Synephrine and phenylephrine act as α-amylase, α-glycosidase, acetylcholinesterase, butyrylcholinesterase, and carbonic anhydrase enzymes inhibitors

The synthesis of novel unnatural amino acid by intramolecular aza-Michael addition reaction as multitarget enzyme inhibitors

Synthesis of novel unnatural amino acids (UAAs) from 4-oxo-4-phenylbut-2-enoic acid derivatives with intramolecular aza-Michael addition reaction in the presence of chlorosulfonyl isocyanate (CSI) was reported in soft conditions without any metal catalyst. Acids and base as a catalyst, and solvents effects were investigated for the synthesis of novel UAAs. This novel method provides inexpensive, practicable, and efficient approach to generate UAAs. The use of UAAs has attracted great interest in the development of therapeutic agents and drug discovery to improve their properties. In this context, in addition to the synthesis of new UAAs, their inhibition effects on important metabolic enzymes of acetylcholinesterase (AChE) and carbonic anhydrases I and II (hCA I and II) enzymes were investigated. The compound 2g showed the best inhibition for CA I and AChE enzymes, while compound 2i exhibited the best inhibition profile against CA II isoenzyme. The inhibition values of these compounds were found as 1.85 ± 0.64 for AChE, 0.53 ± 0.07 for hCA I, 0.44 ± 0.15 µM for hCA II, respectively, and they showed a stronger inhibitory property than acetazolamide (standard inhibitor for hCA I and II) and tacrine (standard inhibitor for AChE) molecules. The activity of the studied molecule against different proteins that are hCA I (PDB ID: 2CAB), hCA II (PDB ID: 5AML), and AChE (PDB ID: 1OCE) was examined. Finally, the drug properties of the studied molecule were examined by performing absorption, distribution, metabolism, excretion, and toxicity analysis.

Comparative risk of infection of medications used for type 2 diabetes

INTRODUCTION

Glucose-lowering drugs pose a potential infection risk among individuals with type 2 diabetes. The U.S. Food and Drug Administration has issued safety warnings regarding increased risks of urinary tract infections (UTIs) and genital infections with sodium-glucose cotransporter 2 (SGLT2) inhibitors. However, the infection risk associated with other glucose-lowering drugs remains unclear. We conducted a PubMed database search to review the infection risk of glucose-lowering drugs, focusing on meta-analysis of randomized controlled trials.

AREAS COVERED

We described the infection risks associated with SGLT2 inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors, glucose-like peptide-1 receptor agonists, metformin, and thiazolidinediones, covering infections of the genitourinary, respiratory, and gastrointestinal systems, including skin and soft tissue infections (SSTIs).

EXPERT OPINION

SGLT2 inhibitors are associated with a higher genital infection risk, while their UTI risk remains inconclusive. DPP-4 inhibitors could be a treatment option for those intolerant to SGLT2 inhibitors, given their lower genital infection risk compared to placebo. Uncertainty persists regarding the risks of respiratory infections, gastroenteritis, and SSTIs with SGLT2 inhibitors. Limited evidence is available regarding the impact of DPP-4 inhibitors on respiratory infections. Additional research is needed to determine the comparative infection risk of other glucose-lowering drugs.

Synthesis and biological studies of pyrimidine derivatives targeting metabolic enzymes

Novel synthesized pyrimidine derivatives were investigated against carbonic anhydrase isoenzymes I and II (hCA I and II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glycosidase, and aldose reductase (AR) enzymes associated with some common diseases such as epilepsy, glaucoma, Alzheimer's disease, diabetes, and neuropathy. When the results were examined, novel synthesized pyrimidine derivatives were found to have effective inhibition abilities toward the metabolic enzymes. IC50 values and Ki values were calculated for each pyrimidine derivative and compared to positive controls. The synthesized novel pyrimidine derivatives exhibited Ki values in the range of 39.16 ± 7.70-144.62 ± 26.98 nM against hCA I, 18.21 ± 3.66-136.35 ± 21.48 nM toward hCA II, which is associated with different pathological and physiological processes, 33.15 ± 4.85-52.98 ± 19.86 nM on AChE, and 31.96 ± 8.24-69.57 ± 21.27 nM on BChE. Also, Ki values were determined in the range of 17.37 ± 1.11-253.88 ± 39.91 nM against α-glycosidase and 648.82 ± 53.74-1902.58 ± 98.90 nM toward AR enzymes. Within the scope of the study, the inhibition types of the novel synthesized pyrimidine derivatives were evaluated.

Pyrano[2,3-b]chromone derivatives as novel dual inhibitors of α-glucosidase and α-amylase: Design, synthesis, biological evaluation, and in silico studies

Inhibition of α-glucosidase and α-amylase is an important target for treatment of type 2 diabetes. In this work, a novel series of pyrano[2,3-b]chromene derivatives 5a-m was designed based on potent α-glucosidase and α-amylase inhibitors and synthesized by simple chemical reactions. These compounds were evaluated against the latter enzymes. Most of the title compounds exhibited high inhibitory activity against α-glucosidase and α-amylase in comparison to standard inhibitor (acarbose). Representatively, the most potent compound, 4-methoxy derivative 5d, was 30.4 fold more potent than acarbose against α-glucosidase and 6.1 fold more potent than this drug against α-amylase. In silico molecular modeling demonstrated that compound 5d attached to the active sites of α-glucosidase and α-amylase with a favorable binding energies and established interactions with important amino acids. Dynamics of compound 5d also showed that this compound formed a stable complex with the α-glucosidase active site. In silicodrug-likeness as well as ADMET prediction of this compound was also performed and satisfactory results were obtained.

Detoxifying Cyanides Using Cyanase Enzyme Complexes Composed of Carbonic Anhydrase via Irreversible Covalent Bonds

Cyanase is a possible solution to reduce the environmental impact of cyanide. However, the enzyme's dependence on HCO3- limits its industrial applications. To overcome this problem, carbonic anhydrase is utilized in this study. Three types of Catcher/Tag systems were introduced into the cyanase (psCYN) from Pseudomonas stutzeri and the carbonic anhydrase (hmCA) from Hydrogenovibrio marinus to construct enzyme complexes via irreversible covalent bonds. Initially, a cyanase complex with the aid of scaffolding proteins was designed. The results of cyanase complexes using scaffolding proteins were similar to or inferior to those of the two free enzymes. To address this, the two enzymes were manipulated to form a direct bioconjugation without the need for scaffolding proteins. The two enzymes forming a direct conjugation showed activity more than 2.5 times higher than that of cyanase alone. In conclusion, this outcome will contribute to solving problems related to residual cyanides in food and the environment.

Ugi four-multicomponent reaction based synthesis, in vitro, and in silico enzymatic evaluations of new pyrazino[1,2-a]indole-1,4-dione-indole-2-phenylacetamides as potent inhibitors against α-glucosidase and α-amylase

In this work, synthesis and evaluation of pyrazino[1,2-a]indole-1,4-dione-indole-2-phenylacetamides 6 a-k as new synthetic anti-diabetes agents were presented. These compounds were synthesized by a four-component Ugi reaction without metal catalyst. All synthesized compounds were evaluated against α-glucosidase and α-amylase as two important targets in the treatment of diabetes. Approximately, all new compounds 6 a-k were more potent than positive control acarbose against these studied enzymes. The obtained potent compounds against the target enzymes were docked in the active site of the related enzyme. Docking study showed that our new potent compounds as well interacted with key residues of the target enzyme.

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

The synthesis, carbonic anhydrase and acetylcholinesterase inhibition effects of sulfonyl chloride moiety containing oxazolidinones using an intramolecular aza-Michael addition

Oxazolidinones are used as various potent antibiotics, in organisms it acts as a protein synthesis inhibitor, focusing on an initial stage that encompasses the tRNA binding process. Novel intramolecular aza-Michael reactions devoid of metal catalysts have been introduced in an oxazolidone synthesis pathway, different from α,β-unsaturated ketones. Oxazolidinone derivatives were tested against acetylcholinesterase (AChE), carbonic anhydrase I and II (hCA I and hCA II) enzymes. All the synthesized compounds had potent inhibition effects with Ki values in the range of 13.57 ± 0.98 - 53.60 ± 6.81 µM against hCA I and 9.96 ± 1.02 - 46.35 ± 3.83 µM against hCA II in comparison to the acetazolamide (AZA) (Ki = 50.46 ± 6.17 µM for hCA I) and for hCA II (Ki = 41.31 ± 5.05 µM). Also, most of the compounds demonstrated potent inhibition ability towards AChE enzyme with Ki values 78.67-231.75 nM and compared to tacrine (TAC) as standard clinical inhibitor (Ki = 142.48 nM). Furthermore, ADMET analysis and molecular docking were calculated using the AChE, hCA I and hCA II enzyme proteins to correlate the data with the experimental data. In this work, recent applications of a stereoselective aza-Michael reaction as an efficient tool for of nitrogen-containing heterocyclic scaffolds and their useful to pharmacology analogs are reviewed and summarized.Communicated by Ramaswamy H. Sarma.

Synephrine and Its Derivative Compound A: Common and Specific Biological Effects

This review is focused on synephrine, the principal phytochemical found in bitter orange and other medicinal plants and widely used as a dietary supplement for weight loss/body fat reduction. We examine different aspects of synephrine biology, delving into its established and potential molecular targets, as well as its mechanisms of action. We present an overview of the origin, chemical composition, receptors, and pharmacological properties of synephrine, including its anti-inflammatory and anti-cancer activity in various in vitro and animal models. Additionally, we conduct a comparative analysis of the molecular targets and effects of synephrine with those of its metabolite, selective glucocorticoid receptor agonist (SEGRA) Compound A (CpdA), which shares a similar chemical structure with synephrine. SEGRAs, including CpdA, have been extensively studied as glucocorticoid receptor activators that have a better benefit/risk profile than glucocorticoids due to their reduced adverse effects. We discuss the potential of synephrine usage as a template for the synthesis of new generation of non-steroidal SEGRAs. The review also provides insights into the safe pharmacological profile of synephrine.

Discovery of novel 4,5-diphenyl-imidazol-α-aminophosphonate hybrids as promising anti-diabetic agents: Design, synthesis, in vitro, and in silico enzymatic studies

Herein, a novel series of 4,5-diphenyl-imidazol-α-aminophosphonate hybrids 4a-m was designed, synthesized, and evaluated as new anti-diabetic agents. These compounds were evaluated against two important target enzymes in the diabetes treatment: α-glucosidase and α-amylase. These new compounds were synthesized in three steps and characterized by different spectroscopic techniques. The in vitro evaluations demonstrated that all the synthesized compounds 4a-m were more potent that standard inhibitor acarbose against studied enzymes. Among these compound, the most potent compound against both studied enzymes was 3-bromo derivative 4l. The latter compound with IC50 = 5.96 nM was 18-times more potent than acarbose (IC50 = 106.63 nM) against α-glucosidase. Moreover, compound 4l with IC50 = 1.62 nM was 27-times more potent than acarbose (IC50 = 44.16 nM) against α-amylase. Molecular docking analysis revealed that this compound well accommodated in the binding site of α-glucosidase and α-amylase enzymes with notably more favorable binding energy as compared to acarbose.

Stachydrine, a Bioactive Equilibrist for Synephrine, Identified from Four Citrus Chinese Herbs

Four Chinese herbs from the Citrus genus, namely Aurantii Fructus Immaturus (Zhishi), Aurantii Fructus (Zhiqiao), Citri Reticulatae Pericarpium Viride (Qingpi) and Citri Reticulatae Pericarpium (Chenpi), are widely used for treating various cardiovascular and gastrointestinal diseases. Many ingredients have already been identified from these herbs, and their various bioactivities provide some interpretations for the pharmacological functions of these herbs. However, the complex functions of these herbs imply undisclosed cholinergic activity. To discover some ingredients with cholinergic activity and further clarify possible reasons for the complex pharmacological functions presented by these herbs, depending on the extended structure-activity relationships of cholinergic and anti-cholinergic agents, a simple method was established here for quickly discovering possible choline analogs using a specific TLC method, and then stachydrine and choline were first identified from these Citrus herb decoctions based on their NMR and HRMS data. After this, two TLC scanning (TLCS) methods were first established for the quantitative analyses of stachydrine and choline, and the contents of the two ingredients and synephrine in 39 samples were determined using the valid TLCS and HPLC methods, respectively. The results showed that the contents of stachydrine (3.04‱) were 2.4 times greater than those of synephrine (1.25‱) in Zhiqiao and about one-third to two-thirds of those of Zhishi, Qingpi and Chenpi. Simultaneously, the contents of stachydrine, choline and synephrine in these herbs present similar decreasing trends with the delay of harvest time; e.g., those of stachydrine decrease from 5.16‱ (Zhishi) to 3.04‱ (Zhike) and from 1.98‱ (Qingpi) to 1.68‱ (Chenpi). Differently, the contents of synephrine decrease the fastest, while those of stachydrine decrease the slowest. Based on these results, compared with the pharmacological activities and pharmacokinetics reported for stachydrine and synephrine, it is indicated that stachydrine can be considered as a bioactive equilibrist for synephrine, especially in the cardio-cerebrovascular protection from these citrus herbs. Additionally, the results confirmed that stachydrine plays an important role in the pharmacological functions of these citrus herbs, especially in dual-directionally regulating the uterus, and in various beneficial effects on the cardio-cerebrovascular system, kidneys and liver.

Mechanistic Insights into the Neuroprotective Potential of Sacred Ficus Trees

Ficus religiosa (Bo tree or sacred fig) and Ficus benghalensis (Indian banyan) are of immense spiritual and therapeutic importance. Various parts of these trees have been investigated for their antioxidant, antimicrobial, anticonvulsant, antidiabetic, anti-inflammatory, analgesic, hepatoprotective, dermoprotective, and nephroprotective properties. Previous reviews of Ficus mostly discussed traditional usages, photochemistry, and pharmacological activities, though comprehensive reviews of the neuroprotective potential of these Ficus species extracts and/or their important phytocompounds are lacking. The interesting phytocompounds from these trees include many bengalenosides, carotenoids, flavonoids (leucopelargonidin-3-O-β-d-glucopyranoside, leucopelargonidin-3-O-α-l-rhamnopyranoside, lupeol, cetyl behenate, and α-amyrin acetate), flavonols (kaempferol, quercetin, myricetin), leucocyanidin, phytosterols (bergapten, bergaptol, lanosterol, β-sitosterol, stigmasterol), terpenes (α-thujene, α-pinene, β-pinene, α-terpinene, limonene, β-ocimene, β-bourbonene, β-caryophyllene, α-trans-bergamotene, α-copaene, aromadendrene, α-humulene, alloaromadendrene, germacrene, γ-cadinene, and δ-cadinene), and diverse polyphenols (tannin, wax, saponin, leucoanthocyanin), contributing significantly to their pharmacological effects, ranging from antimicrobial action to neuroprotection. This review presents extensive mechanistic insights into the neuroprotective potential, especially important phytochemicals from F. religiosa and F. benghalensis. Owing to the complex pathophysiology of neurodegenerative disorders (NDDs), the currently existing drugs merely alleviate the symptoms. Hence, bioactive compounds with potent neuroprotective effects through a multitarget approach would be of great interest in developing pharmacophores for the treatment of NDDs.

Synthesis of Novel Bromophenol with Diaryl Methanes—Determination of Their Inhibition Effects on Carbonic Anhydrase and Acetylcholinesterase

In this work, nine new bromophenol derivatives were designed and synthesized. The alkylation reactions of (2-bromo-4,5-dimethoxyphenyl)methanol (7) with substituted benzenes 8–12 produced new diaryl methanes 13–17. Targeted bromophenol derivatives 18–21 were synthesized via the O-Me demethylation of diaryl methanes with BBr3. Moreover, the synthesized bromophenol compounds were tested with some metabolic enzymes such as acetylcholinesterase (AChE), carbonic anhydrase I (CA I), and II (CA II) isoenzymes. The novel synthesized bromophenol compounds showed Ki values that ranged from 2.53 ± 0.25 to 25.67 ± 4.58 nM against hCA I, from 1.63 ± 0.11 to 15.05 ± 1.07 nM against hCA II, and from 6.54 ± 1.03 to 24.86 ± 5.30 nM against AChE. The studied compounds in this work exhibited effective hCA isoenzyme and AChE enzyme inhibition effects. The results show that they can be used for the treatment of glaucoma, epilepsy, Parkinson’s as well as Alzheimer’s disease (AD) after some imperative pharmacological studies that would reveal their drug potential.

Phthalimide-tethered imidazolium salts: Synthesis, characterization, enzyme inhibitory properties, and in silico studies

A series of new imidazolium salts were prepared in good yield by the reaction between 1-alkylimidazole and a variety of alkyl halides. The structures of the compounds were identified by FT-IR, ¹ H NMR, and ¹³ C NMR spectroscopy, elemental analysis, and mass spectrometry. The crystal structure of 1b was determined by the single-crystal X-ray diffraction method. The phthalimide-tethered imidazolium salts exhibited inhibition abilities toward acetylcholinesterase (AChE) and human carbonic anhydrases (hCAs) I and II, with K_i values in the range of 24.63 ± 3.45 to 305.51 ± 35.98 nM for AChE, 33.56 ± 3.71 to 218.01 ± 25.21 nM for hCA I and 17.75 ± 0.96 to 308.67 ± 13.73 nM for hCA II. The results showed that the new imidazolium salts can play a key role in the treatment of Alzheimer's disease, epilepsy, glaucoma, and leukemia, which is related to their inhibition abilities of hCA I, hCA II, and AChE. Molecular docking and in silico absorption, distribution, metabolism, excretion and toxicity studies were used to look into how the imidazolium salts interacted with the specific protein targets. To better visualize and understand the binding positions and the influence of the imidazolium salts on hCA I, hCA II, and AChE conformations, each one was subjected to molecular docking simulations.

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.

A new specific method for isolation of tomentosin with a high yield from Inula viscosa (L.) and determination of its bioactivities

INTRODUCTION

Tomentosin, the characteristic component of Inula viscosa (L.) is an important sesquiterpene lactone with anticarcinogenic effects. Methods of obtaining pure tomentosin are not sufficient for anticancer drug research.

OBJECTIVES

This study aims to develop a specific method to isolate tomentosin from I. viscosa with high yield. It also aims to investigate the inhibitory effects of tomentosin on human carbonic anhydrase I (hCAI), human carbonic anhydrase II (hCAII), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase, and α-amylase enzymes.

MATERIAL AND METHODS

Tomentosin was purified by a specific column chromatography method. The content of tomentosin in dichloromethane, dichloromethane by Soxhlet method, ethanol and ethanol by Soxhlet method extracts of I. viscosa was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Half maximal inhibitory concentration (IC₅₀ ) and inhibition constant (K_i ) values were calculated to determine in vitro enzyme inhibition effects.

RESULTS

Tomentosin was isolated in high yield (0.64%). The IC₅₀ and K_i values for tomentosin were calculated as 5.00 ± 0.19 (r = 0.9688) and 4.62 ± 0.10 μM for hCAI, 5.40 ± 0.26 (r = 0.9677) and 5.22 ± 0.31 μM for hCAII, 6.75 ± 0.208 (r = 0.9891) and 3.75 ± 0.27 μM for AChE, 6.67 ± 0.307 (r = 0.9820) and 0.51 ± 0.11 μM for BChE, 26.61 ± 0.236 (r = 0.9815) and 2.61 ± 0.71 μM for α-glucosidase and 26.89 ± 1.54 μM (r = 0.9670) for α-amylase, respectively.

CONCLUSION

Tomentosin was isolated in high yield from the paste-like extract of I. viscosa compared to the positive controls, it was determined that tomentosin was weakly effective against hCAI, hCAII, AChE and BChE, but thoroughly effective against α-glucosidase and α-amylase. These results suggested that tomentosin has α-glucosidase and α-amylase inhibitor potential.

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.

A family of amphiphilic dioxidovanadium(V) hydrazone complexes as potent carbonic anhydrase inhibitors along with anti-diabetic and cytotoxic activities

A family of dioxidovanadium(V) complexes (1-4) of the type [Na(H₂O)_x]⁺[V^VO₂(HL^1-4)]^- (x = 4, 4.5 and 7) where HL^2- represents the dianionic form of 2-hydroxybenzoylhydrazone of 2-hydroxyacetophenone (H₂L¹, complex 1), 2-hydroxy-5-methylacetophenone (H₂L², complex 2), 2-hydroxy-5-methoxyacetophenone (H₂L³, complex 3) and 2-hydroxy-5-chloroacetophenone (H₂L⁴, complex 4), have been synthesized and characterized by analytical and spectral methods. These complexes exhibited the potential abilities to suppress the erythrocytes carbonic anhydrase enzymatic activity in type 1 and type 2 diabetic patients (in vitro), promising antidiabetic activity against T2 diabetic mice (in vivo). They also exhibited significant cytotoxic activity against cervical cancer (SiHa) cells (in vitro) as the IC₅₀ value of complexes 1, 2 and 4 is substantially lower than the value found for cisplatin while that of 3 is comparable and follow the order: 4 < 1 < 2 < 3 and can kill the cells by apoptosis via the generation of reactive oxygen species (ROS). The complexes are soluble both in water and octanol media and also non-toxic at working concentrations. The antidiabetic activity of these four complexes follows the order: 4 > 2 > 1 > 3 while both the carbonic anhydrase and cytotoxic activity follow the order: 4 > 1 > 2 > 3 suggesting that complex 4, containing electron withdrawing Cl atom is the most reactive while 3 with electron donating OCH₃ group is the least reactive species. The molecular docking study on hCA-I and hCA-II demonstrates that complexes interact via hydrogen bonding as well as different types of π-stacking.

New Pd(II) complexes of the bisthiocarbohydrazones derived from isatin and disubstituted salicylaldehydes: Synthesis, characterization, crystal structures and inhibitory properties against some metabolic enzymes

Pd(II) complexes (Pd1, Pd2, and Pd3) were synthesized for the first time using asymmetric isatin bisthiocarbohydrazone ligands and PdCl₂(PPh₃)₂. All complexes were characterized by a range of spectroscopic and analytical techniques. The molecular structures of Pd1 and Pd3 have been determined by single-crystal X-ray diffraction analysis. The complexes are diamagnetic and exhibit square planar geometry. The asymmetric isatin bisthiocarbohydrazone ligands coordinate to Pd(II) ion in a tridentate manner, through the phenolic oxygen, imine nitrogen and thiol sulfur, forming five- and six-membered chelate rings within their structures. The fourth coordination site in these complexes is occupied by PPh₃ (triphenylphosphine). The free ligands and their Pd(II) complexes were evaluated for their carbonic anhydrase I, II (hCAs) and acetylcholinesterase (AChE) inhibitor activities. They showed a highly potent inhibition effect on AChE and hCAs. K_i values are in the range of 9 ± 0.6 - 30 ± 5.4 nM for AChE, 7 ± 0.5 - 16 ± 2.2 nM for hCA I and 3 ± 0.3-24 ± 1.9 nM for hCA II isoenzyme. The results clearly demonstrated that the ligands and their Pd(II) complexes effectively inhibited the used enzymes.

p-Synephrine and its various pharmacological effects

There is a number of diseases for which, scientists are constantly looking for a promising new treatments. Isolation of novel substances with biological activity from plants gives hope for its use in treatment. In this review, we focused on the biological activity of p-synephrine (4-(2-aminoethyl)phenol) which was previously confirmed during both in vitro and in vivo tests. The main part of the review is dedicated to the anti-obesity activity of p-synephrine, as obesity is a disease of contemporary civilization. However, synephrine also possesses anti-diabetic, anti-inflammatory and antidepressant activity and it is confirmed to be a hypotensive agent in portal hypertension. The review also emphasize that, based on current knowledge, the use of p-synephrine appears to be exceedingly safe with only limited range of side effects. Therefore, it seems that this substance may be of great importance in the pharmacotherapy of many disease states and further research is necessary.

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.

Synthesis, characterization, crystal structure, α-glycosidase, and acetylcholinesterase inhibitory properties of 1,3-disubstituted benzimidazolium salts

Chloro-/fluorobenzyl-substituted benzimidazolium salts were synthesized from the reaction of 4-fluorobenzyl/2-chloro-4-fluorobenzyl-substituted benzimidazole and chlorinated aromatic hydrocarbons. They were characterized using various spectroscopic techniques (Fourier-transform infrared and nuclear magnetic resonance) and elemental analysis. In addition, the crystal structures of the complexes 1a -d and 2b were determined by single-crystal X-ray diffraction methods. These compounds were crystallized in the triclinic crystal system with a P-1 space group. The crystal packing of all complexes is dominated by O-H⋯Cl hydrogen bonds, which link the water molecules and chloride anions, forming a chloride-water tetrameric cluster. These synthesized salts were found to be effective inhibitors for α-glycosidase and acetylcholinesterase (AChE), with K_i values ranging from 45.77 ± 6.83 to 102.61 ± 11.56 µM for α-glycosidase and 0.94 ± 0.14 to 10.24 ± 1.58 µM for AChE. AChE converts acetylcholine into choline and acetic acid, thus causing the return of a cholinergic neuron to its resting state. Discovering AChE and α-glycosidase inhibitors is one of the important ways to develop new drugs for the treatment of Alzheimer's disease and diabetes.

Design, synthesis, characterization, enzymatic inhibition evaluations, and docking study of novel quinazolinone derivatives

In this study, novel quinazolinone derivatives 7a-n were synthesized and evaluated against metabolic enzymes including α-glycosidase, acetylcholinesterase, butyrylcholinesterase, human carbonic anhydrase I, and II. These compounds exhibited high inhibitory activities in comparison to used standard inhibitors with K_i values in the range of 19.28-135.88 nM for α-glycosidase (K_i value for standard inhibitor = 187.71 nM), 0.68-23.01 nM for acetylcholinesterase (K_i value for standard inhibitor = 53.31 nM), 1.01-29.56 nM for butyrylcholinesterase (K_i value for standard inhibitor = 58.16 nM), 10.25-126.05 nM for human carbonic anhydrase I (K_i value for standard inhibitor = 248.18 nM), and 13.46-178.35 nM for human carbonic anhydrase II (K_i value for standard inhibitor = 323.72). Furthermore, the most potent compounds against each enzyme were selected in order to evaluate interaction modes of these compounds in the active site of the target enzyme. Cytotoxicity assay of the title compounds 7a-n against cancer cell lines MCF-7 and LNCaP demonstrated that these compounds do not show significant cytotoxic effects.

Short-term Cudrania tricuspidata fruit vinegar administration attenuates obesity in high-fat diet-fed mice by improving fat accumulation and metabolic parameters

Previous studies have suggested that vinegar intake can help to reduce body fat and hyperglycemia. Therefore, this study aimed to evaluate the anti-obesity efficacy of vinegar fermented using Cudrania tricuspidata fruits (CTFV) and its main phenolic constituents and to analyze its molecular mechanism and changes in obesity-related metabolizing enzymatic activities. We found that HFD significantly caused hepatic steatosis; increases in body fats, feed efficiency, liver mass, lipids, insulin, oxidative parameters, cardiovascular-associated risk indices, lipase and α-amylase activities, whereas CTFV efficaciously attenuated HFD-induced oxidant stress, fat accumulation, obesity-related enzymatic activity, and the activation or reduction of obesity-related molecular reactions via improving metabolic parameters including phosphorylated insulin receptor substrate 1, protein tyrosine phosphatase 1B, phosphorylated phosphoinositide 3-kinase/protein kinase B, phosphorylated mitogen-activated protein kinases, sterol regulatory element-binding protein 1c, CCAAT/enhancer-binding protein, and fatty acid synthase; and decreases in adiponectin receptor 1, leptin receptor, adenosine monophosphate-activated protein kinase, acetyl-CoA carboxylase, and peroxisome proliferator-activated receptor, subsequently ameliorating HFD-induced obesity. Therefore, CTFV might provide a functional food resource or nutraceutical product for reducing body fat accumulation.

Synthesis, characterisation, biological evaluation and in silico studies of sulphonamide Schiff bases

Sulphonamides are biologically important compounds with low toxicity, many bioactivities and cost-effectiveness. Eight sulphonamide derivatives were synthesised and characterised by FT-IR, 13C NMR, 1H NMR, LC-MS and elemental analysis. Their inhibitory effect on AChE, and carbonic anhydrase I and II enzyme activities was investigated. Their antioxidant activity was determined using different bioanalytical assays such as radical scavenging tests with ABTS•+, and DPPH•+ as well as metal-reducing abilities with CUPRAC, and FRAP assays. All compounds showed satisfactory enzyme inhibitory potency in nanomolar concentrations against AChE and CA isoforms with KI values ranging from 10.14 ± 0.03 to 100.58 ± 1.90 nM. Amine group containing derivatives showed high metal reduction activity and about 70% ABTS radical scavenging activity. Due to their antioxidant activity and AChE inhibition, these novel compounds may be considered as leads for investigations in neurodegenerative diseases.

Novel quinazolin-sulfonamid derivatives: synthesis, characterization, biological evaluation, and molecular docking studies

In the design of novel drugs, the formation of hybrid molecules via the combination of several pharmacophores can give rise to compounds with interesting biochemical profiles. A series of novel quinazolin-sulfonamid derivatives (9a-m) were synthesized, characterized and evaluated for their in vitro antidiabetic, anticholinergics, and antiepileptic activity. These synthesized novel quinazolin-sulfonamid derivatives (9a-m) were found to be effective inhibitor molecules for the α-glycosidase, human carbonic anhydrase I and II (hCA I and hCA II), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) enzyme, with Ki values in the range of 100.62 ± 13.68-327.94 ± 58.21 nM for α-glycosidase, 1.03 ± 0.11-14.87 ± 2.63 nM for hCA I, 1.83 ± 0.24-15.86 ± 2.57 nM for hCA II, 30.12 ± 3.81-102.16 ± 13.87 nM for BChE, and 26.16 ± 3.63-88.52 ± 20.11 nM for AChE, respectively. In the last step, molecular docking calculations were made to compare biological activities of molecules against enzymes which are achethylcholinesterase, butyrylcholinesterase and α-glycosidase.Communicated by Ramaswamy H. Sarma.

Potent Acetylcholinesterase Inhibitors: Potential Drugs for Alzheimer's Disease

Alzheimer's disease (AD) is one of the cognitive or memory-related impairments occurring with advancing age. Since its exact mechanism is not known, the full therapy has still not been found. Acetylcholinesterase (AChE) has been reported to be a viable therapeutic target for the treatment of AD and other dementias. To this end, acetylcholinesterase inhibitors (AChEIs) are commonly used. AChE is a member of the hydrolase enzyme family. A hydrolase is an enzyme that catalyzes the hydrolysis of a chemical bond. AChE is useful for the development of novel and mechanism-based inhibitors. It has a role in the breakdown of acetylcholine (ACh) neurotransmitters, such as acetylcholinemediated neurotransmission. AChEIs are the most effective approaches to treat AD. AChE hydrolyzes ACh to acetate and choline, as an important neurotransmitter substance. Recently, Gülçin and his group explored new AChEIs. The most suggested mechanism for AD is the deficiency of ACh, which is an important neurotransmitter. In this regard, AChEIs are commonly used for the symptomatic treatment of AD. They act in different ways, such as by inhibiting AChE, protecting cells from free radical toxicity and β-amyloid-induced injury or inhibiting the release of cytokines from microglia and monocytes. This review focuses on the role of AChEIs in AD using commonly available drugs. Also, the aim of this review is to research and discuss the role of AChEIs in AD using commonly available drugs. Therefore, in our review, related topics like AD and AChEIs are highlighted. Also, the latest work related to AChEIs is compiled. In recent research studies, novel natural and synthetic AChEIs, used for AD, are quite noteworthy. These studies can be very promising in detecting potent drugs against AD.

Production, purification and applications of raw starch degrading and calcium-independent α-amylase from soil rich in extremophile

Calcium independent, raw starch hydrolyzing, acidic α-amylase (66 kDa) was synthesized by Bacillus subtilis S113 that is an aerobic, rod-shaped and Gram +ve bacteria. Purification of the enzyme was performed by HiTrap Capto Q (Ion-exchange chromatography; 19.28 fold; 22.41% yield). The purified enzyme was found stable at broad acidic pH (4-6.5) and high-temperature range (40-80 °C), that fulfilled the necessary criteria and laid the foundation to be utilized in starch saccharification industry. Kinetic studies of the enzyme revealed that K_m and V_max of the enzyme was 0.22% and 357.14 U/mg respectively. Scanning electron microscopy studies showed that the enzyme was capable of completely hydrolyzing raw wheat and potato starch, further confirming its role in the starch industry. It was found that only 7.93% of the activity was loss at 4 °C when kept for one year.

Novel cyclic thiourea derivatives of aminoalcohols at the presence of AlCl3 catalyst as potent α-glycosidase and α-amylase inhibitors: Synthesis, characterization, bioactivity investigation and molecular docking studies

The article is devoted to the targeted synthesis and study of cyclic thiourea and their various new derivatives as new organic compounds containing polyfunctional group in the molecule. First time the reaction of the corresponding synthesized pyrimidinethione with 1,2-epoxy-3-chlorpropane at the presence of AlCl₃ catalyst in 75-80% yield alkyl-1-(3-chloro-2-hydroxypropyl)-4-alkyl-6-phenyl-2-thioxo-1,2,5,6- tetrahydropyrimidine-5-carboxylates. In the next stage, new cyclic thiourea derivatives of aminoalcohols were synthesised from the reaction of chlorinated derivatives of pyrimidinethiones with single amines and their structures were investigated by spectroscopic methods. In this study, a series of novel compounds were tested towards some metabolic enzymes including α-glycosidase (α-Gly) and α-amylase (α-Amy) enzymes. Novel compounds showed K_is in ranging of 10.43 ± 0.94-111.37 ± 13.25 µM on α-glycosidase and IC₅₀ values in ranging of 14.38-106.51 µM on α-amylase. The novel cyclic thiourea derivatives of aminoalcohols had effective inhibition profiles against all tested metabolic enzymes. Binding affinity and inhibition mechanism of the most active compounds were detected with in silico studies and have shown that 2-Hydroxypropyl and butan-1-aminium moieties play a key role for inhibition of the enzymes.

Determination of the inhibition profiles of pyrazolyl-thiazole derivatives against aldose reductase and α-glycosidase and molecular docking studies

Aldose reductase (AR) is the first and rate-limiting enzyme of the polyol pathway, which converts glucose to sorbitol in an NADPH-dependent reaction. α-Glycosidase breaks down starch and disaccharides to glucose. Hence, inhibition of these enzymes can be regarded a considerable approach in the treatment of diabetic complications. AR was purified from sheep liver using simple chromatographic methods. The inhibitory effects of pyrazolyl-thiazoles ((3aR,4S,7R,7aS)-2-(4-{1-[4-(4-bromophenyl)thiazol-2-yl]-5-(aryl)-4,5-dihydro-1H-pyrazol-3-yl}phenyl)-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindole-1,3(2H)-dione derivatives; 3a-i) on AR and α-glycosidase enzymes were investigated. All compounds showed a good inhibitory action against AR and α-glycosidase. Among these compounds, compound 3d exhibited the best inhibition profiles against AR, with a K_i value of 7.09 ± 0.19 µM, whereas compound 3e showed the lowest inhibition effects, with a K_i value of 21.89 ± 1.87 µM. Also, all compounds showed efficient inhibition profiles against α-glycosidase, with K_i values in the range of 0.43 ± 0.06 to 2.30 ± 0.48 µM, whereas the K_i value of acarbose was 12.60 ± 0.78 µM. Lastly, molecular modeling approaches were implemented to predict the binding affinities of compounds against AR and α-glycosidase. In addition, the ADME analysis of the molecules was performed.

Secondary metabolites of Helichrysum plicatum DC. subsp. plicatum flowers as strong carbonic anhydrase, cholinesterase and α-glycosidase inhibitors

Helichrysum plicatum species are used in Turkish folk medicine as lithagogue, diuretic, and nephritic. Research on the methanol (MeOH) extract of flowers of H. plicatum DC. subsp. plicatum resulted in the isolation of eight known compounds (1-8). The chemical structures of the compounds were determined as β-sitosterol (1), apigenin (2), nonacosanoic acid (3), astragalin (4), β-sitosterol-3-O-β-D-glucopyranoside (5), helichrysin A (6), helichrysin B (7), and isosalipurposide (8) by spectroscopic and chromatographic/spectrometric methods, including 1D and 2D nuclear magnetic resonance and liquid chromatography-tandem mass spectrometry. Nonacosanoic acid (3) was isolated for the first time from H. plicatum DC. subsp. plicatum. The MeOH extract and isolated compounds were evaluated for their in vitro human carbonic anhydrase I (hCAI) and II (hCAII), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase inhibitory activities. The IC50 values of H. plicatum DC. subsp. plicatum MeOH extract for hCAI, hCAII, AChE, BChE, and α-glycosidase were found to be 77.87, 52.90, 115.50, 117.46, and 81.53 mg/mL, respectively. The compounds showed IC50 values of 1.43-4.47, 1.40-4.32, 1.69-2.90, 1.09-3.89, and 1.61-3.80 μM against hCAI, hCAII, AChE, BChE, and α-glycosidase, respectively. In summary, H. plicatum DC. subsp. plicatum secondary metabolites demonstrated strong inhibitory effects especially against hCAI and hCAII, whereas the MeOH extract showed a weak inhibitory effect on all enzymes.