Synthesis, biological evaluation and 3D-QSAR studies of imidazolidine-2,4-dione derivatives as novel protein tyrosine phosphatase 1B inhibitors

A comprehensive review on the research progress of PTP1B inhibitors as antidiabetics

Diabetes mellitus (DM) is a serious global health concern affecting over 500 million people. To put it simply, it is one of the most dangerous metabolic illnesses. Insulin resistance is the root cause of 90% of all instances of diabetes, all of which are classified as Type 2 DM. Untreated, it poses a hazard to civilization since it can lead to terrifying consequences and even death. Oral hypoglycemic medicines presently available act in a variety of ways, targeting various organs and pathways. The use of protein tyrosine phosphatase 1B (PTP1B) inhibitors, on the contrary, is a novel and effective method of controlling type 2 diabetes. PTP1B is a negative insulin signaling pathway regulator; hence, inhibiting PTP1B increases insulin sensitivity, glucose absorption, and energy expenditure. PTP1B inhibitors also restore leptin signaling and are considered a potential obesity target. In this review, we have compiled a summary of the most recent advances in synthetic PTP1B inhibitors from 2015 to 2022 which have scope to be developed as clinical antidiabetic drugs.

GFP-related chromophores: photoisomerization, thermal reversion, and DNA labelling

Due to the pronounced effect of the confined environment on the photochemical properties of 4-hydroxybenzylidene imidazolinone (HBI), a GFP-related chromophore, imidazolidinone and imidazothiazolone analogues have been studied as fluorescent probes. Their photoisomerization and their thermal reversion were studied under 365-nm-irradiation, resulting in observation of an enthalpy-entropy compensation effect. Theoretical studies were carried out to shed light on the thermal reversion mechanism. Moreover, photophysical studies of benzylidene imidazothiazolone in the presence of dsDNA revealed fluorescence enhancement. The prepared compounds could be considered as a valuable tool for the detailed investigation of physicochemical, biochemical, or biological systems.

Status of research on natural protein tyrosine phosphatase 1B inhibitors as potential antidiabetic agents: Update

Protein tyrosine phosphatase 1B (PTP1B) is a crucial therapeutic target for multiple human diseases comprising type 2 diabetes (T2DM) and obesity because it is a seminal part of a negative regulator in both insulin and leptin signaling pathways. PTP1B inhibitors increase insulin receptor sensitivity and have the ability to cure insulin resistance-related diseases. However, the few PTP1B inhibitors that entered the clinic (Ertiprotafib, ISIS-113715, Trodusquemine, and JTT-551) were discontinued due to side effects or low selectivity. Molecules with broad chemical diversity extracted from natural products have been reported to be potent PTP1B inhibitors with few side effects. This article summarizes the recent PTP1B inhibitors extracted from natural products, clarifying the current research progress, and providing new options for designing new and effective PTP1B inhibitors.

Characteristics of the interaction mechanisms of procyanidin B1 and procyanidin B2 with protein tyrosine phosphatase-1B: Analysis by kinetics, spectroscopy methods and molecular docking

Protein tyrosine phosphatase-1B (PTP1B) is a novel and indispensable drug target for the treatment of type 2 diabetes mellitus (T2DM). Procyanidins are flavonoids that exhibit a significant hypoglycemic function. However, the potential inhibitory effects of procyanidins on PTP1B are unclear. In this study, the interaction mechanisms of PTP1B with procyanidin B1 (PB1) and procyanidin B2 (PB2) were investigated through kinetics analysis, UV-visible spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy and molecular docking. The results showed that PB1 and PB2 could inhibit the activity of PTP1B in a mixed inhibition mode, which was one of the reversible inhibition types. Multi-spectral analysis showed that PB1/PB2 formed complexes with PTP1B, which effectively quenched the intrinsic fluorescence of PTP1B based on the static mechanism. The values of the binding constants were K_S(PTP1B-PB1) = 4.06 × 10² L·mol^-1 and K_S(PTP1B-PB2) = 2.53 × 10² L·mol^-1, indicating that the binding affinity of PTP1B to PB1 was higher than that for PB2. PB1 and PB2 both changed the secondary structure of the enzyme, thereby decreasing the PTP1B activity. Thermodynamic investigations revealed that the binding of procyanidin B1 and B2 to PTP1B was spontaneous in both cases, and highlighted the key role of hydrophobic interactions. Molecular docking analysis provided further information regarding the interactions between PB1 or PB2 and the amino acid residues of PTP1B. Moreover, PB1 and PB2 were found to down-regulate the expression level of PTP1B in insulin-resistant HepG2 cells. These findings are the first to elucidate the inhibitory effects of PB1 and PB2 on PTP1B, and highlight the role of procyanidins as dietary supplements in regulating T2DM.

Comparative Evaluation of the Inhibitory Potential of Synthetic N-Heterocycles, Cu/Fe3O4@SiO2 Nanocomposites and Some Natural Products against Non-Resistant and Antibiotic-Resistant Acinetobacter baumannii

Background: Acinetobacter baumannii is a common infectious agent in hospitals. New antimicrobial agents are identified and prepared to combat these bacterial pathogens. In this context, the blocking potentials of a series of synthesized N-heterocyclic compounds, Cu/Fe3O4@SiO2 nanocomposites, glycine, poly-L-lysine, nisin and hydroalcoholic extracts of Trachyspermum ammi, Curcuma longa and green tea catechins were evaluated against non-resistant and multidrug-resistant strains of A. baumannii. Methods: Solutions of heterocyclic derivatives and hydroalcoholic extracts of Trachyspermum ammi, Curcuma longa and green tea catechins were prepared at initial concentration of 10240 μg ml-1 in 10% DMSO. Other compounds were dissolved in water at the same concentrations. Their in vitro inhibitory activity was assessed by determination of IZD, MIC and MBC values. Results: Glycine, poly-L-lysine, nisin, Curcuma longa and green tea catechins extracts, and thiazoles 3a, 3d and 3f were ineffective at their initial concentrations. Heterocyclic derivatives 7a-f, 3c, 3e and 3h, Cu/Fe3O4@SiO2 nanocomposites and Trachyspermum ammi extract could block the growth of bacterial strains with IZDs (7.40-15.51 mm), MICs (32-1024 µg ml-1) and MBCs (128-2048 µg ml-1). Conclusion: Among synthetic chemicals and natural products, the best antimicrobial effects were recorded with (E)-2-(5-acetyl-4-methylthiazol-2-yl)-2-(thiazolidin-2-ylidene)acetonitrile (7b) and the extract of Trachyspermum ammi. It is imperative that their toxic and histopathologic effects were assessed in future researches. It is predicted that the essential oil of Trachyspermum ammi will improve its antibacterial activities.

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.

Identification of Cyanidin-3-arabinoside Extracted from Blueberry as a Selective Protein Tyrosine Phosphatase 1B Inhibitor

Protein tyrosine phosphatase 1B (PTP1B) is an important target for type 2 diabetes. PTP1B inhibitors can reduce blood glucose levels by increasing insulin sensitivity. Anthocyanins often play a hypoglycemic effect, but the research about them have mainly focused on glucosidase. At present, the research about protein tyrosine phosphatase 1B (PTP1B) target is less, and the corresponding molecular mechanism is still unclear. Therefore, in this present study, anthocyanins isolated from blueberry were used to study the inhibitory activity on PTP1B. The isolated cyanidin-3-arabinoside (Cya-3-Ara) exhibited a better inhibitory activity with IC₅₀ = 8.91 ± 0.63 μM, which was higher than the positive control (oleanolic acid, IC₅₀ = 13.9 ± 1.01 μM), and the mechanism of PTP1B inhibition was reversible mixed pattern. The structure-activity relationship (SAR) between anthocyanins and PTP1B inhibition was investigated. The enzyme activity inhibition and molecular docking showed that anthocyanins had high selectivity for PTP1B inhibition. Further study showed that Cya-3-Ara could promote glycogen synthesis through ameliorating PTP1B-involved IRS-1/PI3K/Akt/GSK3β pathways. Cya-3-Ara could also be regarded as a synergistic inhibitor (CI ≤ 0.54) of oleanolic acid to obtain a better inhibitory effect on PTP1B. Taken together, our study clearly illustrates the SAR between anthocyanins and PTP1B inhibition and the mechanism of Cya-3-Ara in the insulin signaling pathway.

Design, synthesis, biological evaluation and molecular dynamics studies of 4-thiazolinone derivatives as protein tyrosine phosphatase 1B (PTP1B) inhibitors

Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of insulin signaling pathway, and more and more studies have shown that it is a potential target for the treatment of type 2 diabetes mellitus (T2DM). In this study, 17 new 4-thiazolinone derivatives were designed and synthesized as novel PTP1B inhibitors, and ADMET prediction confirmed that these compounds were to be drug-like. In vitro enzyme activity experiments were performed on these compounds, and it was found that a plurality of compounds had good inhibitory activity and high selectivity against PTP1B protein. Among them, compound 7p exhibited the best inhibitory activity with an IC₅₀ of 0.92 μM. The binding mode of compound 7p and PTP1B protein was explored, revealing the reason for its high efficiency. In addition, molecular dynamics simulations for the PTP1B^WT and PTP1B^comp#7p systems revealed the effects of compound 7p on PTP1B protein at the molecular level. In summary, the study reported for the first time that 4-thiazolinone derivatives as a novel PTP1B inhibitor had good inhibitory activity and selectivity for the treatment of T2DM, providing more options for the development of PTP1B inhibitors. AbbreviationsBBBblood-brain barrierCDC25Bcell division cycle 25 homolog BCYP2D6Cytochrome P450 2D6 bindingDCCMdynamic cross-correlation mapDSDiscovery StudioH bondhydrogen bondHIAhuman intestinal absorptionLARleukocyte antigen-related phosphataseMDmolecular dynamicsMEG-2maternal-effect germ-cell defective 2MM-PBSAmolecular mechanics Poisson Boltzmann surface area)PCAprincipal component analysisPDBProtein Data BankpNPPp-nitrophenyl phosphatePPBplasma protein bindingPTP1Bprotein tyrosine phosphotase 1BRMSDroot mean square deviationRMSFroot mean square fluctuationSHP-1src homologous phosphatase-1SHP-2src homologous phosphatase-2SPCsingle-point chargeTCPTPT cell protein tyrosine phosphataseT2DMType 2 diabetes mellitusVDWvan der WaalsCommunicated by Ramaswamy H. Sarma.

2,4-Thiazolidinediones as PTP 1B Inhibitors: A Mini Review (2012-2018)

2,4-thiazolidinedione (TZD) scaffold is a synthetic versatile scaffold explored by medicinal chemists for the discovery of novel molecules for the target-specific approach to treat or manage number of deadly ailments. PTP 1B is the negative regulator of insulin signaling cascade, and its diminished activity results in abolishment of insulin resistance associated with T2DM. The present review focused on the seven years journey (2012-2018) of TZDs as PTP 1B inhibitors with the insight into the amendments in the structural framework of TZD scaffold in order to optimize/design potential PTP 1B inhibitors. We have investigated the synthesized molecules based on TZD scaffold with potential activity profile against PTP 1B. Based on the SAR studies, the combined essential pharmacophoric features of selective and potent TZDs have been mapped and presented herewith for further design and synthesis of novel inhibitors of PTP 1B. Compound 46 bearing TZD scaffold with N-methyl benzoic acid and 5-(3-methoxy-4-phenethoxy) benzylidene exhibited the most potent activity (IC50 1.1 µM). Imidazolidine-2,4-dione, isosteric analogue of TZD, substituted with 1-(2,4-dichlorobenzyl)-5-(3-(2,4- dichlorobenzyloxy)benzylidene) (Compound 15) also endowed with very good PTP inhibitory activity profile (IC50 0.57 µM). It is noteworthy that Z-configuration is essential in structural framework around the double bond of arylidene for the designing of bi-dentate ligands with optimum activity.

Acetophenone derivatives from the roots of Melicope ptelefolia

Five new prenylated acetophenones, melicoptelins A-E (1-5), along with one known congener (6) were isolated from the roots of Melicope ptelefolia. Among them, compounds 2a/2b, 3a/3b, and 4a/4b were obtained as inseparable interconverting mixtures of keto and enol tautomers. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D, 2D NMR and HRESIMS. Compouds 2a/2b, 4a/4b and 5 exhibit protein tyrosine phosphatase 1B (PTP1B) inhibitory activity with IC₅₀ values of 34.4, 55.2 and 66.6 μM, respectively.

The discovery of a novel compound with potent antitumor activity: virtual screening, synthesis, biological evaluation and preliminary mechanism study

Farnesyltransferase has been regarded as a promising drug target against cancer as it is critical for membrane association of several signal transduction proteins. In this study, a novel farnesyltransferase inhibitor (IMB-1406) was identified through virtual screening. It exhibits stronger potency (IC₅₀s: 6.92–8.99 μM) than Sunitinib against all of the tested cancer cell lines. Preliminary studies on mechanism reveal that IMB-1406 induces apoptosis in HepG2 cells by arresting the cell cycle at the S phase, altering anti- and pro-apoptotic proteins leading to mitochondrial dysfunction and activation of caspase-3. This anti-tumor effect is most probably related to the inhibition of farnesyltransferase as indicated by molecular docking. Overall, IMB-1406 is a novel lead compound with potent antitumor activity and deserves further structural modifications.

The design of novel inhibitors for treating cancer by targeting CDC25B through disruption of CDC25B-CDK2/Cyclin A interaction using computational approaches

Cell division cycle 25B is a key cell cycle regulator and widely considered as potent clinical drug target for cancers. This research focused on identifying potential compounds in theory which are able to disrupt transient interactions between CDC25B and its CDK2/Cyclin A substrate.By using the method of ZDOCK and RDOCK, the most optimized 3D structure of CDK2/Cyclin A in complex with CDC25B was constructed and validated using two methods: 1) the superimposition of proteins; 2) analysis of the hydrogen bond distances of Arg 488(N1)-Asp 206(OD1), Arg 492(NE)-Asp 206(OD1), Arg 492(N1)-Asp 206(OD2) and Tyr 497(NE)-Asp 210(OD1). A series of new compounds was gained through searching the fragment database derived from ZINC based on the known inhibitor-compound 7 by the means of "replace fragment" technique. The compounds acquired via meeting the requirements of the absorption, distribution, metabolism, and excretion (ADME) predictions. Finally, 12 compounds with better binding affinity were identified. The comp#1, as a representative, was selected to be synthesized and assayed for their CDC25B inhibitory activities. The comp#1 exhibited mild inhibitory activities against human CDC25B with IC50 values at about 39.02 μM. Molecular Dynamic (MD) simulation revealed that the new inhibitor-comp#1 had favorable conformations for binding to CDC25B and disturbing the interactions between CDC25B and CDK2/Cyclin A.

On the virtues of automated quantitative structure-activity relationship: the new kid on the block

Quantitative structure-activity relationship (QSAR) has proved to be an invaluable tool in medicinal chemistry. Data availability at unprecedented levels through various databases have collaborated to a resurgence in the interest for QSAR. In this context, rapid generation of quality predictive models is highly desirable for hit identification and lead optimization. We showcase the application of an automated QSAR approach, which randomly selects multiple training/test sets and utilizes machine-learning algorithms to generate predictive models. Results demonstrate that AutoQSAR produces models of improved or similar quality to those generated by practitioners in the field but in just a fraction of the time. Despite the potential of the concept to the benefit of the community, the AutoQSAR opportunity has been largely undervalued.

Recent Advances in the Synthesis of Hydantoins: The State of the Art of a Valuable Scaffold

The review highlights the hydantoin syntheses presented from the point of view of the preparation methods. Novel synthetic routes to various hydantoin structures, the advances brought to the classical methods in the aim of producing more sustainable and environmentally friendly procedures for the preparation of these biomolecules, and a critical comparison of the different synthetic approaches developed in the last twelve years are also described. The review is composed of 95 schemes, 8 figures and 528 references for the last 12 years and includes the description of the hydantoin-based marketed drugs and clinical candidates.

Synthesis, biological evaluation and in silico studies of 5-(3-methoxybenzylidene)thiazolidine-2,4-dione analogues as PTP1B inhibitors

PTP1B (protein tyrosine phosphatase 1B) dephosphorylates the insulin receptor substrate and thus acts as a negative regulator of the insulin and leptin signalling pathway. Recently, it has been considered as a new therapeutic target of intervention for the treatment of type2 diabetes. A series of aryl/alkylsulfonyloxy-5-(3-methoxybenzylidene)thiazolidine-2,4-dione derivatives were synthesized, screened in vitro for their PTP1B inhibitory activity and in vivo for anti-hyperglycaemic activity. Docking results further helped in understanding the nature of interactions governing the binding mode of ligands inside the active site of PTP1B. Among the synthesized compounds, 13 and 16 were found to be potent PTP1B inhibitors having IC₅₀ of 7.31 and 8.73μM respectively. Significant lowering of blood glucose level was observed in some of the synthesized compounds in in vivo study.

Design, synthesis and preliminary bioactivity studies of imidazolidine-2,4-dione derivatives as Bcl-2 inhibitors

Anti-apoptotic B-cell lymphoma-2 (Bcl-2) proteins are promising targets for cancer therapy. In the present study, a series of imidazolidine-2,4-dione derivatives were designed and synthesized to test their inhibitory activities against anti-apoptotic Bcl-2 proteins. Among them, compound 8k had better growth inhibitory effects on K562 and PC-3 cell lines compared to lead compound WL-276.