Α-glucosidase Activity Research Articles

Exploration of phenolic profile from mangosteen (Garcinia mangostana L.) pericarp and their contribution to inhibitory effects on α-amylase and α-glucosidase

The aim of this study was to reveal the phenolic profile of mangosteen (Garcinia mangostana L.) pericarp and investigate their inhibitory effects on α-amylase and α-glucosidase. Mangosteen pericarp polyphenols (MPP) obtained by acetone extraction were fractionated with gradient ethanol elution. A total of twenty nine phenolic chemicals were found and quantified by UPLC-Q-TOF-MS/MS. MPP eluted by the 60% ethanol solution (MPP60%) showed the highest total phenolic content. Moreover, MPP60% displayed the greatest inhibition activities on α-amylase and α-glycosidase by competitive and mixed inhibitions. Mechanistically, the inhibitory effects of MPP60% on α-amylase and α-glucosidase involved the changes of the secondary structure as well as the static fluorescence quenching of these enzymes. Pearson correlation coefficients revealed that procyanidin B2, quercetin glucoside, and mangostain contributed most to inhibiting the activities of α-amylase and α-glucosidase. This study indicated that polyphenols from mangosteen pericarps can be developed into potential inhibitors of α-amylase and α-glucosidase, offering a viable strategy for the valorization of mangosteen pericarps.

Screening of potential α-glucosidase inhibitors from astragalus membranaceus by affinity ultrafiltration screening coupled with UPLC-ESI-Orbitrap-MS method

Astragalus membranaceus is a traditional Chinese medicine with multiple pharmacological activities. Modern pharmacological research has found that Astragalus membranaceus extract has an inhibitory effect on α-glucosidase, however, which component can inhibit the activity of α-glucosidase and its degree of inhibition are unknown. To address this issue, this study used affinity ultrafiltration screening combined with UPLC-ESI-Orbitrap-MS technology to screen α-glucosidase inhibitors in Astragalus membranaceus. Using affinity ultrafiltration technology, we obtained the active components, and using UPLC-ESI-Orbitrap-MS technology, we quickly analyzed and identified them. As a result, a total of 8 ingredients were selected as α-glucosidase inhibitors.

Phytochemical Analysis, Acetylcholinesterase Inhibition, Antidiabetic and Antioxidant Activities of Atriplex halimus L. (Amaranthaceae Juss.).

Mediterranean saltbush Atriplex halimus L. (Amaranthaceae) from different bioclimatic arid zones (ten wild populations) were studied. Phenols contents, flavonoids, flavonols, tannins and anthocyanins were determined and then tested for their antioxidants, antidiabetic and anti-acetylcholinesterase (AChE) activities. Levels of total polyphenols including flavonoids and flavonols, tannins and anthocyanins were high and varied significantly among analyzed populations. Nine phenolic acids and four flavonoids were identified for the first time in the methanolic fraction and quantified by liquid high-performance chromatography system HPLC (DAD). All extracts showed a substantial antioxidant activity, as assessed by DPPH assay (1,1-diphenyl-2-picrylhydrazyl free radical) (IC50DPPH=147.3for population of Seliena), Ferric Reducing Antioxidant Power (FRAP; IC50FRAP=3.2 for populations of Sousse and Kairouan), and Chelation Fer test (IC50FerCh=1.5 μg/mL for populations of El-hamma and Mednine). Atriplex halimus possessed a high inhibitory effect against α-amylase activity (up to 2.6 mg ACE/gE), a moderate activity for α-glucosidase (up to 91.0 mg ACE/gE) and AChE (up to 147.2 μg/mL) compared to standard. The analyzed populations were isolated and subdivided into three distinct groups, without any bioclimatic structuration. Enzymatic activities seem to be associated with the presence, in plant extracts, of other classes of compounds then phenols such as terpenes, sterols, saponins, coumarins and carotenoids.

A dual-signal triple-readout optical sensing platform for α-glucosidase and β-glucosidase activity monitoring and inhibitor screening based on luminescent covalent organic framework

BackgroundAs promising biomarkers of diabetes, α-glucosidase (α-Glu) and β-glucosidase (β-Glu) play a crucial role in the diagnosis and management of diseases. However, there is a scarcity of techniques available for simultaneously and sensitively detecting both enzymes. What's more, most of the approaches for detecting α-Glu and β-Glu rely on a single-mode readout, which can be affected by multiple factors leading to inaccurate results. Hence, the simultaneous detection of the activity levels of both enzymes in a single sample utilizing multiple-readout sensing approaches is highly attractive. ResultsIn this work, we constructed a facile sensing platform for the simultaneous determination of α-Glu and β-Glu by utilizing a luminescent covalent organic framework (COF) as a fluorescent indicator. The enzymatic hydrolysis product common to both enzymes, p-nitrophenol (PNP), was found to affect the fluorometric signal through an inner filter effect on COF, enhance the colorimetric response by intensifying the absorption peak at 400 nm, and induce changes in RGB values when analyzed using a smartphone-based color recognition application. By combining fluorometric/colorimetric measurements with smartphone-assisted RGB mode, we achieved sensitive and accurate quantification of α-Glu and β-Glu. The limits of detection for α-Glu were determined to be 0.8, 1.22, and 1.85 U/L, respectively. Similarly, the limits of detection for β-Glu were 0.16, 0.42, and 0.53 U/L, respectively. SignificanceApplication of the proposed sensing platform to clinical serum samples revealed significant differences in the two enzymes between healthy people and diabetic patients. Additionally, the proposed sensing method was successfully applied for the screening of α-Glu inhibitors and β-Glu inhibitors, demonstrating its viability and prospective applications in the clinical management of diabetes as well as the discovery of antidiabetic medications.

Discovery of new anti-diabetic potential agents based on paracetamol incorporating sulfa-drugs: Design, synthesis, α-amylase, and α-glucosidase inhibitors with molecular docking simulation

Uncontrolled diabetes can lead to hyperglycemia, which causes neuropathy, heart attacks, retinopathy, and nervous system damage over time, therefore, controlling hyperglycemia using potential drug target inhibitors is a promising strategy. This work focused on synthesizing new derivatives via the diazo group, using a hybridization strategy involving two approved drugs, paracetamol and several sulfonamides. The newly designed diazo-paracetamols 5–12 were fully characterized and then screened for in vitro α-amylase and α-glucosidase activities and exhibited inhibitory percentages (IP) = 92.5–96.5 % and 91.0–95.7 % compared to Acarbose IP = 96.5 and 95.8 %, respectively at 100 μg/mL. The IC50 values of the synthesized derivatives were evaluated against α-amylase and α-glucosidase enzymes, and the results demonstrated moderate to potent activity. Among the tested diazo-paracetamols, compound 11 was found to have the highest potency activity against α-amylase with IC50 value of 0.98 ± 0.015 μM compared to Acarbose IC50 = 0.43 ± 0.009 μM, followed by compound 10 (IC50 = 1.55 ± 0.022 μM) and compound 9 (IC50 = 1.59 ± 0.023 μM). On the other hand, for α-glucosidase, compound 10 with pyrimidine moiety demonstrated the highest inhibitory activity with IC50 = 1.39 ± 0.021 μM relative to Acarbose IC50 = 1.24 ± 0.029 μM and the order of the most active derivatives was 10 >9 (IC50 = 2.95 ± 0.046 μM) >11 (IC50 = 5.13 ± 0.082 μM). SAR analysis confirmed that the presence of 4,5-dimethyl-isoxazole or pyrimidine nucleus attached to the sulfonyl group is important for activity. Finally, the docking simulation was achieved to determine the mode of binding interactions for the most active derivatives in the enzyme's active site.

Ultrasonic-Assisted Extraction and Gastrointestinal Digestion Characteristics of Polysaccharides Extracted from Mallotus oblongfolius

The polysaccharides were extracted from the leaves of Mallotus oblongifolius (MO) using an ultrasonic-assisted extraction method in this study. The main variables affecting the yield of polysaccharides extracted from Mallotus appallatus (MOPS) were identified and optimized while concurrently investigating its antioxidant capacity, hypoglycemic activity, and digestive properties. The results indicated that the optimal ultrasound-assisted extraction of MOPS involved an ultrasound power of 200 W, a liquid-to-solid ratio of 25:1 (mL:g), an extraction temperature of 75 °C, and an ultrasound time of 45 min, leading to an extraction yield of (7.36 ± 0.45)% (m/m). The MOPS extract exhibited significant scavenging activity against DPPH and ABTS radicals with IC50 values of (25.65 ± 0.53) μg/mL and (100.38 ± 0.38) μg/mL, respectively. Furthermore, it effectively inhibited the enzymatic activities of α-glucosidase and α-amylase with IC50 values of (2.27 ± 0.07) mg/mL and (0.57 ± 0.04) mg/mL, respectively. The content of MOPS remained relatively stable in the stomach and small intestine; however, their ability to scavenge DPPH radicals and ABTS radicals and exhibit reducing power was attenuated, and the inhibition of α-amylase and α-glucosidase activity was diminished. In conclusion, the ultrasonic extraction of MOPS showed feasibility and revealed antioxidant and hypoglycemic effects. However, the activities were significantly reduced after gastric and small intestinal digestion despite no significant change in the MOPS content.

Natural pyrite activated peroxydisulfate enhanced short-chain fatty acids production from anaerobic fermentation of waste activated sludge: Performance and mechanisms

Peroxydisulfate (PDS) additive has been proven as an effective strategy to enhance short-chain fatty acids (SCFAs) production from waste activated sludge (WAS), which can achieve dual objectives of waste disposal and resource recovery. However, the high cost of PDS limits its large-scale application in sludge treatment. This study explored the feasibility of using natural pyrite (FeS2) as an activator for PDS to enhance its capacity for promoting SCFAs production while reducing the required dosage. Compared to sole PDS (1 mM/g volatile suspended solids (VSS)), FeS2/PDS co-treatment (0.5 mM/g VSS PDS + 0.6 mM/g VSS FeS2) obviously increased the maximum SCFAs production from 4589.5 mg COD/L to 5951.3 mg COD/L, accompanied with an enhanced proportion of acetate from 62.0 % to 75.2 %. Mechanism exploration revealed that FeS2/PDS enhanced the generation of hydroxyl radicals (•OH) and sulfate radicals (SO4•−), thereby promoting WAS solubilization and hydrolysis. The detectable soluble chemical oxygen demand within the supernatant after 4 days of co-treatment fermentation was 5.3-fold higher than that in the single FeS2 test and 2.0-fold higher than that in the single PDS test. Meanwhile, the activities of key enzymes, including protease, α-glucosidase, acetate kinase, and butyrate kinase, were also significantly enhanced after the FeS2/PDS treatment, accompanied with an increase in the abundance of hydrolytic and acidogenic microorganisms such as Acinetobacter, Clostridium_sensu_stricto, and Fonticella. Besides, FeS2/PDS co-treatment improved the dewaterability (42.7 % reduction in capillary suction time) and reduced operation cost (37.9 % decrease), as compared to the sole PDS (1 mM/g VSS) treatment. These findings suggest that FeS2/PDS co-treatment is a promising and cost-effective technique to enhance WAS anaerobic fermentation.

Evaluation of the Anti-diabetic Activity of Purified Compounds of Ferula assafoetida by in vitro and in silico Methods

Objective Postprandial hyperglycemia is considered an early sign of diabetes. Enzyme inhibitors, such as α-amylase and α-glucosidase inhibitors, are currently being studied as potential drugs for preventing postprandial hyperglycemia. Methods In this study, we investigated the effects of four purified 7-hydroxycoumarine derivatives from Ferula assafoetida: umbelliprenin, farnesiferol A, farnesiferol C, and samarcandin. We evaluated cell toxicity using the MTT method and also examined glucose uptake and inhibition of α-amylase and α-glucosidase enzymes in vitro. Additionally, we conducted a molecular docking study to investigate the mechanism of enzyme inhibition. Results The cell toxicity of the terpenoid coumarin derivatives (umbelliprenin, farnesiferol A, farnesiferol C, and samarcandin) on HepG2 cells was found to be approximately 28 to 37 µg/ml. The glucose uptake assay showed that these compounds (at a concentration of 25 µg/ml) were able to increase glucose consumption by HepG2 cells to a level comparable to that of the positive control (metformin at 50 µg/ml). Furthermore, umbelliprenin significantly inhibited the activity of α-amylase and α-glucosidase (by 35.07% and 4.98%, respectively). Molecular docking results indicated that umbelliprenin, with a farnesyl chain, had a more potent inhibitory effect. Conclusion Our findings suggest that umbelliprenin may be a valuable compound for controlling postprandial hyperglycemia and diabetes. However, further in vivo studies and clinical trials are necessary to validate these effects. While this research offers potential for the development of more effective compounds with coumarin structures, further studies are needed to confirm these findings.

Progress in experimental models to investigate the invivo and invitro antidiabetic activity of drugs.

Diabetes mellitus is one of the world's most prevalent and complex metabolic disorders, and it is a rapidly growing global public health issue. It is characterized by hyperglycemia, a condition involving a high blood glucose level brought on by deficiencies in insulin secretion, decreased activity of insulin, or both. Prolonged effects of diabetes include cardiovascular problems, retinopathy, neuropathy, nephropathy, and vascular alterations in both macro- and micro-blood vessels. Invivo and invitro models have always been important for investigating and characterizing disease pathogenesis, identifying targets, and reviewing novel treatment options and medications. Fully understanding these models is crucial for the researchers so this review summarizes the different experimental invivo and invitro model options used to study diabetes and its consequences. The most popular in vivo studies involves the small animal models, such as rodent models, chemically induced diabetogens like streptozotocin and alloxan, and the possibility of deleting or overexpressing a specific gene by knockout and transgenic technologies on these animals. Other models include virally induced models, diet/nutrition induced diabetic animals, surgically induced models or pancreatectomy models, and non-obese models. Large animals or non-rodent models like porcine (pig), canine (dog), nonhuman primate, and Zebrafish models are also outlined. The invitro models discussed are murine and human beta-cell lines and pancreatic islets, human stem cells, and organoid cultures. The other enzymatic invitro tests to assess diabetes include assay of amylase inhibition and inhibition of α-glucosidase activity.

Nanosupplements based on protein-polysaccharide coacervates loaded with essential oils: Evaluation of antioxidant and antidiabetic properties

Essential oils (EOs) have demonstrated potential in food products to prevent complications related to diabetes. Nevertheless, the physicochemical characteristics of pure EOs, including high volatility and low chemical stability, face significant challenges when considering their utilization as functional ingredients. Thus, this study aimed to develop nanosupplements based on protein-polysaccharide coacervates loaded with EOs, thyme (THY) and oregano (ORE), and to evaluate their colloidal, antioxidant, and α-glucosidase and α-amylase inhibitory properties following an in vitro gastrointestinal digestion process. First, heat-induced egg white protein nanoparticles (EWPn) were used to encapsulate both EOs as nanocomplexes. Second, the process to obtain nanosupplements involved the electrostatic deposition of high methoxyl pectin (HMP) onto the surface of pre-formed nanocomplexes, resulting in the production of EWPn-THY-HMP and EWPn-ORE-HMP powders through a freeze-drying process. The effects of in vitro digestion on particle size, zeta potential, stability, and bioaccessibility of systems were analyzed. HMP exhibited a slight ability to protect EWPn from gastric digestion, while encapsulation within the EWPn-HMP system prevented the chemical degradation of EOs during gastrointestinal digestion. Subsequently, the antioxidant properties and the inhibitory effects of digested systems on α-glucosidase and α-amylase activities were examined. After in vitro digestion, EWPn-THY-HMP and EWPn-ORE-HMP systems showed higher ABTS+ radical scavenging than pure EOs (around 70% vs. 30%, respectively). Additionally, reducing power activities (expressed as mg of ascorbic acid equivalents-AAE mL−1) of EWPn-THY-HMP and EWPn-ORE-HMP systems were higher (1.6 ± 0.0 mg and 1.8 ± 0.1 mg of AAE mL−1, respectively) compared to pure THY and ORE (approximately 1.5 mg of AAE mL−1 for both) after in vitro digestion. The α-glucosidase inhibitory activity of EOs decreased upon encapsulation within EWPn-HMP system from an IC50 value of 0.3–1.0 μg mL−1, approximately. However, the effect of encapsulation on α-amylase inhibitory activity was EOs-dependent, and it was higher for the EWPn-ORE-HMP system, with an IC50 value of 8.6 ± 0.2 μg mL−1. The results highlight the potential of EOs encapsulation within EWPn-HMP coacervate nanosupplements as a promising strategy to facilitate their incorporation into food matrices while preserving their antioxidant and α-glucosidase and α-amylase inhibitory properties.

Investigation into the Phytochemical Composition, Antioxidant Properties, and In-Vitro Anti-Diabetic Efficacy of Ulva lactuca Extracts.

In this research, the chemical compositions of various extracts obtained from Ulva lactuca, a type of green seaweed collected from the Nador lagoon in the northern region of Morocco, were compared. Their antioxidant and anti-diabetic properties were also studied. Using GC-MS technology, the fatty acid content of the samples was analyzed, revealing that palmitic acid, eicosenoic acid, and linoleic acid were the most abundant unsaturated fatty acids present in all samples. The HPLC analysis indicated that sinapic acid, naringin, rutin, quercetin, cinnamic acid, salicylic acid, apigenin, flavone, and flavanone were the most prevalent phenolic compounds. The aqueous extract obtained by maceration showed high levels of polyphenols and flavonoids, with values of 379.67 ± 0.09 mg GAE/g and 212.11 ± 0.11 mg QE/g, respectively. This extract also exhibited an impressive ability to scavenge DPPH radicals, as indicated by its IC50 value of 0.095 ± 0.12 mg/mL. Additionally, the methanolic extract obtained using the Soxhlet method demonstrated antioxidant properties by preventing β-carotene discoloration, with an IC50 of 0.087 ± 0.14 mg/mL. Results from in-vitro studies showed that extracts from U. lactuca were able to significantly inhibit the enzymatic activity of α-amylase and α-glucosidase. Among the various extracts, methanolic extract (S) has been identified as the most potent inhibitor, exhibiting a statistically similar effect to that of acarbose. Furthermore, molecular docking models were used to evaluate the interaction between the primary phytochemicals found in these extracts and the human pancreatic α-amylase and α-glucosidase enzymes. These findings suggest that U. lactuca extracts contain bioactive substances that are capable of reducing enzyme activity more effectively than the commercially available drug, acarbose.

Valorization of pawpaw (Carica papaya L.) leaves as a source of polyphenols by ionic liquid-based microwave-assisted extraction: Comparison with other extraction methods and bioactivity evaluation

This study aimed to valorize pawpaw (Carica papaya L.) leaves as a rich source of polyphenols through the application of ionic liquid-based microwave-assisted extraction (ILMAE). Initially, the ILMAE process was optimized using response surface methodology (RSM), resulting in a total polyphenols yield of 27.84 ± 0.33 mg GAE/g DW under the optimal conditions: [BMIM]Br concentration of 0.57 mol/L, extraction time of 14 min, microwave power of 460 W, extraction temperature of 77 °C, solvent-to-material ratio of 30 mL/g, and three extraction cycles. Compared to conventional methods such as maceration extraction (ME), heat reflux extraction (HRE), and microwave-assisted extraction (MAE), the ILMAE method exhibited a significantly higher PLTP yield. Furthermore, the PLTP extracts demonstrated strong antioxidant activity against DPPH• and ABTS+• radicals, as well as a significant inhibitory effect on α-glucosidase activity. This work demonstrates that ILMAE is a green and efficient strategy for the valorization of pawpaw leaves.

Synthesis of modified 1,3,4-thiadiazole incorporating substituted thiosemicarbazide derivatives: Elucidating the in vitro and in silico studies to develop promising anti-diabetic agent

Hybrid molecules based on the 1,3,4-thiadiazole were always the choice of different researchers due to their significant application in medicinal as well as pharmaceutical application. In the present study, twenty analogs of 1,3,4-thiadiazole-bearingthiosemicarbazide moiety (1–20) were synthesized and screened for their anti-diabetic profile. The synthesized compounds were spectroscopically characterized through different spectroscopic techniques such as 1HNMR, 13CNMR, and HREI-MS. Comparing the whole set of afforded compounds to the standard glimepiride drugs (16.01 ± 0.02 μM), the inhibition profiles against α-amylase ranged from 21.02 ± 0.08 to 54.08 ± 0.04 μM. Comparing synthetic analogs to normal glimepiride (IC50 = 14.06 ± 0.05 μM), the range of α-glucosidase activity was likewise variable, ranging from 18.04 ± 0.07 μM to IC50 = 51.05 ± 0.03 μM (against α-glucosidase). Compound 19 demonstrated high potency among the produced analogs since it had both ortho-nitrosubstitution at the aryl ring. The pattern of substitutions around the aryl ring was used for all analogs to determine the structure–activity relationship. In addition, a molecular docking study was conducted on the potent analogs to examine the interactions between the active residues of the targeted enzymes with the synthesized compound. The synthesized molecule showed different types of interactions with amino acid. The outcome demonstrates that these compounds provide several essential interactions with the active sites of enzymes, hence strengthening their enzymatic activity for the future prediction as drug competitors.

Chemical composition and antioxidant, enzyme inhibition and cytoprotective activity of two Antarctic lichens of the genus Psoroma (Pannariaceae)

Lichens contain different types of chemical compounds with multiple biological activities that demonstrate their potential pharmacological use. This research aims to report the metabolomic identification of the ethanolic extracts of P. antarcticum and P. hypnorum, their antioxidant, enzyme inhibitory, and their cytoprotection activity. Sixteen metabolites were identified in P. antarcticum and twelve in P. hypnorum; the extracts reported variable antioxidant activity with IC50 >350 µg/mL in DPPH·, values >18 µmol Trolox/g in ORAC and >40 µmol Trolox/g in FRAP and a phenolic compound content >10 mg GAE/g, as well as significant results in cholinesterases, α-glucosidase, pancreatic lipase, α-amylase, and tyrosinase enzyme inhibition activities with IC50 ranging from 18 to 510 µg/mL, and which were complemented by molecular docking experiments. Both extracts showed improved cytoprotection at the concentrations of 0.5 to 1.0 μg/mL. This study contributes to the knowledge of the chemical diversity of Antarctic lichen extracts and their effectiveness in the evaluation of biological activities related to neurodegenerative diseases and metabolic syndrome.

Exploring the nutraceutical potential: Evaluating the nutritional and bioactive functions of five pomelo fruit varieties in Bangladesh

Pomelo (Citrus maxima), the largest citrus fruit, provides a variety of nutrients that have several health benefits, including antioxidant and antidiabetic functions. Antioxidants help combat oxidative stress by neutralizing reactive oxygen species (ROS) and reducing cellular damage. On the other hand, antidiabetic properties involve mechanisms such as enhancing insulin secretion, improving insulin sensitivity, inhibiting carbohydrate digestion and absorption, and regulating glucose metabolism. However, there is a lack of data on the comparative analysis of the physicochemical composition, bioactive properties, and antidiabetic effects of pomelo fruits grown in Bangladesh. To address this issue, the most common and popular high-yielding five cultivars of pomelo fruits grown in Bangladesh including LOCAL, BARI-2 (BARI: Bangladesh Agricultural Research Institute, Batabi Lebu-2), BARI-3, BARI-4, and BARI-6 were evaluated concerning proximate, minerals, and physicochemical properties with their antidiabetic and antioxidant properties. Research has revealed that all pomelo varieties contained a significant amount of proximate compositions and major minerals (Ca, Mg, K, Na, and Fe). The highest juice yield (75.37 ± 0.33 %), vitamin C content (79.56 ± 2.26 mg/100 mL of fresh juice), and carotenoid content (919.33 ± 0.62 μM β-Carotene Equivalent/g DM) were found in BARI-3 pomelo fruit and adhered to the sequence (p < 0.05): BARI-3 > LOCAL > BARI-4 > BARI-6 > BARI-2; BARI-3 > LOCAL > BARI-2 > BARI-4 > BARI-6, and BARI-3 > BARI-2 > BARI-6 > LOCAL > BARI-4, respectively. The anthocyanin content and inhibitory activity of α-glucosidase were found to be at their peak in the BARI-2 pomelo variety and the values were 50.65 ± 2.27 μg cyanidin 3-glucoside equivalents/100 g DM and 85.57 ± 0.00 μM acarbose equivalents/g DM, respectively. BARI-3 pomelo variety showed highest DPPH antioxidant capacity (170.47 ± 0.01 μM Trolox equivalents/g DM), while the BARI-6 pomelo variety exhibited the highest total phenolic content (6712.30 ± 1.84 μg gallic acid equivalents/g DM), and ferric-reducing antioxidant power activity (183.16 ± 0.01 μM Fe(II) equivalents/g DM). Therefore, this study explores the nutritional value and bioactivity of five popular pomelo varieties in Bangladesh, offering valuable insights for utilizing high-value citrus resources and understanding their health-promoting functions.

Accentuation of the browning characteristics and functional properties of aged tomatoes (Solanum lycopersicum cv.)

Moisture-assisted aging technology (MAAT) is a green process that improves browning characteristics and functionalities. This study investigated the physicochemical and functional characteristics of aged tomatoes. MAAT modulated carotenoids biotransformation from esterified to free form (Fourier-transform infrared spectroscopy 1738, 2851, and 2922 cm−1) and generated primary and secondary oxidation volatiles, such as 4-terpineol, α-terpineol, and γ-terpineol (Headspace solid-phase microextraction gas chromatography-mass), which contributed woody and clove odors. Total flavonoids and α-glucosidase activity inhibitory were significantly increased from 1207.729 to 2318.204 mg RE/100 g DW and 77.703% to 86.851%, respectively. We discovered different synthesis pathways of 5-HMF and furfural under different water activities; this breakthrough may set furfural as an important factor in quality control of MAAT products in the future. Thus, MAAT can modulate the chemical form of tomato carotenoids, improve functionalities, and generate unique woody odor volatiles. These results may be applied to health food development in the food industry.

Bifunctional Tb(III)-modified Ce-MOF nanoprobe for colorimetric and fluorescence sensing of α-glucosidase activity

α-Glucosidase, which directly involves in the metabolism of starch and glycogen and causes an increase in blood sugar level, is the major target enzyme for the precaution and therapy of type II diabetes. Based on the previous work, we adopted a post-synthetic modification method to encapsulate Tb3+ into Ce-MOF nanozyme which owned mixed valence states. Tb@Ce-MOF displayed induced luminescence characteristic and exceptional oxidase-like activity that could oxidize colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue ox-TMB. α-Glucosidase can hydrolyze the substrate l-ascorbic acid-2-O-α-d-glucopyranosyl (AAG) to generate ascorbic acid (AA), which could increase the Ce3+/Ce4+ redox valence mode in Tb@Ce-MOF, leading to the inhibition of the allochroic reaction of TMB and the decreased absorption of ox-TMB at 652 nm. The energy transfer (EnT) process from Ce3+ to Tb3+ will enhance due to the increased Ce3+/Ce4+ mode in Tb@Ce-MOF, which will result in an enhanced fluorescence signal of Tb@Ce-MOF at 550 nm. But the addition of inhibitor acarbose will inhibit the above process. We have constructed a dual-mode detection platform of α-glucosidase and its inhibitor via colorimetric and fluorometric method. The linear range of α-glucosidase were 0.01–0.5 U/mL (colorimetric mode) and 0.8–1.5 U/mL (fluorometric mode), respectively, with a detection limit as low as 0.0018 U/mL. Furthermore, our approach was also successfully employed to the analysis of α-glucosidase in serum samples.

Inhibition of α-glucosidase activity by potential peptides derived from fermented spent coffee grounds

The control of α-glucosidase activity has been associated with managing diabetes. We previously identified three peptides with high bioactive indices derived from protein hydrolysates of fermented spent coffee grounds. In this study, the peptides YGF, GMCC, and RMYRY were synthesized and tested in vitro for their α-glucosidase inhibition activity, complemented by in silico analyses. Two of the three peptides significantly inhibited α-glucosidase activity, with the more efficient peptides being YGF and GMCC (0.42 mg/mL), resulting in decreased enzymatic activity of 95.31% and 89.79%, respectively. These peptides exhibited binding free energies with the α-glucosidase complex of −8.5 and − 6.6 kcal/mol, respectively, through hydrogen bonds and van der Waals interactions with amino acids from the active site. Pharmacokinetic analysis indicated that YGF and GMCC profiles were unrelated to toxicity. These results underscore the importance of focusing on food waste bioprocessing products to expand the range of alternatives that could aid in diabetes treatment.

Discovering the anti-diabetic potential of thiosemicarbazone derivatives: In vitro α-glucosidase, α-amylase inhibitory activities with molecular docking and DFT investigations

This work describes the synthesis of para-substituted thiosemicarbazone derivatives by refluxing 4-ethoxybenzaldehyde (1) and 4-nitrobenzaldehyde (2) with thiosemicarbazide in ethanol with acetic acid catalyst. The resultant thiosemicarbazones were then treated with various phenacyl bromides to get the product compounds. 1H NMR and EI-MS spectroscopic methods were employed to confirm the structures of these derivatives and screened the compounds for their in vitro α-glucosidase and α-amylase inhibitory activities. Six compounds (4e, 3e, 3c, 3b, 4b, and 4c) exhibited highest α-glucosidase activity in the range of IC50 values of 2.81 ± 1.92 to 16.16 ± 0.15 µM. Similar to this, five compounds (3e, 4e, 3b, 3c, and 4c) attributed excellent inhibitory activity in the range of IC50 values from 3.12 ± 0.13 to 16.56 ± 0.17 µM against the α-amylase enzyme when compare with the standard acarbose. The density functional theory (DFT) study demonstrated the stability, bioactivity, and charge transfer of the compounds, while the molecular docking analysis has provided significant understanding of how the compounds interact with the enzymes. These findings provide prospective directions for the development of innovative therapeutic candidates to regulate postprandial glucose levels in diabetic patients.

Reactive oxygen species independent oxidase like nanozyme for dual-mode analysis of α-glucosidase

Designing highly sensitive and selective assay for analyzing α-glucosidase activity is of critical value for diagnosis of related diseases. Herein, we proposed a biomineralization synthetic route to construct bovine serum albumin templated hybrid nanomaterials of Au nanoclusters (Au NCs) and oxygen deficient manganese dioxide (indicated as BAM). BAM exhibits ultra-fast oxidase (OXD)-like activity that directly oxidized TMB to generate product. Unexpected, the OXD-like activity of BAM is not relied on the reactive oxygen species or dissolved molecular oxygen, which has rarely been reported. The superior OXD-like activity of BAM is derived from the strong interactions between Au NCs and MnO2-x nanosheets that contributes to the partial reduction of MnO2-x and increase of Au(Ⅰ) species. And the catalytic mechanism is related to electron transfer from TMB to MnO2-x with Au NCs as intermediates. The analysis of α-glucosidase activity has been realized by BAM and 2-O-a-D-glucopyranosyl-L-ascorbic acid (AA2G) as the catalytic substrate with dual mode. The AA2G can be hydrolyzed by α-glucosidase into AA, which can obviously inhibit the oxidation of TMB and recover the fluorescence of Au NCs. And the inhibition ratio and recovery efficacy are related the activity of α-glucosidase. Hence, the activity of α-glucosidase can be analyzed by the changes of the signal of absorbance or fluorescence. The dual-mode detection can prevent false negative/ positive results, satisfying different demands in various analytical situation.