A novel series of mixed-ligand M(II) complexes containing 2,2′-bipyridyl as potent α-glucosidase inhibitor: synthesis, crystal structure, DFT calculations, and molecular docking

Synthesis of 2,4-dihydroxyacetophenone derivatives as potent PDE-1 and -3 inhibitors: in vitro and in silico insights

Aim: Synthesis of novel bis-Schiff bases having potent inhibitory activity against phosphodiesterase (PDE-1 and -3) enzymes, potentially offering therapeutic implications for various conditions. Methods: Bis-Schiff bases were synthesized by refluxing 2,4-dihydroxyacetophenone with hydrazine hydrate, followed by treatment of substituted aldehydes with the resulting hydrazone to obtain the product compounds. After structural confirmation, the compounds were screened for their in vitro PDE-1 and -3 inhibitory activities. Results: The prepared compounds exhibited noteworthy inhibitory efficacy against PDE-1 and -3 enzymes by comparing with suramin standard. To clarify the binding interactions between the drugs, PDE-1 and -3 active sites, molecular docking studies were carried out. Conclusion: The potent compounds discovered in this study may be good candidates for drug development.

In vitro α-glucosidase, docking and density functional theory studies on novel azide metal complexes

Aim: The goal of this study is to synthesize new metal complexes containing N-methyl-1-(pyridin-2-yl)methanimine and azide ligands as α-glucosidase inhibitors for Type 2 diabetes. Materials & methods: The target complexes (12-16) were synthesized by reacting N-methyl-1-(pyridin-2-yl)methanimine (L1) with sodium azide in the presence of corresponding metal salts. The investigation of target protein interactions, vibrational, electronic and nonlinear optical properties for these complexes was performed by molecular docking and density functional theory studies. Results: Among these complexes, complex 13 (IC50 = 0.2802 ± 0.62 μM) containing Hg ion showed the highest α-glucosidase inhibitory property. On the other hand, significant results were detected for complexes containing Cu and Ag ions. Conclusion: Complex 13 may be an alternate anti-diabetic inhibitor according to in vitro/docking results.

PTK6: An emerging biomarker for prognosis and immunotherapeutic response in clear cell renal carcinoma (KIRC)

Kidney renal clear cell carcinoma (KIRC), one of the most prevalent form of kidney carcinoma, is highly aggressive cancer known for significant immune infiltration and high mortality rates. The absence of sensitivity to traditional therapy has spurred the search for new treatments. Protein Tyrosine Kinase 6 (PTK6) is implicated in promoting cancer growth, spread, and metastasis. Our review of The Cancer Genome Atlas database revealed PTK6 overexpression in KIRC, though its specific role in this cancer type was unclear. We investigated PTK6's cancer-promoting roles in KIRC using the database and confirmed our findings with patient-derived tissues. Our analysis showed that elevated PTK6 expression is linked to worse outcomes and higher levels of immune infiltration. It also correlates positively with neo-antigens (NEO) and DNA ploidy changes in KIRC. This research delves into PTK6's role in KIRC development, suggesting PTK6 as a possible biomarker for prognosis and treatment in KIRC.

Comparative assessment of structure-property relationships of new Cu(II) complex in selected density functionals

In order to evaluate the structure-property relationships of Cu(II) complex by using DFT methods, the structure of the newly synthesized Cu(II) complex, [Cu(6-Brpic)2(bpy)], was investigated by XRD, FTIR, UV-Vis, and fluorescence spectroscopic methods. In addition, Hirshfeld surface and NBO analyses were fulfilled to identify possible interactions in the intermolecular and coordination environment. The five different DFT methods (HCTH, M06L, TPSSTPSS, B3LYP, and CAM-B3LYP levels), having four different functionalities (the GGA, meta-GGA, hybrid-GGA, and range-separated hybrid), were carried out so as to investigate the structure-property relationship, considering the geometric parameters (bond lengths and angles), vibrational frequencies, electronic absorption wavelengths, electronic transitions, and linear and nonlinear optical parameters. The R2 for structural and vibrational parameters, as well as MPD%, MAD, an optimal scaling factor (λ) and overall root mean square (RMS) deviation, were considered only at vibration frequencies. While it was determined that M06-L and TPSSTPSS levels gave the best results for the bond lengths and angles of the Cu(II) complex, the best results for vibrational frequencies were obtained in the HCTH method along with these methods. In NLO parameters, the static and dynamic first-order hyperpolarizability (<β(0;0,0)> and β(-ω;ω,0)/<β(-2ω;ω,ω)>) values, the largest values were obtained in the HCTH method (38.817 × 10-30 and 437.86 × 10-30/201.55 × 10-30 esu), whereas the smallest values were found to be in the CAM-B3LYP/TPSSTPSS levels (6.118 × 10-30 esu, 8.270 × 10-30/11.730 × 10-30 esu). By regarding the static γ (<γ(0;0,0,0)>) and dynamic (<γ(-ω;ω,0,0)> parameters, the largest values were calculated in the M06L (232.101 × 10-36) and HCTH (1711.52 × 10-36) methods and the smallest values were obtained in the CAM-B3LYP (43.281 × 10-36 and 60.844 × 10-36) method. In fact, it is obviously seen that the β and γ values obtained by the aforementioned DFT levels are many times higher than that of the standard molecule of urea. These results indicate that the Cu(II) complex may be used as a potential NLO material to evolve optoelectronic devices.

New ferrocene integrated amphiphilic guanidines: Synthesis, spectroscopic elucidation, DFT calculation and in vitro α-amylase and α-glucosidase inhibition combined with molecular docking approach

Three N, N', N″-trisubstituted ferrocenyl guanidines (MG-10, MG-12 and MG-14) were synthesized, characterized by several analytical methods such as FT-IR, ¹H and ¹³C NMR, elemental analysis and UV-visible spectroscopy. These compounds have long chain aliphatic groups therefore their aliphatic nature has been evaluated by determining their critical micelle concentration (CMC). CMC point decreases from 0.036 mM to 0.013 mM with increase in the aliphatic chain length. The quantum mechanical parameters such as the energy of frontier molecular orbitals (E_HOMO and E_LUMO) and the Mulliken charge distribution on the optimized structures were determined using a DFT/B3LYP method combined with the 6-31G (d,p) basis set in the gas phase. The in vitro antidiabetic activity of synthesized compounds showed that MG-12 has IC₅₀value 23.10 μg/mL against α-amylase while MG-10 has IC₅₀value 27.32 μg/mL against α-glucosidase with the respective standard Acarbose (IC₅₀value 20.12 μg/mL). Theoretical docking analysis demonstrated that MG-10 and MG-12 interacted with α-amylase by 3 types of interaction, including hydrogen bonds, hydrophobic interactions and electrostatic interactions.

Rational synthesis, biological screening of azo derivatives of chloro-phenylcarbonyl diazenyl hydroxy dipyrimidines/thioxotetrahydropyrimidines and their metal complexes

Herein, a new series of azo ligands HL-1 (5-(2-chloro-6-(phenylcarbonyl)phenyl)diazenyl)-6-hydroxydihydropyrimidines-2,4dione), HL-2 (5-(2-chloro-6-(phenylcarbonyl)phenyl)diazenyl)-6-hydroxy-2-thioxottetrahydropyrimidin-4one), HL-3 (5-(2,4-dichloro-6-(phenylcarbonyl)phenyl) diazenyl)-6-hydroxydihydropyrimidines-2,4dione), HL-4 (5-(2,4-dichloro-6-(phenylcarbonyl) phenyl)diazenyl)-6-hydroxy-2-thioxotetrahydropyrimidin-4one) and their metal complexes with Cu(II) & Ni(II) were synthesized successfully having excellent yield, in reproducible conditions and for structure elucidation different advance spectroscopic techniques (FTIR, ¹H NMR, ¹³C NMR and Mass Spectrometry) were applied. In FTIR analysis, the absence of peak at 3450-3550 cm ^-1 due to -NH₂ and presence of a new peak of N=N at 1390-1520 cm^-1 confirmed synthesis of the ligands. The ¹H NMR spectra of azo ligands showed singlet peak at 11.5-13.5 ppm (Ar-OH) for hydroxyl group and -NH₂ signals disappearance of anilines at 4-5 ppm also gives strong indication for the synthesis of azo compounds. On complexation two most important peaks (M-O, M-N) appeared in all the metal chelates in the range of 400-600 cm^-1 which were not present in any of the ligands, confirmed the formation of complexes. Molecular ion peaks in mass spectra at 273, 388, 407 and 423 m/z value for ligands as well as for complexes at 803, 835, 871 and 904 m/z also give strong indication that proposed ligands and their metal complexes are produced successfully. Biological screening of the synthesized compounds were also carried out against different bacterial strains (E.coli, S.typhi, and B.subtilis), antifungal (C.albicans, A.niger, and C.glabrata) strains and antioxidant activity. From results it was observed that HL-4 and Cu complexes exhibited maximum inhibition against all bacterial and fungal strains as compared to other ligands and standard drug.

A Short Review on Structural Concepts of Metal Complexes of Proton Transfer Salts of Pyridine-2-Carboxylic Acid

In this study, a brief review of the proton transfer salts synthesized from the reaction of piperazine with pyridine-2-carboxylic acid and their metal complexes since 2009 was made. The metals in the studied compounds are mostly d-block metals. In complexes, the anionic component of the salt is coordinated to the metal, while the cationic component is present only as a complementary ion in a complex.

Docking study, molecular dynamic, synthesis, anti-α-glucosidase assessment, and ADMET prediction of new benzimidazole-Schiff base derivatives

The control of postprandial hyperglycemia is an important target in the treatment of type 2 diabetes mellitus (T2DM). As a result, targeting α-glucosidase as the most important enzyme in the breakdown of carbohydrates to glucose that leads to an increase in postprandial hyperglycemia is one of the treatment processes of T2DM. In the present work, a new class of benzimidazole-Schiff base hybrids 8a–p has been developed based on the potent reported α-glucosidase inhibitors. These compounds were synthesized by sample recantations, characterized by ¹H-NMR, ¹³C-NMR, FT-IR, and CHNS elemental analysis, and evaluated against α-glucosidase. All new compounds, with the exception of inactive compound 8g, showed excellent inhibitory activities (60.1 ± 3.6–287.1 ± 7.4 µM) in comparison to acarbose as the positive control (750.0 ± 10.5). Kinetic study of the most potent compound 8p showed a competitive type of inhibition (K_i value = 60 µM). In silico induced fit docking and molecular dynamics studies were performed to further investigate the interaction, orientation, and conformation of the title new compounds over the active site of α-glucosidase. In silico druglikeness analysis and ADMET prediction of the most potent compounds demonstrated that these compounds were druglikeness and had satisfactory ADMET profile.

A review on α-glucosidase inhibitory activity of first row transition metal complexes: a futuristic strategy for treatment of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by high blood glucose levels and has emerged as a controversial public health issue worldwide. The increasing number of patients with T2DM on one hand, and serious long-term complications of the disease such as obesity, neuropathy, and vascular disorders on the other hand, have induced a huge economic impact on society globally. In this regard, inhibition of α-glucosidase, the enzyme responsible for the hydrolysis of carbohydrates in the body has been the main therapeutic approach to the treatment of T2DM. As α-glucosidase inhibitors (α-GIs) have occupied a special position in the current research and prescription drugs are generally α-GIs, researchers have been encouraged to design and synthesize novel and efficient inhibitors. Previously, the presence of a sugar moiety seemed to be crucial for designing α-GIs since they can attach to the carbohydrate binding site of the enzyme mimicking the structure of disaccharides or oligosaccharides. However, inhibitors lacking glycosyl structures have also shown potent inhibitory activity and development of non-sugar based inhibitors is accelerating. In this respect, in vitro anti-α-glucosidase activity of metal complexes has attracted lots of attention and this paper has reviewed the inhibitory activity of first-row transition metal complexes toward α-glucosidase and discussed their probable mechanisms of action.

Spectroscopic Studies for Rhodium (III) Binding to Apo-Transferrin

Transferrin belongs to a class of monomeric glycoproteins, which sequestrate and transport iron inside the body. Apart from iron, transferrin binds with various other metal ions and is assumed to deliver medicinally important metal ions to cells. Hence, the investigation of binding characteristics may provide crucial information for new drug developments. To study the biological impacts of medicinally important metal ions, in this work, we explored the binding behavior of Rh(III) ion with serum apo-transferrin (ApoHST) using FT-IR and UV-Vis spectroscopy. In FT-IR, interaction of Rh(III) with ApoHST was studied at three concentrations (0.25, 0.5, and 1 mM) of metal ion at different time intervals (15, 30, and 60 min). The IR spectra of Rh(III)-ApoHST coordinates revealed a marked reduction in amide I and II band intensities with alterations in band positions. The α-helical part of protein secondary structure reduced considerably (from 53% to 49%, 42%, and 39%), followed by an increment in β-sheet and β-turn components with the increasing concentrations of metal ion. Saturation level reached at 1 mM concentration of Rh(III) ion. In the UV-Vis spectroscopic study, absorption of metal ion-protein coordinates successively raised as concentration of Rh(III) ion increased. The binding constant (K) was calculated as $1.16\times {10}^4{\text{M}}^{-1}$ , which showed a strong binding of the test metal ion with the protein. Upon coordination with a metal ion, the microenvironment of aromatic protein residues changed, which was detected by these spectroscopic techniques. The results revealed the existence of a significant interaction between Rh (III) ion and ApoHST. These research outcome may present new insight into the possible utilization of Rh(III) ion-based compounds in biomedicine. However, more investigations are needed to interpret the exact cellular mechanism.

Structural characterization and antileishmanial activity of newly synthesized organo-bismuth(V) carboxylates: experimental and molecular docking studies

In a quest to discover new formulations for the treatment of various parasitic diseases, a series of heteroleptic triorganobismuth(V) biscarboxylates of type [BiR₃(O₂CR')₂], where R=C₆H₅ for 1-4 and p-CH₃C₆H₄ for 5-8, were synthesized, characterized and evaluated for their biological potential against L. tropica. All the synthesized complexes were fully characterized by elemental analysis, FT-IR, multinuclear (¹H and ¹³C) NMR spectroscopy and X-ray crystallography. The crystal structures for [BiPh₃(O₂CC₆H₄(o-Br))₂] (1), [BiPh₃(O₂CC₂H₂C₆H₄)₂] (2), [BiPh₃(O₂CC₆H₄(m-NO₂))₂] (3) and [BiPh₃(O₂CC₆H₄(2-OH,3-CH₃))₂] (4) were determined and found to have a distorted pentagonal bipyramidal molecular geometry with seven coordinated bismuth center for 1-3 and for 4 distorted octahedral geometry, respectively. All the synthesized complexes demonstrated a moderate to significant activity against leishmania parasites. A broad analytical approach was followed to testify the stability for (1-8) in solid state as well as in solution and in leishmanial culture M199, ensuring them to be stable enough to exert a significant antileishmanial effect with promising results. Cytotoxicity profile suggests that tris(tolyl) derivatives show lower toxicity against isolated lymphocytes with higher antileishmanial potential. Molecular docking studies were carried out to reveal the binding modes for (1-8) targeting the active site of trypanothione reductase (TR) (PDB ID: 4APN) and Trypanothione Synthetase-Amidase structure (PDB ID 2vob).

Concentration effects on optical properties, DFT, crystal characterization and α-glucosidase activity studies: Novel Zn(II) complex

A novel Zn(II) complex of 6-ClpicH and picH was synthesized and its structure was determined by XRD technique. The detailed experimental optical susceptibility and band gap, refractive index, linear polarizability, optical and electrical conductivity parameters in various concentrations were investigated by means of the UV-Vis spectroscopic data. The optical band gap, refractive index (n), linear optical susceptibility (χ⁽¹⁾), third-order nonlinear optical susceptibility (χ⁽³⁾), second- and third-order nonlinear optical (β and γ) parameters were examined by using DFT/M06-L and ωB97XD/6-311++G(d,p) levels. The IC₅₀ value of Zn(II) complex against α-glucosidase was also obtained at 0.44 mM. The experimental band gap of the Zn(II) complex at 13, 33, 44 and 94 µM concentrations in ethanol were found to be 4.38, 4.37, 4.35 and 4.28 eV, respectively. The third-order NLO susceptibility χ⁽³⁾ parameter at 94 µM concentration corresponding to the photon energies of 4.6 and 5.7 eV in the UV-Vis region were observed at 206.6 × 10^-13 and 294.3 × 10^-13 esu, respectively. Besides, the theoretical χ⁽³⁾ values were obtained at 50.58 × 10^-13 and 20.37 × 10^-13 esu by using M06-L level. These results indicate that Zn(II) complex could be an effective third-order NLO candidate material. In brief, the detailed theoretical and experimental structural, spectral and optical properties of the Zn(II) complex were presented comparatively.

Celebrex derivatives: Synthesis, α-glucosidase inhibition, crystal structures and molecular docking studies

Celebrex (1), commonly used as an anti-inflammatory drug, was functionalized (compounds 2-9) to identify new α-glucosidase inhibitors. Initially, all the synthesized derivatives were evaluated for anti-inflammatory activity but none was found to be active. Subsequently a random biological screening was carried out. Interestingly many of them were found to be potent α-glucosidase inhibitors in vitro. All the structures of synthesized derivatives were deduced through ¹H NMR, FAB-MS, HR-MS, FT-IR analysis. The single-crystal X-ray structures of compounds 1, and 5 further confirmed the assigned structures. Compounds exhibited a potent α-glucosidase inhibitory activity (IC₅₀ = 92.32 ± 1.530-445.20 ± 1.04 µM) against tested standard acarbose (IC₅₀ = 875.75 ± 2.08 µM), except compounds 2 and 4, which appeared as inactive. Among them, compound 9 (IC₅₀ = 92.32 ± 1.530 µM) was the most potent inhibitor of α-glucosidase enzyme. Molecular docking studies revealed that compounds 6, and 9 interacted with the key amino acid residues of α-glucosidase via H-bonding, and π-π stacking interactions. α-Glucosidase is a key target for the anti-diabetic drug development, and its inhibitors are known to exert anti hyperglycemic effect and help in lowering of post-prandial blood glucose levels.

Novel metal complexes containing 6-methylpyridine-2-carboxylic acid as potent α-glucosidase inhibitor: synthesis, crystal structures, DFT calculations, and molecular docking

The World Health Organization (WHO) report shows that diabetes mellitus (DM) will be one of the ten deadly diseases in the near future. The best way to prevent DM is to decrease blood glucose levels and keep under control; therefore, it is important to design and synthesize the effective inhibitors that can be used in the treatment of DM disease. In this respect, a series of ten metal complexes containing 6-methylpyridine-2-carboxylic acid {[Cr(6-mpa)₂(H₂O)₂]·H₂O·NO₃, (1), [Mn(6-mpa)₂(H₂O)₂], (2), [Ni(6-mpa)₂(H₂O)₂]·2H₂O, (3), [Hg(6-mpa)₂(H₂O)], (4), [Cu(6-mpa)₂(Py)], (5), [Cu(6-mpa)₂(H₂O)]·H₂O, (6), [Zn(6-mpa)₂(H₂O)]·H₂O, (7), [Fe(6-mpa)₃], (8), [Cd(6-mpa)₂(H₂O)₂]·2H₂O, (9), and [Co(6-mpa)₂(H₂O)₂]·2H₂O, (10)} were synthesized as α-glucosidase inhibitors. We found that the IC₅₀ values of the synthesized complexes ranged from 0.247 ± 0.10 to > 600 μM against α-glucosidase. The spectral analyses for these complexes characterized by XRD and LC-MS/MS were also carried out by FT-IR and UV-Vis spectra. Additionally, the DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level was applied to obtain optimal molecular geometries and spectral behaviors as well as significant contributions to the electronic transitions for the complexes. The molecular docking study was also performed to display interactions between the target protein (the template structure Saccharomyces cerevisiae isomaltase) and the synthesized complexes (1-10).