Selective Aldose Reductase Inhibitors Research Articles

Randomized Trial of a Selective Aldose Reductase Inhibitor in Patients With Diabetic Cardiomyopathy

BackgroundProgression to symptomatic heart failure is a complication of type 2 diabetes; heart failure onset in this setting is commonly preceded by deterioration in exercise capacity. ObjectivesThis study sought to determine whether AT-001, a highly selective aldose reductase inhibitor, can stabilize exercise capacity among individuals with diabetic cardiomyopathy (DbCM) and reduced peak oxygen uptake (Vo2). MethodsA total of 691 individuals with DbCM meeting inclusion and exclusion criteria were randomized to receive placebo or ascending doses of AT-001 twice daily. Stratification at inclusion included region of enrollment, cardiopulmonary exercise test results, and use of sodium-glucose cotransporter 2 inhibitors or glucagon-like peptide-1 receptor agonists. The primary endpoint was proportional change in peak Vo2 from baseline to 15 months. Subgroup analyses included measures of disease severity and stratification variables. ResultsThe mean age was 67.5 ± 7.2 years, and 50.4% of participants were women. By 15 months, peak Vo2 fell in the placebo-treated patients by −0.31 mL/kg/min (P = 0.005 compared to baseline), whereas in those receiving high-dose AT-001, peak Vo2 fell by −0.01 mL/kg/min (P = 0.21); the difference in peak Vo2 between placebo and high-dose AT-001 was 0.30 (P = 0.19). In prespecified subgroup analyses among those not receiving sodium-glucose cotransporter 2 inhibitors or glucagon-like peptide-1 receptor agonists at baseline, the difference between peak Vo2 in placebo vs high-dose AT-001 at 15 months was 0.62 mL/kg/min (P = 0.04; interaction P = 0.10). ConclusionsAmong individuals with DbCM and impaired exercise capacity, treatment with AT-001 for 15 months did not result in significantly better exercise capacity compared with placebo. (Safety and Efficacy of AT-001 in Patients With Diabetic Cardiomyopathy [ARISE-HF]; NCT04083339)

Selectivity of N(2)-substituted oxotriazinoindole aldose reductase inhibitors is determined by the interaction pattern with Pro301-Arg312 loop of aldehyde reductase

Novel oxotriazinoindoles (OTIs) were recently reported as highly efficient and selective aldose reductase inhibitors. Here, a series of novel N(2)-substituted oxotriazinoindoles was developed with the aim to investigate molecular interactions within the aldose reductase (ALR2) inhibitor binding site. About twice increased inhibition efficacy of the most efficient derivative 14 (N(2)-CH2CH2COOH) compared to the unsubstituted lead OTI was obtained, yet at the expense of selectivity relative to anti-target aldehyde reductase (ALR1). To explain the major drop in selectivity, observed also in other N(2)-substituted derivatives, in silico molecular modeling approach revealed the role of extra interactions with the residues of Arg309, Arg312 and Met302 located in the additional C-terminal loop of ALR1 missing in ALR2, which can prevent or enhance binding in ALR1. These key findings will be used for development of the next generation of selective OTI inhibitors.

Discovery of a Novel Benzothiadiazine-Based Selective Aldose Reductase Inhibitor as Potential Therapy for Diabetic Peripheral Neuropathy.

Aldose reductase2 (ALR2), an activated enzyme in polyol pathway by hyperglycemia, has long been recognized as one of the most promising targets for diabetic complications especially in diabetic peripheral neuropathy (DPN). However, lots of ALR2 inhibitors showed serious sideeffects due to poor selectivity over aldehyde reductase (ALR1). Herein, we described the discovery of a series of benzothiadiazine acetic acid derivatives as potent and selective inhibitors against ALR2 and evaluation of their anti-DPN activities in vivo. Compound 15c carrying carbonyl group at the 3-position of thiadiazine ring showed high potent inhibition against ALR2 (IC50 = 33.19 nM) and about 16109-fold selectivity for ALR2 over ALR1. Cytotoxicity assays ensured the primary biosafety of 15c. Further pharmacokinetic assay in rats indicated 15c had a good pharmacokinetic feature (T1/2 = 5.60 h, AUC(0-t) = 598.57±216.5 μg/mL*h), which was superior to Epalrestat (T1/2 = 2.23 h, AUC(0-t) = 20.43±3.7 μg/mL*h). Finally, in streptozotocin (STZ)-induced diabetic rat model, 15c significantly increased the nerve conduction velocities (NCVs) of impaired sensory and motor nerve, achieved potent inhibition of D-sorbitol production in the sciatic nerves, and significantly increased the paw withdrawal mechanical threshold (PWMT). Combined the above investigations, we proposed that 15c might represent a promising lead compound for discovery of anti-diabetic peripheral neuropathy drug.

450-P: N-Terminal Pro-B Type Natriuretic Peptide Concentrations in Diabetic Cardiomyopathy—Baseline Data from the ARISE-HF Trial

Background: Diabetic Cardiomyopathy (DbCM) is a form of Stage B heart failure (HF). Concentrations of N-terminal pro-B type natriuretic peptide (NT-proBNP) may predict risk for HF progression in persons with DbCM. The ARISE-HF study (NCT04083339) is evaluating efficacy of AT-001, a highly selective aldose reductase inhibitor (AT-001) to improve exercise tolerance in affected patients. The aim of this analysis was to assess association between baseline NT-proBNP and cardiac status in type 2 diabetes participants with DbCM. Methods: Impaired exercise tolerance and baseline characteristics were evaluated in 679 patients with DbCM as a function of NT-proBNP at enrollment. Results: Median NT-proBNP in the overall study population was 71 ng/L (IQR 35-133). Baseline characteristics were similar across NT-proBNP concentrations, however, participants with higher NT-proBNP had higher left atrial volume (p<0.001) and higher right ventricular systolic pressure (p=0.04) on baseline echocardiogram. Higher NT-proBNP concentrations were associated with reduced physical activity reflected in lower PASE Score and a worse functional capacity reflected in lower peak VO2 (p<0.001) (Table 1). Conclusion: Among patients with DbCM, elevated NT-proBNP is associated with echocardiographic abnormalities and worse cardiac functional capacity and inversely associated with activity. Disclosure J.Butler: Consultant; Abbott,, Amgen, Applied Therapeutics, Array, Astra Zeneca, Bayer,, Boehringer Ingelheim, Bristol Myers Squibb, CVRx, G3 Pharma,, Impulse Dynamics, Innolife, Janssen, LivaNova, Luitpold, Medtronic, Merck, Novartis, NovoNordisk, Relypsa, Roche, Sequana Medical, Vifor, Speaker's Bureau; Novartis, Boehringer Ingelheim-Lilly, Astra Zeneca, Janssen. F.Zannad: Advisory Panel; BMS, Novo Nordisk, Pfizer Inc., Servier Laboratories, Other Relationship; Applied Therapeutics Inc., Bayer Inc., Boehringer Ingelheim and Eli Lilly Alliance, Merck & Co., Inc., Novartis. J.L.Januzzi: Consultant; Boehringer Ingelheim Inc., Janssen Pharmaceuticals, Inc., AstraZeneca, Research Support; Applied Therapeutics Inc., Abbott, Roche Diagnostics, Novartis, Innolife Co., Ltd. S.Del prato: Advisory Panel; Abbott Diagnostics, Altimmune, Amarin Corporation, Applied Therapeutics Inc., Eli Lilly and Company, Merck & Co., Inc., Novo Nordisk A/S, Vertex Pharmaceuticals Incorporated, Novartis, Consultant; A. Menarini Diagnostics, Research Support; AstraZeneca, Boehringer Ingelheim International GmbH, Speaker's Bureau; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck & Co., Inc., Novo Nordisk A/S, Sanofi. J.Ezekowitz: Advisory Panel; Applied Therapeutics Inc. N.E.Ibrahim: None. C.S.Lam: Other Relationship; Actelion, Alleviant Medical, Allysta Pharma, Amgen, AnaCardio, Applied Therapeutics, AstraZeneca, Bayer, Boehringer-Ingelheim, Boston Scientific, Cytokinetics, Darma Inc, EchoNous Inc, Eli Lilly, Impulse Dynamics, Intellia Therapeutics, Ionis Pharmaceutical, Janssen Research & Development LLC, Medscape/WebMD Global LLC, Merck, Novartis, Novo Nordisk, Prosciento Inc, Radcliffe Group Ltd, Recardio Inc, ReCor Medical, Roche Diagnostics, Sanofi, Siemens Healthcare Diagnostics, Us2.ai. R.Perfetti: None. J.Rosenstock: Advisory Panel; Applied Therapeutics Inc., Boehringer Ingelheim Inc., Eli Lilly and Company, Novo Nordisk, Oramed Pharmaceuticals, Sanofi, Zealand Pharma A/S, Intarcia Therapeutics, Inc., Hanmi Pharm. Co., Ltd., Research Support; Applied Therapeutics Inc., Boehringer Ingelheim Inc., Eli Lilly and Company, Merck & Co., Inc., Novartis, Novo Nordisk, Pfizer Inc., Sanofi, Intarcia Therapeutics, Inc. W.Tang: Consultant; Sequana Medical NV, Cardiol Therapeutics, Genomics plc, Zehna Therapeutics LLC, Renovacor, Boston Scientific Corporation, Kiniksa Pharmaceuticals Inc, WhiteSwell Inc, CardiaTec Biosciences Inc, Other Relationship; American Board of Internal Medicine, Springer Nature, Research Support; National Heart, Lung, and Blood Institute. A.Urbinati: None.

1238-P: The Face of Diabetic Cardiomyopathy—Baseline Characteristics from the ARISE-HF Trial

Background: Diabetic Cardiomyopathy (DbCM) is a severe complication of diabetes and a cause of heart failure (HF) occurring in the absence of other causes of cardiac dysfunction. Methods and Results: ARISE-HF (NCT04083339) is a global Phase 3 randomized study evaluating the safety and efficacy of a novel highly selective aldose reductase inhibitor (AT-001) versus placebo to improve exercise capacity in individuals with DbCM (defined by elevated cardiac biomarkers or structural/functional cardiac abnormalities along with impaired exercise capacity). Table 1 details the 684 study participants with DbCM in the study: 50% female, with a mean age 67.5 years. Glycemic control at enrollment was excellent (HbA1c of 6.99%). At baseline, the median NT-proBNP was 71 ng/L and hs-cTnT was 9 ng/L. Among echocardiographic abnormalities evaluated at enrollment, the most common were abnormal global longitudinal strain and impaired diastolic relaxation. Daily physical activity was low (mean PASE score of 154.3 + 89.6). Significant impairment in cardiac functional capacity was present at enrollment with a peak VO2 of 15.7 + 3.8 ml/kg/min. Conclusion: The ARISE-HF trial is an ongoing phase 3 clinical trial evaluating the safety and efficacy of aldose reductase inhibition on exercise capacity in patients with DbCM. The baseline analysis of the study cohort provides a unique characterization of individuals with DbCM. Disclosure J.Butler: Consultant; Abbott,, Amgen, Applied Therapeutics, Array, Astra Zeneca, Bayer,, Boehringer Ingelheim, Bristol Myers Squibb, CVRx, G3 Pharma,, Impulse Dynamics, Innolife, Janssen, LivaNova, Luitpold, Medtronic, Merck, Novartis, NovoNordisk, Relypsa, Roche, Sequana Medical, Vifor, Speaker's Bureau; Novartis, Boehringer Ingelheim-Lilly, Astra Zeneca, Janssen. F.Zannad: Advisory Panel; BMS, Novo Nordisk, Pfizer Inc., Servier Laboratories, Other Relationship; Applied Therapeutics Inc., Bayer Inc., Boehringer Ingelheim and Eli Lilly Alliance, Merck & Co., Inc., Novartis. J.L.Januzzi: Consultant; Boehringer Ingelheim Inc., Janssen Pharmaceuticals, Inc., AstraZeneca, Research Support; Applied Therapeutics Inc., Abbott, Roche Diagnostics, Novartis, Innolife Co., Ltd. S.Del prato: Advisory Panel; Abbott Diagnostics, Altimmune, Amarin Corporation, Applied Therapeutics Inc., Eli Lilly and Company, Merck & Co., Inc., Novo Nordisk A/S, Vertex Pharmaceuticals Incorporated, Novartis, Consultant; A. Menarini Diagnostics, Research Support; AstraZeneca, Boehringer Ingelheim International GmbH, Speaker's Bureau; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck & Co., Inc., Novo Nordisk A/S, Sanofi. J.Ezekowitz: Advisory Panel; Applied Therapeutics Inc. N.E.Ibrahim: None. C.S.Lam: Other Relationship; Actelion, Alleviant Medical, Allysta Pharma, Amgen, AnaCardio, Applied Therapeutics, AstraZeneca, Bayer, Boehringer-Ingelheim, Boston Scientific, Cytokinetics, Darma Inc, EchoNous Inc, Eli Lilly, Impulse Dynamics, Intellia Therapeutics, Ionis Pharmaceutical, Janssen Research & Development LLC, Medscape/WebMD Global LLC, Merck, Novartis, Novo Nordisk, Prosciento Inc, Radcliffe Group Ltd, Recardio Inc, ReCor Medical, Roche Diagnostics, Sanofi, Siemens Healthcare Diagnostics, Us2.ai. R.Perfetti: None. J.Rosenstock: Advisory Panel; Applied Therapeutics Inc., Boehringer Ingelheim Inc., Eli Lilly and Company, Novo Nordisk, Oramed Pharmaceuticals, Sanofi, Zealand Pharma A/S, Intarcia Therapeutics, Inc., Hanmi Pharm. Co., Ltd., Research Support; Applied Therapeutics Inc., Boehringer Ingelheim Inc., Eli Lilly and Company, Merck & Co., Inc., Novartis, Novo Nordisk, Pfizer Inc., Sanofi, Intarcia Therapeutics, Inc. W.Tang: Consultant; Sequana Medical NV, Cardiol Therapeutics, Genomics plc, Zehna Therapeutics LLC, Renovacor, Boston Scientific Corporation, Kiniksa Pharmaceuticals Inc, WhiteSwell Inc, CardiaTec Biosciences Inc, Other Relationship; American Board of Internal Medicine, Springer Nature, Research Support; National Heart, Lung, and Blood Institute. A.Urbinati: None.

A molecular hybridization approach for the design of selective aldose reductase (ALR2) inhibitors and exploration of their activities against protein tyrosine phosphatase 1B (PTP1B)

Type II diabetes mellitus is a metabolic disease associated with insulin resistance and high blood glucose levels. Under hyperglycemic conditions the polyol pathway is significantly activated resulting in a series of stress conditions and, finally, in cellular damage. Aldose reductase is the first enzyme of the polyol pathway which is implicated in the onset of long-term diabetic complications. Although many efforts have been focused on developing clinical aldose reductase inhibitors in previous years, they were fruitless due to the poor selectivity profile over the detoxifying aldehyde reductase enzyme. A series of novel benzothiazole-based 4-oxothiazolidin-2-yl-imino acetic acid derivatives has been designed based on our experience from previously reported (Z)-2-(benzo[d]thiazol-2-ylimino)thiazolidin-4-one derivatives. In addition, we followed a molecular hybridization of two well-known aldose reductase inhibitors (zopolrestat and epalrestat) by replacing toxicophore moieties and combining crucial fragments for aldose reductase inhibitory activity as well as selectivity. The most promising compounds in this series (5b and 5d) exhibited potent aldose reductase inhibitory activity with IC50 values of 46 and 67 nM, respectively, and optimal selectivity towards aldehyde reductase. Moreover, inspired by the idea that certain pharmacophoric features of aldose reductase inhibitors overlap with that of protein tyrosine phosphatase 1B inhibitors, we investigated the inhibitory activity of synthesized compounds towards this enzyme. Finally, an extensive docking simulation study was carried out in order to explore the binding modes of examined compounds in the active sites of these enzymes and to interpret the influence of fluorinated moieties in compounds 5b and 5d on their selectivity profiles.

207-LB: Aldose Reductase Inhibition by AT-001 Limits Diastolic Dysfunction and Adverse Remodelling in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DbCM) increases mortality and morbidity in type 2 diabetes (T2D) subjects. Increased cardiac aldose reductase (AR) activity has been correlated with impaired cardiac function and less effective energy metabolism in DbCM subjects. The aim of the present study was to evaluate the effect AT-001, a potent and selective AR inhibitor, on cardiac function, structure, and energy metabolism in diabetic cardiomyopathic mice that overexpress the human AR (hAR-Tg) . The effects of AT-001 were compared to those of dapagliflozin, a sodium-glucose cotransporter inhibitor that decreases the risk of cardiovascular death. DbCM was induced in human AR overexpressing transgenic (hAR-Tg) mice by subjecting them to a high-fat diet (60% kcal from lard) for 10-wk with a single intraperitoneal streptozotocin injection (75 mg/kg) at 4-wk. Male mice were randomized to receive either vehicle, AT-001 (40 mg/kg/day) ,or dapagliflozin (1 mg/kg/day) for the final 3-wk. AT-001 treatment improved diastolic function in vivo (a decrease in the E/e’ ratio and an increase in the E’/A’) and reduced left ventricular mass (LV) mass in DbCM mice compared to vehicle-treated DbCM mice. Cardioprotection by AT-001 was associated with reduced cardiac AR activity, decreased circulating blood sorbitol levels, and a reduction in cardiac fatty acid oxidation rates in the DbCM mice. Treatment with dapagliflozin did not significantly affect either diastolic function or LV mass in DbCM mice. In addition, dapagliflozin did not have a significant effect on cardiac fatty acid oxidation rates. In summary, the present study demonstrates that AT-001 attenuates diastolic dysfunction and cardiac hypertrophy in DbCM. AT-001-induced cardioprotection is accompanied by reduced cardiac fatty oxidation rates in DbCM. Disclosure Q. G. Karwi: None. R. Ramasamy: Consultant; Applied Therapeutics. J. R. Ussher: None. G. Lopaschuk: None. K. Gopal: None. S. Tabatabaei dakhili: None. C. S. Wagg: None. L. Zhang: None. Q. Sun: None. C. T. Saed: None. S. Panidarapu: None. R. Perfetti: Employee; Applied Therapeutics.

Identification of 9H-purin-6-amine derivatives as novel aldose reductase inhibitors for the treatment of diabetic complications.

A series of 9H-purin-6-amine derivatives as aldose reductase (ALR) inhibitors were designed and synthesized. Most of these derivatives, having a C6-substituted benzylamine side chain and N9 carboxylic acid on the core structure, were found to be potent and selective ALR inhibitors, with submicromolar IC50 values against ALR2. Particularly, compound 4e was the most active with an IC50 value of 0.038 μM, and it was also proved to be endowed with excellent inhibitory selectivity. The structure-activity relationship and molecular docking studies highlighted the importance of the carboxylic acid head group along with different halogen substituents on the C6 benzylamine side chain of the 9H-purin-6-amine scaffold for the construction of strong and selective ALR inhibitors.

(4-Oxo-2-thioxothiazolidin-3-yl)acetic acids as potent and selective aldose reductase inhibitors

(4-Oxo-2-thioxothiazolidin-3-yl)acetic acids exhibit a wide range of pharmacological activities. Among them, the only derivative used in clinical practice is the aldose reductase inhibitor epalrestat. Structurally related compounds, [(5Z)-(5-arylalkylidene-4-oxo-2-thioxo-1,3-thiazolidin-3-yl)]acetic acid derivatives were prepared previously as potential antifungal agents. This study was aimed at the determination of aldose reductase inhibitory action of the compounds in comparison with epalrestat and evaluation of structure-activity relationships (SAR).The aldose reductase (ALR2) enzyme was isolated from the rat eye lenses, while aldehyde reductase (ALR1) was obtained from the kidneys. The compounds studied were found to be potent inhibitors of ALR2 with submicromolar IC50 values. (Z)-2-(5-(1-(5-butylpyrazin-2-yl)ethylidene)-4-oxo-2-thioxothiazolidin-3-yl)acetic acid (3) was identified as the most efficacious inhibitor (over five times more potent than epalrestat) with mixed-type inhibition. All the compounds also exhibited low antiproliferative (cytotoxic) activity to the HepG2 cell line. Molecular docking simulations of 3 into the binding site of the aldose reductase enzyme identified His110, Trp111, Tyr48, and Leu300 as the crucial interaction counterparts responsible for the high-affinity binding. The selectivity factor for 3 in relation to the structurally related ALR1 was comparable to that for epalrestat. SAR conclusions suggest possible modifications to improve further inhibition efficacy, selectivity, and biological availability in the group of rhodanine carboxylic acids.

Aldose reductase and protein tyrosine phosphatase 1B inhibitors as a promising therapeutic approach for diabetes mellitus.

Diabetes mellitus is a metabolic disease characterized by high blood glucose levels and usually associated with several chronic pathologies. Aldose reductase and protein tyrosine phosphatase 1B enzymes have identified as two novel molecular targets associated with the onset and progression of type II diabetes and related comorbidities. Although many inhibitors against these enzymes have already found in the field of diabetic mellitus, the research for discovering more effective and selective agents with optimal pharmacokinetic properties continues. In addition, dual inhibition of these target proteins has proved as a promising therapeutic approach. A variety of diverse scaffolds are presented in this review for the future design of potent and selective inhibitors of aldose reductase and protein tyrosine phosphatase 1B based on the most important structural features of both enzymes. The discovery of novel dual aldose reductase and protein tyrosine phosphatase 1B inhibitors could be effective therapeutic molecules for the treatment of insulin-resistant type II diabetes mellitus. The methods used comprise a literature survey and X-ray crystal structures derived from Protein Databank (PDB). Despite the available therapeutic options for type II diabetes mellitus, the inhibitors of aldose reductase and protein tyrosine phosphatase 1B could be two promising approaches for the effective treatment of hyperglycemia and diabetes-associated pathologies. Due to the poor pharmacokinetic profile and low invivo efficacy of existing inhibitors of both targets, the research turned to more selective and cell-permeable agents as well as multi-target molecules.

A Study of the Electrophilic Aroylation of 1-Aryl-1H-pyrroles: An Improved Preparation of an Active and Selective Aldose Reductase Inhibitor

The aroyl-1-aryl-1H-pyrrole moiety is an important scaffold present in a number of biologically active compounds.1–5 Based on such precedent, we were prompted to study the electrophilic benzoylatio...

3-Mercapto-5H-1,2,4-Triazino[5,6-b]Indole-5-Acetic Acid (Cemtirestat) Alleviates Symptoms of Peripheral Diabetic Neuropathy in Zucker Diabetic Fatty (ZDF) Rats: A Role of Aldose Reductase.

Peripheral neuropathy is the most prevalent chronic complication of diabetes mellitus. Good glycemic control can delay the appearance of neuropathic symptoms in diabetic patients but it is not sufficient to prevent or cure the disease. Therefore therapeutic approaches should focus on attenuation of pathogenetic mechanisms responsible for the nerve injury. Considering the role of polyol pathway in the etiology of diabetic neuropathy, we evaluated the effect of a novel efficient and selective aldose reductase inhibitor, 3-mercapto-5H-1,2,4-triazino[5,6-b]indole-5-acetic acid (cemtirestat), on symptoms of diabetic peripheral neuropathy in Zucker Diabetic Fatty (ZDF) rats. Since the age of 5months, male ZDF rats were orally administered cemtirestat, 2.5 and 7.5mg/kg/day, for two following months. Thermal hypoalgesia was evaluated by tail flick and hot plate tests. Tactile allodynia was determined by a von Frey flexible filament test. Two-month treatment of ZDF rats with cemtirestat (i) did not affect physical and glycemic status of the animals; (ii) partially inhibited sorbitol accumulation in red blood cells and the sciatic nerve; (iii) markedly decreased plasma levels of thiobarbituric acid reactive substances; (iv) normalized symptoms of peripheral neuropathy with high significance. The presented findings indicate that inhibition of aldose reductase by cemtirestat is not solely responsible for the recorded improvement of the behavioral responses. In future studies, potential effects of cemtirestat on consequences of diabetes that are not exclusively dependent on glucose metabolism via polyol pathway should be taken into consideration.

Novel 2-phenoxypyrido[3,2-b]pyrazin-3(4H)-one derivatives as potent and selective aldose reductase inhibitors with antioxidant activity

To develop multifunctional aldose reductase (AKR1B1) inhibitors for anti-diabetic complications, a novel series of 2-phenoxypyrido[3,2-b]pyrazin-3(4H)-one derivatives were designed and synthesised. Most of the derivatives were found to be potent and selective against AKR1B1, and 2-(7-chloro-2-(3,5-dihydroxyphenoxy)-3-oxopyrido[3,2-b]pyrazin-4(3H)-yl) acetic acid (4k) was the most active with an IC50 value of 0.023 µM. Moreover, it was encouraging to find that some derivatives showed strong antioxidant activity, and among them, the phenolic 3,5-dihydroxyl compound 4l with 7-bromo in the core structure was proved to be the most potent, even comparable to that of the well-known antioxidant Trolox. Thus the results suggested success in the construction of potent and selective AKR1B1 inhibitors with antioxidant activity.

Antidiabetic potential: In vitro inhibition effects of bromophenol and diarylmethanones derivatives on metabolic enzymes.

Aldose reductase converts glucose to sorbitol in the polyol pathway. It is an important enzyme to prevent diabetic complications. In this study, we studied the inhibitory effects of bromophenol derivatives on aldose reductase (AR), α-glucosidase, and α-amylase enzymes. In the bromophenols series, compound 1f showed the maximum inhibition effect against AR with a Ki value of 0.05 ± 0.01 μM, while compound 1d showed the lowest inhibition effect against AR with a Ki value of 1.13 ± 0.99 μM. In addition, α-amylase from porcine pancreas and α-glucosidase from Saccharomyces cerevisiae were used as enzymes. In this study, all compounds were tested for the inhibition of the α-glucosidase enzyme and demonstrated efficient inhibition profiles with Ki values in the range of 43.62 ± 5.28 to 144.37 ± 16.37 nM against α-glucosidase. Additionally, these compounds were tested against the α-amylase enzyme, which determined an effective inhibition profile with IC50 values in the range of 9.63-91.47 nM. These compounds can be selective inhibitors of AR, α-glucosidase, and α-amylase enzymes as antidiabetic agents.

Molecular modelling and synthesis of spiroimidazolidine-2,4-diones with dual activities as hypoglycemic agents and selective inhibitors of aldose reductase

Novel derivatives of spiroimidazolidinedione were synthesized and evaluated as hypoglycemic agents through binding to sulfonylurea receptor 1 (SUR1) in pancreatic beta-cells. Their selectivity index was calculated against both aldehyde reductase (ALR1) and aldose reductase (ALR2). Aldehyde reductase is a key enzyme in the polyol pathway that is involved in the etiology of the secondary diabetic complications. All structures were confirmed by microanalysis and by IR, 1H NMR, 13C NMR and EI-MS spectroscopy. The investigated compounds were subjected to molecular docking and an in silico prediction study to determine their free energy of binding (ΔG) values and predict their physicochemical properties and drug-likeness scores. Compound 1′-(5-chlorothiophene-2-ylsulfonyl)spiro[cyclohexane-1,5′-imidazolidine]-2′,4′-dione showed IC50 0.47 µM and 79% reduction in blood glucose level with a selectivity index 127 for ALR2.

Design, synthesis, structure-activity relationships and X-ray structural studies of novel 1-oxopyrimido[4,5-c]quinoline-2-acetic acid derivatives as selective and potent inhibitors of human aldose reductase

Human aldose reductase (AKR1B1, AR) is a key enzyme of the polyol pathway, catalyzing the reduction of glucose to sorbitol at high glucose concentrations, as those found in diabetic condition. Indeed, AKR1B1 overexpression is related to diabetes secondary complications and, in some cases, with cancer. For many years, research has been focused on finding new AKR1B1 inhibitors (ARIs) to overcome these diseases. Despite the efforts, most of the new drug candidates failed because of their poor pharmacokinetic properties and/or unacceptable side effects. Here we report the synthesis of a series of 1-oxopyrimido[4,5-c]quinoline-2-acetic acid derivatives as novel ARIs. IC50 assays and X-ray crystallographic studies proved that these compounds are promising hits for further drug development, with high potency and selectivity against AKR1B1. Based on the determined X-ray structures with hit-to-lead compounds, we designed and synthesized a second series that yielded lead compound 68 (Kiappvs. AKR1B1 = 73 nM). These compounds are related to the previously reported 2-aminopyrimido[4,5-c]quinolin-1(2H)-ones, which exhibit antimitotic activity. Regardless of their similarity, the 2-amino compounds are unable to inhibit AKR1B1 while the 2-acetic acid derivatives are not cytotoxic against fibrosarcoma HT-1080 cells. Thus, the replacement of the amino group by an acetic acid moiety changes their biological activity, improving their potency as ARIs.

N-(Aroyl)-N-(arylmethyloxy)-α-alanines: Selective inhibitors of aldose reductase

Aldose reductase (ALR2), a NADPH-dependent reductase, is the first and rate-limiting enzyme of the polyol pathway of glucose metabolism and is implicated in the pathogenesis of secondary diabetic complications. In the last decades, this enzyme has been targeted for inhibition but despite the numerous efforts made to identify potent and safe ALR2 inhibitors, many clinical candidates have been a failure. For this reason the research of new ALR2 inhibitors highly effective, selective and with suitable pharmacokinetic properties is still of great interest. In this paper some new N-(aroyl)-N-(arylmethyloxy)alanines have been synthesized and tested for their ability to inhibit ALR2. Some of the synthesized compounds exhibit IC50 in the low micromolar range and all have proved to be highly selective towards ALR2. The N-(aroyl)-N-(arylmethyloxy)-α-alanines are a promising starting point for the development of new ALR2 selective drugs with the aim of delaying the onset of diabetic complications.

Coumarin-thiazole and -oxadiazole derivatives: Synthesis, bioactivity and docking studies for aldose/aldehyde reductase inhibitors

In continuation of our previous efforts directed towards the development of potent and selective inhibitors of aldose reductase (ALR2), and to control the diabetes mellitus (DM), a chronic metabolic disease, we synthesized novel coumarin-thiazole 6(a–o) and coumarin-oxadiazole 11(a–h) hybrids and screened for their inhibitory activity against aldose reductase (ALR2), for the selectivity against aldehyde reductase (ALR1). Compounds were also screened against ALR1. Among the newly designed compounds, 6c, 11d, and 11g were selective inhibitors of ALR2. Whereas, (E)-3-(2-(2-(2-bromobenzylidene)hydrazinyl)thiazol-4-yl)-2H-chromen-2-one 6c yielded the lowest IC50 value of 0.16±0.06μM for ALR2. Moreover, compounds (E)-3-(2-(2-benzylidenehydrazinyl)thiazol-4-yl)-2H-chromen-2-one (6a; IC50=2.94±1.23μM for ARL1 and 0.12±0.05μM for ARL2) and (E)-3-(2-(2-(1-(4-bromophenyl)ethylidene)hydrazinyl)thiazol-4-yl)-2H-chromen-2-one (6e; IC50=1.71±0.01μM for ARL1 and 0.11±0.001μM for ARL2) were confirmed as dual inhibitors. Furthermore, compounds 6i, 6k, 6m, and 11b were found to be selective inhibitors for ALR1, among which (E)-3-(2-(2-((2-amino-4-chlorophenyl)(phenyl)methylene)hydrazinyl)thiazol-4-yl)-2H-chromen-2-one (6m) was most potent (IC50=0.459±0.001μM). Docking studies performed using X-ray structures of ALR1 and ALR2 with the given synthesized inhibitors showed that coumarinyl thiazole series lacks the carboxylate function that could interact with the anionic binding site being a common ALR1/ALR2 inhibitors trait. Molecular docking study with dual inhibitor 6e also suggested plausible binding modes for the ALR1 and ALR2 enzymes. Hence, the results of this study revealed that coumarinyl thiazole and oxadiazole derivatives could act as potential ALR1/ALR2 inhibitors.

A series of pyrido[2,3-b]pyrazin-3(4H)-one derivatives as aldose reductase inhibitors with antioxidant activity

A series of pyrido[2,3-b]pyrazin-3(4H)-one based derivatives were designed as inhibitors of aldose reductase (ALR2), the enzyme which plays a key role in the development of diabetes complications as well as in the oxidative stress processes associated with diabetes and other pathologies. Most of the derivatives, having a substituted C2 aromatic group and a N4 acetic acid group on the core structure, were found to be potent and selective aldose reductase inhibitors with submicromolar IC50 values, and 9c was the most active with IC50 value 0.009 μM. Particularly, a number of the designed compounds bearing phenolic hydroxyl substituted C2-styryl side chain showed excellent not only in ALR2 inhibition but also in antioxidant, and among these 11i was proved to be the top one with an antioxidant ability even comparable to that of the well-known antioxidant Trolox. Structure-activity relationship and molecular docking studies highlighted the importance of phenolic hydroxyl substituents and vinyl spacer in C2 side chain of the scaffold for the construction of efficient and multifunctional ALR2 inhibitors.

ChemInform Abstract: Synthesis of Optically Pure (S)‐2‐Amino‐5‐arylpent‐4‐ynoic Acids by Sonogashira Reactions and Their Potential Use as Highly Selective Potent Inhibitors of Aldose Reductase.

AbstractA Ni complex is prepared and then arylated via a Sonogashira cross‐coupling reaction.