The synthesis of axially disubstituted silicon phthalocyanines, their quaternized derivatives and first inhibitory effect on human cytosolic carbonic anhydrase isozymes hCA I and II

Tail-approach based design, synthesis, and molecular modeling of benzenesulfonamides carrying thiadiazole and urea moieties as novel carbonic anhydrase inhibitors

We synthesized herein 16 compounds (SUT1-SUT16) as potential carbonic anhydrase (CA) inhibitors utilizing the tail-approach design. Based on this strategy, we connected benzenesulfonamide, the zinc-binding scaffold, to different urea moieties with the 1,3,4-thiadiazole ring as a linker. We obtained the target compounds by the reaction of 4-(5-amino-1,3,4-thiadiazol-2-yl)benzenesulfonamide with aryl isocyanates. Upon confirmation of their structures, the compounds were screened for their ability to inhibit the tumor-related human (h) isoforms human carbonic anhydrase (hCA) IX and XII, as well as the physiologically dominant hCA I and II. Most of the molecules demonstrated Ki values ≤ 10 nM with different selectivity profiles. The binding modes of SUT9, SUT10, and SUT5, the most effective inhibitors of hCA II, IX, and XII, respectively, were predicted by molecular docking. SUT16 (4-{5-[3-(naphthalen-1-yl)ureido]-1,3,4-thiadiazol-2-yl}benzenesulfonamide) was found to be the most selective inhibitor of the cancer-associated isoforms hCA IX and XII over the off-target isoforms, hCAI and II. The interaction dynamics and stability of SUT16 within hCA IX and XII were investigated by molecular dynamics simulations as well as dynophore analysis. Based on computational data, increased hydrophobic contacts and hydrogen bonds in the tail part of these molecules within hCA IX and XII were found as favorable interactions leading to effective inhibitors of cancer-related isoforms.

The potential of carbonic anhydrase enzymes as a novel target for anti-cancer treatment

Carbonic anhydrase (CA) is a zinc-dependent metal enzyme that maintains the pH and carbon dioxide (CO2) homeostasis in cells by catalyzing the reversible hydration and dehydration of CO2 and bicarbonate (HCO3-). In mammals, there are 16 isozymes of CA existed, namely CAI to CAXIV, but only 15 isozymes are found in humans except CAXV. Human CAs have highly conserved catalytic domains, all of which are distributed in different tissues and play important physiological roles. Changes in their functions may disrupt the typical distribution of CAs throughout human body and therefore CAs can be used as diagnostic biomarkers for many diseases. Furthermore, the expression of CAs is correlated to the progression of numerous tumors, therapeutic sensitivity and patient prognosis. In this review, we discuss thoroughly the structure of CAs, their functional activities in human physiology, dysregulations and diseases related to CAs, and different types of CA inhibitors that can reverse their dysregulation.

Efficient, rapid, and high-yield synthesis of aryl Schiff base derivatives and their in vitro and in silico inhibition studies of hCA I, hCA II, AChE, and BuChE

This study reports a rapid and efficient synthesis of four novel aryl Schiff base derivatives. Biological activity and molecular modeling studies were conducted to evaluate the inhibitory effects of these compounds on human carbonic anhydrases (hCA) and cholinesterases. The results indicate that the triazole-ring-containing compounds have strong inhibitory effects on hCA I, hCA II, acetylcholinesterase (AChE), and butyrylcholinesterase (BuChE) targets. Besides comparing the Schiff bases synthesized in our study to reference molecules, we conducted in silico investigations to examine how these compounds interact with their targets. Our studies revealed that these compounds can occupy binding sites and establish interactions with crucial residues, thus inhibiting the functions of the targets. These findings have significant implications as they can be utilized to develop more potent compounds for treating the diseases that these target proteins play crucial roles in or to obtain drug precursors with enhanced efficacy.

Synthesis of Novel Hydrazide-Hydrazone Compounds and In Vitro and In Silico Investigation of Their Biological Activities against AChE, BChE, and hCA I and II

The abnormal levels of the human carbonic anhydrase isoenzymes I and II (hCA I and II) and cholinesterase enzymes, namely, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), are linked with various disorders including Alzheimer's disease. In this study, six new nicotinic hydrazide derivatives (7-12) were designed and synthesized for the first time, and their inhibitory profiles against hCA I, hCA II, AChE, and BChE were investigated by in vitro assays and in silico studies. The structures of novel molecules were elucidated by using spectroscopic techniques and elemental analysis. These molecules showed inhibitory activities against hCA I and II with IC50 values ranging from 7.12 to 45.12 nM. Compared to reference drug acetazolamide (AZA), compound 8 was the most active inhibitor against hCA I and II. On the other hand, it was determined that IC50 values of the tested molecules ranged between 21.45 and 61.37 nM for AChE and between 18.42 and 54.74 nM for BChE. Among them, compound 12 was the most potent inhibitor of AChE and BChE, with IC50 values of 21.45 and 18.42 nM, respectively. In order to better understand the mode of action of these new compounds, state-of-the-art molecular modeling techniques were also conducted.

Biological activity and molecular docking studies of some N-phenylsulfonamides against cholinesterases and carbonic anhydrase isoenzymes

In this research, a series of N-phenylsulfonamide derivatives (1-12) were designed, synthesized and investigated for their inhibitory potencies against carbonic anhydrase isoenzymes I, II and IX (hCA I, hCA II, and hCA IX) and cholinesterases (ChE), namely, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). These compounds, whose inhibition potentials were evaluated for the first time, were characterized by spectroscopic techniques (¹ H- and ¹³ C NMR and FT-IR). CA isoenzyme inhibitors are significant therapeutic targets, especially owing to their preventive/activation potential in the therapy processes of some diseases such as cancer, osteoporosis, and glaucoma. On the other hand, Cholinesterase inhibitors are valuable molecules with biological importance that can be employed in the therapy process of Alzheimer's patients. The results showed that the tested molecules had enzyme inhibition activities ranging from 9.7 to 93.7 nM against these five metabolic enzymes. Among the tested molecules, the methoxy and the hydroxyl group-containing compounds 10, 11, and 12 exhibited more enzyme inhibition activities when compared to standard compounds acetazolamide (AAZ), sulfapyridine, and sulfadiazine for CA isoenzymes and neostigmine for ChE, respectively. Of these three molecules, compound 12, which had a hydroxyl group in the para position in the aromatic ring, was determined to be the most active molecule against all enzymes. In silico work, molecular docking has also shown similar results and consistent with the experimental data in the study. As a result, we can say that some of the tested molecules might be used as promising inhibitor candidates for further studies on this topic.

Synthesis, characterization, and biological evaluation of some novel Schiff bases as potential metabolic enzyme inhibitors

In this study, a series of novel Schiff base derivatives containing a pyrazolone ring (2a-e) were designed, successfully synthesized for the first time, and characterized by elemental analysis and some spectroscopic methods. These compounds were tested for their inhibitory activities on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and the human carbonic anhydrase isoenzymes I and II (hCA I and II). All synthesized molecules indicated significant inhibition effects with IC₅₀ values ranging from 14.15 to 107.62 nM against these enzymes. Compound 2d showed the most potent inhibitory activity among the tested molecules toward AChE and BChE (IC₅₀  = 15.07 and 14.15 nM) compared to the standard drug neostigmine. We determined that the IC₅₀ values of the tested molecules ranged between 16.86 and 57.96 nM for hCA I and 15.24-46.21 nM for hCA II. As a consequence, we may say that some of the Schiff base derivatives may be used as potential drug candidates in later studies.

Synthesis, Structural Characterizations, and Quantum Chemical Investigations on 1-(3-Methoxy-phenyl)-3-naphthalen-1-yl-propenone

In the present study, 1-(3-methoxy-phenyl)-3-naphthalen-1-yl-propenone (MPNP) is synthesized and characterized by several experimental techniques such as Fourier transform-infrared spectroscopy (FT-IR), FT-Raman, NMR and UV-vis spectral methods. The similar techniques are also investigated by the computational method using Gaussian software. The density functional theory (DFT) method is used to obtain the optimized structure using the B3LYP/6-311++G(d,p) basis set. This optimization procedure of the molecule gives the minimum energy confirmation of the structure. The computed geometrical parameters are compared with experimental data. The experimental FT-IR and FT-Raman spectra of MPNP are obtained in the regions 4000-400 and 4000-50 cm-1 respectively. The detailed vibrational assignments of the molecule are obtained with the support of potential energy distribution. The theoretical NMR (1H and 13C) analysis is conducted by the GIAO method for its structural characterization and compared with experimental chemical shifts. The experimental UV-vis spectrum is obtained in the dimethyl sulfoxide solvent and compared with the theoretically computed spectrum by the time-dependent DFT method. In addition to these studies, other analyses such as nonlinear optical, natural bonds orbital, frontier molecular orbital, molecular electrostatic potential, and NCI have been conducted to understand the nature of the molecule. The title molecule is docked and also the drug-likeness, ADMET studies were carried out. The RBD domain bound to the ACE2 receptor during the fusion makes spike glycoprotein an elusive therapeutic target in SARS-CoV-2 infection.

Carbonic Anhydrase Inhibition Potential and Some Bioactivities of the Peripherally Tetrasubstituted Cobalt(II), Titanium(IV), Manganese(III) Phthalocyanines

Background:

Peripherally tetrasubstituted cobalt(II), titanium(IV), manganese(III) phthalocyanines carrying redox-active metal centers were previously synthesized. Metallophthalocyanines (MPcs) exhibited the potential to use in medicinal applications due to biological activities, such as antibacterial, antioxidant and enzyme inhibition.

Objective:

This study's aim was to evaluate the previously synthesized metallophthalocyanines in terms of carbonic anhydrase inhibition, antioxidant, and antimicrobial activities.

Methods:

In this study, the inhibition potential of the metallophthallocyanines against carbonic anhydrase (CA) enzyme, which is important for treatments of many disorders, was evaluated. The metallophthalocyanines showed high CA inhibitory activity with IC50 values in the range of 74-317 nM, which was similar or better when compared with the standard CA inhibitors sulfanilamide and acetazolamide. In addition, antibacterial and antioxidant activities were determined. The metallophthallocyanines exhibited moderate antibacterial activity, especially against S. aureus and S. epidermis. The antioxidant activities of the compounds in both tests were quite high, even exceeding the standards Trolox and BHT, with SC50 values of 0.0048-0.0257 and TEAC values of 1143.3- 1543.7 μM, being 2 to 73 fold better activity.

Results:

In this study, the inhibition potential of the metallophthallocyanines against carbonic anhydrase (CA) enzyme, which is important for treatments of many disorders, was evaluated. The metallophthalocyanines showed high CA inhibitory activity with IC50 values in the range of 74-317 nM, which was similar or better when compared with the standard CA inhibitors sulfanilamide and acetazolamide. In addition, antibacterial and antioxidant activities were determined. The metallophthallocyanines exhibited moderate antibacterial activity, especially against S. aureus and S. epidermis. The antioxidant activities of the compounds in both tests were quite high, even exceeding the standards Trolox and BHT, with SC50 values of 0.0048-0.0257 and TEAC values of 1143.3- 1543.7 μM, being 2 to 73 fold better activity.

Conclusion:

In conclusion, all three metallophthalocyanines exhibit excellent carbonic anhydrase and antioxidant potential and deserve further interest for the synthesis of new derivatives.

Biologically active phthalocyanine metal complexes: Preparation, evaluation of α-glycosidase and anticholinesterase enzyme inhibition activities, and molecular docking studies

In this study, preparation, as well as investigation of α-glycosidase and cholinesterase (ChE) enzyme inhibition activities of furan-2-ylmethoxy-substituted compounds 1-7, are reported. Peripherally, tetra-substituted copper and manganese phthalocyanines (5 and 6) were synthesized for the first time. The substitution of furan-2-ylmethoxy groups provides remarkable solubility to the complex and redshift of the phthalocyanines Q-band. Besides, the inhibitory effects of these compounds on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase (α-Gly) enzymes have been investigated. The AChE was inhibited by these compounds (1-7) in low micromolar levels, and K _i values were recorded between 11.17 ± 1.03 and 83.28 ± 11.08 µM. Against the BChE, the compounds demonstrated K _i values from 7.55 ± 0.98 to 81.35 ± 12.80 µM. Also, these compounds (1-7) effectively inhibited α-glycosidase, with K _i values in the range of 744.87 ± 67.33 to 1094.38 ± 88.91 µM. For α-glycosidase, the most effective K _i values of phthalocyanines 3 and 6 were with K _i values of 744.87 ± 67.33 and 880.36 ± 56.77 µM, respectively. Moreover, the studied metal complexes were docked with target proteins PDB ID: 4PQE, 1P0I, and 3WY1. Pharmacokinetic parameters and secondary chemical interactions that play an active role in interaction were predicted with docking simulation results. Overall, furan-2-ylmethoxy-substituted phthalocyanines can be considered as potential agents for the treatment of Alzheimer's diseases and diabetes mellitus.

Synthesis of N-phenylsulfonamide derivatives and investigation of some esterase enzymes inhibiting properties

In this study, synthesis of nine N-phenylsulfonamide derivatives was designed by starting from aniline, which is the simplest aromatic amine. These compounds were obtained in yields between 69 and 95%. Inhibitory properties of synthesized compounds on carbonic anhydrase I (CA I), CA II isoenzymes, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes were investigated. Inhibitors of CA isoenzymes are important therapeutic targets, particularly due to their preventive/activation potential in the treatment of diseases such as edema, glaucoma, cancer and osteoporosis. Cholinesterase inhibitors are valuable compounds that can be used in many different therapeutic applications, including Alzheimer's disease. The compound 8 for CA I, AChE and BChE, 2 for CA II showed a very active inhibition profile (K_I 45.7 ± 0.46 for CA I, 33.5 ± 0.38 nM for CA II, 31.5 ± 0.33 nM for AChE and 24.4 ± 0.29 nM for BChE). The results indicate that these N-phenyl-sulfonamide derivatives are potent CA and cholinesterases and new potential drugs.

Synthesis, in vitro inhibition effect of novel phthalocyanine complexes as carbonic anhydrase and paraoxonase enzyme inhibitors

The preparation and assessment of carbonic anhydrase and paraoxonase enzyme inhibition properties of 3-(2-(5-amino-4-(4-bromophenyl)-3-methyl-1H-pyrazol-1-yl)ethoxy)phthalonitrile (2) and its nitrogen-containing non-peripheral phthalocyanine derivatives (3 and 4) are reported for the first time. The new phthalonitrile and its phthalocyanine derivatives have been elucidated by FT-IR spectroscopy, 1H-NMR, [Formula: see text]C-NMR, mass and UV-vis spectroscopy. The results demonstrated that all synthesized compounds moderately inhibited carbonic anhydrase and paraoxonase enzymes. Among the compounds, the most active ones were found to be compound 4 for PON (Ki : 0.14 [Formula: see text]M), compound 3 for hCA I (Ki : 22.52 [Formula: see text]M) and compound 1 for hCA II (Ki : 13.62 [Formula: see text]M).

Design, synthesis, characterization of peripherally tetra-pyridine-triazole-substituted phthalocyanines and their inhibitory effects on cholinesterases (AChE/BChE) and carbonic anhydrases (hCA I, II and IX)

In this study, phthalocyanine precursors (5and9) and 1,2,3-triazole-substituted metal-free and metallo phthalocyanines (9a–c) were designed and synthesized for the first time and evaluatedin vitrofor key molecular targets.

Phthalocyanines with bromobenzenesulfanyl substituents at non-peripheral position: Preparation, photophysical and photochemical properties

Electron-donating bromobenzenesulfanyl-group-substituted phthalonitrile derivative (1) and its novel non-peripherally tetra-substituted metal-free, indium and zinc phthalocyanine complexes (2–4) have been prepared for the first time. The chemical structures of this new phthalonitrile and its phthalocyanine derivatives were characterized by UV-vis, FT-IR, NMR, and MALDI-TOF mass spectrometry. The introduction of this electron-donating sulfanyl type of non-peripheral substituent accounts for a remarkable red shift of the phthalocyanine Q band to approximately 730 nm. Photophysical and photochemical properties of the novel functional complexes were also examined as photosensitizers for PDT applications.

Triazole substituted metal-free, metallo-phthalocyanines and their water soluble derivatives as potential cholinesterases inhibitors: Design, synthesis and in vitro inhibition study

In this study, 1,2,3-triazole substituted metal-free and metallo phthalocyanines (4, 5, 6) and their water soluble derivatives (4a, 5a, 6a) were designed, synthesized for the first time and tested in vitro on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Most phthalocyanines exhibited good inhibitory activities on these enzymes. Among the six phthalocyanines and starting compounds, 4a showed the most interesting profile as a submicromolar selective inhibitor of AChE (IC₅₀ = 0.040 µM) and 5a showed the most effective inhibitor of BChE (IC₅₀ = 0.1198 µM).