Synthesis, biological evaluation and molecular docking studies of chromone hydrazone derivatives as α -glucosidase inhibitors

4-Hydroxybenzoic Acid-Based Hydrazide-Hydrazones as Potent Growth Inhibition Agents of Laccase-Producing Phytopathogenic Fungi That Are Useful in the Protection of Oilseed Crops

The research on new compounds against plant pathogens is still socially and economically important. It results from the increasing resistance of pests to plant protection products and the need to maintain high yields of crops, particularly oilseed crops used to manufacture edible and industrial oils and biofuels. We tested thirty-five semi-synthetic hydrazide-hydrazones with aromatic fragments of natural origin against phytopathogenic laccase-producing fungi such as Botrytis cinerea, Sclerotinia sclerotiorum, and Cerrena unicolor. Among the investigated molecules previously identified as potent laccase inhibitors were also strong antifungal agents against the fungal species tested. The highest antifungal activity showed derivatives of 4-hydroxybenzoic acid and salicylic aldehydes with 3-tert-butyl, phenyl, or isopropyl substituents. S. sclerotiorum appeared to be the most susceptible to the tested compounds, with the lowest IC50 values between 0.5 and 1.8 µg/mL. We applied two variants of phytotoxicity tests for representative crop seeds and selected hydrazide-hydrazones. Most tested molecules show no or low phytotoxic effect for flax and sunflower seeds. Moreover, a positive impact on seed germination infected with fungi was observed. With the potential for application, the cytotoxicity of the hydrazide-hydrazones of choice toward MCF-10A and BALB/3T3 cell lines was lower than that of the azoxystrobin fungicide tested.

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.

Novel sulfonamide derivatives as multitarget antidiabetic agents: design, synthesis, and biological evaluation

A series of new sulfonamide derivatives connected through an imine linker to five or seven membered heterocycles were designed and synthesized. All synthesized derivatives were characterized using a variety of spectroscopic methods, including IR, 1HNMR, and 13CNMR. In vitro α-glucosidase and α-amylase inhibition activities, as well as glucose uptake were assessed for each of the synthesized compounds. Four sulfonamide derivatives namely 3a, 3b, 3h and 6 showed excellent inhibitory potential against α-glucosidase with IC50 values of 19.39, 25.12, 25.57 and 22.02 μM, respectively. They were 1.05- to 1.39-fold more potent than acarbose. Sulfonamide derivatives 3g, 3i and 7 (EC50 values of 1.29, 21.38 and 19.03 μM, respectively) exhibited significant glucose uptake activity that were 1.62- to 27-fold more potent than berberine. Both α-glucosidase protein (PDB: 2QMJ) and α-amylase (PDB: 1XCW) complexed with acarbose were adopted for docking investigations for the most active synthesized compounds. The docked compounds were able to inhabit the same space as the acarviosin ring of acarbose. The docking of the most active compounds showed an analogous binding with the active site of α-glucosidase as acarbose. The superior activity of the synthesized compounds against α-glucosidase enzyme than α-amylase enzyme can be rationalized by the weak interaction with the α-amylase. The physiochemical parameters of all synthesized compounds were aligned with Lipinski's rule of five.

Discovery of N-(phenylsulfonyl)thiazole-2-carboxamides as potent α-glucosidase inhibitors

In a search for novel nonsugar α-glucosidase inhibitors for diabetes treatment, a series of N-(phenylsulfonyl)thiazole-2-carboxamide derivatives were designed and synthesized, the α-glucosidase inhibitory activities were then evaluated. Several compounds with promising α-glucosidase inhibitory effects were identified. Among these, compound W24 which shows low cytotoxicity and good α-glucosidase inhibitory activity with an IC50 value of 53.0 ± 7.7 μM, is more competitive compared with the commercially available drug acarbose (IC50  = 228.3 ± 9.2 μM). W24 was identified as a promising candidate in the development of α-glucosidase inhibitors. Molecular docking studies and molecular dynamics simulation were also performed to reveal the binding pattern of the active compound to α-glucosidase, and the binding free energy of the best compound W24 was 36.3403 ± 3.91 kcal/mol.

Synthesis of 3-hydroxy-2-naphthohydrazide-based hydrazones and their implications in diabetic management via in vitro and in silico approaches

Diabetes mellitus (DM) has prevailed as a chronic health condition and has become a serious global health issue due to its numerous consequences and high prevalence. We have synthesized a series of hydrazone derivatives and tested their antidiabetic potential by inhibiting the essential carbohydrate catabolic enzyme, "α-glucosidase." Several approaches including fourier transform infrared, 1 H NMR, and 13 C NMR were utilized to confirm the structures of all the synthesized derivatives. In vitro analysis of compounds 3a-3p displayed more effective inhibitory activities against α-glucosidase with IC50 in a range of 2.80-29.66 µM as compared with the commercially available inhibitor, acarbose (IC50  = 873.34 ± 1.67 M). Compound 3h showed the highest inhibitory potential with an IC50 value of 2.80 ± 0.03 µM, followed by 3i (IC50  = 4.13 ± 0.06 µM), 3f (IC50  = 5.18 ± 0.10 µM), 3c (IC50  = 5.42 ± 0.11 µM), 3g (IC50  = 6.17 ± 0.15 µM), 3d (IC50  = 6.76 ± 0.20 µM), 3a (IC50  = 9.59 ± 0.14 µM), and 3n (IC50  = 10.01 ± 0.42 µM). Kinetics analysis of the most potent compound 3h revealed a concentration-dependent form of inhibition by 3h with Ki value = 4.76 ± 0.0068 µM. Additionally, an in silico docking approach was applied to predict the binding patterns of all the compounds, which indicates that the hydrazide and the naphthalene-ol groups play a vital role in the binding of the compounds with the essential residues (i.e., Glu277 and Gln279) of the α-glucosidase enzyme.

Synthesis, biological evaluation and molecular modelling of 3-Formyl-6-isopropylchromone derived thiosemicarbazones as α-glucosidase inhibitors

Type-2 Diabetes Mellitus (T2DM) is one of the most common metabolic disorders in the world and over the past three decades its incidence has increased drastically. α-Glucosidase inhibitors are used to control the hyperglycemic affect of T2DM. Herein, we report the synthesis, α-glucosidase inhibition, structure activity relationship, pharmacokinetics and docking analysis of various novel chromone based thiosemicarbazones 3(a-r). The derivatives displayed potent activity against α-glucosidase with IC50 in range of 0.11 ± 0.01-79.37 ± 0.71 µM. Among all the synthesized compounds, 3a (IC50 = 0.17 ± 0.026 µM), 3 g (IC50 = 0.11 ± 0.01 µM), 3n (IC50 = 0.55 ± 0.02 µM), and 3p (IC50 = 0.43 ± 0.025 µM) displayed higher inhibitory activity as compared to the standard, acarbose. Moreover, we have developed a statistically significant 2D-QSAR model (R2tr:0.9693; F: 50.4647 and Q2LOO:0.9190), which can be used in future to further design potent thiosemicarbazones as inhibitors of α-glucosidase.

Bioactive-Guided Phytochemical Investigations, In Vitro and In Silico Alpha-Glucosidase Inhibition of Two Vietnamese Medicinal Plants Dicranopteris linearis and Psychotria adenophylla

Little is known about the chemical and biological profiles of Dicranopteris linearis and Psychotria adenophylla. No previous studies have investigated alpha-glucosidase inhibition using extracts from D. linearis and P. adenophylla. In this paper, bioactive-guided isolation procedures were applied to the plants D. linearis and P. adenophylla based on alpha-glucosidase inhibition. From the most active fractions, 20 compounds (DL1-DL13 and PA1-PA7) were isolated. The chemical structures were elucidated using spectroscopic data and compared with those available in the literature. These compounds were evaluated for alpha-glucosidase inhibition, while a molecular docking study was performed to elucidate the mechanisms involved. Consequently, D. linearis and P. adenophylla might serve as a good potential for developing new antidiabetic preparations.

Chromone Containing Hybrid Analogs: Synthesis and Applications in Medicinal Chemistry

The use of privileged scaffolds has proven beneficial for generating novel bioactive scaffolds in drug discovery program. Chromone is one such privileged scaffold that has been exploited for designing pharmacologically active analogs. The molecular hybridization technique combines the pharmacophoric features of two or more bioactive compounds to avail a better pharmacological activity in the resultant hybrid analogs. The current review summarizes the rationale and techniques involved in developing hybrid analogs of chromone, which show potential in fields of obesity, diabetes, cancer, Alzheimer's disease and microbial infections. Here the molecular hybrids of chromone with various pharmacologically active analogs or fragments (donepezil, tacrine, pyrimidines, azoles, furanchalcones, hydrazones, quinolines, etc.) are discussed with their structure-activity relationship against above-mentioned diseases. Detailed methodologies for the synthesis of corresponding hybrid analogs have also been described, with suitable synthetic schemes. The current review will shed light on various strategies utilized for the design of hybrid analogs in the field of drug discovery. The importance of hybrid analogs in various disease conditions is also illustrated.

Synthesis and characterization of novel acyl hydrazones derived from vanillin as potential aldose reductase inhibitors

In the polyol pathway, aldose reductase (AR) catalyzes the formation of sorbitol from glucose. In order to detoxify some dangerous aldehydes, AR is essential. However, due to the effects of the active polyol pathway, AR overexpression in the hyperglycemic state leads to microvascular and macrovascular diabetic problems. As a result, AR inhibition has been recognized as a potential treatment for issues linked to diabetes and has been studied by numerous researchers worldwide. In the present study, a series of acyl hydrazones were obtained from the reaction of vanillin derivatized with acyl groups and phenolic Mannich bases with hydrazides containing pharmacological groups such as morpholine, piperazine, and tetrahydroisoquinoline. The resulting 21 novel acyl hydrazone compounds were investigated as an inhibitor of the AR enzyme. All the novel acyl hydrazones derived from vanillin demonstrated activity in nanomolar levels as AR inhibitors with IC50 and KI values in the range of 94.21 ± 2.33 to 430.00 ± 2.33 nM and 49.22 ± 3.64 to 897.20 ± 43.63 nM, respectively. Compounds 11c and 10b against AR enzyme activity were identified as highly potent inhibitors and showed 17.38 and 10.78-fold more effectiveness than standard drug epalrestat. The synthesized molecules' absorption, distribution, metabolism, and excretion (ADME) effects were also assessed. The probable-binding mechanisms of these inhibitors against AR were investigated using molecular-docking simulations.

In-vitro high-throughput library screening-Kinetics and molecular docking studies of potent inhibitors of α-glucosidase

High throughput screening of synthetic compounds against vital enzymes is the way forward for the determination of potent enzyme inhibitors. In-vitro high throughput library screening of 258 synthetic compounds (comp. 1-258), was performed against α-glucosidase. The active compounds out of this library were investigated for their mode of inhibition and binding affinities towards α-glucosidase through kinetics as well as molecular docking studies. Out of all the compounds selected for this study, 63 compounds were found active within the IC50 range of 3.2 μM to 50.0 μM. The most potent inhibitor of α-glucosidase out of this library was the derivative of an oxadiazole (comp. 25). It showed the IC50 value of 3.23 ± 0.8 μM. Other highly active compounds were the derivatives of ethyl-thio benzimidazolyl acetohydrazide with IC50 values of 6.1 ± 0.5 μM (comp. 228), 6.84 ± 1.3 μM (comp. 212), 7.34 ± 0.3 μM (comp. 230) and 8.93 ± 1.0 μM (comp. 210). For comparison, the standard (acarbose) showed IC50 = 378.2 ± 0.12 μM. Kinetic studies of oxadiazole (comp. 25) and ethylthio benzimidazolyl acetohydrazide (comp. 228) derivatives indicated that Vmax and Km, both change with changing concentrations of inhibitors which suggests an un-competitive mode of inhibition. Molecular docking studies of these derivatives with the active site of α-glucosidase (PDB ID:1XSK), revealed that these compounds mostly interact with acidic or basic amino acid residues through conventional hydrogen bonds along with other hydrophobic interactions. The binding energy values of compounds 25, 228, and 212 were -5.6, -8.7 and -5.4 kcal.mol-1 whereas RMSD values were 0.6, 2.0, and 1.7 Å, respectively. For comparison, the co-crystallized ligand showed a binding energy value of -6.6 kcal.mol-1 along with an RMSD value of 1.1 Å. Our study predicted several series of compounds as active inhibitors of α-glucosidase including some highly potent inhibitors.

Synthetic α-glucosidase inhibitors as promising anti-diabetic agents: Recent developments and future challenges

Diabetes mellitus is one of the biggest challenges for the scientific community in the 21st century. It is a well-recognized multifactorial health problem contributes significantly to high mortality rates by causing serious health complications mainly related to cardiovascular diseases, kidney damage and neuropathy. The inhibition of α-glucosidase (enzyme that catalyses starch hydrolysis in the intestine) is an effective therapeutic approach for controlling hyperglycemia associated with type-2 diabetes. However, the presently approved drugs/inhibitors such as acarbose, miglitol and voglibose have several undesirable gastrointestinal side effects impeding their applications. Therefore, search for novel and more effective inhibitors with reduced side effects and less cost remains a fascinating area of research. In this context, a large variety of α-glucosidase inhibitors have been identified in recent years that demands attention from drug development community. This review is therefore an effort to summarize and highlight the promising α-glucosidase inhibitors especially those which are primarily based on aromatic heterocyclic scaffolds such as coumarin, imidazole, isatin, pyrimidine, quinazoline, triazine, thiazole etc, having improved safety and pharmacological profiles.

Fragment-Based Dynamic Combinatorial Chemistry for Identification of Selective α-Glucosidase Inhibitors

Efforts to combine advantages of fragment-based drug design (FBDD) and dynamic combinatorial chemistry (DCC) for the development of selective α-glucosidase inhibitors were described. Starting from 5 rationally designed fragments, two iterative dynamic combinatorial libraries (DCLs) comprising 29 acylhydrazone products were generated and screened using α-glucosidase and α-amylase as the templates. The optimal ligand identified showed substantial α-glucosidase inhibition with high selectivity over α-amylase as well as low cytotoxicity. Furthermore, inhibition type and detailed ligand/enzyme binding interactions were elucidated by the binding kinetic study and docking simulation, respectively.

Experimental and Computational Analysis of Newly Synthesized Benzotriazinone Sulfonamides as Alpha-Glucosidase Inhibitors

Diabetes mellitus is a chronic metabolic disorder in which the pancreas secretes insulin but the body cells do not recognize it. As a result, carbohydrate metabolism causes hyperglycemia, which may be fatal for various organs. This disease is increasing day by day and it is prevalent among people of all ages, including young adults and children. Acarbose and miglitol are famous alpha-glucosidase inhibitors but they complicate patients with the problems of flatulence, pain, bloating, diarrhea, and loss of appetite. To overcome these challenges, it is crucial to discover new anti-diabetic drugs with minimal side effects. For this purpose, benzotriazinone sulfonamides were synthesized and their structures were characterized by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopy. In vitro alpha-glucosidase inhibition studies of all synthesized hybrids were conducted using the spectrophotometric method. The synthesized compounds revealed moderate-to-good inhibition activity; in particular, nitro derivatives 12e and 12f were found to be the most effective inhibitors against this enzyme, with IC₅₀ values of 32.37 ± 0.15 µM and 37.75 ± 0.11 µM. In silico studies, including molecular docking as well as DFT analysis, also strengthened the experimental findings. Both leading compounds 12e and 12f showed strong hydrogen bonding interactions within the enzyme cavity. DFT studies also reinforced the strong binding interactions of these derivatives with biological molecules due to their lowest chemical hardness values and lowest orbital energy gap values.

Flavone-1,2,3-triazole derivatives as potential α-glucosidase inhibitors: Synthesis, enzyme inhibition, kinetic analysis and molecular docking study

α-Glucosidase inhibitors are considered prime therapeutics in the management of type-2 diabetes and are preferred due to their localized action ushered by limited side effects. In this regard, nineteen new flavone-1,2,3-triazole derivatives have been designed and synthesized via utilizing an efficient click reaction protocol, and screened for the inhibition of the α-glucosidase enzyme. The reaction conditions were mild, good yielding and required easy work up. All the synthesized flavone-triazole derivatives were found more active against the yeast α-glucosidase with IC₅₀ values ranging from 24.37 ± 0.55-168.44 ± 0.77 μ M as compared to standard inhibitor acarbose (IC₅₀ = 844.81 ± 0.53 μM). The derivatives with 2,5‑dichloro 9k (IC₅₀ = 24.37 ± 0.55 μM) and 4‑chloro 9d (IC₅₀ = 24.77 ± 0.30 μM) substituent bearing an amide linkage were the most active. In the kinetic study of most active derivatives 9k and 9d, they were found to be mixed and uncompetitive inhibitors, respectively. In molecular docking studies, blind docking of the most active compounds was accomplished to find the interactions between the compounds and α-glucosidase that further confirms the mixed or uncompetitive nature of the inhibitors.

Design, synthesis, in vitro α-glucosidase inhibition, docking, and molecular dynamics of new phthalimide-benzenesulfonamide hybrids for targeting type 2 diabetes

In the present work, a new series of 14 novel phthalimide-benzenesulfonamide derivatives 4a-n were synthesized, and their inhibitory activity against yeast α-glucosidase was screened. The obtained results indicated that most of the newly synthesized compounds showed prominent inhibitory activity against α-glucosidase. Among them, 4-phenylpiperazin derivative 4m exhibited the strongest inhibition with the IC50 value of 52.2 ± 0.1 µM. Enzyme kinetic study of compound 4m proved that its inhibition mode was competitive and Ki value of this compound was calculated to be 52.7 µM. In silico induced fit docking and molecular dynamics studies were performed to further investigate the interaction, orientation, and conformation of the target compounds over the active site of α-glucosidase. Obtained date of these studies demonstrated that our new compounds interacted as well with the α-glucosidase active site with the acceptable binding energies. Furthermore, in silico druglikeness/ADME/Toxicity studies of compound 4m were performed and predicted that this compound is druglikeness and has good ADME and toxicity profiles.

Chromone a Privileged Scaffold in Drug Discovery: Developments on the Synthesis and Bioactivity

Chromones are the class of secondary metabolites broadly occurred in the plant kingdom in a noticeable quantity. This rigid bicyclic system has been categorized "as privileged scaffolds in compounds" in medicinal chemistry. The wide biological responses made them an important moiety in a drug discovery program. This review provides updates on the various methods of synthesis of chromones and biological applications in medicinal chemistry. Various synthetic strategies for the construction of chromones include readily available phenols, salicylic acid and its derivatives, ynones, chalcones, enaminones, chalcones and 2-hydroxyarylalkylketones as starting materials. Synthesis of chromones by using metal, metal free, nanomaterials and different catalysts are included. Details of diverse biological activities such as anti-cancer agents, antimicrobial agents, anti-viral property, anti-inflammatory agents, antioxidants, Monoamine Oxidase-B (MAO-B) Inhibitors, anti-Alzheimer's agents, anti-diabetic agent, antihistaminic potential, antiplatelet agents of chromone derivatives are diecussed.

Inhibitory Potential of New Phenolic Hydrazide-Hydrazones with a Decoy Substrate Fragment towards Laccase from a Phytopathogenic Fungus: SAR and Molecular Docking Studies

Laccase from pathogenic fungi participates in both the delignification and neutralization of phytoantibiotics. Furthermore, it interferes with the hormone signaling in plants and catalyzes melanization. Infections of these pathogens contribute to loss in forestry, agriculture, and horticulture. As there is still a need to expand knowledge on efficient defense strategies against phytopathogenic fungi, the present study aimed to reveal more information on the molecular mechanisms of laccase inhibition with natural and natural-like carboxylic acid semi-synthetic derivatives. A set of hydrazide-hydrazones derived from carboxylic acids, generally including electron-rich arene units that serve as a decoy substrate, was synthesized and tested with laccase from Trametes versicolor. The classic synthesis of the title inhibitors proceeded with good to almost quantitative yield. Ninety percent of the tested molecules were active in the range of K_I = 8–233 µM and showed different types of action. Such magnitude of inhibition constants qualified the hydrazide-hydrazones as strong laccase inhibitors. Molecular docking studies supporting the experimental data explained the selected derivatives’ interactions with the enzyme. The results are promising in developing new potential antifungal agents mitigating the damage scale in the plant cultivation, gardening, and horticulture sectors.

Design, synthesis, and α-glucosidase-inhibitory activity of phenoxy-biscoumarin-N-phenylacetamide hybrids

Thirteen new phenoxy-biscoumarin-N-phenylacetamide derivatives (7a-m) were designed based on a molecular hybridization approach as new α-glucosidase inhibitors. These compounds were synthesized with high yields and evaluated in vitro for their inhibitory activity against yeast α-glucosidase. The obtained results revealed that a significant proportion of the synthesized compounds showed considerable α-glucosidase-inhibitory activity in comparison to acarbose as a positive control. Representatively, 2-(4-(bis(4-hydroxy-2-oxo-2H-chromen-3-yl)methyl)phenoxy)-N-(4-bromophenyl)acetamide (7f), with IC₅₀  = 41.73 ± 0.38 µM against α-glucosidase, was around 18 times more potent than acarbose (IC₅₀  = 750.0 ± 10.0 µM). This compound was a competitive α-glucosidase inhibitor. Molecular modeling and dynamic simulation of these compounds confirmed the obtained results through in vitro experiments. Prediction of the druglikeness/ADME/toxicity of the compound 7f and comparison with the standard drug acarbose showed that the new compound 7f was probably better than the standard drug in terms of toxicity.

Rational Design of Novel Inhibitors of α-Glucosidase: An Application of Quantitative Structure Activity Relationship and Structure-Based Virtual Screening

α-Glucosidase is considered a prime drug target for Diabetes Mellitus and its inhibitors are used to delay carbohydrate digestion for the treatment of diabetes mellitus. With the aim to design α-glucosidase inhibitors with novel chemical scaffolds, three folds ligand and structure based virtual screening was applied. Initially linear quantitative structure activity relationship (QSAR) model was developed by a molecular operating environment (MOE) using a training set of thirty-two known inhibitors, which showed good correlation coefficient (r² = 0.88), low root mean square error (RMSE = 0.23), and cross-validated correlation coefficient r² (q² = 0.71 and RMSE = 0.31). The model was validated by predicting the biological activities of the test set which depicted r² value of 0.82, indicating the robustness of the model. For virtual screening, compounds were retrieved from zinc is not commercial (ZINC) database and screened by molecular docking. The best docked compounds were chosen to assess their pharmacokinetic behavior. Later, the α-glucosidase inhibitory potential of the selected compounds was predicted by their mode of binding interactions. The predicted pharmacokinetic profile, docking scores and protein-ligand interactions revealed that eight compounds preferentially target the catalytic site of α-glucosidase thus exhibit potential α-glucosidase inhibition in silico. The α-glucosidase inhibitory activities of those Hits were predicted by QSAR model, which reflect good inhibitory activities of these compounds. These results serve as a guidelines for the rational drug design and development of potential novel anti-diabetic agents.

Artificial Intelligence, Big Data and Machine Learning Approaches in Precision Medicine & Drug Discovery

Artificial Intelligence revolutionizes the drug development process that can quickly identify potential biologically active compounds from millions of candidate within a short period. The present review is an overview based on some applications of Machine Learning based tools, such as GOLD, Deep PVP, LIB SVM, etc. and the algorithms involved such as support vector machine (SVM), random forest (RF), decision tree and Artificial Neural Network (ANN), etc. at various stages of drug designing and development. These techniques can be employed in SNP discoveries, drug repurposing, ligand-based drug design (LBDD), Ligand-based Virtual Screening (LBVS) and Structure- based Virtual Screening (SBVS), Lead identification, quantitative structure-activity relationship (QSAR) modeling, and ADMET analysis. It is demonstrated that SVM exhibited better performance in indicating that the classification model will have great applications on human intestinal absorption (HIA) predictions. Successful cases have been reported which demonstrate the efficiency of SVM and RF models in identifying JFD00950 as a novel compound targeting against a colon cancer cell line, DLD-1, by inhibition of FEN1 cytotoxic and cleavage activity. Furthermore, a QSAR model was also used to predict flavonoid inhibitory effects on AR activity as a potent treatment for diabetes mellitus (DM), using ANN. Hence, in the era of big data, ML approaches have been evolved as a powerful and efficient way to deal with the huge amounts of generated data from modern drug discovery to model small-molecule drugs, gene biomarkers and identifying the novel drug targets for various diseases.

Chemical synthesis, inhibitory activity and molecular mechanism of 1-deoxynojirimycin–chrysin as a potent α-glucosidase inhibitor

Hyperglycemia can be efficaciously regulated by inhibiting α-glucosidase activity and this is regarded as an effective strategy to treat type 2 diabetes.

Inhibitory potential of 4-hexylresorcinol against α-glucosidase and non-enzymatic glycation: Activity and mechanism

Inhibition of α-glucosidase as well as non-enzymatic glycation is thought as an effective method for treating type-2 diabetes mellitus. In this study, we investigated the inhibitory potential and mechanism of 4-hexylresorcinol against α-glucosidase and non-enzymatic glycation by using multispectroscopic analyses and molecular docking. The results of enzyme kinetics showed that 4-hexylresorcinol reversibly inhibited α-glucosidase activity in a noncompetitive way. Fluorescence quenching then revealed that it increased the hydrophobicity of α-glucosidase and changed the conformation of the enzyme by forming the α-glucosidase-hexylresorcinol complex. Thermodynamic analysis and molecular docking further demonstrated that the inhibition of 4-hexylresorcinol on the α-glucosidase was mainly dependent on hydrogen bond and hydrophobic interaction. Moreover, the 4-hexylresorcinol moderately inhibited the formation of fructosamine, and strongly suppressed the generation of α-dicarbonyl compounds and advanced glycation end products (AGEs). The interaction between 4-hexylresorcinol and bovine serum albumin was mainly driven by hydrophobic interaction. This study showed a novel inhibitor of α-glucosidase as well as non-enzymatic glycation, and provided a drug candidate for the prevention and treatment of type-2 diabetes.

Chromon-3-aldehyde derivatives restore mitochondrial function in rat cerebral ischemia

Objectives

This work aimed to assess the effect of 10 new chromon-3-aldehyde derivatives on changes of mitochondrial function under the conditions of brain ischemia in rats.

Materials and Methods

The work was executed on BALB/c male-mice (acute toxicity was evaluated) and male Wistar rats, which were used to model cerebral ischemia by permanent middle cerebral artery occlusion. The test-substances, 10 derivatives of chromon-3-aldehyde and the reference drug, N-acetylcysteine, were injected after modeling of ischemia for 3 days. After that, neurological symptoms, the area of cerebral infarction, and change in mitochondrial function were evaluated.

Results

It was established that use of all chromon-3-aldehyde derivatives contributed to the recovery of mitochondrial function, which was reflected in enhanced ATP-generating activity, maximum respiration level, respiratory capacity, as well as reduction in the intensity of anaerobic reactions, apoptosis, and normalization of the mitochondrial membrane potential. The most pronounced changes were noted with the use of 6-acetyl substituted chromon-3-aldehyde derivative, the administration of which decreased neurological symptoms and size of brain necrosis area.

Conclusion

The obtained data may indicate the most pronounced neurotropic effect in a number of test-objects has the 6-acetyl substituted derivative of chromon-3 aldehyde, realized by restoration of mitochondrial function, which may be the basis for further study of chromon-3-aldehyde derivatives.

Current Strategies in Development of New Chromone Derivatives with Diversified Pharmacological Activities: A Review

Chromone derivatives possess a spectrum of biological activities. Chromone has been recognized as a privileged structure for new drug invention and development. Substitution pattern of chromone scaffold determines different type of biological activities. The type, number and position of substituents connected to the chromone core play a vital role in determining pharmacological activities. In the present review, we have discussed new chromone derivatives as anticancer, anti-diabetic, antimicrobial, anti-inflammatory, antioxidant and as anti-Alzheimer agents. This review deals with the chromone derivatives prepared by combining chromone molecule with various natural and synthetic pharmacophores and pharmacological activities presented by them. The main aim is to highlight the diversified pharmacological activities exhibited by chromone hybrid molecules during the last eight to ten years.

Synthesis and Structure-Activity Relationship Studies of Hydrazide-Hydrazones as Inhibitors of Laccase from Trametes versicolor

A series of hydrazide-hydrazones 1-3, the imine derivatives of hydrazides and aldehydes bearing benzene rings, were screened as inhibitors of laccase from Trametes versicolor. Laccase is a copper-containing enzyme which inhibition might prevent or reduce the activity of the plant pathogens that produce it in various biochemical processes. The kinetic and molecular modeling studies were performed and for selected compounds, the docking results were discussed. Seven 4-hydroxybenzhydrazide (4-HBAH) derivatives exhibited micromolar activity Ki = 24-674 µM with the predicted and desirable competitive type of inhibition. The structure-activity relationship (SAR) analysis revealed that a slim salicylic aldehyde framework had a pivotal role in stabilization of the molecules near the substrate docking site. Furthermore, the presence of phenyl and bulky tert-butyl substituents in position 3 in salicylic aldehyde fragment favored strong interaction with the substrate-binding pocket in laccase. Both 3- and 4-HBAH derivatives containing larger 3-tert-butyl-5-methyl- or 3,5-di-tert-butyl-2-hydroxy-benzylidene unit, did not bind to the active site of laccase and, interestingly, acted as non-competitive (Ki = 32.0 µM) or uncompetitive (Ki = 17.9 µM) inhibitors, respectively. From the easily available laccase inhibitors only sodium azide, harmful to environment and non-specific, was over 6 times more active than the above compounds.

Synthesis of Dihydrazones as Potential Anticancer and DNA Binding Candidates: A Validation by Molecular Docking Studies

BACKGROUND

Accounting for mortality nearly one in four of human and second highest leading cause of death worldwide. Every year, about 10 million new cancers are diagnosed and causing major health issues in both developing and developed countries.

METHODS

A series of new dihydrazones were synthesized and screened for in vitro anticancer activity against three different MDA-MB-231, A546 and MCF7 cell lines and validated by DNA binding and molecular docking approaches.

RESULT

In the present investigations, synthesized compounds 21, 22, 23 and 24 exhibited potent anticancer activity against tested cancer cell lines and DNA binding study using methyl green comparing to Doxorubicin and ethidium bromide as a positive control respectively.

CONCLUSION

The Structure Activity Relationship (SAR) showed that the electron withdrawing groups (-Cl, -NO2, - F, and -Br) favored the DNA binding studies and anticancer activity whereas, electron donating groups (-OH and - OCH3) showed moderate activity. In the molecular docking study, binding interactions of the most active compounds 21, 22, 23 and 24 stacked with A-T rich regions of the DNA minor groove by surface binding interactions were confirmed. Further, the tuning of active analogs for targeted therapy was warranted.

Anti-diabetic drugs recent approaches and advancements

Diabetes is one of the major diseases worldwide and is the third leading cause of death in the United States. Anti-diabetic drugs are used in the treatment of diabetes mellitus to control glucose levels in the blood. Most of the drugs are administered orally, except for a few of them, such as insulin, exenatide, and pramlintide. In this review, we are going to discuss seven major types of anti-diabetic drugs: Peroxisome proliferator-activated receptor (PPAR) agonist, protein tyrosine phosphatase 1B (PTP1B) inhibitors, aldose reductase inhibitors, α-glucosidase inhibitors, dipeptidyl peptidase IV (DPP-4) inhibitors, G protein-coupled receptor (GPCR) agonists and sodium-glucose co-transporter (SGLT) inhibitors. Here, we are also discussing some of the recently reported anti-diabetic agents with its multi-target pharmacological actions. This review summarises recent approaches and advancement in anti-diabetes treatment concerning characteristics, structure-activity relationships, functional mechanisms, expression regulation, and applications in medicine.

Exploring the inhibitory mechanism of piceatannol on α-glucosidase relevant to diabetes mellitus

Due to their association with type 2 diabetes mellitus treatment, α-glucosidase inhibitors have attracted increasing attention of researchers. In this study, we systemically investigated the kinetics and inhibition mechanism of piceatannol on α-glucosidase. Enzyme kinetics analyses showed that piceatannol exhibited strong inhibition on α-glucosidase in a non-competitive manner. Spectroscopy analyses indicated that piceatannol could bind with α-glucosidase to form complexes via high affinity. Further, computational molecular dynamics and molecular docking studies validated that the binding of piceatannol was outside the catalytic site of α-glucosidase, which would induce conformational changes of α-glucosidase and block the entrance of substrate, causing declines in α-glucosidase activities. Our results provide useful information not only for the inhibition mechanism of piceatannol against α-glucosidase but also for a novel target site for developing novel α-glucosidase inhibitors as potential therapeutic agents in the treatment of type 2 diabetes mellitus.

The non-competitive inhibition of piceatannol on α-glucosidase. A combination of dynamic and static process with one binding site. The involvement of hydrophobic interactions and hydrogen bonding. Dietary recommendations for diabetes or potential antidiabetic drug.

Efficient synthesis of pyrazolopyridines containing a chromane backbone through domino reaction

An efficient approach for the synthesis of pyrazolopyridines containing the aminochromane motif through a base-catalyzed cyclization reaction is reported. The synthesis was carried out through a three-component reaction of (arylhydrazono)methyl-4H-chromen-4-one, malononitrile, primary amines in the presence of Et₃N at room temperature. However, carrying out the reaction under the same conditions without base led to a fused chromanyl-cyanopyridine. High selectivity, high atom economy, and good to high yields in addition to mild reaction conditions are the advantages of this approach.

Novel C-2 Symmetric Molecules as α-Glucosidase and α-Amylase Inhibitors: Design, Synthesis, Kinetic Evaluation, Molecular Docking and Pharmacokinetics

A series of symmetrical salicylaldehyde-bishydrazine azo molecules, 5a–5h, have been synthesized, characterized by ¹H-NMR and ¹³C-NMR, and evaluated for their in vitro α-glucosidase and α-amylase inhibitory activities. All the synthesized compounds efficiently inhibited both enzymes. Compound 5g was the most potent derivative in the series, and powerfully inhibited both α-glucosidase and α-amylase. The IC₅₀ of 5g against α-glucosidase was 0.35917 ± 0.0189 µM (standard acarbose IC₅₀ = 6.109 ± 0.329 µM), and the IC₅₀ value of 5g against α-amylase was 0.4379 ± 0.0423 µM (standard acarbose IC₅₀ = 33.178 ± 2.392 µM). The Lineweaver-Burk plot indicated that compound 5g is a competitive inhibitor of α-glucosidase. The binding interactions of the most active analogues were confirmed through molecular docking studies. Docking studies showed that 5g interacts with the residues Trp690, Asp548, Arg425, and Glu426, which form hydrogen bonds to 5g with distances of 2.05, 2.20, 2.10 and 2.18 Å, respectively. All compounds showed high mutagenic and tumorigenic behaviors, and only 5e showed irritant properties. In addition, all the derivatives showed good antioxidant activities. The pharmacokinetic evaluation also revealed promising results

Pharmaceutical and medicinal significance of sulfur (SVI)-Containing motifs for drug discovery: A critical review

Sulfur (S^VI) based moieties, especially, the sulfonyl or sulfonamide based analogues have showed a variety of pharmacological properties, and its derivatives propose a high degree of structural diversity that has established useful for the finding of new therapeutic agents. The developments of new less toxic, low cost and highly active sulfonamides containing analogues are hot research topics in medicinal chemistry. Currently, more than 150 FDA approved Sulfur (S^VI)-based drugs are available in the market, and they are widely used to treat various types of diseases with therapeutic power. This comprehensive review highlights the recent developments of sulfonyl or sulfonamides based compounds in huge range of therapeutic applications such as antimicrobial, anti-inflammatory, antiviral, anticonvulsant, antitubercular, antidiabetic, antileishmanial, carbonic anhydrase, antimalarial, anticancer and other medicinal agents. We believe that, this review article is useful to inspire new ideas for structural design and developments of less toxic and powerful Sulfur (S^VI) based drugs against the numerous death-causing diseases.