Potent PTP1B Inhibitors Research Articles

Structure-Agnostic Bioactivity-Driven Combinatorial Biosynthesis Reveals New Antidiabetic and Anticancer Triterpenoids.

Although combinatorial biosynthesis can dramatically expand the chemical structures of bioactive natural products to identify molecules with improved characteristics, progress in this direction has been hampered by the difficulty in isolating and characterizing the numerous produced compounds. This challenge could be overcome with improved designs that enable the analysis of the bioactivity of the produced metabolites ahead of the time-consuming isolation procedures. Herein, we showcase a structure-agnostic bioactivity-driven combinatorial biosynthesis workflow that introduces bioactivity assessment as a selection-driving force to guide iterative combinatorial biosynthesis rounds towards enzyme combinations with increasing bioactivity. We apply this approach to produce triterpenoids with potent bioactivity against PTP1B, a promising molecular target for diabetes and cancer treatment. We demonstrate that the bioactivity-guided workflow can expedite the combinatorial process by enabling the narrowing down of more than 1000 possible combinations to only five highly potent candidates. By focusing the isolation and structural elucidation effort on only these five strains, we reveal 20 structurally diverse triterpenoids, including four new compounds and a novel triterpenoid-anthranilic acid hybrid, as potent PTP1B inhibitors. This workflow expedites hit identification by combinatorial biosynthesis and is applicable to many other types of bioactive natural products, therefore providing a strategy for accelerated drug discovery.

Discovery of Novel PTP1B Inhibitors by High-throughput Virtual Screening.

To Discover novel PTP1B inhibitors by high-throughput virtual screening Background: Type 2 Diabetes is a significant global health concern. According to projections, the estimated number of individuals affected by the condition will reach 578 million by the year 2030 and is expected to further increase to 700 million deaths by 2045. Protein Tyrosine Phosphatase 1B is an enzymatic protein that has a negative regulatory effect on the pathways involved in insulin signaling. This regulatory action ultimately results in the development of insulin resistance and the subsequent elevation of glucose levels in the bloodstream. The proper functioning of insulin signaling is essential for maintaining glucose homeostasis, whereas the disruption of insulin signaling can result in the development of type 2 diabetes. Consequently, we sought to utilize PTP1B as a drug target in this investigation. The purpose of our study was to identify novel PTP1B inhibitors as a potential treatment for managing type 2 diabetes. To discover potent PTP1B inhibitors, we have screened the Maybridge HitDiscover database by SBVS. Top hits have been passed based on various drug-likeness rules, toxicity predictions, ADME assessment, Consensus Molecular docking, DFT, and 300 ns MD Simulations. Two compounds have been identified with strong binding affinity at the active site of PTP1B along with drug-like properties, efficient ADME, low toxicity, and high stability. The identified molecules could potentially manage T2DM effectively by inhibiting PTP1B, providing a promising avenue for therapeutic strategies.

Structure‐Agnostic Bioactivity‐Driven Combinatorial Biosynthesis Reveals New Antidiabetic and Anticancer Triterpenoids

Although combinatorial biosynthesis can dramatically expand the chemical structures of bioactive natural products to identify molecules with improved characteristics, progress in this direction has been hampered by the difficulty in isolating and characterizing the numerous produced compounds. This challenge could be overcome with improved designs that enable the analysis of the bioactivity of the produced metabolites ahead of the time‐consuming isolation procedures. Herein, we showcase a structure‐agnostic bioactivity‐driven combinatorial biosynthesis workflow that introduces bioactivity assessment as a selection‐driving force to guide iterative combinatorial biosynthesis rounds towards enzyme combinations with increasing bioactivity. We apply this approach to produce triterpenoids with potent bioactivity against PTP1B, a promising molecular target for diabetes and cancer treatment. We demonstrate that the bioactivity‐guided workflow can expedite the combinatorial process by enabling the narrowing down of more than 1000 possible combinations to only five highly potent candidates. By focusing the isolation and structural elucidation effort on only these five strains, we reveal 20 structurally diverse triterpenoids, including four new compounds and a novel triterpenoid‐anthranilic acid hybrid, as potent PTP1B inhibitors. This workflow expedites hit identification by combinatorial biosynthesis and is applicable to many other types of bioactive natural products, therefore providing a strategy for accelerated drug discovery.

Exploring Plant-Derived Bioactive Compounds in Olea Europaea L. Leaves as Potent Inhibitors of PTP-1B Using an In silico Approach

In this study, we focus on exploring the medicinal potential of Olea Europaea L., a commonly used plant with diverse indigenous medicinal applications. The main aim is to identify promising phytoconstituents from Olea Europaea L. leaves that can act as inhibitors for the PTP-1B target, utilizing an in silico approach. The phytoconstituents were sourced from the IMMPAT database, and molecular docking was employed to assess their binding affinities. The docking results revealed that rutin (−10.05 kcal/mol) and quercetin (−8.28 kcal/mol) displayed the highest binding scores against PTP-1B, outperforming reference compounds. Furthermore, MM-GBSA calculations indicated favorable free binding energy. To ensure stability, 200 ns Molecular Dynamics simulations were conducted on the 2QBS-Rutin complex. The results revealed that the 2QBS-Rutin complex showed stable conformation throughout the simulation, maintaining consistency with RMSD values below 1 Å. This study highlights rutin and quercetin as promising phytoconstituents from Olea Europaea L. leaves, demonstrating potent-binding affinities against PTP-1B inhibitors.

Molecular Docking and Dynamic Simulation Analysis of Natural Polyphenols for Identifying Potential PTP1B Inhibitors for Type 2 Diabetes

Molecular Docking and Dynamic Simulation Analysis of Natural Polyphenols for Identifying Potential PTP1B Inhibitors for Type 2 Diabetes

New phenylthiosemicarbazide-phenoxy-1,2,3-triazole-N-phenylacetamides as dual inhibitors against α-glucosidase and PTP-1B for the treatment of type 2 diabetes.

This study describes the design, synthesis, and evaluation of a novel series of phenylthiosemicarbazide-phenoxy-1,2,3-triazole-N-phenylacetamide derivatives (7a-l) as dual inhibitors of α-glucosidase and protein tyrosine phosphatase 1-B (PTB-1B). The latter enzymes are two important targets in the treatment of type 2 diabetes. The in vitro obtained data demonstrated that all title compounds 7a-l were more potent than the standard inhibitor acarbose against α-glucosidase while only four derivatives (7a, 7g, 7h, and 7h) were more potent than the standard inhibitor suramin against PTP-1B. Furthermore, these data showed that the most potent α-glucosidase inhibitor was compound 7i, with sixfold higher inhibitory activity than acarbose, and the most potent PTP-1B inhibitor was compound 7a with 3.5-fold higher inhibitory activity than suramin. Kinetic studies of compounds 7i and 7a revealed that they inhibited their target enzymes in a competitive mode. The docking study demonstrated that compounds 7i and 7a well occupied the active site pockets of α-glucosidase and PTP-1B, respectively. In silico pharmacokinetic and toxicity assays of the most potent compounds were performed, and the obtained results were compared with those of the standard inhibitors.

New chromone derivatives bearing thiazolidine-2,4-dione moiety as potent PTP1B inhibitors: Synthesis and biological activity evaluation

A series of chromone derivatives bearing thiazolidine-2,4-dione moiety (5 ∼ 37) were synthesized and evaluated for their PTP1B inhibitory activity, interaction analysis and effects on insulin pathway in palmitic acid (PA)-induced HepG2 cells. The results showed that all derivatives presented potential PTP1B inhibitory activity with IC50 values of 1.40 ± 0.04 ∼ 16.83 ± 0.54 μM comparing to that of positive control lithocholic acid (IC50: 9.62 ± 0.14 μM). Among them, compound 9 had the strongest PTP1B inhibitory activity with the IC50 value of 1.40 ± 0.04 μM. Inhibition kinetic study revealed that compound 9 was a reversible mixed-type inhibitor against PTP1B. CD spectra results confirmed that compound 9 changed the secondary structure of PTP1B by their interaction. Molecular docking explained the detailed binding between compound 9 and PTP1B. Compound 9 also showed 19-fold of selectivity for PTP1B over TCPTP. Moreover compound 9 could recovery PA-induced insulin resistance by increasing the phosphorylation of IRSI and AKT. CETSA results showed that compound 9 significantly increased the thermal stability of PTP1B.

Fungal Metabolites: A Potential Source of Antidiabetic Agents with Particular Reference to PTP1B Inhibitors.

Diabetes is a growing health concern worldwide because it affects people of all age groups and increases the risk of other diseases such as renal impairment and neural and cardiovascular disorders. Oral hypoglycemic drugs mainly control diabetes; however, their associated side effects limit their use in patients with other complications. PTP1B is a viable drug target to explore new antidiabetic drugs. PTP1B acts as a negative regulator of the insulin-signaling pathway, and therefore, PTP1B inhibitors display antihyperglycemic activity. Several classes of compounds from natural and synthetic sources act as PTP1B inhibitors. Fungi are comprehensive in their diversity and recognized as a valuable source for therapeutically active molecules. In recent years, researchers have reported diverse classes of fungal secondary metabolites as potent PTP1B inhibitors. Some metabolites such as 6-O-methylalaternin, fumosorinone A, nordivaricatic acid, and the divarinyl divarate showed good activity and can be taken forward as a lead to develop novel PTP1B inhibitors and antidiabetic drugs. Therefore, the present review focuses on the fungal metabolites identified in the last five years possessing PTP1B inhibitory activity. A total of 128 metabolites are reviewed. Their fungal species and source, chemical structure, and activity in terms of IC50 are highlighted.

Ursolic Acid Derivatives Bearing 1,2,3-triazole Moieties as Potential PTP1B Inhibitors

Ursolic Acid Derivatives Bearing 1,2,3-triazole Moieties as Potential PTP1B Inhibitors

Integrated use of ligand and structure-based virtual screening, molecular dynamics, free energy calculation and ADME prediction for the identification of potential PTP1B inhibitors.

Protein tyrosine phosphatases (PTPs) are the group of enzymes that control both cellular activity and the dephosphorylation of tyrosine (Tyr)-phosphorylated proteins. Dysregulation of PTP1B has contributed to numerous diseases including Diabetes Mellitus, Alzheimer's disease, and obesity rendering PTP1B as a legitimate target for therapeutic applications. It is highly challenging to target this enzyme because of its highly conserved and positively charged active-site pocket motivating researchers to find novel lead compounds against it. The present work makes use of an integrated approach combining ligand-based and structure-based virtual screening to find hit compounds targeting PTP1B. Initially, pharmacophore modeling was performed to find common features like two hydrogen bond acceptors, an aromatic ring and one hydrogen bond donor from the potent PTP1B inhibitors. The dataset of compounds matching with the common pharmacophoric features was filtered to remove Pan-Assay Interference substructure and to match the Lipinski criteria. Then, compounds were further prioritized using molecular docking and top fifty compounds with good binding affinity were selected for absorption, distribution, metabolism, and excretion (ADME) predictions. The top five compounds with high solubility, absorption and permeability holding score of - 10 to - 9.3kcal/mol along with Ertiprotafib were submitted to all-atom molecular dynamic (MD) studies. The MD studies and binding free energy calculations showed that compound M4, M5 and M8 were having better binding affinity for PTP1B enzyme with ∆Gtotal score of - 24.25, - 31.47 and - 33.81kcal/mol respectively than other compounds indicating that compound M8 could be a suitable lead compound as PTP1B inhibitor.

Synthesis, In Vitro, and Computational Studies of PTP1B Phosphatase Inhibitors Based on Oxovanadium(IV) and Dioxovanadium(V) Complexes.

One of the main goals of recent bioinorganic chemistry studies has been to design and synthesize novel substances to treat human diseases. The promising compounds are metal-based and metal ion binding components such as vanadium-based compounds. The potential anticancer action of vanadium-based compounds is one of area of investigation in this field. In this study, we present five oxovanadium(IV) and dioxovanadium(V) complexes as potential PTP1B inhibitors with anticancer activity against the MCF-7 breast cancer cell line, the triple negative MDA-MB-231 breast cancer cell line, and the human keratinocyte HaCaT cell line. We observed that all tested compounds were effective inhibitors of PTP1B, which correlates with anticancer activity. [VO(dipic)(dmbipy)]·2 H2O (Compound 4) and [VOO(dipic)](2-phepyH)·H2O (Compound 5) possessed the greatest inhibitory effect, with IC50 185.4 ± 9.8 and 167.2 ± 8.0 nM, respectively. To obtain a better understanding of the relationship between the structure of the examined compounds and their activity, we performed a computer simulation of their binding inside the active site of PTP1B. We observed a stronger binding of complexes containing dipicolinic acid with PTP1B. Based on our simulations, we suggested that the studied complexes exert their activity by stabilizing the WPD-loop in an open position and limiting access to the P-loop.

Rearranged Diels-Alder Adducts and Prenylated Flavonoids as Potential PTP1B Inhibitors from Morus nigra.

Two novel rearranged Diels-Alder adducts, morunigrines A (1) and B (2), and four new prenylated flavonoids, morunigrols A-D (3-6), were isolated from the twigs of Morus nigra, together with four known prenylated phenolic compounds, including two flavonoids (7 and 8) and two 2-arylbenzofurans (9 and 10). Morunigrines A (1) and B (2) are a novel class of Diels-Alder adducts with unprecedented carbon skeletons featuring a rearranged chalcone-stilbene/2-arylbenzofuran core decorated with a unique methylbiphenyl moiety. The structures of the new compounds were assigned by analysis of spectroscopic data. The absolute configuration of compound 6 was determined by the measurement of specific rotation. A plausible biogenetic pathway for 1 and 2 is also proposed. Compounds 1 and 2 exhibited more potent protein tyrosine phosphatase 1B inhibitory activity with IC50 values of 1.8 ± 0.2 and 1.3 ± 0.3 μM, respectively, than that of the positive control oleanolic acid (IC50, 2.5 ± 0.1 μM).

Role of protein tyrosine phosphatase 1B inhibitor in central insulin resistance and associated cognitive deficits

BackgroundProtein tyrosine phosphatase 1B (PTP1B) inhibitors are potential candidates for the treatment of peripheral insulin resistance and diabetes mellitus. Similar to peripheral action within the brain also, PTP1B activation impairs insulin signaling pathways. Activation of PTP1B in brain also accentuates neuroinflammation, oxidative stress and decreases neurotrophic factors in various brain dysfunctions including cognitive decline. ObjectivesThe main objective of our study was to elucidate the role of alendronate, a potent PTP1B inhibitor (blood brain barrier crossing bisphosphonate) in central insulin resistance and associated memory deficits. MethodologyTo induce central insulin resistance, streptozotocin (3 mg/kg) intracerebroventricular (ICV) was administered in two alternate days (1st and 3rd). After 21 days, memory was assessed via using the passive avoidance and Morris water maze paradigm. At the end of behavioral studies, animals were sacrificed to assess a variety of biochemical and molecular parameters in the hippocampus and cerebral cortex region of the brain. Treatment drug alendronate (3 mg/kg/day, p.o) and standard drug donepezil (3 mg/kg/i.p.) were administered from the 3rd day of STZ administration till the end of the study. Inhibition of PTP1B activates phosphoinsotide-3 kinase (PI3 K) (down-stream regulator of insulin signaling pathway).Thus, to illuminate the mechanism of action of alendronate, PI3 K inhibitor, wortmannin was administered in presence of alendronate in one group. ResultsAdministration of alendronate to ICV streprozotocin treated rats resulted in modulation of the insulin signaling pathway and associated behavioral, biochemical and molecular changes in central insulin resistance. However, the protective effect of alendronate was entirely vanished when it was administered in the presence of wortmannin. ConclusionAlendronate can be an important treatment strategy in central insulin signaling pathway dysfunction and associated cognitive deficits. Protective effect of alendronate is via modulation of PI3-K/Akt signaling pathway.

Discovery of highly functionalized 5,6-seco-grayanane diterpenoids as potent competitive PTP1B inhibitors

Three competitive PTP1B inhibitory diterpenoids with a 5,6-seco-grayanane carbon skeleton (1–3) were isolated and identified fromRhododendron molle. A more potent competitive PTP1B inhibitor (9) was designed and prepared based on a docking study.

Morusalones A-D, Diels-Alder Adducts with 6/7/6/6/6/6 Hexacyclic Ring Systems as Potential PTP1B Inhibitors from Cell Cultures of Morus alba.

Morusalones A-D (1-4), a new class of Diels-Alder adducts featuring unprecedented 6/7/6/6/6/6 hexacyclic core skeletons with a unique bridged cycloheptenone ring, were isolated from Morus alba cell cultures. The biosyntheses for 1-4 were proposed through an unusual Diels-Alder cycloaddition with quinostilbenes as dienophiles and prenyl 2-phenylbenzofuran as a diene to yield the typical methylhexene unit and a rare intramolecular nucleophilic addition to form the cycloheptenone ring. Compounds 1-4 exhibited protein tyrosine phosphatase 1B inhibitory activity.

Psiguadiols A-J, Rearranged Meroterpenoids as Potent PTP1B Inhibitors from Psidium guajava.

Psiguadiols A-J (1-10), new meroterpenoids with rearranged skeletons, were isolated from the leaves of Psidium guajava. Compounds 1-3 represent the first examples of 6,8-diformyl-5,7-dihydroxy-4-phenylchromane-coupled sesquiterpenoids with an unprecedented C-8-spiro-fused 6/6/9/4 tetracyclic ring system. Compounds 4 and 5 represent two unusual scaffolds featuring 1β,6β- and 3α,5α-epoxy rings, respectively. The combination of spectroscopic data analyses, comparison of experimental and calculated ECD data, and single-crystal X-ray diffraction data of 1, 6, and 8 allowed for the assignment of the structures. A putative biosynthetic pathway for 1-10 is discussed. Compounds 1, 7, and 8 exhibited inhibitory activities against PTP1B with IC50 values of 4.7, 6.2, and 9.2 μM, respectively. In addition, molecular docking was performed to investigate the mechanism of action.

Synthesis, SAR and docking studies of substituted aryl phenylthiazolyl phenylcarboxamide as potential protein tyrosine phosphatase 1B (PTP1B) inhibitors.

In our continued effort to discover novel PTP1B inhibitor with improved in vivo activity, we attempted to optimize our previously discovered lead compound by replacing the sulfonyl group with benzoyl group to yield compound II. Additional structural modifications were performed on compound II to yield a series of 24 aryl phenylthiazolyl phenylcarboxamides as potential PTP1B inhibitors. Of the 24 tested, 6 compounds showed good PTP1B inhibitory activity while compound 38 as the most promising one. The plausible PTP1B-binding site interaction of compound 38 showed favourable binding similar to known PTP1B binders and suggests its selectivity towards PTP1B. Compound 38 also showed promising antihyperglycaemic, antidyslipidaemic and insulin resistant reversal activities in vivo in STZ model and db/db mice model. Altogether, the compound 38 presents an excellent candidate for future PTP1B targeted drug discovery.

Thirty Years of Protein Tyrosine Phosphatases – From Housekeeping Enzymes to Therapeutic Targets

Thirty years ago, while working with Eddy Fischer at the UW in Seattle, I succeeded in purifying a protein tyrosine phosphatase (PTP) to homogeneity for the first time. Together with Harry Charbonneau and Ken Walsh, we sequenced the protein, PTP1B, and demonstrated homology with CD45, going on to show that CD45 possessed intrinsic PTP activity. This was important because CD45 is a receptor‐like protein – this observation illustrated the existence of receptor‐like PTPs with the potential to regulate signaling through ligand‐modulated protein tyrosine de‐phosphorylation. Now, we know that PTP1B was the prototype for a large family of such enzymes, comprising ~100 members in humans. Although initially viewed merely as constitutively active housekeeping enzymes, it has now become apparent that the protein phosphatases are critical, specific regulators of signaling in their own right and serve an essential function, in a coordinated manner with the kinases, to determine the response to a physiological stimulus. My lab takes a multidisciplinary approach to characterizing the structure, regulation and function of members of the PTP family of enzymes, with the goal of defining their role in the control of normal and pathophysiological cell function and using them as the basis for identifying novel therapeutic targets and strategies for treatment of major human diseases.As functional studies have established links to disease, the PTPs have been garnering attention as potential therapeutic targets; however, they remain a largely untapped resource for drug development. As a validated target for diabetes and obesity, as well as HER2‐positive cancer, PTP1B has been the subject of extensive drug discovery efforts. Nevertheless, in following established approaches to develop small molecule drugs that bind to the active site of an enzyme, industry has found PTPs to be challenging therapeutic targets. Although it was possible to generate potent, specific and reversible inhibitors of PTP1B, such molecules were highly charged, due to the chemistry underlying PTP‐mediated catalysis, and thus of limited drug development potential. This led industry to conclude that the members of the PTP family are “undruggable”. Consequently, new approaches are required to exploit this important target effectively and to reinvigorate drug discovery efforts.In this presentation, I will discuss how a detailed understanding of the structure, regulation and function of PTP1B, generated in an academic setting, is revealing new approaches to the development of small molecule drug candidates. This is also being extended to other members of the PTP family. Continued progress in this area is now leading to the establishment of novel PTP‐based therapeutics for the treatment of major human diseases.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Synthesis and biological evaluation of tryptophan-derived rhodanine derivatives as PTP1B inhibitors and anti-bacterial agents

Several series of novel tryptophan-derived rhodanine derivatives were synthesized and identified as potential competitive PTP1B inhibitors and antibacterial agents. Among the compounds studied, 10b was found to have the best in vitro inhibition activity against PTP1B (IC50 = 0.36 ± 0.02 μM). In addition, the compounds also showed potent inhibition against other PTPs, especially CDC25B. Molecular docking analysis demonstrated that compounds 7c and 10b could occupy both the catalytic site and the adjacent pTyr binding site simultaneously. The compounds also showed higher levels of activity against gram-positive strains, the gram-negative strain Escherichia coli 1924, and multidrug-resistant gram-positive bacterial strains. Compounds 7c, 8c, 9e, 10a, and 10c had comparable or more potent antibacterial activity than the positive controls.

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.