Synthesis of New Nitrogen Analogues of Salacinol and Deoxynojirimycin and Their Evaluation as Glycosidase Inhibitors

β-Aldehyde ketones as dual inhibitors of aldose reductase and α-glucosidase with antioxidant properties

The synthesized β-aldehyde ketone compounds have strong biological activity because of their ionizable hydroxyl groups.

New biologically dynamic hybrid pharmacophore triazinoindole-based-thiadiazole as potent α-glucosidase inhibitors: In vitro and in silico study

Triazinoindole bearing thiadiazole derivatives (1-25) have been synthesized and characterized through different spectroscopic techniques such as ¹H, ¹³C-NMR and HREI-MS. The purpose of the study was to investigate the anti-diabetic activity of the synthesized triazinoindole bearing thiadiazole derivatives by inhibition of α-glucosidase. All synthesized analogues showed outstanding inhibition of α-glucosidase enzyme with IC₅₀ values ranging from 2.5 ± 0.10 to 38.10 ± 0.10 µM as compared to the standard drug acarbose (IC₅₀ = 38.45 ± 0.80 µM). Analogue 4 (IC₅₀ = 2.5 ± 0.10 µM) was identifies as the most potent analogue in the series with fifteen folds more active than standard acarbose. Structure activity relationship (SAR) studies suggested that α-glucosidase activities of triazinoindole bearing thiadiazole are primarily dependent upon on number and position of different substitutions present on phenyl parts. Molecular docking study were conducted of the optimized compounds (i.e., compound 4, 6, and 3 etc. using MOE default parameters), the results revealed that compound 4, 6, and 3 showed numerous key interactions with the target protein, which indicate the high potential of these compounds against the target compound. All these compounds were screened for cytotoxic activity against normal normal Vero cell line and found non-toxic.

Novel oxazolxanthone derivatives as a new type of α-glucosidase inhibitor: synthesis, activities, inhibitory modes and synergetic effect

Xanthone derivatives have shown good α-glucosidase inhibitory activity and have drawn increased attention as potential anti-diabetic compounds. In this study, a series of novel oxazolxanthones were designed, synthesized, and investigated as α-glucosidase inhibitors. Inhibition assays indicated that compounds 4-21 bearing oxazole rings exhibited up to 30-fold greater inhibitory activity compared to their corresponding parent compound 1b. Among them, compounds 5-21 (IC₅₀ = 6.3 ± 0.4-38.5 ± 4.6 μM) were more active than 1-deoxynojirimycin (IC₅₀ = 60.2 ± 6.2 μM), a well-known α-glucosidase inhibitor. In addition, the kinetics of enzyme inhibition measured by using Lineweaver-Burk analysis shows that compound 4 is a competitive inhibitor, while compounds 15, 16 and 20 are non-competitive inhibitors. Molecular docking studies showed that compound 4 bound to the active site pocket of the enzyme while compounds 15, 16, and 20 did not. More interestingly, docking simulations reveal that some of the oxazolxanthone derivatives bind to different sites in the enzyme. This prediction was further confirmed by the synergetic inhibition experiment, and the combination of representative compounds 16 and 20 at the optimal ratio of 4:6 led to an IC₅₀ value of 1.9 ± 0.7 μM, better than the IC₅₀ value of 7.1 ± 0.9 μM for compound 16 and 8.6 ± 0.9 μM for compound 20.

New carbazole linked 1,2,3-triazoles as highly potent non-sugar α-glucosidase inhibitors

In the present study, a series of new carbazole linked 1H-1,2,3-triazoles (2-27) were synthesized via click reaction of N-propargyl-9H-carbazole (1) and azides of appropriate acetophenones and heterocycles. Synthesized carbazole triazoles including 7, 9, 10, 19, 20, and 23-26 (IC₅₀=0.8±0.01-100.8±3.6μM), exhibited several folds more potent α-glucosidase inhibitory in vitro activity as compared to standard drug, acarbose. Compounds 2-5, 7-13, and 17-27 did not show any cytotoxicity against 3T3 cell lines, except triazoles 6, and 14-16. Among the series, carbazole triazoles 23 (IC₅₀=1.0±0.057μM) and 25 (IC₅₀=0.8±0.01μM) were found to be most active, and could serve as an attractive building block in the search of new non-sugar derivatives as anti-diabetic agents.

Aspects of extraction and biological evaluation of naturally occurring sugar-mimicking sulfonium-ion and their synthetic analogues as potent α-glucosidase inhibitors from Salacia: a review

A review of the selective inhibitory activities of sulfonium compounds ofSalaciaagainst intestinal α-glucosidases, structural features important for effective inhibition and the toggling approach for controlling starch digestion and glucose release.

Syntheses of new 3-thiazolyl coumarin derivatives, in vitro α-glucosidase inhibitory activity, and molecular modeling studies

3-Thiazolylcoumarin derivatives 1-14 were synthesized via one-pot two step reactions, and screened for in vitro α-glucosidase inhibitory activity. All compounds showed inhibitory activity in the range of IC50 = 0.12 ± 0.01-16.20 ± 0.23 μM as compared to standard acarbose (IC50 = 38.25 ± 0.12 μM), and also found to be nontoxic. Molecular docking study was carried out in order to establish the structure-activity relationship (SAR) which demonstrated that electron rich centers at one and electron withdrawing centers at the other end of the molecules showed strong inhibitory activity. All the synthesized compounds were characterized by spectroscopic techniques such as EI-MS, HREI-MS, (1)H NMR and (13)C NMR. CHN analysis was also performed.

Synthesis, molecular docking and α-glucosidase inhibition of 5-aryl-2-(6'-nitrobenzofuran-2'-yl)-1,3,4-oxadiazoles

Twenty derivatives of 5-aryl-2-(6'-nitrobenzofuran-2'-yl)-1,3,4-oxadiazoles (1-20) were synthesized and evaluated for their α-glucosidase inhibitory activities. Compounds containing hydroxyl and halogens (1-6, and 8-18) were found to be five to seventy folds more active with IC50 values in the range of 12.75±0.10-162.05±1.65μM, in comparison with the standard drug, acarbose (IC50=856.45±5.60μM). Current study explores the α-glucosidase inhibition of a hybrid class of compounds of oxadiazole and benzofurans. These findings may invite researchers to work in the area of treatment of hyperglycemia. Docking studies showed that most compounds are interacting with important amino acids Glu 276, Asp 214 and Phe 177 through hydrogen bonds and arene-arene interaction.

A concise synthesis and evaluation of new malonamide derivatives as potential α-glucosidase inhibitors

A series of new malonamide derivatives were synthesized by Michael addition reaction of N(1),N(3)-di(pyridin-2-yl)malonamide into α,β-unsaturated ketones mediated by DBU in DCM at ambient temperature. The inhibitory potential of these compounds in vitro, against α-glucosidase enzyme was evaluated. Result showed that most of malonamide derivatives were identified as a potent inhibitors of α-glucosidase enzyme. Among all the compounds, 4K (IC50=11.7 ± 0.5 μM) was found out as the most active one compared to standard drug acarbose (IC50=840 ± 1.73 μM). Further cytotoxicity of 4a-4m were also evaluated against a number of cancer and normal cell lines and interesting results were obtained.

Novel thiosemicarbazide–oxadiazole hybrids as unprecedented inhibitors of yeast α-glucosidase and in silico binding analysis

Novel hybrids of thiosemicarbazide–oxadiazole as potent α-glucosidase agents.

A THEORETICAL STUDY ON THE MECHANISM OF 2:1 1, 3 DIPOLAR CYCLOADDITION REACTIONS

The reactions between nitrile oxides and alkenes are of considerable interest in organic synthesis as the resulting heterocycles are versatile intermediates for the synthesis of natural products and biologically active compounds. In this paper, we design a series of reactions of phosphonyl nitrile oxides with acrylonnitrile, which can give 2:1 cycloaddition products with no crystal structure released so far, and present a detailed theoretical study on the mechanism of the 2:1 1, 3-dipolar cycloaddition reaction, which has been explored with density functional theory calculations at B3LYP/6-31G* level. The results reveal that the following mechanism is quite possible. Firstly, it starts as a normal 1,3-dipolar cycloaddition reaction to produce a regiospecific 1:1 product. Subsequently, highly reactive diisopropanyl phosphonyl nitrile oxide sequentially reacts with the aforementioned regiospecific 1:1 product and gives the corresponding cycloadduct. Further study is underway to expand the scope of this methodology, as well as to ascertain mechanistic details of the cycloaddition process.

Zwitterionic glycosidase inhibitors: salacinol and related analogues

Natural products with interesting biological properties and structural diversity have often served as valuable lead drug candidates for the treatment of human diseases. Salacinol, a naturally occurring alpha-glucosidase inhibitor, was shown to be one of the active principles of the aqueous extract of a medicinal plant that has been prescribed traditionally as an Ayurvedic treatment for type II diabetes. Salacinol contains an intriguing zwitterionic sulfonium-sulfate structure that comprises a 1,4-anhydro-4-thio-D-arabinitol core and a polyhydroxylated acyclic chain. Due to the unique structural features and its potential to become a lead drug candidate in the treatment of type II diabetes, a great deal of attention has been focused on salacinol and its analogues. Since the isolation of salacinol, several papers describing various synthetic routes to salacinol and its analogues have appeared in the literature. This review is aimed at highlighting the synthetic aspects of salacinol and related compounds as well as their structure-activity relationship studies.

Attempted Synthesis of 2-Acetamido and 2-Amino Derivatives of Salacinol. Ring Opening Reactions

The attempted synthesis of the 2-acetamido and 2-amino derivatives of salacinol, a naturally occurring glycosidase inhibitor, is described. Reaction of the protected acetamidothioarabinitol unit with the cyclic sulfate derived from L-erythritol gave the corresponding sulfonium sulfate, which underwent ring opening to give an acyclic amido sulfate. The corresponding reaction of the protected azidothioarabinitol unit with the cyclic sulfate proceeded to give the sulfonium sulfate. However, upon reduction of the azido function to an amine it formed an acyclic ammonium sulfate.