Novel propanolamine derivatives attached to 2-metoxifenol moiety: Synthesis, characterization, biological properties, and molecular docking studies

Novel hydrazones derived from anthranilic acid as potent cholinesterases and α-glycosidase inhibitors: Synthesis, characterization, and biological effects

N-substitued anthranilic acid derivatives are commonly found in the structure of many biologically active molecules. In this study, new members of hydrazones derived from anthranilic acid (1-15) were synthesized and investigated their effect on some metabolic enzymes such as acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase (α-Gly). Results indicated that all the molecules exhibited potent inhibitory effects against all targets as compared to the standard inhibitors, revealed by IC50 values. Ki values of compounds for AChE, BChE, and α-Gly enzymes were obtained in the ranges 66.36 ± 8.30-153.82 ± 13.41, 52.68 ± 6.38-113.86, and 2.13 ± 0.25-2.84 nM, respectively. The molecular docking study was performed for the most active compounds to the determination of ligand-enzyme interactions. Binding affinities of the most active compound were found at the range of -9.70 to -9.00 kcal/mol for AChE, -11.60 to -10.60 kcal/mol for BChE, and -10.30 to -9.30 kcal/mol for α-Gly. Molecular docking simulations showed that the novel compounds had preferential interaction with AChE, BChE, and α-Gly. Drug-likeness properties and ADMET (absorption, distribution, metabolism, excretion, and toxicity) analyzes of all synthesized compounds (1-15) were estimated and their toxic properties were evaluated as well as their therapeutic properties. Moreover, molecular dynamics simulations were carried out to understand the accuracy of the most potent derivatives of docking studies.

Potential antioxidant, anticholinergic, antidiabetic and antiglaucoma activities and molecular docking of spiraeoside as a secondary metabolite of onion (Allium cepa)

Onion contains many dietary and bioactive components including phenolics and flavonoids. Spiraeoside (quercetin-4-O-β-D-glucoside) is one of the most putative flavonoids in onion. Several antioxidant techniques were used in this investigation to assess the antioxidant capabilities of spiraeoside, including 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging, N,N-dimethyl-p-phenylenediamine radical (DMPD•+) scavenging, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS•+) scavenging activities, cupric ions (Cu2+) reducing and potassium ferric cyanide reduction abilities. In contrast, the water-soluble α-tocopherol analogue trolox and the conventional antioxidants butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and α-tocopherol were utilized as the standards for evaluation. Spiraeoside scavenged the DPPH radicals an IC50 of 28.51 μg/mL (r2: 0.9705) meanwhile BHA, BHT, trolox, and α-tocopherol displayed IC50 of 10.10 μg/mL (r2: 0.9015), 25.95 μg/mL (r2: 0.9221), 7.059 μg/mL (r2: 0.9614) and 11.31 μg/mL (r2: 0.9642), accordingly. The results exhibited that spiraeoside had effects similar to BHT, but less potent than α-tocopherol, trolox and BHA. Also, inhibitory effects of spiraeoside were evaluated toward some metabolic enzymes including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase II (CA II) and α-glycosidase, which are related to a number of illnesses, such as Alzheimer's disease (AD), diabetes mellitus and glaucoma disorder. Spiraeoside exhibited IC50 values of 4.44 nM (r2: 0.9610), 7.88 nM (r2: 0.9784), 19.42 nM (r2: 0.9673) and 29.17 mM (r2: 0.9209), respectively against these enzymes. Enzyme inhibition abilities were compared to clinical used inhibitors including acetazolamide (for CA II), tacrine (for AChE and BChE) and acarbose (for α-glycosidase). Spiraeoside demonstrated effective antioxidant, anticholinergic, antidiabetic and antiglaucoma activities. With these properties, it has shown that Spiraeoside has the potential to be a medicine for some metabolic diseases.

Electrochemical study of 2-amino-5-mercapto-1,3,4-thiadiazole in the absence and presence of p-benzoquinone: an efficient strategy for the electrosynthesis of new 1,3,4-thiadiazole derivatives

In this study, first, the electrochemical behavior of 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) was fully investigated in the absence and presence of electrochemically generated p-benzoquinone (p-BQ, which is the oxidized form of hydroquinone), as an electrophile, via cyclic voltammetry (CV) at a glassy carbon electrode (GCE) and in an acetic acid buffer (0.2 M)/ethanol solution mixture. Then, an E-pH diagram was proposed for different structures of AMT at various pH values. The obtained voltammograms also exhibited an "electron transfer + chemical reaction" (EC) mechanism. Besides the voltammetric exploration, electrosynthesis of new 1,3,4-thiadiazole derivatives was conducted by constant current electrolysis (CCE) as a facile and cost-effective method for the formation of S-S and S-C bonds. Finally, the biological activity of products was also analyzed via an in silico method.

Antioxidant, Antidiabetic, Anticholinergic, and Antiglaucoma Effects of Magnofluorine

Magnofluorine, a secondary metabolite commonly found in various plants, has pharmacological potential; however, its antioxidant and enzyme inhibition effects have not been investigated. We investigated the antioxidant potential of Magnofluorine using bioanalytical assays with 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+), N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD^•+), and 1,1-diphenyl-2-picrylhydrazyl (DPPH^•) scavenging abilities and K₃[Fe(CN)₆] and Cu²⁺ reduction abilities. Further, we compared the effects of Magnofluorine and butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-Tocopherol, and Trolox as positive antioxidant controls. According to the analysis results, Magnofluorine removed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals with an IC₅₀ value of 10.58 μg/mL. The IC₅₀ values of BHA, BHT, Trolox, and α-Tocopherol were 10.10 μg/mL, 25.95 μg/mL, 7.059 μg/mL, and 11.31 μg/mL, respectively. Our results indicated that the DPPH· scavenging effect of Magnofluorine was similar to that of BHA, close to that of Trolox, and better than that of BHT and α-tocopherol. The inhibition effect of Magnofluorine was examined against enzymes, such as acetylcholinesterase (AChE), α-glycosidase, butyrylcholinesterase (BChE), and human carbonic anhydrase II (hCA II), which are linked to global disorders, such as diabetes, Alzheimer’s disease (AD), and glaucoma. Magnofluorine inhibited these metabolic enzymes with Ki values of 10.251.94, 5.991.79, 25.411.10, and 30.563.36 nM, respectively. Thus, Magnofluorine, which has been proven to be an antioxidant, antidiabetic, and anticholinergic in our study, can treat glaucoma. In addition, molecular docking was performed to understand the interactions between Magnofluorine and target enzymes BChE (D: 6T9P), hCA II (A:3HS4), AChE (B:4EY7), and α-glycosidase (C:5NN8). The results suggest that Magnofluorine may be an important compound in the transition from natural sources to industrial applications, especially new drugs.

Screening of Carbonic Anhydrase, Acetylcholinesterase, Butyrylcholinesterase, and α-Glycosidase Enzyme Inhibition Effects and Antioxidant Activity of Coumestrol

Coumestrol (3,9-dihydroxy-6-benzofuran [3,2-c] chromenone) as a phytoestrogen and polyphenolic compound is a member of the Coumestans family and is quite common in plants. In this study, antiglaucoma, antidiabetic, anticholinergic, and antioxidant effects of Coumestrol were evaluated and compared with standards. To determine the antioxidant activity of coumestrol, several methods—namely N,N-dimethyl-p-phenylenediamine dihydrochloride radical (DMPD^•+)-scavenging activity, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS^•+)-scavenging activity, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^•)-scavenging activity, potassium ferric cyanide reduction ability, and cupric ion (Cu²⁺)-reducing activity—were performed. Butylated hydroxyanisole (BHA), Trolox, α-Tocopherol, and butylated hydroxytoluene (BHT) were used as the reference antioxidants for comparison. Coumestrol scavenged the DPPH radical with an IC₅₀ value of 25.95 μg/mL (r²: 0.9005) while BHA, BHT, Trolox, and α-Tocopherol demonstrated IC₅₀ values of 10.10, 25.95, 7.059, and 11.31 μg/mL, respectively. When these results evaluated, Coumestrol had similar DPPH^•-scavenging effect to BHT and lower better than Trolox, BHA and α-tocopherol. In addition, the inhibition effects of Coumestrol were tested against the metabolic enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase II (CA II), and α-glycosidase, which are associated with some global diseases such as Alzheimer’s disease (AD), glaucoma, and diabetes. Coumestrol exhibited K_i values of 10.25 ± 1.94, 5.99 ± 1.79, 25.41 ± 1.10, and 30.56 ± 3.36 nM towards these enzymes, respectively.

Enzyme Inhibition Properties and Molecular Docking Studies of 4-Sulfonate Containing Aryl α-Hydroxyphosphonates Based Hybrid Molecules

In this study, a series of new hybrid molecules containing two important functional groups on the same skeleton were designed. 4-Hydroxybenzaldehyde and its two different derivatives were converted into their respective sulphonates by interacting with tosylchloride and methanesulfonyl chloride. Then, the desired molecules were synthesized by adding diethoxyphosphonate to the aldehyde group. Also, novel synthesis of hybrid compounds (4a-c and 5a-c) were tested toward some metabolic enzymes like carbonic anhydrase I and II isoenzymes (hCA I and hCA II) and acetylcholinesterase (AChE) enzyme. The synthesis of hybrid compounds (4a-c and 5a-c) showed K_i values of in range of 25.084±4.73-69.853±15.19 nM against hCA I, 32.325±1.67-82.761±22.73 nM against hCA II and 1.699±0.25 and 3.500±0.91 nM against AChE. For these compounds, compound 4c showed maximum inhibition effect against hCA I and hCA II isoenzymes and compound 5b showed maximum inhibition effect against AChE enzyme. By performing docking studies of the most active compounds for their binding modes and interactions were determined.

Novel amino acid Schiff base Zn(II) complexes as new therapeutic approaches in diabetes and Alzheimer's disease: Synthesis, characterization, biological evaluation, and molecular docking studies

Schiff bases are compounds that have gained importance in the paint industry due to their colorful nature and in the field of chemistry and biochemistry due to their biological activities. Various biological applications of Schiff bases, such as antitumor, antifungal, antibacterial, antioxidant, antituberculosis, and anthelmintic, have been widely studied. Within the scope of the study, 5-bromo-2-hydroxybenzaldehyde and amino acid methyl esters (isoleucine, phenylalanine, and methionine) and amino acid Schiff bases were synthesized first. The synthesis of the new Zn(II) complexes of these Schiff bases was carried out by the reaction of synthesized Schiff bases and Zn(OAc)₂ ·2H₂ O. The structures of the synthesized complexes were elucidated using elemental analysis, Fourier transform infrared, nuclear magnetic resonance, UV-visible, and thermal analysis spectroscopy techniques. These synthesized salts were found to be effective inhibitor compounds for the α-glycosidase, and acetylcholinesterase enzyme with Ki values in the range of 30.50 ± 3.82-38.17 ± 6.26 µM for α-glycosidase, 3.68 ± 0.54-10.27 ± 1.68 µM for butyrylcholinesterase, and 6.26 ± 0.83-15.73 ± 4.73 µM for acetylcholinesterase, respectively.

Synthesis and some enzyme inhibition effects of isoxazoline and pyrazoline derivatives including benzonorbornene unit

Four new and four known isoxazoline derivatives were synthesized from the reactions of benzonorbornadiene with nitrile oxides formed from the corresponding benzaldehydes. Three new and one known pyrazoline derivatives were also synthesized from the reactions of the benzonorbornadiene with nitrile imines formed from the corresponding compounds. The synthesized nitrogen-based novel heterocyclic compounds were evaluated against the human carbonic anhydrase isoenzymes I and II (hCA I and hCA II), acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) enzymes. The synthesized nitrogen-based novel heterocyclic compounds showed IC₅₀ values in the range of 2.69-7.01 against hCA I, 2.40-4.59 against hCA II, 0.81-1.32 µM against AChE, and 20.83-1.70 µM against BChE enzymes. On the contrary, nitrogen-based novel heterocyclic compounds demonstrated K_i values between 2.93 ± 0.59-8.61 ± 1.39 against hCA I, 2.05 ± 0.62-4.97 ± 0.95 against hCA II, 0.34 ± 0.02-0.92 ± 0.17 nM against AChE, and 0.50 ± 0.04-1.20 ± 0.16 µM against BChE enzymes. The synthesized nitrogen-based novel heterocyclic compounds exhibited effective inhibition profiles against both indicated metabolic enzymes. These results may contribute to the development of new drugs particularly to treat some disorders, which are widespread in the world including glaucoma and Alzheimer's diseases.

Discovery of sulfadrug-pyrrole conjugates as carbonic anhydrase and acetylcholinesterase inhibitors

Human carbonic anhydrase (hCA) isoenzymes are zinc ion-containing, widespread metalloenzymes and they classically play a role in pH homeostasis maintenance. CA inhibitors suppress the CA activity and their usage has been clinically established as antiglaucoma agents, antiepileptics, diuretics, and in some other disorders. Alzheimer's disease (AD) is a slowly progressive neurodegenerative disorder and a fatal disease of the brain. An advanced method to cure AD includes the strategy to design acetylcholinesterase (AChE) inhibitors. A novel series of pyrrole-3-one derivatives containing sulfa drugs (5a-i) were determined to be highly potent inhibitors for AChE and hCA I and hCA II (inhibitory constant [K_i ] values are in the range of 6.50 ± 1.02-37.46 ± 4.12 nM, 1.20 ± 0.19-44.21 ± 1.09 nM, and 8.93 ± 1.58-46.86 ± 8.41 nM for AChE, hCA I, and hCA II, respectively). The designed compounds often show a more effective inhibition than the chemicals used as the standard. Among these compounds, 5f was the most effective compound against hCA I, and compound 5e was the most effective compound against hCA II. It was determined that compound 5c was the most effective inhibitor for AChE.

Dual targeting of acetylcholinesterase and tau aggregation: Design, synthesis and evaluation of multifunctional deoxyvasicinone analogues for Alzheimer's disease

Development of multitargeted ligands have demonstrated remarkable efficiency as potential therapeutics for Alzheimer's disease (AD). Herein, we reported a new series of deoxyvasicinone analogues as dual inhibitor of acetylcholinesterase (AChE) and tau aggregation that function as multitargeted ligands for AD. All the multitargeted ligands 11(a-j) and 15(a-g) were designed, synthesized, and validated by ¹HNMR, ¹³CNMR and mass spectrometry. All the synthesized compounds 11(a-j) and 15(a-g) were screened for their ability to inhibit AChE, BACE1, amyloid fibrillation, α-syn aggregation, and tau aggregation. All the screened compounds possessed weak inhibition of BACE-1, Aβ₄₂ and α-syn aggregation. However, several compounds were identified as potential hits in the AChE inhibitory screening assay and cellular tau aggregation screening. Among all compounds, 11f remarkably inhibited AChE activity and cellular tau oligomerization at single-dose screening (10 µM). Moreover, 11f displayed a half-maximal inhibitory concentration (IC₅₀) value of 0.91 ± 0.05 µM and half-maximal effective concentration (EC₅₀) value of 3.83 ± 0.51 µM for the inhibition of AChE and cellular tau oligomerization, respectively. In addition, the neuroprotective effect of 11f was determined in tau-expressing SH-SY5Y cells incubated with Aβ oligomers. These findings highlighted the potential of 11f to function as a multifunctional ligand for the development of promising anti-AD drugs.

Tailored Functionalization of Natural Phenols to Improve Biological Activity

Phenols are widespread in nature, being the major components of several plants and essential oils. Natural phenols' anti-microbial, anti-bacterial, anti-oxidant, pharmacological and nutritional properties are, nowadays, well established. Hence, given their peculiar biological role, numerous studies are currently ongoing to overcome their limitations, as well as to enhance their activity. In this review, the functionalization of selected natural phenols is critically examined, mainly highlighting their improved bioactivity after the proper chemical transformations. In particular, functionalization of the most abundant naturally occurring monophenols, diphenols, lipidic phenols, phenolic acids, polyphenols and curcumin derivatives is explored.

Cholinesterases, carbonic anhydrase inhibitory properties and in silico studies of novel substituted benzylamines derived from dihydrochalcones

A series of novel urea, sulfamide and N,N-dipropargyl substituted benzylamines were synthesized from dihydrochalcones. The synthesized compounds were evaluated for their cholinesterases and carbonic anhydrase inhibitory actions. The known dihydrochalcones were converted into four new benzylamines via reductive amination. N,N-Dipropargylamines, ureas and sulfamides were synthesized following the reactions of benzylamines with propargyl bromide, N,N-dimethyl sulfamoyl chloride and N,N-dimethyl carbamoyl chloride. The novel substituted benzylamines derived from dihydrochalcones were evaluated against some enzymes such as human erythrocyte carbonic anhydrase I and II isoenzymes (hCA I and hCA II), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The novel substituted benzylamines derived from dihydrochalcones exhibited K_i values in the range of 0.121-1.007 nM on hCA I, and 0.077-0.487 nM on hCA II closely related to several pathological processes. On the other hand, K_i values were found in the range of 0.112-0.558 nM on AChE, 0.061-0.388 nM on BChE. As a result, novel substituted benzylamines derived from dihydrochalcones showed potent inhibitory profiles against indicated metabolic enzymes. In addition, Induced-Fit Docking (IFD) simulations and ADME prediction studies have also been carried out to elucidate the inhibition mechanisms and drug-likeness of the synthesized compounds. Therefore, these results can make significant contributions to the treatment of some global diseases, especially Alzheimer's diseases and glaucoma, and the development of new drugs.

Inhibition Profiles of Some Symmetric Sulfamides Derived from Phenethylamines on Human Carbonic Anhydrase I, and II Isoenzymes

In this work, the inhibitory effect of some symmetric sulfamides derived from phenethylamines were determined against human carbonic anhydrase (hCA) I, and II isoenzymes, and compared with standard compound acetazolamide. IC₅₀ values were obtained from the Enzyme activity (%)-[Symmetric sulfamides] graphs. Also, K_i values were calculated from the Lineweaver-Burk graphs. Some symmetric sulfamides compounds (11-18) demonstrated excellent inhibition effects against hCA I, and II isoenzymes. These compounds demonstrated effective inhibitory profiles with IC₅₀ values in ranging from 21.66-28.88 nM against hCA I, 14.44-30.13 nM against hCA II. Among these compounds, the best K_i value for hCA I (K_i : 8.34±1.60 nM) and hCA II (K_i : 16.40±1.00 nM) is compound number 11. Besides, the IC₅₀ value of acetazolamide used as a standard was determined as hCA I, hCA II 57.75 nM, 49.50 nM, respectively. Moreover, in silico ADME-Tox study showed that all synthesized compounds (11-18) had good oral bioavailability in light of Jorgensen's rule of three, and of Lipinski's rule of five.

Novel Mannich bases with strong carbonic anhydrases and acetylcholinesterase inhibition effects: 3-(aminomethyl)-6-{3-[4-(trifluoromethyl)phenyl]acryloyl}-2(3H)-benzoxazolones

In this study, a new series of Mannich bases, 3-(aminomethyl)-6-{3-[4-(trifluoromethyl)phenyl]acryloyl}-2( 3H )-benzoxazolones ( 1a-g ), were synthesized by the Mannich reaction. Inhibitory effects of the newly synthesized compounds towards carbonic anhydrases (CAs) and acetylcholinesterase (AChE) enzymes were evaluated to find out new potential drug candidate compounds. According to the inhibitory activity results, Ki values of the compounds 1 and 1a-g were in the range of 12.3 ± 1.2 to 154.0 ± 9.3 nM against hCA I, and they were in the range of 8.6 ± 1.9 to 41.0 ± 5.5 nM against hCA II. Ki values of acetazolamide (AZA) that was used as a reference compound were 84.4 ± 8.4 nM towards hCA I and 59.2 ± 4.8 nM towards hCA II. Ki values of the compounds 1 and 1a-g were in the range of 35.2 ± 2.0 to 158.9 ± 33.5 nM towards AChE. Ki value of Tacrine (TAC), the reference compound, was 68.6 ± 3.8 nM towards AChE. Furthermore, docking studies were done with the most potent compounds 1d , 1g , and 1f (in terms of hCA I, hCA II, and AChE inhibition effects, respectively) to determine the binding profiles of the series with these enzymes. Additionally, the prediction of ADME profiles of the compounds pointed out that the newly synthesized compounds had desirable physicochemical properties as lead compounds for further studies.

New quinoxalin-1,3,4-oxadiazole derivatives: Synthesis, characterization, in vitro biological evaluations, and molecular modeling studies

A new series of quinoxalin-1,3,4-oxadiazole (10a-l) derivatives was synthesized and evaluated against some metabolic enzymes including human carbonic anhydrase (hCA) isoenzymes I and II (carbonic anhydrases I and II), cholinesterase (acetylcholinesterase and butyrylcholinesterase), and α-glucosidase. Obtained data revealed that all the synthesized compounds were more potent as compared with the used standard inhibitors against studied target enzymes. Among the synthesized compounds, 4-fluoro derivative (10f) against hCA I, 4-chloro derivative (10i) against hCA II, 3-fluoro derivative (10e) against acetylcholinesterase and butyrylcholinesterase, and 3-bromo derivative (10k) against α-glucosidase were the most potent compounds with inhibitory activity around 1.8- to 7.37-fold better than standard inhibitors. Furthermore, docking studies of these compounds were performed at the active site of their target enzymes.

ADME properties, bioactivity and molecular docking studies of 4-amino-chalcone derivatives: new analogues for the treatment of Alzheimer, glaucoma and epileptic diseases

In this study, in vitro inhibition effects of (E)-1-(4-aminophenyl)-3-(aryl) prop-2-en-1-one (4-amino-chalcones) derivatives (3a-o) on acetylcholinesterase (AChE) enzyme and human erythrocyte carbonic anhydrase I and II isoenzymes (hCA I- II) were investigated. And also, the biological activities of 4-amino-chalcone derivatives against enzymes which names are acetylcholinesterase (PDB ID: 1OCE), human Carbonic Anhydrase I (PDB ID: 2CAB), human carbonic anhydrase II (PDB ID: 3DC3), were compared. After the results obtained, ADME/T analysis was performed in order to use 4-amino-chalcone derivatives as a drug in the future. Effective inhibitors of carbonic anhydrase I and II isozymes (hCAI and II) and acetylcholinesterase (AChE) enzymes with Ki values in the range of 2.55 ± 0.35-11.75 ± 3.57 nM for hCA I, 4.31 ± 0.78-17.55 ± 5.86 nM for hCA II and 96.01 ± 25.34-1411.41 ± 32.88 nM for AChE, respectively, were the 4-amino-chalcone derivatives (3a-o) molecules.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-021-00094-x.

Enhanced recombinant Sulfurihydrogenibium yellowstonense carbonic anhydrase activity and thermostability by chaperone GroELS for carbon dioxide biomineralization

Biological carbon fixation is a feasible strategy to reduce atmospheric carbon dioxide levels (CO₂). In this platform, carbonic anhydrase (CA) enzyme is employed to accelerate the sequestration of CO₂. The present work explored the effect of chaperone GroELS and TrxA-tag on improving soluble expression of the recombinant Sulfurihydrogenibium yellowstonense CA which activity and biomineralization capability were taken into consideration. At first, the expression of GroELS using the inducible T7 promoter and constitutive J23100 promoter were investigated. The results indicated that 1.4 folds increment of soluble protein and 100% of CA activity enhancement were achieved with GroELS co-expression driven by J23100 promoter. Furthermore, the involvement of TrxA fusion tag displayed a significant enhancement of soluble protein production which was about 2.67 times higher than that of original SyCA. Besides, co-expression with GroELS intensified the thermostability of SyCA at 60 °C owing to changes in the structural conformation of the protein, which was proved by an in vitro assay. The SyCA was further entrapped and immobilized into polyacrylamide gel (i.e., PAGE-SyCA). The biomineralization capability of the PAGE-SyCA and whole-cell (WC) was compared in a two-column system. After 5 cycles of reuse, PAGE-SyCA maintained 29.8% activity and formed 774 mg of CaCO₃ solids in the B::JG strain. This study presents the recombinant engineering strategies to improve SyCA productivity, activity, thermostability, and effective carbon dioxide conversion.

Anti-quorum sensing activity in Pseudomonas aeruginosa PA01 of benzimidazolium salts: electronic, spectral and structural investigations as theoretical approach

Quorum sensing (QS) is a system used in the expression of virulence factors by many pathogenic bacteria, and blockage of the system is seen as a new and effective strategy in combating with resistant bacteria. The inhibition effects of two benzimidazolium salts, namely 1-(2-methylbenzonitrile)-3-benzylbenzimidazolium bromide (2) and 1-(N-methylphthalimide)-3-(4-methylbenzyl)benzimidazolium bromide (3), on quorum sensing-related virulence factors such as pyocyanin, elastase, biofilm formation and swarming motility, which is an opportunistic pathogen Pseudomonas aeruginosa PA01, were investigated in this study. The results show that the compound 3 has a significant inhibition on biofilm formation with 94%. Furthermore, the compounds 2 and 3 reduced swarming motility by 64-69% as well as pyocyanin production by 49-64% in P. aeruginosa PA01 without preventing bacterial growth in the tested concentrations. HF, B3LYP and M06-2X methods were used with 3-21 g, 6-31 g, sdd basis sets to compare the chemical activity of the compounds. Theoretically, ¹H NMR, ¹³C NMR and Infrared spectra of the compounds were calculated in the HF/6-31++g basis set. The biological activities of the relative compounds were theoretically studied against cancer proteins. Crystal structure of the BRCT repeat region from the breast cancer associated protein, ID: 1JNX, crystal structure of liver cancer protein, ID: 3WZE and crystal structure of lung cancer protein, ID: 5ZMA, were compared. In the docking studies, the best result was obtained with compound 2 against the lung cancer cell with a docking score parameter of -5.85.Communicated by Ramaswamy H. Sarma.

Design, synthesis, molecular docking, and some metabolic enzyme inhibition properties of novel quinazolinone derivatives

3-Amino-2-ethylquinazolin-4(3H)-one (3) was synthesized in two steps from the reaction of amide (2), which was obtained from the treatment of methyl anthranilate (1) with propionyl chloride, with hydrazine. From the reaction of 3-amino-2-ethylquinazolin-4(3H)-one (3) with various aromatic aldehydes, novel benzylidenaminoquinazolin-4(3H)-one (3a-n) derivatives were synthesized. The structures of the novel molecules were characterized using infrared spectroscopy, nuclear magnetic resonance spectroscopy (¹ H-NMR and ¹³ C-NMR), and high-resolution mass spectroscopy. The novel compounds were tested against some metabolic enzymes, including α-glucosidase (α-Glu), acetylcholinesterase (AChE), and human carbonic anhydrases I and II (hCA I and II). The novel compounds showed K_i values in the range of 244-988 nM for hCA I, 194-900 nM for hCA II, 30-156 nM for AChE, and 215-625 nM for α-Glu. The binding affinities of the most active compounds were calculated as -7.636, -6.972, -10.080, and -8.486 kcal/mol for hCA I, hCA II, AChE, and α-Glu enzymes, respectively. The aromatic ring of the quinazoline moiety plays a critical role in the inhibition of the enzymes.

Characterization, biological evaluation and molecular docking of mulberry fruit pectin

Contemplating the exemplary benefits of pectin on human health, we precisely characterized and evaluated the antibacterial and anticancer activities from purified Mulberry Fruit Pectins (MFP). Here, we tested BR-2 and S-13 varieties of mulberry fruit pectins against six bacterial strains and two human cancer cell lines (HT-29 and Hep G-2), using MIC and an in vitro cell-based assay respectively. The BR-2 mulberry fruit pectin performs superior to S-13 by inhibiting strong bacterial growth (MIC = 500–1000 μg/mL) against tested bacterial strains and cytotoxic activities at the lowest concentration (10 µg/ml) against the Hep G-2 cell line. However, both tested drugs failed to exhibit cytotoxicity on the human colon cancer cell line (HT-29). Based on molecular interaction through docking, pectin binds effectively with the receptors (1e3g, 3t0c, 5czz, 6j7l, 6v40, 5ibs, 5zsy, and 6ggb) and proven to be a promising antimicrobial and anti-cancer agents. The pursuit of unexploited drugs from mulberry fruit pectin will potentially combat against bacterial and cancer diseases. Finally, future perspectives of MFP for the treatment of many chronic diseases will help immensely due to their therapeutic properties.

Stabilization of a potential anticancer thiosemicarbazone derivative in Sudlow site I of human serum albumin: In vitro spectroscopy coupled with molecular dynamics simulation

Human Serum Albumin (HSA) is the most important protein in human blood plasma and can acts as a major transporting agent for various drug molecules with flexible binding interaction. To elucidate the interaction of a newly designed potential anticancer thiosemicarbazone based luminophore (E)-1-(4-(diethylamino)-2-hydroxybenzylidene)-4,4-dimethyl-thiosemicarbazide (DAHTS) with HSA under physiological condition, in vitro optical spectroscopic experiments viz UV-Vis absorption, steady state fluorescence, fluroscence anisotropy, time resolved fluorscence (TRF) and cicular dichroism (CD) spectroscopy have been scrutinised. The experimental findings have been corroborated with in silico molecular docking analysis and Molecular Dynamics (MD) simulation. The spectroscopic results demonstrated that the conventionally anion-favouring Sudlow site I of HSA copiously adapt neutral DAHTS molecule with moderate binding affinity. The mean fluorescence lifetime of the sole tryptophan (Trp-214) present in the macromolecule experiences an appreciable diminution with an increase in concentration of the synthesized molecule. DAHTS localize itself close to Trp-214 within subdomain IIA (Sudlow site I) and surrounded by multiple hydrophobic amino acid residues (Val-235, Val-231, Ala-229, Phe-228, Val-325, Phe-326, Leu-327, Met-329, Phe-330, Leu-331, Tyr-332, Leu-346, Leu-347, Val-482, Leu-349, Ala-350, Ala-210, Trp-214, Ala- 213 and Val-216) in HSA. The distinct fluorescence lifetime, diverse pathways and changing rate of population indicates that the rotamerisation of Trp-214 residue is controlled by the guest molecule. Sudlow site I of HSA behaves flexibly and induces an allosteric modulation in the macromolecule resulting a minor deformation in the protein secondary structure as observed in CD (observed 11% change of α-helix content) as well as in MD simulation. The integrated multi-spectroscopic research described herein provides several important information about the binding interaction of a thiosemicarbazone Schiff base with HSA, which can be very significant for thiosemicarbazone based drug designing for academia as well as industry.

Molecular docking and inhibition profiles of some antibiotics on lactoperoxidase enzyme purified from bovine milk

Antibiotics are generally used for human and veterinary applications to preserve and to control microbial diseases. Milk has a biologically significant enzyme known as lactoperoxidase (LPO) that is a member of peroxidase family. In metabolism, LPO has ability to catalyze the transformation of thiocyanate (SCN^-) to hypothiocyanite (OSCN^-) that is an antibacterial agent and the reaction occurs with hydrogen peroxide. In this work, LPO inhibition effects of some antibiotics including cefazolin, oxytetracycline, flunixin meglumine, cefuroxime, tylosin, vancomycin, chloramphenicol and lincomycin were tested. Among the antibiotics cefazolin was indicated the strongest inhibitory efficacy. The half maximal inhibitory concentration (IC₅₀) and the inhibition constant (K_i) values of cefazolin were found as 8.19 and 34.66 µM, respectively. It was shown competitive inhibition. 5-Methyl-1,3,4-thiadiazol-2-yl moiety activity plays a key role in the inhibition mechanism of cefazolin.Communicated by Ramaswamy H. Sarma.

Synthesis of nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds - Determination of their carbonic anhydrase, acetylcholinesterase, butyrylcholinesterase and α-glycosidase inhibition properties

Sulfur-containing pyrroles (1-3), tris(2-pyridyl)phosphine(selenide) sulfide (4-5) and 4-benzyl-6-(thiophen-2-yl)pyrimidin-2-amine (6) were synthesized and characterized by elemental analysis, IR and NMR spectra. In this study, the synthesized compounds of nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds (1-6) were evaluated against the human erythrocyte carbonic anhydrase I, and II isoenzymes, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase enzymes. The synthesized heterocyclic compounds showed IC₅₀ values in range of 33.32-60.79 nM against hCA I, and 37.05-66.64 nM against hCA II closely associated with various physiological and pathological processes. On the other hand, IC₅₀ values were found in range of 13.13-22.21 nM against AChE, 0.54-31.22 nM against BChE, and 13.51-26.55 nM against α-glycosidase as a hydrolytic enzyme. As a result, nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds (1-6) demonstrated potent inhibition profiles against indicated metabolic enzymes. Therefore, we believe that these results may contribute to the development of new drugs particularly in the treatment of some global disorders including glaucoma, Alzheimer's disease and diabetes.