ABSTRACT
Polyphenol oxidase (PPO) is an industrially important enzyme associated with browning reactions. In the present study, a set of ten new dihydropyridine [2,3-d] pyrimidines (TD-Hid-1-10) were synthesized and was found to be proven characteristically by 1H NMR, 13C NMR, IR, elemental analysis, and assessed as possible PPO inhibitors. PPO was purified from banana using three-phase partitioning, achieving an 18.65-fold purification and 136.47% activity recovery. Enzyme kinetics revealed that the compounds TD-Hid-6 and TD-Hid-7 are to be the most potent inhibitors, exhibiting mixed-type inhibition profile with IC50 values of 1.14 µM, 5.29 µM respectively against purified PPO enzyme. Electronic structure calculations at the B3LYP/PBE0 level of theories using def-2 SVP, def2-TZVP basis sets with various molecular descriptors characterized the electronic behavior of studied derivatives TD-Hid-1-10. Molecular electrostatic potential (MEP) and reduced density gradient analyses of RDG-NCI provided insights into charge distributions and weak intermolecular interactions. Docking study simulations predicted binding poses within crucial amino acid sequence in the 2y9x enzyme's active site, which is typically similar in sequence to the PPO form is not allowed. Ligands were analysed in terms of binding energies, inhibitor concentrations (mM) and various molecular interactions such as H-bonds, H-carbon, π-carbon, π-sigma, π-sigma, π-π T-shaped, π-π stacked, π-alkyl, Van der Waals and Cu interactions. The lowest binding energy (-7.83 kcal/mol) and the highest inhibitory effect (1.83 mM) were shown by the ligand Td-Hid-6, which forms H-bonds with Met280 and Asn260, exhibits π-sigma interactions with His61 and π-alkyl interactions with Val283. Other ligands also showed different interactions with various amino acids; for example, the Td-Hid-1 ligand formed H-bonds with His244 and showed π-sigma interactions with His244 and Val283.
Subject(s)
Catechol Oxidase , Drug Design , Enzyme Inhibitors , Molecular Docking Simulation , Pyrimidines , Catechol Oxidase/chemistry , Catechol Oxidase/antagonists & inhibitors , Catechol Oxidase/metabolism , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/chemical synthesis , Pyrimidines/chemistry , Musa/chemistry , Musa/enzymology , Plant Proteins/chemistry , Plant Proteins/antagonists & inhibitors , Dihydropyridines/chemistry , Dihydropyridines/pharmacology , Structure-Activity RelationshipABSTRACT
Pyruvate kinase (PK) activators have potential therapeutic applications in diseases such as sickle cell anemia. In this study, N-Substituted sulfonamide derivatives of 1,4-dihydropyridines were synthesized and evaluated as PK activators in vitro and using molecular docking studies. The compounds were synthesized by reacting dicarbonyl compounds with ammonium acetate, 5-nitrobenzaldehyde, and alumina sulfuric acid (ASA), followed by reduction and sulfonylation. The structures of the compounds were analyzed using spectroscopic techniques. DFT calculations provided insights into the electronic properties. Molecular docking of the compounds into the active site of PK showed favorable binding interactions. ADME evaluation indicated suitable solubility, BBB permeation, and lack of CYP450 inhibition. Overall, this study demonstrates the potential of new hybrid 1,4-dihydropyridine substituted sulfonamides as PK activators for further development. According to AC50 values, the compound (DTSF7, 0.97µM) is about 100-fold higher affective than the clinically used sulfonamide compound (AC50 = 90µM) for PK.
Subject(s)
Molecular Docking Simulation , Pyruvate Kinase , Sulfonamides , Sulfonamides/chemistry , Sulfonamides/pharmacology , Sulfonamides/chemical synthesis , Animals , Rabbits , Pyruvate Kinase/metabolism , Pyruvate Kinase/chemistry , Muscles/drug effects , Muscles/enzymology , Muscles/metabolism , Enzyme Activators/pharmacology , Enzyme Activators/chemistry , Enzyme Activators/chemical synthesis , Catalytic Domain , Structure-Activity RelationshipABSTRACT
This paper describes the in vitro inhibition potential of bisoxadiazole-substituted sulfonamide derivatives (6a-t) against bovine carbonic anhydrase (bCA) after they were designed through computational analyses and evaluated the predicted interaction via molecular docking. First, in silico ADMET predictions and physicochemical property analysis of the compounds provided insights into solubility and permeability, then density functional theory (DFT) calculations were performed to analyse their ionization energies, nucleophilicity, in vitro electron affinity, dipole moments and molecular interactions under vacuum and dimethyl sulfoxide (DMSO) conditions. After calculating the theoretical inhibition constants, IC50 values determined from enzymatic inhibition were found between 12.93 and 45.77 µM. Molecular docking evaluation revealed favorable hydrogen bonding and π-interactions of the compounds within the bCA active site. The experimentally most active compound, 6p, exhibited the strongest inhibitory activity with a theoretical inhibition constant value of 9.41 nM and H-bonds with Gln91, Thr198, and Trp4 residues and His63 Pi-cation interactions with His63 residues. Overall, the study reveals promising bCA blocking potential for the synthesized derivatives, similar to acetazolamide.
Subject(s)
Carbonic Anhydrase Inhibitors , Molecular Docking Simulation , Oxadiazoles , Sulfonamides , Cattle , Carbonic Anhydrase Inhibitors/chemistry , Carbonic Anhydrase Inhibitors/chemical synthesis , Carbonic Anhydrase Inhibitors/pharmacology , Animals , Sulfonamides/chemistry , Sulfonamides/pharmacology , Sulfonamides/chemical synthesis , Oxadiazoles/chemistry , Oxadiazoles/chemical synthesis , Oxadiazoles/pharmacology , Carbonic Anhydrases/chemistry , Carbonic Anhydrases/metabolism , Hydrogen Bonding , Structure-Activity Relationship , Catalytic DomainABSTRACT
BACKGROUND: Total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI), nitric oxide (NO), zinc (Zn), copper (Cu) levels, paraoxonase (PON1), arylesterase (ARES) activities, and biochemical changes were studied on sheep with cystic echinococcosis. METHODS: The materials were taken from 2-3 yr old sheep slaughtered in Van Province, Turkey in 2017. Before the slaughter, blood samples were collected from the healthy sheep, while various organs of animals were examined for hydatid cysts after the slaughter. Thirty sheep were protoscolex positive, hydatic group, while 30 sheep that did not have any pathological lesions in organ examinations were accepted as the control group. TOS levels, PON1 and ARES activities, and Zn levels were determined by commercial kits, while Cu levels were determined by atomic absorption spectrophotometer. The collected data were then statistically analyzed. RESULTS: Serum TOS and OSI levels were significantly higher in sheep with cystic echinococcosis compared to the control group (P<0.001). TAS levels (P<0.01), PON1 and ARES activities, on the other hand, were significantly higher in control group compared to the cystic echinococcosis group (P<0.001). There were no significant differences in Zn, NO and Cu levels between the groups. CONCLUSION: PON1 and ARES activities increased in sheep infected with cyst hydatid. The decline of antioxidant reserves in the metabolism results in excessive amounts of free radicals, along with alterations of the normal histological structure of the cystic organ and changes in trace element metabolism.
ABSTRACT
Xanthine Oxidase (XO) is related with different diseases such as vascular, gout, nephropathy and renal stone diseases that are relevant to high uric acid levels and oxidative stress. Some common natural inhibitors of xanthine oxidase are known as rosmarinic acid and apigenin. With this study, we aimed to determine inhibitory effects of originally synthesized new generation transition metal vanadates on Xanthine Oxidase (XO) from bovine milk. Because, Xanthine oxidase inhibitors are typically used in the treatment of gout and nephropathy and renal stone diseases linked to hyperuricaemia. We found considerable IC50 constants for inhibition of XO. Among the synthesized compounds, CuâVâO was found to be the most active (IC50 = 7.119 mM) for inhibition of XO.
Subject(s)
Enzyme Inhibitors/pharmacology , Transition Elements/pharmacology , Vanadates/pharmacology , Xanthine Oxidase/antagonists & inhibitors , Inhibitory Concentration 50ABSTRACT
Human serum paraoxonase 1 (PON1, EC 3.1.1.2) is a high density lipoprotein (HDL)-associated antioxidant enzyme that not only decreases oxidative stress, but it is also implicated in development of many cancers. Genetic information provides a means of identifying people who have an increased risk of cancer, thus this knowledge of cancer genetics helps to identify the ability to characterize malignancies leading to the development of new therapeutic approaches. Because of this reason, in this preliminary study we aimed to investigate the role of human serum PON1 enzyme activity and phenotypic distribution in 32 breast cancer (BC) patients (age range 28-82) and 35 cancer free (CF) control group (age range 21-67). PON1 enzyme was prepared from the serum pool of BC patients using hydrophobic interaction chromatography on L-tyrosine-9-aminophenanthrene-coupled Sepharose 4Bgel. The PON1 enzyme activity towards paraoxon substrate was quantified spectrophotometrically. The basal activity of PON1 was statistically decreased in cancer cases compared to the control group. In addition, individuals were classified according to phenotyping of human PON1 Q and R types. In the cohort of BC patients, an increase in the frequency of the PON homozygote Q (AA) genotype was observed (31% in the BC group versus 14% in the CF controls). The frequency of the PON heterozygote QR (AB) genotype was 34.5% in the patients with BC and 37% in the CF group. The same trend was observed in PON homozygote R (BB) genotype frequency (BC cases 34.5% versus controls 49%). We determined that the kinetic parameters of the purified enzyme by Lineweaver-Burk method. We obtained Km and Vmax values of 0.227 mM and 62 U/mL min for the BC enzyme, compared with 0.775 mM and 206 U/mL min for the CF control enzyme. As a conclusion, it is clear from our results that while the PON1 AA allele frequency in BC cases is much higher, that of BB allele is much lower, in comparison with the control group. The most significant finding of this study is AA allele activity which is low in BC cases was found high. We concluded that decreased AA allele PON1 activity might have a relation with BC.
Subject(s)
Aryldialkylphosphatase/metabolism , Breast Neoplasms/genetics , Genetic Predisposition to Disease , Adult , Aged , Aged, 80 and over , Aryldialkylphosphatase/genetics , Aryldialkylphosphatase/isolation & purification , Breast Neoplasms/enzymology , Female , Heterozygote , Humans , Middle AgedABSTRACT
In this study, a new affinity gel for the purification of bovine testicular hyaluronidase (BTH) was synthesized. L-Tyrosine was added as the extension arm to the Sepharose-4B activated with cyanogen bromide. m-Anisidine is a specific inhibitor of BTH enzyme. m-Anisidine was clamped to the newly formed Sepharose-4B-L-tyrosine as a ligand. As a result, an affinity gel having the chemical structure of Sepharose-4B-L-tyrosine-m-anisidine was obtained. BTH purified by ammonium sulfate precipitation and affinity chromatography was obtained with a 16.95% yield and 881.78 degree of purity. The kinetic constants K(M) and V(Max) for BTH were determined by using hyaluronic acid as a substrate. K(M) and V(Max) values obtained from the Lineweaver-Burk graph were found to be 2.23 mM and 19.85 U/mL, respectively. In vitro effects of some chemicals were determined on purified BTH enzyme. Some chemically active ingredients were 1,1-dimethyl piperidinium chloride, ß-naphthoxyacetic acid and gibberellic acid. Gibberellic acid showed the best inhibition effect on BTH.
Subject(s)
Chromatography, Affinity/methods , Hyaluronoglucosaminidase/isolation & purification , Testis/enzymology , Animals , Cattle , Electrophoresis, Polyacrylamide Gel , Hyaluronoglucosaminidase/drug effects , MaleABSTRACT
In this preliminary study, a new series of some cerium vanadate derivatives have been investigated as new type of inhibitors of xanthine oxidase (XO; E.C 1.17.3.2). XO is a superoxide-producing enzyme found normally in serum and the lungs, and its activity is concerned with several important health problems such as gout, severe liver damage, vascular dysfunction and injury, oxidative eye injury and renal failure. In this study, we present a critical overview of the effects of these novel type agents on XO with comparing the efficacy and safety profiles of allopurinol, the efficient classical inhibitor of XO.
Subject(s)
Enzyme Inhibitors/pharmacology , Vanadates/pharmacology , Xanthine Oxidase/antagonists & inhibitors , Allopurinol/adverse effects , Allopurinol/pharmacology , Animals , Calcium/chemistry , Enzyme Inhibitors/chemistry , In Vitro Techniques , Kinetics , Magnesium/chemistry , Milk/enzymology , Vanadates/chemistry , X-Ray DiffractionABSTRACT
A new series of tetrazole-, oxadiazole- and cyanosubstituted 1,4-dihydropyrimidinone compounds were synthesized, and their inhibitory effects on the activity of purified human carbonic anhydrase (hCA) I were evaluated. 4-Cyanophenyl-1,4-dihydropyrimidinone compounds were prepared with 1,3-diketone, cyanobenzaldehyde and urea. The compounds were reacted with sodium azide and then with anhydride to get the final products. The results showed that all the synthesized compounds inhibited the CA isoenzyme activity. The compound 4-(1,7,7-trimethyl-2,5-dioxo-1,2,3,4,5,6,7,8-octahydroquinazoline-4-yl)benzonitrile 6c (IC50 = 0.0547 mM) has the most inhibitory effect.