Molecular Insight and Mode of Inhibition of α-Glucosidase and α-Amylase by Pahangensin A from Alpinia pahangensis Ridl

Characterization of four new cycloartane triterpenoids from Swietenia macrophylla and their angiotensin-I-converting enzyme inhibitory activity

Angiotensin I-converting enzyme (ACE) inhibition is currently a common method for the treatment and control of hypertension. In this study, four new (1-4) and one known (5) cycloartane triterpenoids were isolated from the leaves of Swietenia macrophylla by chromatographic techniques and identified by their spectroscopic data and a comprehensive comparison of published data. The triterpenoids were evaluated for their ACE inhibitory potential using in vitro inhibition assays and in silico methods. The inhibition assay and enzyme kinetics results showed that the most active triterpenoid, compound 4, inhibited ACE in a mixed-type manner with an IC50 value of 57.7 ± 6.07 μM. Computer simulations revealed that compound 4 reduces the catalytic efficiency of ACE by competitive insertion into the active pocket blocking the substrate, and the binding activity occurs mainly through hydrogen bonds and hydrophobic interactions. The study showed that S. macrophylla can be a source of bioactive material and the ACE inhibitory triterpenoid could be a potential antihypertensive agent.

New Molecules of Diterpene Origin with Inhibitory Properties toward α-Glucosidase

The incidence of diabetes mellitus (DM), one of the most common chronic metabolic disorders, has increased dramatically over the past decade and has resulted in higher rates of morbidity and mortality worldwide. The enzyme, α-Glucosidase (α-GLy), is considered a therapeutic target for the treatment of type 2 DM. Herein, we synthesized arylidene, heterocyclic, cyanoetoxy- and propargylated derivatives of quinopimaric acid (levopimaric acid diene adduct with p-benzoquinone) 1-50 and, first, evaluated their ability to inhibit α-GLy. Among the tested compounds, quinopimaric acid 1, 2,3-dihydroquinopimaric acid 8 and its amide and heterocyclic derivatives 9, 30, 33, 39, 44, with IC50 values of 35.57-65.98 μM, emerged as being good inhibitors of α-GLy. Arylidene 1β-hydroxy and 1β,13α-epoxy methyl dihydroquinopimarate derivatives 6, 7, 26-29, thiadiazole 32, 1a,4a-dehydroquinopimaric acid 40 and its indole, nitrile and propargyl hybrids 35-38, 42, 45, 48, and 50 showed excellent inhibitory activities. The most active compounds 38, 45, 48, and 50 displayed IC50 values of 0.15 to 0.68 μM, being 1206 to 266 more active than acarbose (IC50 of 181.02 μM). Kinetic analysis revealed the most active diterpene indole with an alkyne substituent 45 as a competitive inhibitor with Ki of 50.45 μM. Molecular modeling supported this finding and suggested that the indole core plays a key role in the binding. Compound 45 also has favorable pharmacokinetic and safety properties, according to the computational ADMET profiling. The results suggested that quinopimaric acid derivatives should be considered as potential candidates for novel alternative therapies in the treatment of type 2 diabetes.

Identification of Major Compounds and α-Amylase and α-Glucosidase Inhibitory Activity of Rhizome of Musa balbisiana Colla: An In-vitro and insilico Study

BACKGROUND

α-Amylase and α-glucosidase inhibitors are widely used to suppress postprandial glycemia in the treatment of type 2 diabetes.

OBJECTIVES

To evaluate the metallic content, major phytoconstituents, and α-amylase and α-glucosidase inhibitory activity of Musa balbisiana rhizome using in-vitro and in-silico methods.

MATERIALS AND METHODS

Heavy metal content was detected by AAS following standard protocol. Major phytochemicals of the plant were analysed by GC-MS technique. Enzyme inhibition study was carried out by UV/VIS spectrophotometric methods. The druglikeness and bioavailability properties of major compounds were carried out using computer-aided tools - SwissADME and ADMElab. Docking and visualization were performed in AutoDock vina and Discovery studio tools.

RESULTS

The study found that the fruits of M. balbisiana contain negligible amount toxic elements. GC-MS analysis showed five major compounds from the rhizome of M. balbisiana. In-vitro enzyme assays revealed strong α-amylase and αglucosidase inhibitory property of the plant. All the five compounds were predicted to have druglikeness property with high cell membrane permeability and bioavailability. The compounds were also predicted to have low to moderate toxicity property. The Docking study showed strong binding affinities of plant compounds with α-amylase and α-glucosidase. Out of five compounds, C5 showed best binding affinity with active pockets of α-amylase and α-glucosidase.

CONCLUSION

The present in-vitro and in-silico study suggests the antihyperglycemic property of the rhizome of Musa balbisiana and possible candidate for therapeutic antidiabetic agent(s).