Inhibition Of Α-chymotrypsin Research Articles

An Efficient Synthesis of N'',N'''-Bis[(E)-phenylmethylidene]carbonic Dihydrazide Derivatives and Their Evaluation as α-Chymotrypsin Inhibitors

N'',N'''-Bis[(E)-phenylmethylidene]carbonic dihydrazide, azotic ligands with lone electron pairs, have wide range of applications in catalysis, medicine, corrosion, and analytical chemistry. Keeping this broad range of applications in view, we have developed a new green method for the rapid synthesis of N'',N'''-Bis[(E)-phenylmethylidene]carbonic dihydrazide and its derivatives. By using a new protocol, a range of carbonic dihydrazides 1-22 has been synthesized in excellent yields. All synthesized compounds have been characterized by elemental analyses, 1H-NMR, EI-MS and HR-MS. These carbonic dihydrazides have also been synthesized via conventional method. On comparisons of new and conventional methods, it is evident that newly developed solvent-free method is more proficient, high yielding, and simple. As protease inhibitors are known to inhibit not only proliferation of cancer cell lines but also to cure hepatitis C virus and HIV aids infections, therefore, all purified and characterized compounds have also been evaluated for their potential to act as in vitro α-chymotrypsin (an enzyme belongs to protease family) inhibitors. Among tested compounds, ten compounds have shown varying degree of α-chymotrypsin inhibition potential.

Identification, Characterization, and Synthesis of Natural Parasitic Cysteine Protease Inhibitors: Pentacitidins Are More Potent Falcitidin Analogues.

Protease inhibitors represent a promising therapeutic option for the treatment of parasitic diseases such as malaria and human African trypanosomiasis. Falcitidin was the first member of a new class of inhibitors of falcipain-2, a cysteine protease of the malaria parasite Plasmodium falciparum. Using a metabolomics dataset of 25 Chitinophaga strains for molecular networking enabled identification of over 30 natural analogues of falcitidin. Based on MS/MS spectra, they vary in their amino acid chain length, sequence, acyl residue, and C-terminal functionalization; therefore, they were grouped into the four falcitidin peptide families A-D. The isolation, characterization, and absolute structure elucidation of two falcitidin-related pentapeptide aldehyde analogues by extensive MS/MS spectrometry and NMR spectroscopy in combination with advanced Marfey's analysis was in agreement with the in silico analysis of the corresponding biosynthetic gene cluster. Total synthesis of chosen pentapeptide analogues followed by in vitro testing against a panel of proteases revealed selective parasitic cysteine protease inhibition and, additionally, low-micromolar inhibition of α-chymotrypsin. The pentapeptides investigated here showed superior inhibitory activity compared to falcitidin.

Comparing Nutritional Quality, Antioxidant, and Antiulcer Activity of Two Amaranthaceae Plants: Achyranthes aspera and Amaranthus spinosus

Achyranthes aspera and Amaranthus spinosus are species of medicinal plants from the Amaranthaceae family, used to treat wounds, asthma, malaria, gonorrhea, burns, and diabetes. In this study, the nutritional value and phytochemical constituents in A. aspera and A. spinosus were determined using inductively coupled plasma-optical emission spectrometry and column chromatography, respectively. The antiulcer activity was determined using the α-chymotrypsin assay while the antioxidant activity was evaluated using the 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reducing antioxidant power, and phosphomolybdate assay. The results showed leaves of A. spinosus to contribute between 43.4% and 97.8% toward the recommended dietary allowance for iron; therefore, it is recommended for consumption by patients suffering from chronic anemia. Arsenic, cadmium, and lead were not detected in the leaves of the two species giving credence to their use as nutraceuticals in South Africa while the concentration of cobalt, nickel, and selenium were below the detection limit of the instrument. The phytochemical analysis resulted in the isolation of oleanolic acid, lutein, pheophytin a, and chondrillasterol glucoside. The antioxidant activity was high for lutein, ethyl acetate extract from A. aspera, chondrillasterol glucoside, and the methanol extract from A. spinosus, relative to the control. The antiulcer activity using the α-chymotrypsin inhibition assay showed lutein to have maximum chymotrypsin inhibitory activity. Findings from this study show lutein, pheophytin a, chondrillasterol, and its derivatives to serve as potential taxonomic markers for species in the Amaranthaceae family.

Roles of Edges and Surfaces of Graphene Oxide in Molecular Recognition of Proteins: Implications for Enzymatic Inhibition of α-Chymotrypsin

Many biomedical applications of graphene oxide (GO) rely on GO-biomolecular interactions. These interactions can be tuned in two ways: (1) by controlling surface/edge ratio via tuning the lateral s...

Inhibition of α-chymotrypsin by pristine single-wall carbon nanotubes: Clogging up the active site

The preferred spatial orientation of single-wall carbon nanotubes (SWCNTs) in their interaction with enzymes determines their behavior either as nano-supports or as inhibitors. α -chymotrypsin (α-CT) is considered a serine protease model for studying nanomaterial/proteases interactions. The interaction of α-CT with pristine single-wall carbon nanotubes is still unknown. Here α-CT/SWCNT hybrids are synthesized and characterized. Spectroscopic, microscopic and kinetic measurements, coupled to molecular dynamics simulations, provide a detailed description of the interaction between α-CT and SWCNTs. The SWCNT binding pocket was unambiguously identified. A perfect match is observed with the crevice structure of the α-CT substrate binding pocket. The activity of α-CT, upon SWCNT binding, is dramatically reduced, as expected by the interaction of the SWCNT in the active site of the protein. π-π stacking between aromatic residues and the conjugated surface of SWCNT governs α-CT/SWCNT interactions. An important role in the bonding appears also for purely hydrophobic residues and with residues able to establish surfactant-like interactions. The secondary structure of α-CT and the catalytic triad structure are not perturbed by the complex formation, on the contrary the volume of the substrate binding pocket is strongly reduced by SWCNT binding because SWCNT occupies the α-CT substrate binding site, clogging the active site.

Divergent Protein Synthesis of Bowman–Birk Protease Inhibitors, their Hydrodynamic Behavior and Co-crystallization with α-Chymotrypsin

A divergent protein synthesis strategy was executed to effectively synthesize Bowman–Birk protease inhibitor (BBI) analogues using native chemical ligation of peptide hydrazides. Grafting selected residues from a potent trypsin inhibitor, sunflower trypsin inhibitor-1, onto the α-chymotrypsin-binding loop of BBI, resulted in a fourfold improvement of α-chymotrypsin inhibition. The crystal structure of a synthetic BBI analogue co-crystallized with α-chymotrypsin confirmed the correct protein fold and showed a similar overall structure to unmodified BBI in complex with α-chymotrypsin. Dynamic light scattering showed that C-terminal truncation of BBI led to increased self-association.

Synthesis, structure-activity relationships studies of benzoxazinone derivatives as α-chymotrypsin inhibitors

A series of benzoxazinones 1–28 were synthesized via reaction of anthranilic acid with various substituted benzoyl chlorides in the presence of triethylamine in chloroform. Compounds 1–18 showed a good inhibition of α-chymotrypsin with IC50±SEM values between 6.5 and 341.1μM. Preliminary structure-activity relationships studies indicated that the presence of substituents on benzene ring reduces the inhibitory potential of benzoxazinone. Also the increased inhibitory potential due to fluoro group at phenyl substituent was observed followed by chloro and bromo substituents. Compounds with strong electron donating or withdrawing groups on phenyl substituent, showed a good inhibitory potential at ortho>meta>para position. Kinetics studies showed diverse types of inhibition, except uncompetitive-type inhibition. The Ki values ranged between 4.7 and 341.2μM. Interestingly, most of these compounds were non-cytotoxic to 3T3 cell line at 30μM, except compounds 6, 14 and 15. Competitive inhibitors of chymotrypsin are like to inhibit other α-chymotrypsin-like serine proteases due to structural and functional similarities between them. The inhibitors identified during the current study deserve to be further studied for their therapeutic potential against abnormalities mediated by chymotrypsin or other serine protease.

Electrostatics-mediated α-chymotrypsin inhibition by functionalized single-walled carbon nanotubes.

The α-chymotrypsin (α-ChT) enzyme is extensively used for studying nanomaterial-induced enzymatic activity inhibition. A recent experimental study reported that carboxylized carbon nanotubes (CNTs) played an important role in regulating the α-ChT activity. In this study, parallel tempering Monte Carlo and molecular dynamics simulations were combined to elucidate the interactions between α-ChT and CNTs in relation to the CNT functional group density. The simulation results indicate that the adsorption and the driving force of α-ChT on different CNTs are contingent on the carboxyl density. Meanwhile, minor secondary structural changes are observed in adsorption processes. It is revealed that α-ChT interacts with pristine CNTs through hydrophobic forces and exhibits a non-competitive characteristic with the active site facing towards the solution; while it binds to carboxylized CNTs with the active pocket through a dominant electrostatic association, which causes enzymatic activity inhibition in a competitive-like mode. These findings are in line with experimental results, and well interpret the activity inhibition of α-ChT at the molecular level. Moreover, this study would shed light on the detailed mechanism of specific recognition and regulation of α-ChT by other functionalized nanomaterials.

<i>In vitro</i> Studies on Anti-diabetic and Anti-ulcer Potentials of <i>Jatropha gossypifolia</i> (Euphorbiaceae)

Purpose: To evaluate α-glucosidase and α-chymotrypsin enzyme inhibitory activity of Jatropha gossypifolia as a probable remedy for the management of diabetes and ulcer.Methods: Different extracts and fractions of the root, leaf and stem bark of the plant were screened for their α-glucosidase and α-chymotrypsin inhibitory activity using standard in vitro inhibition assays. Acarbose and chymostatin were used as positive control, respectively.Results: n-Butanol and ethyl acetate fraction showed maximum enzyme inhibition for α-glucosidase with 67.93 ± 0.66 and 67.67 ± 0.71 % and half maximal concentration (IC50) of 218.47 ± 0.23 and 213.45 ± 0.12 μg/ml, respectively. Dichloromethane and ethyl acetate leaf fractions exhibited maximum α-chymotrypsin inhibition activity of 85.08 ± 0.38 and 83.87 ± 0.70 %, and IC50 of 133.1 ± 0.68 and 134.5 ± 0.12 μg/ml, respectively, Acarbose exhibited enzyme inhibition activity of 92.14 ± 0.38 % with IC50 of 38.24 ± 0.1 μg/ml, while chymostatin exhibited 93.67 ± 0.38 % enzyme inhibition and IC50 of 8.24 ± 0.11 μg/ml.Conclusion: The presence of bioactive secondary metabolities with enzyme-inhibiting activity lends some support for the traditional use of this plant in the management of diabetes and ulcer. However, further investigation of the plant including identification of its active components is required.Keywords: α-Chymotrypsin, α-Glucosidase, Inhibition, Jatropha gossypifolia, Anti-diabetic, Anti-ulcer

A mechanistic study on the inhibition of α-chymotrypsin by a macrocyclic peptidomimetic aldehyde.

Here we describe an NMR and X-ray crystallography-based characterisation of the mechanism by which a new class of macrocyclic peptidomimetic aldehyde inhibits α-chymotrypsin. In particular, a (13)C-labelled analogue of the inhibitor was prepared and used in NMR experiments to confirm formation of a hemiacetal intermediate on binding with α-chymotrypsin. Analysis of an X-ray crystallographic structure in complex with α-chymotrypsin reveals that the backbone adopts a stable β-strand conformation as per its design. Binding is further stabilised by interaction with the oxyanion hole near the S1 subsite and multiple hydrogen bonds.

Biosensor for Aluminum(III) Based on α-Chymotrypsin Inhibition using a Disposable Screen-Printed Carbon Electrode and Acetyl-Tyrosine Ethyl Ester as Substrate

We report on a new amperometric assay for Al(III) ions based on the inhibition of α-chymotrypsin enzyme. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles and polyvinyl alcohol. N-acetyl-tyrosine ethyl ester, used as enzyme substrate, produces an oxidation amperometric signal, which at increasing aluminum concentration is diminished. The developed system has a detection limit of 1.5 ± 0.1 μM (n=7) for Al(III). The reproducibility of the method is 6.6% (n=5) and its repeatability is 8.2% (n=3). Main interferences at low concentration, include As(V), Cd(II), and Mo(VI) ions. The developed method was successfully applied to the determination of Al(III) in spiked white wine sample. Results agree with the certified value giving a value of percent recovery of 103 ± 4% (n=4).

Hydrolytic inhibition of α-chymotrypsin by 2,8,14,20-tetrakis(d-leucyl-d-valinamido)resorc[4]arenecarboxylic acid: a spectroscopic NMR and computational combined approach

The stereochemical features of 2,8,14,20-tetrakis(D-leucyl-D-valinamido)resorc[4]arenecarboxylic acid and the N-succinyl-L-alanyl-L-alanyl-L-prolyl-L-phenylalanine-4-nitroanilide polypeptide substrate were investigated by nuclear magnetic resonance spectroscopy. Proton selective relaxation parameters gave the basis for the inhibitory activity of resorcin[4]arene in the hydrolysis of the polypeptide substrate by α-chymotrypsin. Results showed that an interaction between the resorcin[4]arene and α-chymotrypsin does occur, and involves the hydrophobic moiety of the macrocycle. This interaction is further reinforced by polar groups located on the side chains of the resorcin[4]arene, whereas the macrocycle-polypeptide substrate interaction is negligible. Conformational analysis and interaction studies carried out by molecular modeling are in good agreement with the NMR data, thus providing an additional support to the rationalization of the inhibitory potential of resorcin[4]arenes on the α-chymotrypsin activity.

Unsymmetrical 1,3-disubstituted urea derivatives as α-chymotrypsin inhibitors

The objective of this study was to synthesize potent and/or novel inhibitors for α-chymotrypsin activity. Eighteen derivatives of N-methylphenyl-N′-(alkyl/aryl) urea (1–18) were synthesized, and their inhibitory effects on α-chymotrypsin enzyme were evaluated. Two compounds exhibited potent inhibitory activities. The most potent, N-(2-methylphenyl)-2-oxo-1-pyrrolidinecarboxamide (15) having a methyl group at ortho position was the most active inhibitor with an IC50 value of 8.10 ± 0.14 μM, which was comparable to standard chymostatin (IC50 = 8.24 ± 0.11 μM). A slightly less potent, N-(2-acetylphenyl)-N′-(3-methylphenyl) urea (10), exhibited an IC50 of 13.6 ± 0.23 μM. Compounds 3, 4, 7, 11, and 13 exhibited moderate activities. The results demonstrated that α-chymotrypsin inhibition is related to the position of the methyl group and the presence of substituent at the nitrogen of the urea bridge. The inhibitory trend suggests that α-chymotrypsin inhibitory activity declines with ortho > meta > para substitution order. In conclusion, our data suggest that the compound 15 may serve as a lead compound for further designing of other potent or novel α-chymotrypsin inhibitors.

Urease and α-chymotrypsin inhibitory activities of transition metal complexes of new Schiff base ligand: Kinetic and thermodynamic studies of the synthesized complexes using TG–DTA pyrolysis

The Schiff base 2-[(E)-(quinolin-3-ylimino)methyl]phenol (H-QMP) was crystallized in Pc space group and complexed with Ni(II) and Co(II) in [M(QMP)2] and Cu(II) and Zn(II) in [M(QMP)(CH3COO)]H2O compositions. Elemental analyses, mass spectrometry, IR, UV–vis spectroscopy, conductance study and magnetic susceptibilities were used to characterize the complexes. The thermograms obtained in the range of 30–1000°C were used for kinetic and thermodynamic calculations. The activation energies and order of pyrolysis were calculated using Horowitz–Metzger method. The calculated activation energies were subsequently used for the calculations of thermodynamic parameters including ΔS*, ΔH* and ΔG*. It was found that the thermal stability and activation energy follow the order Cu(II)>Ni(II)>Co(II)>Zn(II) and ENi*>ECu*>ECo*>EZn*, respectively. All the compounds were also studied for their urease and α-chymotrypsin inhibition, showing medium to moderate activities for both the enzymes except nickel complex. Nickel complex shows IC50=9.9±0.124μM±SEM, and the activity was rationalized by carrying out molecular modeling studies.

Anticancer and α-chymotrypsin inhibiting diterpenes and triterpenes from Salvia leriifolia

Salvialeriol (1), a new abietane-type diterpene, was isolated from Salvia leriifolia Benth. (Salvia leriaefolia), along with two known abietane-type diterpenoids, 6-hydroxysalvinolone (2) and deacetylnemorone (3), and two known triterpenes, 2-acetoxylupeol (4), and lupine-2,3-diol (5). Compounds 2–5 are reported here for the first time from this species. Compound 4 was previously reported as a synthetic derivative of 5 and this is the first report of its isolation from a natural source. Compounds 2, 3 and 5 exhibited a potent antiproliferative activity against the prostate cancer cell lines (PC3) with IC50 of 3.9±0.1, 6.2±0.1 and 2.8±0.1μM, respectively, and cervical cancer cell lines (HeLa) with IC50 of 8.0±0.3, 2.6±0.1 and 2.7±0.1μM, respectively. Whereas compounds 1 and 4 showed moderate antiproliferative activities against the cell lines. Compounds 1–5 were also evaluated for the inhibition of α-chymotrypsin, a protease enzyme, and 2 exhibited a competitive inhibition of the enzyme (IC50=188.8μM).

Biosensor for aluminium(III) based on its inhibition of α-chymotrypsin immobilized on a screen-printed carbon electrode modified with gold nanoparticles

We report on an amperometric assay for Al(III) ions that is based on the inhibition of the enzyme α-chymotrypsin. Screen-printed carbon electrodes modified with gold nanoparticles were used as solid supports for the immobilization of the enzyme. The amperometric response of the synthetic enzyme substrate substrate N-benzoyl-L-tyrosine ethyl ester is affected by Al(III) ions, and this leads to a decrease in the amperometric oxidation current. The assay has a detection limit of 3.3 μM of Al(III). The repeatability and reproducibility of the method are 6.9% (n = 3) and 6.4% (n = 5), respectively. Main interferents include Mo(VI), W(VI) and Fe(III) ions. The method was successfully applied to the determination of Al(III) in tap water.

Inhibition of alpha-chymotrypsin by 5-substituted -3-phenyl-2-thioxo-4-imidazolidinones and derivatives.

Journal Article Inhibition of α-chymotrypsin by 5-substituted -3-phenyl-2-thioxo-4-imidazolidinones and derivatives Get access Layla A Mammo, Layla A Mammo The Welsh School of Pharmacy, University of Wales Institute of Science & Technology, Cathays Park, Cardiff, U.K. Search for other works by this author on: Oxford Academic Google Scholar Al K Faden, Al K Faden The Welsh School of Pharmacy, University of Wales Institute of Science & Technology, Cathays Park, Cardiff, U.K. Search for other works by this author on: Oxford Academic Google Scholar H J Smith, H J Smith The Welsh School of Pharmacy, University of Wales Institute of Science & Technology, Cathays Park, Cardiff, U.K. Search for other works by this author on: Oxford Academic Google Scholar R D E Sewell R D E Sewell The Welsh School of Pharmacy, University of Wales Institute of Science & Technology, Cathays Park, Cardiff, U.K. Search for other works by this author on: Oxford Academic Google Scholar Journal of Pharmacy and Pharmacology, Volume 34, Issue 11, November 1982, Pages 752–754, https://doi.org/10.1111/j.2042-7158.1982.tb06219.x Published: 12 April 2011 Article history Received: 15 February 1982 Published: 12 April 2011

Fluorinated β²- and β³-Amino Acids: Synthesis and Inhibition of α-Chymotrypsin

Victoria Peddie, Markus Pietsch, Karen M. Bromfield, Robert N. Pike, Peter J. Duggan, Andrew D. Abell

Urease and α-Chymotrypsin Inhibitory Effects of Selected Urea Derivatives

A number of urea derivatives were synthesized and screened for their urease and α-chymotrypsin inhibition effects, whereby one of the compounds, N-4-nitrophenyl-N’-4’-nitrophenylurea (3), showed strong urease inhibition (IC50 = 1.25μM). We found that the same compound is also an efficient α-chymotrypsin inhibitor having an IC50 value of 3.15μM.

Kinetics study on a novel natural inhibitor of α-chymotrypsin

The mechanism of inhibition of alpha-chymotrypsin by benzoylsalireposide (1), a phenolic glycoside isolated from Symplocos racemosa, was investigated. Lineweaver-Burk and Dixon plots and their secondary replots showed that 1 was a non-competitive inhibitor of this enzyme with the Ki value of 29.60 microM.