Exploring the interaction of phytochemicals from Hibiscus rosa-sinensis flowers with glucosidase and acetylcholinesterase: An integrated in vitro and in silico approach.

Targeting multiple factors such as oxidative stress, alpha glucosidase and acetylcholinesterase (AChE) are considered advantageous for the treatment of diabetes and diabetes associated-cognitive dysfunction. In the present study, Hibiscus rosa-sinensis flowers anthocyanin-rich extract (HRA) was prepared. Phytochemical analysis of HRA using LC-ESI/MS/MS revealed the presence of various phenolic acids, flavonoids and anthocyanins. HRA showed in vitro antioxidant activity at low concentrations. HRA inhibited all the activities of mammalian glucosidases and AChE activity. The IC50 value of HRA for the inhibition of maltase, sucrase, isomaltase, glucoamylase and AChE was found to be 308.02 ± 34.25 µg/ml, 287.8 ± 19.49 µg/ml, 424.58 ± 34.75 µg/ml, 408.94 ± 64.82 µg/ml and 264.13 ± 30.84 µg/ml, respectively. Kinetic analysis revealed mixed-type inhibition against all the activities except for glucoamylase (competitive) activity. In silico analysis confirmed the interaction of two active constituents cyanidin 3-sophoroside (CS) and quercetin 3-O-sophoroside (QS) with four subunits, n-terminal and c-terminal subunits of human maltase-glucoamylase and sucrase-isomaltase as well as with AChE. Molecular dynamics simulation, binding free energy calculation, DCCM, PCA, PCA-based free energy surface analysis ascertained the stable binding of CS and QS with target proteins studied. HRA could be used as complementary therapy for diabetes and cognitive improvement.

Two new isoquinoline alkaloids from Cryptocarya wrayi and their biological activities.

Two new isoquinoline alkaloids, cryptowrayines A (1) and B (2), along with one known pavine alkaloid (-)-12-hydroxyeschscholtzidine (3), were isolated from the twigs of Cryptocarya wrayi. The structures of new compounds were elucidated by extensive spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Both compounds 1 and 2 exhibited moderate quinone reductase inducing activity in Hepa 1c1c7 cells.

Biological activity, phytochemical parameters, and potential bioaccessibility of wheat bread enriched with powder and microcapsules made from Saskatoon berry.

The aim of the present study was to determine the impact of Saskatoon powder addition on phytochemical parameters, biological activity, and nutritional value of wheat bread. Supplementation increased phenolics content up to 72% in the bread with 6% powder content. This increase was reflected in the improved antioxidative properties of breads, especially after their supplementation with the microencapsulated additives (an increase by 93% in the bread enriched with 6% of powder covered with maltodextrin). The in vitro digestion released the antioxidative compounds, leading to higher bioaccessibility of the breads enriched with the microencapsulated powders. The highest inhibition of activities of cyclooxygenase 1 and -2, as well as amylase and glucosidase was recorded for the breads enriched with the additive microencapsulated with maltodextrin and inulin. Thus, Saskatoon berry powders, especially the microencapsulated ones, may be used as functional components in designing innovative bakery products.

Identification and Characterization of a-Glucosidase Inhibition Flavonol Glycosides from Jack Bean (Canavalia ensiformis (L.) DC.

Although the intake of jack bean (Canavalia ensiformis (L.) DC.), an underutilized tropical legume, can potentially decrease the risk of several chronic diseases, not much effort has been directed at profiling the polyphenolics contained therein. Hence, this work aimed to identify and quantify the dominant jack bean polyphenolics, which are believed to have antioxidant and other bioactivities. Four major compounds were detected and identified as kaempferol glycosides with three or four glycoside units. Their structures were established based on UV-visible, 1d, 2D NMR, and HR-ESI-MS analyses. Specifically, kaempferol 3-O-a-l-rhamnopyranosyl (1®6)- b-d-glucopyranosyl (1®2)-b-d-galactopyranosyl-7-O-[3-O-o-anisoyl]-a-l-rhamnopyranoside was detected for the first time, while the other three compounds have already been described in plants other than jack bean. This new compound was found to have a higher a-glucosidase inhibition activity compared to acarbose.

Chemical characterization of the antioxidant, antihyperglycemic and antihypertensive capacities of red rice (Oryza sativa L. ) whole flour / Caracteristicas físico-químicas, capacidad antioxidante, anti-hiperlucémica y antihipertensiva de la harina de arroz rojo (Oryza sativa L. )

Oryza sativa L. rice has large amounts of proteins and minerals, besides presenting several pigmented varieties. Red rice is distinguishable due to its great nutritional value compared to the regular white variety. Its red pericarp pigmentation is due to the bioactive compounds that are responsible for its health benefits. The objective of this study was to evaluate the physical-chemical characterization, antioxidant, antihyperglycemic and antihypertensive capacity of flours of three different red rice cultures (Rubi, Virgínia and Pequeno). All samples presented specific levels of carbohydrates for cereals with low fat content and excellent levels of protein and resistant starch. In addition, the samples had a high antioxidant, antihyperglycemic and antihypertensive capacity. Antihyperglycemic capacities were measured as percent inhibition for amylase (56.7-76.5%) and glycosidase (81.0-76.6%), respectively, and antihypertensive capacity as the percentage inhibition of the angiotensin converting enzyme (38.4-34.7%). In addition, Pequeno flour presented the best results for antioxidant and antihyperglycemic capacity in comparison to the two flours tested. Thus, all red rice flours can be a source of functional compounds when added to food.

El arroz integral (Oryza sativa L.) posee importantes cantidades de proteínas, vitaminas, minerales y fitoquímicos. El arroz rojo se destaca por su gran valor nutricional. La pigmentación roja del pericarpio está asociado al contenido de compuestos bioactivos, que están directamente relacionados a los beneficios de salud humana. Teniendo en cuenta lo antes expuesto se propuso evaluar las caracteristicas físico-químicas, capacidad antioxidante, anti-hiperglucémica y antihipertensiva de las harinas de tres diferentes cultivos de arroz rojo (Rubí, Virginia y Pequeño). Todas las muestras presentaron niveles específicos de carbohidratos para cereales con bajo contenido de grasa y altos contenidos de proteína y almidón resistente. Además, las muestras presentaron una alta capacidad antioxidante, anti-hiperglucémica y antihipertensiva. La capacidad anti-hiperglicémica se midió en porcentaje de inhibidores de α-amilasa (56.7-76.5%) y α-glucosidasa (81.0-76.6%), respectivamente; y capacidad antihipertensiva como el porcentaje de inhibición de la enzima convertidora de la angiotensina (38.4-34.7%). El cultivar Pequeño presentó mayor capacidad antioxidante y anti-hiperglucémica en comparación a los demás cultivares. Así, todas las harinas de arroz rojo pueden ser vehículos de compuestos funcionales en los alimentos.

Charge-Assisted Chalcogen Bonds: CSD and DFT Analyses and Biological Implication in Glucosidase Inhibitors.

This study reports a combined Cambridge Structural Database and theoretical DFT study of charge assisted chalcogen bonds involving sulfonium, selenonium, and telluronium cations. The chalcogen bond has been recently defined by IUPAC as the net attractive interaction between an electrophilic region associated with a chalcogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. Divalent chalcogen atoms typically have up to two σ-holes and forms up to two ChBs; the same holds for tetravalent chalcogens which adopt a seesaw arrangement. In sulfonium, selenonium, and telluronium salts chalcogen atoms form three covalent bonds, three σ-holes are located opposite to these bonds, and up to three charge assisted ChBs can be formed between these holes and the counterions. The covalent bond arrangement around these chalcogen atoms is similar to trivalent pnictogen atoms and translates into a similar pattern of noncovalent interactions. We have found and studied this type of charge-assisted chalcogen bonds in various sulfonium ion-containing inhibitors of glucosidase, for example, salacinol and kotalanol.

Effects of extraction methods on physicochemical properties and hypoglycemic activities of polysaccharides from coarse green tea.

Coarse tea is made of mature tea plant (Camellia sinensis L.) shoots and is generally discarded as a worthless crop product, but has been proved an excellent material for the treatment of diabetes. This study aims to evaluate the effects of the extraction techniques WE (water extraction), UAE (ultrasound-assisted extraction), MAE (microwave-assisted extraction), and EE (enzyme extraction) on the physicochemical properties and antidiabetic activities of polysaccharides from coarse tea (CTPSs). The results showed that all four CTPSs had homogeneity in the monosaccharide types and similar IR (Infrared spectroscopy) characteristic absorption peaks, but differed in monosaccharide proportion and molecular weight distribution. Compared with the other three extraction techniques, CCTPS extracted by EE had the lowest protein content, the highest total sugar content of 71.83% and a polysaccharide yield of 4.52%. In addition, EE-CTPS had the best hypoglycemic activity that was better than ordinary green tea polysaccharides, the α-glucosidase and α-amylase inhibitory activities of EE-CTPS were highest in the range of 2-10 mg/mL compared with the other three CTPSs, which may be related to its smaller molecular weight and porous structure. The results suggested that the EE method was a good way to extract polysaccharides from coarse tea for food and pharmaceutical production.

Adipocytes utilize sucrose as an energy source-Effect of different carbohydrates on adipocyte differentiation.

Adipose tissue is a complex and heterogenic tissue exhibiting high variability and appears to have multiple functions, especially in metabolic regulation. Change in carbohydrate source is reported to have a profound effect in the regular functioning of adipocytes. Here, we analyzed the role of two monosaccharides namely, glucose (5.2 and 25 nM), galactose (25 mM), and two disaccharides namely, lactose and sucrose (both at 25 mM) in the adipocyte differentiation process and its utilization by adipocytes as an energy source. The change in cell morphology, adipocyte-specific gene expression, and protein levels were analyzed at three different time points: 2, 6, and 48 hr. Oil Red O staining at Day 8 of differentiation showed that no other carbohydrates were able to increase lipid content as better as 25 mM glucose. Gene expression pattern was altered by the change in glucose concentration and sucrose was able to mimic the effect of glucose even though, the lipid synthesis was solely promoted by high glucose levels. Galactose and lactose did not show any effect in promoting adipocyte differentiation. The expression of PPAR γ was high in the presence of sucrose and galactose, possibly of adipogenic cocktail in enhancing the expression rather than the effect of carbohydrate. Acarbose, a potent glucosidase inhibitor was able to inhibit the lipid content in adipocytes grown with sucrose as a carbohydrate source and shows the possibility of its direct utilization. Lactate production by cells upon differentiation also proved the possible uptake of glucose after sucrose cleavage.

Comparative analysis of isoflavone aglycones using microwave-assisted acid hydrolysis from soybean organs at different growth times and screening for their digestive enzyme inhibition and antioxidant properties.

The objectives of this research were to demonstrate the changes in isoflavone-aglycones, total phenolics, and biological properties (digestive enzyme inhibition; antioxidant) from six organs including leaves, leafstalks, roots, stems, seeds, and pods at different growth times of soybean plant. Three isoflavone-aglycones in microwave-assisted acid hydrolysis extracts were elucidated using UHPLC-ESI-Q-TOF-MS/MS and their contents exhibited remarkable differences in leaves (245.93-2239.33 µg/g), roots (854.96-4425.34 µg/g), and seeds (ND-2339.62 µg/g). Specifically, the collected samples on 15-Oct (leaves: 2239.33; seeds: 2339.62 µg/g) and 31-Aug (roots: 4425.34 µg/g) showed the highest isoflavone-aglycones, and daidzein was observed the most abundant component, comprising approximately 70%. Moreover, the inhibitions against α-glucosidase and α-amylase displayed the predominant effects in roots (89;91%) and leaves (81;85%) of samples on 31-Aug and 15-Oct at 300 µg/ml. The antioxidant activities on ABTS, DPPH, and hydroxyl radicals increased considerably with the increases of growth times in leaves and seeds, especially, ABTS showed the highest scavenging abilities: leaves (15-Oct;83%) > roots (31-Aug;75%) > seeds (15-Oct;68%). Therefore, our results suggest that soybean leaves, roots and seeds may be considered as excellent natural sources for nutraceuticals.

New insights into the chemical profiling, cytotoxicity and bioactivity of four Bunium species.

Bunium species have been reported to be used both as food and in traditional medicines. The scientific community has attempted to probe into the pharmacological and chemical profiles of this genus. Nonetheless, many species have not been investigated fully to date. In this study, we determined the phenolic components, antimicrobial, antioxidant, and enzyme inhibitory activities of aerial parts of four Bunium species (B. sayai, B. pinnatifolium, B. brachyactis and B. macrocarpum). Results showed that B. microcarpum and B. pinnatifolium were strong antioxidants as evidenced in the DPPH, ABTS, CUPRAC, and FRAP assays. B. brachyactis was the most effective metal chelator, and displayed high enzyme inhibition against cholinesterase, tyrosinase, amylase, glucosidase, and lipase. The four species showed varied antimicrobial activity against each microorganism. Overall, they showed high activity against P. mirabilis and E. coli (MIC and MBC <1 mg mL-1). B. brachyactis was more effective against Aspergillus versicolor compared to the standard drug ketoconazole. B. brachyactis was also more effective than both ketoconazole and bifonazole against Trichoderma viride. B. sayai was more effective than ketoconazole in inhibiting A. fumigatus. B. sayai was most non-toxic to HEK 293 (cellular viability = 117%) and HepG2 (cellular viability = 104%). The highest level of TPC was observed in B. pinnatifolium (35.94 mg GAE g-1) while B. microcarpum possessed the highest TFC (39.21 mg RE g-1). Seventy four compounds were detected in B. microcarpum, 70 in B. brachyactis, 66 in B. sayai, and 51 in B. pinnatifolium. Quinic acid, chlorogenic acid, pantothenic acid, esculin, isoquercitrin, rutin, apigenin, and scopoletin were present in all the four species. This study showed that the four Bunium species are good sources of biologically active compounds with pharmaceutical and nutraceutical potential.

Ohmic heating for processing of whey-raspberry flavored beverage.

Different Ohmic heating conditions (OH, 10, 100, and 1000 Hz at 25 V; 45, 60, and 80 V at 60 Hz) were assessed to manufacture whey-raspberry flavored beverages. The inhibition of α-glucosidase, α-amylase, and angiotensin-converting I enzymes, antioxidant capacity, fatty acid profile, and volatile organic compounds (VOCs) were determined. OH treated samples presented lower anthocyanins content than the conventional treatment (2.91 ±â€¯0.23 mg/g), while the mild-intermediate conditions (10,100-Hz at 25 V and 45,60-V at 60 Hz) presented the highest chemical antioxidant activity when compared to the extreme processing conditions (1000 Hz-25 V and 80 V-60 Hz). OH led to an increase of 10% in both α-glucosidase (>99%) and α-amylase (≥70%). Among the VOCs, furfural and 5-hydroxymethylfurfural, a major intermediate Maillard reaction product was found in all treatments. Overall, OH can be used in the processing of whey-flavored raspberry beverages.

Dual targeting of PTP1B and glucosidases with new bifunctional iminosugar inhibitors to address type 2 diabetes.

The diffusion of type 2 diabetes (T2D) throughout the world represents one of the most important health problems of this century. Patients suffering from this disease can currently be treated with numerous oral anti-hyperglycaemic drugs, but none is capable of reproducing the physiological action of insulin and, in several cases, they induce severe side effects. Developing new anti-diabetic drugs remains one of the most urgent challenges of the pharmaceutical industry. Multi-target drugs could offer new therapeutic opportunities for the treatment of T2D, and the reported data on type 2 diabetic mice models indicate that these drugs could be more effective and have fewer side effects than mono-target drugs. α-Glucosidases and Protein Tyrosine Phosphatase 1B (PTP1B) are considered important targets for the treatment of T2D: the first digest oligo- and disaccharides in the gut, while the latter regulates the insulin-signaling pathway. With the aim of generating new drugs able to target both enzymes, we synthesized a series of bifunctional compounds bearing both a nitro aromatic group and an iminosugar moiety. The results of tests carried out both in vitro and in a cell-based model, show that these bifunctional compounds maintain activity on both target enzymes and, more importantly, show a good insulin-mimetic activity, increasing phosphorylation levels of Akt in the absence of insulin stimulation. These compounds could be used to develop a new generation of anti-hyperglycemic drugs useful for the treatment of patients affected by T2D.

Madeira moneywort (Sibthorpia peregrina L.) as a new source of verbascoside and its derivatives with potential phyto-pharmaceutical applications.

The qualitative and quantitative characterization of Madeira moneywort (Sibthorpia peregrina L.) compounds was investigated for the first time. The antioxidant activity and the effect of the methanolic extract on digestive enzymes activity linked to type-2 diabetes and obesity were also determined by in vitro assays. A total of 56 components were characterized in S. peregrina. Phenylethanoids glycosides (PhEGs) represented the main classes of compounds (95.23 mg g-1 of dry extract), almost all verbascoside and its derivatives (up to 98.85% of the total individual phenolic content). The analysed sample was active against ABTS, DPPH, nitric oxide and superoxide radicals, suggesting a potential beneficial effect against oxidative stress. In addition, the methanolic extract was able to inhibit the catalytic activity of α-, ß-glucosidases, α-amylase and pancreatic lipase. Overall, S. peregrina showed good perspectives to be explored as a rich source of verbascoside and its derivatives for nutraceutical/pharmaceutical products.

Two new 12-membered macrolides from the endophytic fungal strain Cladosprium colocasiae A801 of Callistemon viminalis.

Two new polyketide metabolites, the 12-membered macrolides 4-hydroxy-12-methyloxacyclododecane-2,5,6-trione (1) and 12-methyloxacyclododecane-2,5,6-trione (2), were isolated from the endophytic fungal strain Cladosprium colocasiae A801 of the plant Callistemon viminalis, together with five known derivatives. Their structures were fully characterized by means of detailed spectroscopic analysis for new structures, and in comparison with published data for known compounds. The antibacterial, cytotoxic, and α-glucosidase inhibitory activities of the new compounds 1 and 2 were evaluated.

Developing hybrid molecule therapeutics for diverse enzyme inhibitory action: Active role of coumarin-based structural leads in drug discovery.

Hybrid drugs featuring two or more potentially bioactive pharmacophores have been recognized as advanced and superior chemical entities to simultaneously modulate multiple drug targets of multifactorial diseases, thus overcoming the severe side effects associated with a single drug molecule. The selection of these chemical moieties to produce hybrid structures with druggable properties is generally facilitated by the observed and/or anticipated synergistic pharmacological activities of the individual molecules. In this perspective, coumarin template has extensively been studied in pursuit of structurally diverse leads for drug development due to high affinity and specificity to different molecular targets. This review highlights the most commonly exploited approaches conceptualizing the design and construction of hybrid molecules by coupling two or more individual fragments with or without an appropriate linker. In addition to the design strategies, this review also summarizes and reflects on the therapeutic potential of these hybrid molecules for diverse enzyme inhibitory action as well as their observed structure-activity relationship (SAR). Several key features of the synthesized hybrid structures that assert a profound impact on the inhibitory function have also been discussed alongside computational investigations, inhibitor molecular diversity and selectivity toward multiple drug targets. Finally, these drug discovery and development efforts should serve as a handy reference aiming to provide a useful platform for the exploration of new coumarin-based compounds with enhanced enzyme inhibitory profile.

Stereoselective synthesis of new rac-quercitols containing hydroxymethyl groups as glucosidase inhibitors.

Stereoselective and efficient synthesis of hydroxymethyl-substituted rac-quercitols (13-15) was achieved, starting from cis-furan (Kobayashi, 2008) with photooxygenation reaction, which is readily available by the reduction of cis-phtalic anhydride. α- and ß-Glucosidase enzyme activity of the target molecules was evaluated and good inhibitor activity was seen. One- and two-dimensional NMR spectroscopy, IR spectroscopy and X-ray crystallography were utilized in the structure characterization of products.

Synthesis, in vitro [Formula: see text]-glucosidase inhibitory activity, and in silico study of (E)-thiosemicarbazones and (E)-2-(2-(arylmethylene)hydrazinyl)-4-arylthiazole derivatives.

This study is focused on the identification of thiazole-based inhibitors for the [Formula: see text]-glucosidase enzyme. For that purpose, (E)-2-(2-(arylmethylene)hydrazinyl)-4-arylthiazole derivatives were synthesized in two steps and characterized by various spectroscopic techniques. All derivatives and intermediates were evaluated for their in vitro [Formula: see text]-glucosidase inhibitory activity. Thiosemicarbazones 20 and 35, and cyclized thiazole derivatives 2, 5-11, 13, 15, 21-24, 27-31, and 36-37 showed significant inhibitory potential in the range of [Formula: see text]-[Formula: see text] as compared to standard acarbose ([Formula: see text]). A molecular modeling study was carried out to understand the binding interactions of compounds with the active site of enzyme.

Chemical characterization with in vitro biological activities of Gypsophila species.

Methanol-aqueous extracts from the aerial parts of Gypsophila glomerata (GGE), G. trichotoma (GTE) and G. perfoliata (GPE) were investigated for antioxidant potential using different in vitro models, as well as for phenolic and flavonoid contents. The possible anti-cholinesterase, anti-tyrosinase, anti-amylase and anti-glucosidase activities were also tested. The flavonoid variability was analyzed using ultra high-performance liquid chromatography (UHPLC) coupled with hybrid quadrupole-Orbitrap high resolution mass spectrometry (HRMS). Eleven C-glycosyl flavones and 4 O-glycosyl flavonoids, including 2"-O-pentosyl-6-C-hexosyl-apigenin/methylluteolin, as well as their mono(di)-acetyl derivatives were found in GGE. Both GGE and GTE shared 2"-pentosyl-6-C-hexosyl-luteolin together with the common saponarin, homoorientin, orientin, isovitexin and vitexin, while di C-glycosyl flavones were evidenced only in GPE. The highest radical scavenging in both ABTS and DPPH assays was noted in GPE, as well as ferric and cupric reducing abilities. However, GTE had the strongest metal chelating activity (17.44 ±â€¯0.51 mg EDTAE/g extract). GPE and GGE were more potent as acetylcholinesterases inhibitors witnessed by 2.09 ±â€¯0.02 mg GALAE/g extract and 1.59 ±â€¯0.09 mgGALAE/g extract, respectively. All flavonoids were found in G. glomerata for the first time. Therefore, further isolation and structural elucidation of newly described acetylated flavonoids are needed in order to determine their relevance in the beneficial properties of the plant.

Phytochemical profiling and in vitro screening for anticholinesterase, antioxidant, antiglucosidase and neuroprotective effect of three traditional medicinal plants for Alzheimer's Disease and Diabetes Mellitus dual therapy.

BACKGROUND: Extensive epidemiological and clinical studies revealed that Alzheimer's Disease (AD) and Type 2 Diabetes Mellitus (T2D) are most likely to appear simultaneously in aged people as T2D is a major risk factor for AD. Therefore, development of potential multifunctional agents for dual therapy of AD and T2D has received much attention. Buchanania axillaris, Hemidesmus indicus and Rhus mysorensis have been used extensively in popular medicine. The present study was aimed at phytochemical profiling and evaluating multifunctional ability of titled plants in the AD and T2D dual therapy. METHODS: Methanolic extracts and their derived fractions were evaluated for their inhibitory capacities against acetylcholinesterase (AChE) & butyrylcholinesterase (BuChE), and α- & ß-glucosidase besides kinetic analysis of inhibition using methods of Elmann and Shibano, respectively. Antioxidant potency of active fractions was assessed by their DPPH and ABTS radical scavenging activities. Active fractions were tested by the MTT assay to verify cytotoxicity and neuroprotective ability in human nueroblastoma cell lines. Phytochemical screening was done with the aid of spectrophotometric methods. RESULTS: All the methanolic extracts of test plants (BAM, HIM, RMM) showed concentration dependent inhibitory activities against AChE, BuChE, α- and ß-glucosidase enzymes. Subsequent fractionation and evaluation revealed that chloroform fractions BAC, HIC and RMC with IC50 values of 12.29±2.14, 9.94±2.14, 16.65±1.99 and 27.38±1.24; 28.14±0.9, 5.16±0.22, 11.03±0.5 and 87.64±15.41; 41.35±1.6, 15.86±7.3, 26.04±0.37 and 25.33±0.3 were most prominent with regard to inhibition potential against AChE, BuChE, α- and ß-glucosidase, respectively. Kinetic analysis of these active fractions proved that they disclosed mixed-type inhibition against AChE, BuChE, α- and ß-glucosidase enzymes. In the MTT assay, active fractions BAC, HIC, RMC showed significant cell viability at high concentrations (400 µg). Moreover, in MTT assay, the active fractions displayed excellent neuroprotective effects against oxidative stress induced cell death and significant cell viability in SK N SH cells at all concentrations. CONCLUSION: The strong anticholinesterase, antiglucosidase, antioxidant and neuroprotective activities of methanolic extracts and their derived chloroform fractions indicate the potential of Buchanania axillaris, Hemidesmus indicus and Rhus mysorensis as multifunctional therapeutic remedies for the dual therapy of T2D and AD.

Multiplex Fluorescent, Activity-Based Protein Profiling Identifies Active α-Glycosidases and Other Hydrolases in Plants.

With nearly 140 α-glycosidases in 14 different families, plants are well equipped with enzymes that can break the α-glucosidic bonds in a large diversity of molecules. Here, we introduce activity-based protein profiling (ABPP) of α-glycosidases in plants using α-configured cyclophellitol aziridine probes carrying various fluorophores or biotin. In Arabidopsis (Arabidopsis thaliana), these probes label members of the GH31 family of glycosyl hydrolases, including endoplasmic reticulum-resident α-glucosidase-II Radial Swelling3/Priority for Sweet Life5 (RSW3/PSL5) and Golgi-resident α-mannosidase-II Hybrid Glycosylation1 (HGL1), both of which trim N-glycans on glycoproteins. We detected the active state of extracellular α-glycosidases such as α-xylosidase XYL1, which acts on xyloglucans in the cell wall to promote cell expansion, and α-glucosidase AGLU1, which acts in starch hydrolysis and can suppress fungal invasion. Labeling of α-glycosidases generates pH-dependent signals that can be suppressed by α-glycosidase inhibitors in a broad range of plant species. To demonstrate its use on a nonmodel plant species, we applied ABPP on saffron crocus (Crocus sativus), a cash crop for the production of saffron spice. Using a combination of biotinylated glycosidase probes, we identified and quantified 67 active glycosidases in saffron crocus stigma, of which 10 are differentially active. We also uncovered massive changes in hydrolase activities in the corms upon infection with Fusarium oxysporum using multiplex fluorescence labeling in combination with probes for serine hydrolases and cysteine proteases. These experiments demonstrate the ease with which active α-glycosidases and other hydrolases can be analyzed through ABPP in model and nonmodel plants.