Synthetic Strategies toward SGLT2 Inhibitors

Development of a Concise Synthetic Approach to Gliflozin Aglycones from Regioselective Deprotonation of 1,4-Dihalobenzenes

Herein, we report a concise synthetic approach to gliflozin (SGLT2 inhibitors) aglycones from generating regioselective ortho-lithiation based on differentiating the acidifying effect of 1,4-dihalobenzenes and reacting with (hetero)aromatic aldehydes. Then, the resulting diarylmethyl alcohol was converted to diarylmethane using acid-mediated reduction, offering a two-step practical method for synthesizing aglycones of various gliflozins such as Dapagliflozin, Empagliflozin, and Ipragliflozins.

Update in non-alcoholic fatty liver disease management: role of sodium-glucose cotransporter 2 inhibitors

Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive lipid accumulation in hepatocytes without significant alcohol consumption. It is closely associated with sedentarism, hypercaloric diets, obesity, dyslipidemia, insulin resistance, type 2 diabetes mellitus, and genetic predisposition. NAFLD comprises a spectrum of liver disorders, from simple steatosis to non-alcoholic (NASH) and liver cirrhosis. The complex etiological mechanisms include oxidative stress, inflammation, apoptosis, and fibrosis; therefore, its management is challenging. Sodium-glucose cotransporter type 2 inhibitors (SGLT2i), a class of antidiabetic drugs, have emerged as promising therapeutic agents due to their ability to improve key metabolic parameters, including obesity, dyslipidemia, insulin resistance, and hyperglycemia. This review explores the cellular mechanisms by which SGLT2i, either as monotherapy or combined with other treatments, modulate signaling pathways involved in lipid and carbohydrate metabolism. Additionally, we examine their effects on oxidative stress, inflammation, fibrosis, and apoptosis, which are critical drivers of NAFLD progression. This review is intended to summarize the multiple benefits of SGLT2 inhibitors and to educate healthcare providers on the therapeutic potential of these drugs in order to foster their incorporation into effective NAFLD management plans.

Synthetic Approaches to the New Drugs Approved during 2023

This review is the next installment of an annual series that discusses the synthetic routes to access 28 small molecule drugs that were approved worldwide in 2023. A brief description of each drug's mechanism of action, the history of its discovery and development, and the synthetic approaches published in primary or patent literature that were most likely used for clinical studies or development are included. Synthetic chemistry, used to convert complex intermediates to active compounds or build a new drug from basic building block chemicals, is critical to delivery of new drugs and treatments for disease to patients.

Extrarenal Benefits of SGLT2 Inhibitors in the Treatment of Cardiomyopathies

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have emerged as pivotal medications for heart failure, demonstrating remarkable cardiovascular benefits extending beyond their glucose-lowering effects. The unexpected cardiovascular advantages have intrigued and prompted the scientific community to delve into the mechanistic underpinnings of these novel actions. Preclinical studies have generated many mechanistic theories, ranging from their renal and extrarenal effects to potential direct actions on cardiac muscle cells, to elucidate the mechanisms linking these drugs to clinical cardiovascular outcomes. Despite the strengths and limitations of each theory, many await validation in human studies. Furthermore, whether SGLT2 inhibitors confer therapeutic benefits in specific subsets of cardiomyopathies akin to their efficacy in other heart failure populations remains unclear. By examining the shared pathological features between heart failure resulting from vascular diseases and other causes of cardiomyopathy, certain specific molecular actions of SGLT2 inhibitors (particularly those targeting cardiomyocytes) would support the concept that these medications will yield therapeutic benefits across a broad range of cardiomyopathies. This article aims to discuss the important mechanisms of SGLT2 inhibitors and their implications in hypertrophic and dilated cardiomyopathies. Furthermore, we offer insights into future research directions for SGLT2 inhibitor studies, which hold the potential to further elucidate the proposed biological mechanisms in greater detail.

An efficient C-glycoside production platform enabled by rationally tuning the chemoselectivity of glycosyltransferases

Despite the broad potential applications of C-glycosides, facile synthetic methods remain scarce. Transforming glycosyltransferases with promiscuous or natural O-specific chemoselectivity to C-glycosyltransferases is challenging. Here, we employ rational directed evolution of the glycosyltransferase MiCGT to generate MiCGT-QDP and MiCGT-ATD mutants which either enhance C-glycosylation or switch to O-glycosylation, respectively. Structural analysis and computational simulations reveal that substrate binding mode govern C-/O-glycosylation selectivity. Notably, directed evolution and mechanism analysis pinpoint the crucial residues dictating the binding mode, enabling the rational design of four enzymes with superior non-inherent chemoselectivity, despite limited sequence homology. Moreover, our best mutants undergo testing with 34 substrates, demonstrating superb chemoselectivities, regioselectivities, and activities. Remarkably, three C-glycosides and an O-glycoside are produced on a gram scale, demonstrating practical utility. This work establishes a highly selective platform for diverse glycosides, and offers a practical strategy for creating various types of glycosylation platforms to access pharmaceutically and medicinally interesting products.

Expanding the Scope of C-Glycoside Synthesis from Unstable Organolithium Reagents Using Flow Microreactors

C-glycosides are versatile scaffolds for drugs and bioactive compounds. The common organolithium-based synthesis of C-glycosides is limited by low reaction temperatures and a restricted substrate scope. To address these issues, a flow microreactor (FMR) was utilized for rapid mixing and precise temperature control, enabling C-glycoside synthesis at temperatures up to 40 °C and expanding the substrate scope. Continuous C-glycoside synthesis was achieved with a throughput of 21.9 g h-1, demonstrating the industrial potential of FMRs.

A Population Pharmacokinetic Study to Compare a Novel Empagliflozin L-Proline Formulation with Its Conventional Formulation in Healthy Subjects

Empagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor that is commonly used for the treatment of type 2 diabetes mellitus (T2DM). CKD-370 was newly developed as a cocrystal formulation of empagliflozin with co-former L-proline, which has been confirmed to be bioequivalent in South Korea. This study aimed to quantify the differences in the absorption phase and pharmacokinetic (PK) parameters of two empagliflozin formulations in healthy subjects by using population PK analysis. The plasma concentration data of empagliflozin were obtained from two randomized, open-label, crossover, phase 1 clinical studies in healthy Korean subjects after a single-dose administration. A population PK model was constructed by using a nonlinear mixed-effects (NLME) approach (Monolix Suite 2021R1). Interindividual variability (IIV) and interoccasion variability (IOV) were investigated. The final model was evaluated by goodness-of-fit (GOF) diagnostic plots, visual predictive checks (VPCs), prediction errors, and bootstrapping. The PK of empagliflozin was adequately described with a two-compartment combined transit compartment model with first-order absorption and elimination. Log-transformed body weight significantly influenced systemic clearance (CL) and the volume of distribution in the peripheral compartment (V2) of empagliflozin. GOF plots, VPCs, prediction errors, and the bootstrapping of the final model suggested that the proposed model was adequate and robust, with good precision at different dose strengths. The cocrystal form did not affect the absorption phase of the drug, and the PK parameters were not affected by the different treatments.

TiCl4-mediated deoxygenative reduction of aromatic ketones to alkylarenes with ammonia borane

A rapid and mild protocol for the exhaustive deoxygenation of various aromatic ketones to corresponding alkanes was described, which was mediated by TiCl4 and used ammonia borane (AB) as the reductant. This reduction protocol applies to a wide range of substrates in moderate to excellent yields at room temperature. The gram-scale reaction and syntheses of some key building blocks for SGLT2 inhibitors demonstrated the practicability of this methodology. Preliminary mechanistic studies revealed that the ketone is first converted into an alcohol, which then undergoes a carbocation to give the alkane via hydrogenolysis.

Linkage-Editing Pseudo-Glycans: A Reductive α-Fluorovinyl-C-Glycosylation Strategy to Create Glycan Analogs with Altered Biological Activities

The acetal (O-glycoside) bonds of glycans and glycoconjugates are chemically and biologically vulnerable, and therefore C-glycosides are of interest as more stable analogs. We hypothesized that, if the O-glycoside linkage plays a vital role in glycan function, the biological activities of C-glycoside analogs would vary depending on their substituents. Based on this idea, we adopted a "linkage-editing strategy" for the creation of glycan analogs (pseudo-glycans). We designed three types of pseudo-glycans with CH2 and CHF linkages, which resemble the O-glycoside linkage in terms of bond lengths, angles, and bulkiness, and synthesized them efficiently by means of fluorovinyl C-glycosylation and selective hydrogenation reactions. Application of this strategy to isomaltose (IM), an inducer of amylase expression, and α-GalCer, which activates iNKT cells, resulted in the discovery of CH2-IM, which shows increased amylase production ability, and CHF-α-GalCer, which shows activity opposite that of native α-GalCer, serving as an antagonist of iNKT cells.

Pharmacokinetic Comparison Between a Fixed-Dose Combination of Empagliflozin L-Proline/Metformin and Empagliflozin/Metformin in Healthy Korean Subjects

Empagliflozin and metformin are oral antidiabetic drugs commonly used to treat type 2 diabetes mellitus as a combination therapy. This study aimed to compare the pharmacokinetics and safety of a newly developed fixed-dose combination of 5-mg empagliflozin L-proline and 1000-mg metformin with the reference drug. A randomized, open-label, single-dose, 2-period, 2-treatment, crossover study was conducted in healthy Korean subjects. The subjects received a single oral dose of reference drug or test drug at each period. The pharmacokinetic (PK) parameters were calculated using a noncompartmental method. The geometric mean ratios and 90% confidence intervals of the plasma maximum concentration (Cmax ) and area under the concentration-time curve from time zero to the last quantifiable concentration (AUClast ) were calculated. A total of 27 healthy subjects were included in the PK analysis. For empagliflozin, the geometric mean ratios (90% confidence intervals) of the test to reference drug for Cmax and AUClast were 1.03 (0.99-1.08) and 1.03 (1.00-1.06), respectively. For metformin, the corresponding values for Cmax  and AUClast were 0.99 (0.92-1.06) and 1.00 (0.94-1.06), respectively. In conclusion, a fixed-dose combination of empagliflozin L-proline and metformin showed similar PK characteristics to the reference drug, and both drugs were safe in healthy subjects.

Cobalt's Dual Role in Promoting C3-Glycosylation of Indoles: Unraveling Mechanistic Insights

In this study, we present a cobalt-catalyzed C3-glycosylation of indoles using unfunctionalized glycals, yielding 3-indolyl-C-deoxyglycosides. These compounds hold promise as sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors for treating type 2 diabetes. Control experiments unveiled that cobalt assumes a dual role, facilitating catalytic C-glycosylation while unexpectedly driving the anomerization of α-anomers through endocyclic cleavage of the C1-O5 bond, resulting in the formation of β-C-deoxyglycosides. Furthermore, density functional theory (DFT) calculations shed light on the reaction mechanism, emphasizing the significant role of the pyridine group of indole in stabilizing transition states and intermediates.

Comparison of the Pharmacokinetics, Safety, and Tolerability of Two Empagliflozin Formulations in Healthy Korean Subjects

Purpose

Empagliflozin is a sodium-glucose cotransporter 2 inhibitor that is commonly used for the treatment of type 2 diabetes mellitus. As cocrystal formulation can improve the chemical properties of drugs, CKD-370 was newly developed as a cocrystal formulation of empagliflozin with solvate L-proline. This study aimed to compare the pharmacokinetics, safety, and tolerability of these two empagliflozin formulations in healthy Korean subjects.

Methods

A randomized, open-label, two-sequence, two-period crossover study was conducted on healthy Korean participants. The subjects received a single oral 25 mg dose of either test (CKD-370) or reference treatment (Jardiance^®) tablet at each period. Plasma empagliflozin concentrations were determined using liquid chromatography with tandem mass spectrometry. Pharmacokinetic (PK) parameters were analyzed using non-compartmental methods. The primary PK parameters included the maximum concentration (C_max) and the area under the concentration-time curve from 0 to last (AUC_last). The safety of both formulations was monitored and evaluated.

Results

A total of 28 healthy Korean adult subjects were randomized, and 27 subjects were included in the PK analysis. The mean ± standard deviation values of the primary PK parameters, C_max and AUC_last after administration of the test treatment, were 442.02 ± 103.37 μg/L and 3131.08 ± 529.30 μg·h/L, respectively, and those after administration of the reference treatment were 436.29 ± 118.74 μg/L and 3006.88 ± 514.21 μg·h/L, respectively. The geometric mean ratio and its 90% confidence interval of test to reference treatment for C_max and AUC_last were 1.0221 (0.9527-1.0967) and 1.0411 (1.0153-1.0677), respectively, which were within the commonly accepted bioequivalence criteria of 0.80 to 1.25. Both treatments were well-tolerated.

Conclusion

The two formulations of empagliflozin showed similar PK characteristics and were generally well tolerated in healthy subjects.

New Synthesis of Diarylmethanes, Key Building Blocks for SGLT2 Inhibitors

Synthesis of diarylmethanes, a key building block for SGLT2 inhibitors, has been developed through ketone synthesis by Friedel-Crafts acylation with TiCl₄, followed by reduction with TiCl₄/NaBH₄. The new protocol proceeded more cleanly than the previous methods employing AlCl₃ and BF₃·OEt₂/Et₃SiH to provide the diarylmethanes corresponding to canagliflozin, empagliflozin, and luseogliflozin in a highly expedient and affordable manner. In the case of a diarylmethane for the synthesis of dapagliflozin, the reduction step took place by an alternative method using InCl₃/Al/BF₃·OEt₂.

Redox-driven cardioprotective effects of sodium-glucose co-transporter-2 inhibitors: comparative review

Sodium-glucose co-transporter-2 inhibitors are used in the treatment of diabetes but are also emerging as cardioprotective agents in heart diseases even in the absence of type 2 diabetes. In this paper, upon providing a short overview of common pathophysiological features of diabetes, we review the clinically reported cardio- and nephroprotective potential of sodium-glucose co-transporter-2 inhibitors currently available on the market, including Dapagliflozin, Canagliflozin, and Empagliflozin. To that end, we summarize findings of clinical trials that have initially drawn attention to the drugs' organ-protective potential, before providing an overview of their proposed mechanism of action. Since we particularly expect that their antioxidative properties will broaden the application of gliflozins from therapeutic to preventive care, special emphasis was put on this aspect.

Copper(I)-Catalyzed Sandmeyer-Type S-Arylation of 1-Thiosugars with Aryldiazonium Salts under Mild Conditions

Preparation of S-aryl thioglycosides from 1-thiosugars via S-arylation was demonstrated under mild reaction conditions. A wide range of protected and unprotected 1-thiosugars derived from glucose, glucosamine, galactose, mannose, ribose, maltose, and lactose underwent cross-coupling reactions with functionalized aryldiazonium salts in the presence of copper(I) chloride and DBU. The desired products were obtained in 55-88% yields within 5 min. Various functional groups, including halogens, were tolerated under standard reaction conditions. Synthesis of the biologically relevant antidiabetic dapagliflozin S-analogue and arbutin S-analogues (tyrosinase inhibitors) was demonstrated.

Exploring sodium glucose cotransporter (SGLT2) inhibitors with machine learning approach: A novel hope in anti-diabetes drug discovery

Conventional anti-diabetes agents exhibit some undesirable side effects. Recently, lactic acidosis and/or bladder cancer were also reported with the use of these agents. Hence, there is an urgent need for alternative anti-diabetes in order to reduce/avoid the unwanted effects. In this scenario sodium glucose cotransporter 2 (SGLT2) inhibitors has already been established as an important class of anti-diabetic drug. The search for new generation SGLT2 inhibitors with high affinity is still an ongoing process. Here, we aim to develop computational models to predict the SGLT2 inhibitory activity of small molecules based on chemical structures. This work provides in-silico analysis to propose possible fragment/fingerprint identification recommended for SGLT2 inhibitors. Up-to-our knowledge, this study is an initiative to propose fingerprints responsible for SGLT2 inhibition. Furthermore, we used nine different algorithms to build machine learning (ML) models that could be used to prioritize compounds as SGLT2 inhibitors from large libraries. The best performing ML models were applied to virtually screen a large collection of FDA approved drugs. The best predicted compounds have been recommended to be biologically investigated in future in order to identify next generation SGLT2 inhibitors with different chemical structure.

Facile Approach to C-Glucosides by Using a Protecting-Group-Free Hiyama Cross-Coupling Reaction: High-Yielding Dapagliflozin Synthesis

Access to unprotected (hetero)aryl pseudo-C-glucosides via a mild Pd-catalysed Hiyama cross-coupling reaction of protecting-group-free 1-diisopropylsilyl-d-glucal with various (hetero)aryl halides has been developed. In addition, selected unprotected pseudo-C-glucosides were stereoselectively converted into the corresponding α- and β-C-glucosides, as well as 2-deoxy-β-C-glucosides. This methodology was applied to the efficient and high-yielding synthesis of dapagliflozin, a medicament used to treat type 2 diabetes mellitus. Finally, the versatility of our methodology was proved by the synthesis of other analogues of dapagliflozin.

Dual-Target Compounds against Type 2 Diabetes Mellitus: Proof of Concept for Sodium Dependent Glucose Transporter (SGLT) and Glycogen Phosphorylase (GP) Inhibitors

A current trend in the quest for new therapies for complex, multifactorial diseases, such as diabetes mellitus (DM), is to find dual or even multi-target inhibitors. In DM, the sodium dependent glucose cotransporter 2 (SGLT2) in the kidneys and the glycogen phosphorylase (GP) in the liver are validated targets. Several (β-D-glucopyranosylaryl)methyl (het)arene type compounds, called gliflozins, are marketed drugs that target SGLT2. For GP, low nanomolar glucose analogue inhibitors exist. The purpose of this study was to identify dual acting compounds which inhibit both SGLTs and GP. To this end, we have extended the structure-activity relationships of SGLT2 and GP inhibitors to scarcely known (C-β-D-glucopyranosylhetaryl)methyl arene type compounds and studied several (C-β-D-glucopyranosylhetaryl)arene type GP inhibitors against SGLT. New compounds, such as 5-arylmethyl-3-(β-D-glucopyranosyl)-1,2,4-oxadiazoles, 5-arylmethyl-2-(β-D-glucopyranosyl)-1,3,4-oxadiazoles, 4-arylmethyl-2-(β-D-glucopyranosyl)pyrimidines and 4(5)-benzyl-2-(β-D-glucopyranosyl)imidazole were prepared by adapting our previous synthetic methods. None of the studied compounds exhibited cytotoxicity and all of them were assayed for their SGLT1 and 2 inhibitory potentials in a SGLT-overexpressing TSA201 cell system. GP inhibition was also determined by known methods. Several newly synthesized (C-β-D-glucopyranosylhetaryl)methyl arene derivatives had low micromolar SGLT2 inhibitory activity; however, none of these compounds inhibited GP. On the other hand, several (C-β-D-glucopyranosylhetaryl)arene type GP inhibitor compounds with low micromolar efficacy against SGLT2 were identified. The best dual inhibitor, 2-(β-D-glucopyranosyl)-4(5)-(2-naphthyl)-imidazole, had a K_i of 31 nM for GP and IC₅₀ of 3.5 μM for SGLT2. This first example of an SGLT-GP dual inhibitor can prospectively be developed into even more efficient dual-target compounds with potential applications in future antidiabetic therapy.

SGLT2 inhibitors, an accomplished development in field of medicinal chemistry: an extensive review

Diabetes is a chronic progressive metabolic disease caused by insulin deficiency or insulin resistance. In spite of the availability of several antihyperglycaemics, there is a need for the development of safer antidiabetic drugs due to their undesirable effects. Sodium-glucose cotransporter-2 inhibitors are a class of antidiabetics, which hinder the reabsorption of glucose in the kidneys, causing excretion of glucose via urine. Sodium-glucose cotransporter-2 inhibitors are a well-tolerated class with no significant adverse effects and are found to be favorable in certain conditions, which may be rudimentary to cardiovascular and renal diseases. The current advancements in their design and development, their mechanism of action, structure–activity relationship, synthesis and in silico development along with their auxiliary roles have been extensively reviewed.

Development of Routes for the Stereoselective Preparation of β-Aryl-C-glycosides via C-1 Aryl Enones

A wide range of enones derived from d-glucal, d-galactal, l-rhamnal, d-rhamnal, and l-arabinal underwent Heck-coupling with various arylboronic acids bearing electron-donating and -withdrawing groups in the presence of palladium acetate and 1,10-phenanthroline. These reactions provided synthetically useful C-1 aryl enones in good yields. Many sensitive functional groups as well as protecting groups present in arylboronic acids and enones, respectively, remained intact under optimized conditions. The stereoselective hydrogenation of C-1 aryl enones with Pd-C/H₂ provides the β-isomer of 2-deoxy-aryl-C-glycosides in excellent yield. The C-1 aryl enones were also used as precursors for the synthesis of 2-hydroxy-β-aryl-C-glycosides. Regioselective C-2 halogenations and vinylations of C-1 aryl enones were achieved in excellent yields.

Syntheses of SGLT2 Inhibitors by Ni- and Pd-Catalyzed Fukuyama Coupling Reactions

Nickel- and palladium-catalyzed Fukuyama coupling reactions of a d-gluconolactone-derived thioester with arylzinc reagents at ambient temperature provided the corresponding multifunctional aryl ketones in high yield. Ligand screening for the nickel-catalyzed Fukuyama coupling reactions indicated that 1,2-bis(dicyclohexylphosphino)ethane (dCype) served as a superior supporting ligand to improve the product yield. In addition, Pd/C was a practical alternative that enabled ligand-free Fukuyama coupling reactions and was efficiently applied to the key C-C bond-forming step to prepare canagliflozin and dapagliflozin, which are diabetic SGLT2 inhibitors of current interest.

Optimising the Benefits of SGLT2 Inhibitors for Type 1 Diabetes

Sodium-glucose cotransporter 2 (SGLT2) inhibitor clinical studies in type 1 diabetes mellitus (T1DM) have demonstrated reduced HbA1c and lower glucose variability with increased time in optimal glucose range as well as additional benefits of reductions in weight and insulin dose without increasing the incidence of hypoglycaemia. However, the appropriate use of SGLT2 inhibitor therapies within clinical practise to treat people with T1DM remains unclear. In this article we have used consensus expert opinion alongside the available evidence, product indication and most recent clinical guidance to provide support for the diabetes healthcare community regarding the appropriate use of SGLT2 inhibitors, focussing on specific considerations for appropriate prescribing of dapagliflozin within the T1DM management pathway. Its purpose is to provide awareness of the issues surrounding treatment with dapagliflozin in T1DM as well as offer practical guidance that also includes a checklist tool for appropriate dapagliflozin prescribing. The checklist aims to support clinicians in identifying those people with T1DM most likely to benefit from dapagliflozin treatment as well as situations where caution may be required.Funding: AstraZeneca UK Ltd.

Glucopyranosylidene-spiro-benzo[ b][1,4]oxazinones and -benzo[ b][1,4]thiazinones: Synthesis and Investigation of Their Effects on Glycogen Phosphorylase and Plant Growth Inhibition

Glucopyranosylidene-spiro-benzo[ b][1,4]oxazinones were obtained via the corresponding 2-nitrophenyl glycosides obtained by two methods: (a) AgOTf-promoted glycosylation of 2-nitrophenol derivatives by O-perbenzoylated methyl (α-d-gluculopyranosyl bromide)heptonate or (b) Mitsunobu-type reactions of O-perbenzoylated methyl (α-d-gluculopyranose)heptonate with bulky 2-nitrophenols in the presence of diethyl azodicarboxylate (DEAD) and PPh₃. Catalytic hydrogenation (H₂-Pd/C) or partial reduction (e.g., H₂-Pd/C, pyridine) of the 2-nitro groups led to spiro-benzo[ b][1,4]oxazinones and spiro-benzo[ b][1,4]-4-hydroxyoxazinones by spontaneous ring closure of the intermediate 2-aminophenyl or 2-hydroxylamino glycosides, respectively. The analogous 2-aminophenyl thioglycosides, prepared by reactions of O-perbenzoylated methyl (α-d-gluculopyranosyl bromide)heptonate with 2-aminothiophenols, were cyclized in m-xylene at reflux temperature to the corresponding spiro-benzo[ b][1,4]thiazinones. O-Debenzoylation was effected by Zemplén transesterification in both series. Spiro-configurations were determined by NMR and electronic circular dichroism time-dependent density functional theory (ECD-TDDFT) methods. Inhibition assays with rabbit muscle glycogen phosphorylase b showed (1' R)-spiro{1',5'-anhydro-d-glucitol-1',2-benzo[ b][1,4]oxazin-3(4 H)-one} and (1' R)-spiro{1',5'-anhydro-d-glucitol-1',2-benzo[ b][1,4]thiazin-3(4 H)-one} to be the most efficient inhibitors (27 and 28% inhibition at 625 μM, respectively). Plant growth tests with white mustard and garden cress indicated no effect except for (1' R)-4-hydroxyspiro{1',5'-anhydro-d-glucitol-1',2-benzo[ b][1,4]oxazin-3(4 H)-one} with the latter plant to show modest inhibition of germination (95% relative to control).

New syntheses towards C-glycosyl type glycomimetics

Glycomimetics are compounds that resemble carbohydrate molecules in their chemical structure and/or biological effect. A large variety of compounds can be designed and synthesized to get glycomimetics, however, C-glycosyl derivatives represent one of the most frequently studied subgroup. In the present survey syntheses of a range of five- and six membered C-glycopyranosyl heterocycles, anhydro-aldimine type compounds, exo-glycals, C-glycosyl styrenes, carbon-sulfur bonded oligosaccharide mimics are described. Some of the C-glycopyranosyl azoles, namely 1,2,4-triazoles and imidazoles belong to the most efficient glucose analog inhibitors of glycogen phosphorylase known to date. Biological studies revealed the therapeutical potential of such inhibitors. Other synthetic derivatives offer versatile possibilities to get further glycomimetics.

Diuretic Effects of Sodium Glucose Cotransporter 2 Inhibitors and Their Influence on the Renin-Angiotensin System

The renin-angiotensin system (RAS) plays an important role in regulating body fluids and blood pressure. However, inappropriate activation of the RAS contributes to the pathogenesis of cardiovascular and renal diseases. Recently, sodium glucose cotransporter 2 (SGLT2) inhibitors have been used as anti-diabetic agents. SGLT2 inhibitors induce glycosuria and improve hyperglycemia by inhibiting urinary reabsorption of glucose. However, in the early stages of treatment, these inhibitors frequently cause polyuria and natriuresis, which potentially activate the RAS. Nevertheless, the effects of SGLT2 inhibitors on RAS activity are not straightforward. Available data indicate that treatment with SGLT2 inhibitors transiently activates the systemic RAS in type 2 diabetic patients, but not the intrarenal RAS. In this review article, we summarize current evidence of the diuretic effects of SGLT2 inhibitors and their influence on RAS activity.

Rethinking Carbohydrate Synthesis: Stereoretentive Reactions of Anomeric Stannanes

In this Concept article, recent advances are highlighted in the synthesis and applications of anomeric nucleophiles, a class of carbohydrates in which the C1 carbon bears a carbon-metal bond. First, the advantages of exploiting the carboanionic reactivity of carbohydrates and the methods for the synthesis of mono- and oligosaccharide stannanes are discussed. Second, recent developments in the glycosyl cross-coupling method resulting in the transfer of anomeric configuration from C1 stannanes to C-aryl glycosides are reviewed. These highly stereoretentive processes are ideally suited for the preparation of carbohydrate-based therapeutics and were demonstrated in the synthesis of antidiabetic drugs. Next, the application of the glycosyl cross-coupling method to the preparation of Se-glycosides and to glycodiversification of small molecules and peptides are highlighted. These reactions proceed with exclusive anomeric control for a broad range of substrates and tolerate carbohydrates with free hydroxyl groups. Taken together, anomeric nucleophiles have emerged as powerful tools for the synthesis of oligosaccharides and glycoconjugates and their future applications will open new possibilities to incorporate saccharides into small molecules and biologics.

Stereoselective Preparation of α- C-Vinyl/Aryl Glycosides via Nickel-Catalyzed Reductive Coupling of Glycosyl Halides with Vinyl and Aryl Halides

Facile preparation of the α- C-vinyl and -aryl glycosides has been developed via mild Ni-catalyzed reductive vinylation and arylation of C1-glycosyl halides with vinyl/aryl halides. Good to high α-selectivities were achieved for C-glucosides, galactosides, maltoside, and mannosides, which were dictated by the employment of pyridine type ligands. As such, the present work represents unprecedented control for a high level of α-selectivity for C-vinyl-glucosides using cross-coupling approaches and offers hitherto optimal α-selective preparation of C-aryl glucosides via catalyst-controlled coupling strategies.

Stereocontrolled Synthesis of 2-Fluorinated C-Glycosides

A systematic study of the addition of C-based nucleophiles to fluorinated lactones based on 2-deoxy-2-fluoro-d-pyranoses is disclosed. This high yielding, α-selective process was found to be independent on the nature or configuration [(R)-C(sp3)-F, (S)-C(sp3)-F] of the substituent at C2. Representative, fluorinated analogues of Trehalose, Carminic acid, and the spirocyclic cores of Tofogliflozin and Papulacandin D are also reported. These glycomimics constitute a valuable series of 19F NMR active probes for application in structural biology.