds with silver nanoparticles further augmented the capabilities of the compounds against amoebae.

Matched MeSH terms: Indazoles
Fulltext Prospective observational study on Pazopanib in patients treated for advanced or metastatic renal cell carcinoma in countries in Asia Pacific, North Africa, and Middle East regions: PARACHUTE study

Erman M, Biswas B, Danchaivijitr P, Chen L, Wong YF, Hashem T, et al.

BMC Cancer, 2021 Sep 14;21(1):1021.
PMID: 34521387 DOI: 10.1186/s12885-021-08738-z

BACKGROUND: Clinical effectiveness and safety data of pazopanib in patients with advanced or mRCC in real-world setting from Asia Pacific, North Africa, and Middle East countries are lacking.
METHODS: PARACHUTE is a phase IV, prospective, non-interventional, observational study. Primary endpoint was the proportion of patients remaining progression free at 12 months. Secondary endpoints were ORR, PFS, safety and tolerability, and relative dose intensity (RDI).
RESULTS: Overall, 190 patients with a median age of 61 years (range: 22.0-96.0) were included. Most patients were Asian (70%), clear-cell type RCC was the most common (81%), with a favourable (9%), intermediate (47%), poor (10%), and unknown (34%) MSKCC risk score. At the end of the observational period, 78 patients completed the observational period and 112 discontinued the study; 60% of patients had the starting dose at 800 mg. Median RDI was 82%, with 52% of patients receiving 10%) TEAEs related to pazopanib included diarrhoea (30%), palmar-plantar erythrodysesthesia syndrome (15%), and hypertension (14%).
CONCLUSIONS: Results of the PARACHUTE study support the use of pazopanib in patients with advanced or mRCC who are naive to VEGF-TKI therapy. The safety profile is consistent with that previously reported by pivotal and real-world evidence studies.

Matched MeSH terms: Indazoles/administration & dosage; Indazoles/adverse effects; Indazoles/therapeutic use*
Biomolecular interaction mechanism of an anticancer drug, pazopanib with human serum albumin: a multi-spectroscopic and computational approach

Kandandapani S, Kabir MZ, Ridzwan NFW, Mohamad SB, Tayyab S

J Biomol Struct Dyn, 2022 Nov;40(18):8312-8323.
PMID: 33870854 DOI: 10.1080/07391102.2021.1911850

Pazopanib (PZP) is a multi-targeting tyrosine kinase inhibitor and is currently approved by FDA for the treatment of soft tissue sarcoma and renal cancer. Molecular interaction mechanism of PZP with human serum albumin (HSA) was explored under simulated physiological conditions (pH = 7.4), using fluorescence and UV absorption spectroscopy along with computational methods. Based on the inverse correlation between the Stern-Volmer constant (Ksv) and temperature, it was concluded that PZP quenched the protein fluorescence through static quenching mechanism. This was also confirmed from the UV-vis absorption spectral results. Moderate binding affinity between PZP and HSA was evident from the Ka values (5.51 - 1.05 × 105 M-1) while PZP-HSA complex formation was driven by hydrophobic and van der Waals interactions as well as hydrogen bonds, as revealed by positive entropy change (ΔS = +98.37 J mol-1 K-1) and negative enthalpy change (ΔH = -60.31 kJ mol-1). Three-dimensional fluorescence spectral results disclosed microenvironmental perturbations around Trp and Tyr residues of the protein upon PZP binding. Interestingly, the addition of PZP to HSA significantly protected the protein against thermal stress. Competitive drug displacement results obtained with warfarin, phenylbutazone and diazepam elucidated Sudlow's Site I, positioned in subdomain IIA of HSA, as the preferred binding site of PZP which was well supported by molecular docking analysis, while molecular dynamics simulation results suggested the stability of the PZP-HSA complex.Communicated by Vsevolod Makeev.

Matched MeSH terms: Indazoles
Synthesis of new indazole based dual inhibitors of α-glucosidase and α-amylase enzymes, their in vitro, in silico and kinetics studies

Rafique R, Khan KM, Arshia, Kanwal, Chigurupati S, Wadood A, et al.

Bioorg Chem, 2020 01;94:103195.
PMID: 31451297 DOI: 10.1016/j.bioorg.2019.103195

The current study describes the discovery of novel inhibitors of α-glucosidase and α-amylase enzymes. For that purpose, new hybrid analogs of N-hydrazinecarbothioamide substituted indazoles 4-18 were synthesized and fully characterized by EI-MS, FAB-MS, HRFAB-MS, 1H-, and 13C NMR spectroscopic techniques. Stereochemistry of the imine double bond was established by NOESY measurements. All derivatives 4-18 with their intermediates 1-3, were evaluated for in vitro α-glucosidase and α-amylase enzyme inhibition. It is worth mentioning that all synthetic compounds showed good inhibition potential in the range of 1.54 ± 0.02-4.89 ± 0.02 µM for α-glucosidase and for α-amylase 1.42 ± 0.04-4.5 ± 0.18 µM in comparison with the standard acarbose (IC50 value of 1.36 ± 0.01 µM). In silico studies were carried out to rationalize the mode of binding interaction of ligands with the active site of enzymes. Moreover, enzyme inhibitory kinetic characterization was also performed to understand the mechanism of enzyme inhibition.

Matched MeSH terms: Indazoles