Discovery of N-Arylsulfonyl-Indole-2-Carboxamide Derivatives as Potent, Selective, and Orally Bioavailable Fructose-1,6-Bisphosphatase Inhibitors—Design, Synthesis, In Vivo Glucose Lowering Effects, and X-ray Crystal Complex Analysis

Exploration of N-Arylsulfonyl-indole-2-carboxamide Derivatives as Novel Fructose-1,6-bisphosphatase Inhibitors by Molecular Simulation

A series of N-arylsulfonyl-indole-2-carboxamide derivatives have been identified as potent fructose-1,6-bisphosphatase (FBPase) inhibitors (FBPIs) with excellent selectivity for the potential therapy of type II diabetes mellitus. To explore the structure–activity relationships (SARs) and the mechanisms of action of these FBPIs, a systematic computational study was performed in the present study, including three-dimensional quantitative structure–activity relationship (3D-QSAR) modeling, pharmacophore modeling, molecular dynamics (MD), and virtual screening. The constructed 3D-QSAR models exhibited good predictive ability with reasonable parameters using comparative molecular field analysis (q² = 0.709, R² = 0.979, r_pre² = 0.932) and comparative molecular similarity indices analysis (q² = 0.716, R² = 0.978, r_pre² = 0.890). Twelve hit compounds were obtained by virtual screening using the best pharmacophore model in combination with molecular dockings. Three compounds with relatively higher docking scores and better ADME properties were then selected for further studies by docking and MD analyses. The docking results revealed that the amino acid residues Met18, Gly21, Gly26, Leu30, and Thr31 at the binding site were of great importance for the effective bindings of these FBPIs. The MD results indicated that the screened compounds VS01 and VS02 could bind with FBPase stably as its cognate ligand in dynamic conditions. This work identified several potential FBPIs by modeling studies and might provide important insights into developing novel FBPIs.

Update of Indoles: Promising molecules for ameliorating metabolic diseases

Obesity and metabolic disorders have gradually become public health-threatening problems. The metabolic disorder is a cluster of complex metabolic abnormalities which are featured by dysfunction in glucose and lipid metabolism, and results from the increasing prevalence of visceral obesity. With the core driving factor of insulin resistance, metabolic disorder mainly includes type 2 diabetes mellitus (T2DM), micro and macro-vascular diseases, non-alcoholic fatty liver disease (NAFLD), dyslipidemia, and the dysfunction of gut microbiota. Strategies and therapeutic attention are demanded to decrease the high risk of metabolic diseases, from lifestyle changes to drug treatment, especially herbal medicines. Indole is a parent substance of numerous bioactive compounds, and itself can be produced by tryptophan catabolism to stimulate glucagon-like peptide-1 (GLP-1) secretion and inhibit the development of obesity. In addition, in heterocycles drug discovery, the indole scaffold is primarily found in natural compounds with versatile biological activity and plays a prominent role in drug molecules synthesis. In recent decades, plenty of natural or synthesized indole deriviatives have been investigated and elucidated to exert effects on regulating glucose hemeostasis and lipd metabolism. The aim of this review is to trace and emphasize the compounds containing indole scaffold that possess immense potency on preventing metabolic disorders, particularly T2DM, obesity and NAFLD, along with the underlying molecular mechanisms, therefore facilitate a better comprehension of their druggability and application in metabolic diseases.

Discovery of Novel Indole Derivatives as Fructose-1,6-bisphosphatase Inhibitors and X-ray Cocrystal Structures Analysis

Liver fructose-1,6-bisphosphatase (FBPase) is a key enzyme in the gluconeogenesis, and its inhibitors are expected to be novel antidiabetic agents. Herein, a series of new indole and benzofuran analogues were designed and synthesized to evaluate the inhibitory activity against FBPase. As a result, the novel FBPase inhibitors bearing N-acylsulfonamide moiety on the 3-position of the indole-2-carboxylic acid scaffold (compounds 22f and 22g) were identified with IC₅₀s at the submicromolar levels. Three X-ray crystal structures of the complexes were solved and revealed the structural basis for the inhibitory activity. The chemoinformatics analysis further disclosed the distinct binding features of this class of inhibitors, providing an insight for further modifications to create structurally distinct FBPase inhibitors with high potency and drug-like properties.

Hypoglycemic and hypolipidemic dual activities of extracts and flavonoids from Desmodium caudatum and an efficient synthesis of the most potent 8-prenylquercetin

Since glucolipid metabolism disorders is often the mono-target therapy fails in managing blood glucose and lipid levels and the other complications, it is urgent and necessary to seek for the new potential drugs or functional food acting on multi-targets. The hypoglycemic and hypolipidemic dual activities of the root, stems and leaves of Desmodium caudatum, which is used for traditional Chinese medicine, was evaluated. Twelve extracts with different extraction conditions were prepared and extract 9 was find to exhibit potential inhibitory activities of fructose-1, 6-bisphosphatase (FBPase), α-glucosidase, and pancrelipase, as well as promote cellular glucose consumption and reduce cellular content of lipid. Five flavonoids were isolated and identified from extract 9, among which 8-prenylquercetin exhibited potent α-glucosidase (IC₅₀ = 4.38 μM) and FBPase (IC₅₀ = 3.62 μM) dual inhibitory activity, which were 75-fold higher than acarbose (IC₅₀ = 330.10 μM) and comparable with AMP (IC₅₀ = 2.92 μM). In addition, 8-prenylquercetin was able to promote glucose consumption and reduce lipid content. Besides, an efficient synthesis of the most potent 8-prenylquercetin was developed from inexpensive and commercially available rutin in 21% overall yield by 6 steps, which lay the foundation of preparation sufficient amount for follow-up study.

Selective Gram-Scale C-H Carbenoid Functionalization of N-Sulfonylarylamides with a Rhodium Catalyst

This work describes an effective Cp*Rh^III-catalyzed C-H carbenoid functionalization of N-sulfonylarylamides. Compared to the previous late-stage C-H modification methods of N-sulfonylarylamide analogues, this method efficiently achieves the gram-scale transformation with 2.5 mol % Rh-catalyst loading at 0 °C or with a 0.1 mol % Rh-catalyst loading at room temperature. The reaction medium has a great influence on the reaction rate. Methanol is optimal, and adding a nonpolar solvent (such as toluene or 1,2-dichloroethane) causes the rate to decrease. Experiments and density functional theory calculations were performed to rationalize the mechanism of rate control by a polar medium.

Recent Advances on Photoinduced Cascade Strategies for the Synthesis of N-Heterocycles

Over the last decade, visible-light photocatalysis has proved to be a powerful tool for the construction of N-heterocyclic frameworks, important constituents of natural products, insecticides, pharmacologically relevant therapeutic agents and catalysts. This account highlights recent developments and established methods towards the photocatalytic cascades for preparation of different classes of N-heterocycles, giving emphasis on our contribution to the field.

Quantitative determination of Cpd118, A novel FBPase inhibitor, in dog plasma by HPLC-MS/MS

Aim: A HPLC-MS/MS method was first developed and validated for the quantification of Cpd118, a novel fructose-1, 6-bisphosphatase inhibitor for controlling gluconeogenesis in Type 2 diabetes mellitus. Materials & methods: Cpd118 was extracted from dog plasma following acetonitrile protein precipitation, separated by HPLC on a CAPCELL PAK ADME column (3.5 μm, 2.1 mm × 100 mm) and quantified using negative heated electrospray ion source-MS/MS. Results: Cpd118 was quantified from plasma using the method described above over a linear range of 10-20,000 ng/ml, with interday and intraday assay accuracy from -11.78 to 4.01% and the precision was ≤11.15%. Conclusion: The method was sensitive and selective for the quantification of Cpd118 and was successfully used to the pharmacokinetic and bioavailability study of Cpd118 in dogs.