Search

As a crucial enzyme for cellulose degradation, β-glucosidase finds extensive applications in food, feed, and bioethanol production; however, its potential is often limited by inadequate thermal stability and glucose tolerance. In this study, a functional gene (lq-bg5) for a GH1 family β-glucosidase was obtained from the metagenomic DNA of a hot spring sediment sample and heterologously expressed in E. coli and the recombinant enzyme was purified and characterized. The optimal temperature and pH of LQ-BG5 were 55 °C and 4.6, respectively. The relative residual activity of LQ-BG5 exceeded 90% at 55 °C for 9 h and 60 °C for 6 h and remained above 100% after incubation at pH 5.0–10.0 for 12 h. More importantly, LQ-BG5 demonstrated exceptional glucose tolerance with more than 40% activity remaining even at high glucose concentrations of 3000 mM. Thus, LQ-BG5 represents a thermophilic β-glucosidase exhibiting excellent thermal stability and remarkable glucose tolerance, making it highly promising for lignocellulose development and utilization. [ABSTRACT FROM AUTHOR]

Objectives: Silver nanoparticles (AgNPs) are gaining increasing attention in biomedical applications due to their unique properties. Green synthesis methods are environmentally friendly and have demonstrated potential for AgNP production. This study explores the green synthesis of AgNPs using the methanolic extract of Euphorbia milii, a plant known for its medicinal properties. The primary objectives of this research were to synthesize AgNPs using E. milii extract, characterize the nanoparticles (NPs) using various techniques, and evaluate their antibacterial and enzyme inhibitory activities. Methods: E. milii plant extract was utilized for the green synthesis of AgNPs. The characterization of the NPs was performed through ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX). Antibacterial activity was assessed against Staphylococcus aureus, while enzyme inhibitory assays were conducted against urease, α-glucosidase, carbonic anhydrase II, and xanthine oxidase. Results: The synthesized AgNPs exhibited significant antibacterial effects, with a remarkable 20-mm zone of inhibition against S. aureus, surpassing the efficacy of the plant extract alone. Furthermore, the AgNPs demonstrated remarkable enzyme inhibition, achieving impressive percentages of 77.98% against α-glucosidase and 88.54% against carbonic anhydrase II. Half-maximal inhibitory concentration values for enzyme inhibition were highly promising, including 78.09 ± 1.98 µM for α-glucosidase, 0.22 ± 0.10 µM for carbonic anhydrase II, and 7.11 ± 0.55 µM for xanthine oxidase. Conclusion: In this study, AgNPs were successfully synthesized using E. milii extract and characterized using various techniques. The AgNPs exhibited significant antibacterial and enzyme-inhibitory activities, showcasing their potential for biomedical applications. [ABSTRACT FROM AUTHOR]

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the pursuit of identifying the novel resin glycoside modulators glucose-6-phosphatase and α-glucosidase enzymes, associated with blood sugar regulation, methanol-soluble extracts from the flowers of Ipomoea murucoides (cazahuate, Nahuatl), renowned for its abundance of glycolipids, were employed. The methanol-soluble extracts were fractionated by applying the affinity-directed method with glucose-6-phosphatase enzymes from a rat's liver and α-glucosidase enzymes from its intestines. Mass spectrometry and nuclear magnetic resonance were employed to identify the high-affinity compound as a free ligand following the release from the enzymatic complex. Gel permeation through a spin size-exclusion column allowed the separated high-affinity molecules to bind to glucose-6-phosphatase and α-glucosidase enzymes in solution, which led to the identification of some previously reported resin glycosides in the flowers of cazahuate, where a glycolipid mainly structurally related to murucoidin XIV was observed. In vitro studies demonstrated the modulating properties of resin glycosides on the glucose-6-phosphatase enzyme. Dynamic light scattering revealed conformational variations induced by resin glycosides on α-glucosidase enzyme, causing them to become more compact, akin to observations with the positive control, acarbose. These findings suggest that resin glycosides may serve as a potential source for phytotherapeutic agents with antihyperglycemic properties. [ABSTRACT FROM AUTHOR]

Debranching enzymes are unable to fully meet the requirements of green production of starch sugars and comprehensive utilization of by-products. Therefore, it is necessary to explore suitable new types of debranching enzymes. This study screened an oligo-1,6-glucosidase gene (oga) from Paenibacillus sp. STB16 and constructed its Bacillus subtilis expression system. This system achieved heterologous expression of the oligo-1,6-glucosidase. The enzymatic properties and substrate specificity of the recombinant oligo-1,6-glucosidase were explored. The results showed that the enzyme activity of the fermentation supernatant of B. subtilis could reach 162.33 U/mL. The recombinant oligo-1,6-glucosidase had the optimum reaction temperature at 50 °C and optimum reaction pH at 6.0. It specifically acted on the &#945-1, 6-glycosidic bonds of branches with degree of polymerization of 1. Compared to other types of debranching enzymes (substrate conversion rate under the detection limit), the recombinant oligo-1,6-glucosidase exhibited stronger hydrolytic activity towards isomaltose, isomaltotriose, and panose. The substrate conversion rate reach 97.4%-100%, with glucose as the product. Therefore, it is more suitable for treating glucose mother liquor. The glucose content in the first mother liquor, second mother liquor and tail liquor of chromatographic separation was significantly increased by 3.6%, 12.7% and 34.4%, respectively. The research results provide a theoretical basis for the development and utilization of new types of debranching enzymes, and also serve as an important reference for the comprehensive utilization of by-products in starch sugar processing. [ABSTRACT FROM AUTHOR]

The industry has increasingly explored the development of foods with functional properties, where supplementation with probiotics and bioactive compounds has gained prominence. In this context, the study aimed to evaluate the influence of in vitro biological digestion on the content of phenolic compounds, antioxidant activity, and inhibition of α-amylase and α-glucosidase activities of probiotic yogurt supplemented with the lactic acid bacteria Lactococcus lactis R7 and red guava extract (Psidium cattleianum). A yogurt containing L. lactis R7 (0.1%) and red guava extract (4%) was characterized for the content of phenolic compounds, antioxidant activity, and potential for inhibition of digestive enzymes after a simulated in vitro digestion process. After digestion, the caffeic and hydroxybenzoic acids remained, and sinapic acid only in the last digestive phase. Antioxidant activity decreased during digestion by 28.93, 53.60, and 27.97% for DPPH, nitric oxide and hydroxyl radicals, respectively, and the inhibition of the α-amylase enzyme decreased only 4.01% after the digestion process. α-glucosidase was more efficient in intestinal digestion, demonstrating an increase of almost 50% in probiotic yogurt with red guava extract before digestion. Possibly, the phenolics change their conformation during digestion, generating new compounds, reducing antioxidant activity, and increasing the inhibitory activity of α-glucosidase digestive enzymes. It was concluded that the probiotic yogurt formulation supplemented with red guava extract could interfere with the concentration of phenolic compounds and the formation of new compounds, suggesting a positive and effective inhibition of the digestive enzymes, even after the digestive process. [ABSTRACT FROM AUTHOR]

Four new glycosides, named amplexicosides A-D (1–4), and five known compounds: benzyl 2-[β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyloxy]-benzoate (5), benzyl 2-neohesperidosyloxy-6-hydroxybenzoate (6), chrysandroside A (7), chrysandroside B (8) and camelliquercetiside C (9) were isolated from the branches and leaves of Camellia amplexicaulis (Pit.) Cohen-Stuart. Their structures were elucidated using HR-ESI-MS and 1D- and 2D-NMR spectra and compared to reported NMR data. All of the isolated compounds were screened in an α-glucosidase assay. Compounds 4, 8, and 9 significantly inhibited α-glucosidase with respective IC50 values of 254.9 ± 4.2, 304.8 ± 11.9 and 228.1 ± 16.4 μM. [ABSTRACT FROM AUTHOR]

Diabetes is often associated with increased oxidative stress caused by an imbalance between detoxification and ROS production. Unfortunately, many commercial drugs available today for treating this disease have adverse side effects and ultimately fail to restore glucose homeostasis. Therefore, finding a dietary anti-diabetic remedy that is safe, effective, and economical is crucial. In this study, GC–MS analysis, subsequent HPLC-assisted fractionation, and SPE-based purification led to identifying and purifying of key components such as phloroglucinol and total procyanidin dimer (procyanidin dimer and procyanidin dimer gallate) from methanolic seed extract of Vitis vinifera. In-vitro anti-diabetic screening of various fractions derived from methanolic extract along with individual components and their combinations revealed the potential synergistic behaviour of phloroglucinol and total procyanidin dimer with the lowest IC50 of 48.21 ± 3.54 µg/mL for α-glucosidase and 63.06 ± 5.38 µg/mL for α-amylase inhibition which is found to be superior to the effect shown by the standard Epigallocatechin gallate. Later Glucose utilization studies demonstrated the concentration-dependent effect of Phloroglucinol and total procyanidin dimer, and that has raised the glucose uptake by approximately 36–57% in HepG2 cells and 35–58% in L6 myocytes over a concentration of 50–100 µg/mL. The superior anti-diabetic effect of Phloroglucinol and total procyanidin dimer was proved by the suppression of oxidative stress with an IC50 of 7.92 ± 0.36 µg/mL for DPPH scavenging and 16.87 ± 1.24 µg/mL for SOD scavenging which is competent with the standard ascorbic acid. According to this study, suppressing ROS levels by phloroglucinol and total procyanidin dimer would be the underlying mechanism for the synergistic anti-diabetic effect of this combination. [ABSTRACT FROM AUTHOR]

The cellobiose-responsive regulator ClbR, a Zn(II)2Cys6 binuclear-cluster transcription factor, is a positive regulator of carbohydrate-active enzyme (CAZyme) genes responsive to cellulose in Aspergillus aculeatus. Because Zn(II)2Cys6 transcription factors tend to dimerize with proteins of the same family, we searched for a counterpart of ClbR and identified ClbR2, which is 42% identical to ClbR, as an interacting partner of ClbR by yeast two-hybrid screening. Genetic analyses suggested that ClbR and ClbR2 cooperatively regulate the expression of CAZyme genes in response to cellulose and 1,4-β-mannobiose in A. aculeatus. CAZyme genes under the control of the transcription factor ManR were regulated by ClbR and ClbR2, whereas those controlled by the transcription factor XlnR were regulated by ClbR, but not ClbR2. These findings suggest that ClbR participates in multiple regulatory pathways in A. aculeatus by altering an interacting factor. [ABSTRACT FROM AUTHOR]

The regulation of plant biomass degradation by fungi is critical to the carbon cycle, and applications in bioproducts and biocontrol. Trichoderma harzianum is an important plant biomass degrader, enzyme producer, and biocontrol agent, but few putative major transcriptional regulators have been deleted in this species. The T. harzianum ortholog of the transcriptional activator XYR1/XlnR/XLR-1 was deleted, and the mutant strains were analyzed through growth profiling, enzymatic activities, and transcriptomics on cellulose. From plate cultures, the Δxyr1 mutant had reduced growth on D-xylose, xylan, and cellulose, and from shake-flask cultures with cellulose, the Δxyr1 mutant had ~90% lower β-glucosidase activity, and no detectable β-xylosidase or cellulase activity. The comparison of the transcriptomes from 18 h shake-flask cultures on D-fructose, without a carbon source, and cellulose, showed major effects of XYR1 deletion whereby the Δxyr1 mutant on cellulose was transcriptionally most similar to the cultures without a carbon source. The cellulose induced 43 plant biomass-degrading CAZymes including xylanases as well as cellulases, and most of these had massively lower expression in the Δxyr1 mutant. The expression of a subset of carbon catabolic enzymes, other transcription factors, and sugar transporters was also lower in the Δxyr1 mutant on cellulose. In summary, T. harzianum XYR1 is the master regulator of cellulases and xylanases, as well as regulating carbon catabolic enzymes. [ABSTRACT FROM AUTHOR]

In response to the increasing prevalence of diabetes mellitus and the limitations associated with the current treatments, there is a growing need to develop novel medications for this disease. This study is focused on creating new compounds that exhibit a strong inhibition of alpha-glucosidase, which is a pivotal enzyme in diabetes control. A set of 33 triazole derivatives underwent an extensive QSAR analysis, aiming to identify the key factors influencing their inhibitory activity against α-glucosidase. Using the multiple linear regression (MLR) model, seven promising compounds were designed as potential drugs. Molecular docking and dynamics simulations were employed to shed light on the mode of interaction between the ligands and the target, and the stability of the obtained complexes. Furthermore, the pharmacokinetic properties of the designed compounds were assessed to predict their behavior in the human body. The binding free energy was also calculated using MMGBSA method and revealed favorable thermodynamic properties. The results highlighted three novel compounds with high biological activity, strong binding affinity to the target enzyme, and suitability for oral administration. These results offer interesting prospects for the development of effective and well-tolerated medications against diabetes mellitus. Dataset License: License under which the dataset is made available (CC0, CC-BY, CC-BY-SA, CC-BY-NC, etc.) [ABSTRACT FROM AUTHOR]

Fusarium is a genus that mostly consists of plant pathogenic fungi which are able to produce a broad range of toxic secondary metabolites. In this study, we focus on a type A trichothecene-producing isolate (15-39) of Fusarium sporotrichioides from Lower Austria. We assessed the secondary metabolite profile and optimized the toxin production conditions on autoclaved rice and found that in addition to large amounts of T-2 and HT-2 toxins, this strain was able to produce HT-2-glucoside. The optimal conditions for the production of T-2 toxin, HT-2 toxin, and HT-2-glucoside on autoclaved rice were incubation at 12 °C under constant light for four weeks, darkness at 30 °C for two weeks, and constant light for three weeks at 20 °C, respectively. The HT-2-glucoside was purified, and the structure elucidation by NMR revealed a mixture of two alpha-glucosides, presumably HT-2-3-O-alpha-glucoside and HT-2-4-O-alpha-glucoside. The efforts to separate the two compounds by HPLC were unsuccessful. No hydrolysis was observed with two the alpha-glucosidases or with human salivary amylase and Saccharomyces cerevisiae maltase. We propose that the two HT-2-alpha-glucosides are not formed by a glucosyltransferase as they are in plants, but by a trans-glycosylating alpha-glucosidase expressed by the fungus on the starch-containing rice medium. [ABSTRACT FROM AUTHOR]

To investigate the inhibitory mechanism of small peptides on carbohydrate digestion, α-amylase and α-glucosidase inhibitory fractions from the water extract and the gastropancreatic digest of dry-cured ham muscle of Wanzhe spotted pigs were separated, purified, identified, and screened for peptide sequences. And the quantum chemical calculation was used to calculate structural and charge parameters including the distribution and energy of the frontier orbitals, electrostatic charge distribution and bond length, in order to speculate the active sites. It was found that the particle size of ham muscle decreased and its hypoglycemic activity increased after proteolysis. Two (S-I and S-II) and three fractions (WY-I, WY-II and WY-III) were obtained from the water extract and the digest after Sephadex column chromatography, respectively. Using mass spectrometry, 104 peptide sequences consisting of 8–24 amino acids were identified from fraction WY-II and five sequences with Peptide Ranker scores greater than 0.7 were selected. The highest occupied orbitals of the five sequences were mainly distributed in the guanidine groups of arginine and the groups close to the amino-terminal end, while the lowest unoccupied orbitals were in the carboxyl terminals and nearby groups. Sequences with lower ΔEL-H values, GPMGPSGPR, LGFGGPSGPNAGR and APAPAPAPAPPK, might be more active. According to Coulomb’s law, the active sites of these three peptides were located at –C106H108 of arginine, –C10H12 of leucine and –C176H177 of lysine, respectively. This study could provide theoretical support for understanding the blood glucose-regulating mechanism of peptides and the nutritional value of local pig breeds. [ABSTRACT FROM AUTHOR]

α-Glucosidase inhibitory assay-guided purification of Thunbergia laurifolia L. stems yielded a new compound named 5-acetoxyfuranonapthoquinone (1) along with nineteen known compounds (2-20). The structures of the isolated compounds were elucidated by the analysis of multiple spectroscopic data. The isolated compounds were evaluated for α-glucosidase inhibition. Syringaresinol (7), rosmarinic acid (11), 1,2,8-trihydroxyxanthone (16), and isojacareubin (18) showed the most potent inhibitory activity among isolated compounds. Kinetic study indicated that syringaresinol (7), 1,2,8-trihydroxyxanthone (16) and isojacareubin (18) could inhibit maltase and sucrase function by non-competitive manner, and rosmarinic acid (11) was identified as a non-competitive inhibitor against maltase and a mixed-manner inhibitor against sucrase. [ABSTRACT FROM AUTHOR]

The ginger family (Zingiberaceae) is one of the most diverse and abundant families in the plant kingdom in terms of number of species. In terms of chemistry, this is a family of plants containing much essential oil with mainly monoterpene and sesquiterpene derivatives, which has been widely used in medicine, food, and flavor industries. In our series of studies on ginger family plants, the two new species including Wurfbainia schmidtii (K. Schum.) Škorničk. & A.D. Poulsen and Zingiber atroporphyreus Škorničk. & Q.B. Nguyen has been investigated for the first time. This study aimed to identify the chemical compositions of essential oils extracted from the rhizomes and leaves of these two species using gas chromatography-mass spectrometry (GC/MS) analysis and evaluate their hypoglycemic effects through the α-glucosidase and α-amylase inhibitory assays. In terms of chemical composition, in general, the main compounds appearing in the essential oils of both leaves and rhizomes of each species are similar but they are differences in the percentage of the main components, for example, 1,8-cineole is a main component in leaves whereas fenchyl acetate is the main one in rhizomes of W. schmidtii. Several distinctive compounds, in comparison with other members in the genus Zingiber, namely β-pinene, α-pinene, β-elemene, and sabinene, were found in the essential oil of Z. atroporphyreus. Regarding hypoglycemic effects, the essential oils from the two species tested possessed weak α-glucosidase and α-amylase inhibitory effects. For the first time, this study was designed to investigate the chemical composition as well as the hypoglycemic effect of essential oils distilled from the rhizomes and leaves of two species W. schmidtii and Z. atroporphyreus have been reported, serving as a premise for further systematic research on their phytochemistry and pharmacological effects being conducted. [ABSTRACT FROM AUTHOR]

Onion skin waste (OSW), the primary non-edible byproduct from onion processing, offers a renewable source of bioactive compounds. This study aims to valorize OSW through subcritical water extraction (SWE), aligning with a circular economy and biorefinery principles. SWE was carried out at 145 °C and 50 bar for 50 min in a discontinuous reactor, producing a phenolic-rich extract (32.3 ± 2.6 mg/g) dominated by protocatechuic acid (20.3 ± 2.5 mg/g), quercetin-4′-O-glucoside (7.5 ± 0.2 mg/g), and quercetin (3.2 ± 0.6 mg/g). Additionally, the extract contains sugars (207.1 ± 20.3 mg sucrose-Eq/g), proteins (22.8 ± 1.6 mg BSA-Eq/g), and free amino acids (20.4 ± 1.2 mg arginine-Eq/g). Its phenolic richness determines its scavenging activity against ●NO and O2●− radicals and its α-glucosidase and aldose-reductase inhibition without affecting α-amylase. Notably, the extract demonstrates significant α-glucosidase inhibition (IC50 = 75.6 ± 43.5 µg/mL), surpassing acarbose (IC50 = 129.5 ± 1.0 µg/mL) in both pure enzyme and cell culture tests without showing cytotoxicity to AGS, HepG2, and Caco-2 human cell lines. The extract's bioactivity and nutritional content make it suitable for developing antioxidant and antidiabetic nutraceutical/food components, highlighting SWE's potential for OSW valorization without using organic solvents. [ABSTRACT FROM AUTHOR]

The world's population is in a demographical transition, with an increase in the number of older adults and prevalence of diseases related to aging. This study evaluated in vitro the potential of using Durvillaea incurvata extract (extracted using ultrasound-assisted extraction) to inhibit key enzymes associated with the development of age-related diseases. Our results show that an extract extracted via ultrasound-assisted extracted, as well as an extract conventional extracted from Durvillaea incurvata, presented antidiabetes potential by exhibiting inhibitory activity against α-glucosidase (91.8 ± 1.0% and 93.8 ± 0.3%, respectively, at 500 µg/mL) and α-amylase (42.2 ± 1.4% and 61.9 ± 0.9%, respectively, at 1500 µg/mL) enzymes related to starch digestion and postprandial glycemic response. Also, the extracts showed inhibitory activity against the enzymes acetylcholinesterase (51.5% and 50.8%, respectively, at 500 µg/mL) and butyrylcholinesterase (32.8% and 34.4%, respectively, at 0.5 mg/mL), the biomarkers associated with Alzheimer's disease, and angiotensin-converting enzyme (98.7 ± 7.4% and 93.0 ± 3.4%, respectively, at 2.0 mg/mL), which is key in the regulation of vascular tone and blood pressure and helps to prevent the development of hypertension. In conclusion, the extract of Durvillaea incurvata obtained from ultrasound-assisted extraction has the potential to prevent the development of age-related pathologies such as diabetes, Alzheimer's disease, and hypertension. [ABSTRACT FROM AUTHOR]

Recently, we reported the discovery of a novel endoglucanase of the glycoside hydrolase family 12 (GH12), designated IfCelS12A, from the haloalkaliphilic anaerobic bacterium Iocasia fonsfrigidae strain SP3-1, which was isolated from a hypersaline pond in the Samut Sakhon province of Thailand (ca. 2017). IfCelS12A exhibits high substrate specificity on carboxymethyl cellulose and amorphous cellulose but low substrate specificity on b-1,3;1,4-glucan. Unlike some endoglucanases of the GH12 family, IfCelS12A does not exhibit hydrolytic activity on crystalline cellulose (i.e., Avicel™). High-Pressure Liquid Chromatography (HPLC) and Thin Layer Chromatography (TLC) analyses of products resulting from IfCelS12-mediated hydrolysis indicate mode of action for this enzyme. Notably, IfCelS12A preferentially hydrolyzes cellotetraoses, cellopentaoses, and cellohexaoses with negligible activity on cellobiose or cellotriose. Kinetic analysis with cellopentaose and barely b-d-glucan as cellulosic substrates were conducted. On cellopentaose, IfCelS12A demonstrates a 16-fold increase in activity (KM = 0.27 mM; kcat = 0.36 s−1; kcat/KM = 1.34 mM−1 s−1) compared to the enzymatic hydrolysis of barley b-d-glucan (KM: 0.04 mM, kcat: 0.51 s−1, kcat/KM = 0.08 mM−1 s−1). Moreover, IfCelS12A enzymatic efficacy is stable in hypersaline sodium chlorids (NaCl) solutions (up to 10% NaCl). Specifically, IfCel12A retains notable activity after 24 h at 2M NaCl (10% saline solution). IfCelS12A used as a cocktail component with other cellulolytic enzymes and in conjunction with mobile sequestration platform technology offers additional options for deconstruction of ionic liquid–pretreated cellulosic feedstock. Key points: • IfCelS12A from an anaerobic alkaliphile Iocasia fronsfrigidae shows salt tolerance • IfCelS12A in cocktails with other enzymes efficiently degrades cellulosic biomass • IfCelS12A used with mobile enzyme sequestration platforms enhances hydrolysis [ABSTRACT FROM AUTHOR]

Classical fungal mutant strains obtained by mutagenesis have helped to elucidate fundamental metabolic pathways in the past. In the filamentous fungus Neurospora crassa, the gluc-1 strain was isolated long ago and characterized by its low level of β-glucosidase activity, which is essential for the degradation of cellulose, the most abundant biopolymer on Earth and the main polymeric component of the plant cell wall. Based on genomic resequencing, we hypothesized that the causative mutation resides in the β-glucosidase gene gh3-3 (bgl6, NCU08755). In this work, growth patterns, enzymatic activities and sugar utilization rates were analyzed in several mutant and overexpression strains related to gluc-1 and gh3-3. In addition, different mutants affected in the degradation and transport of cellobiose were analyzed. While overexpression of gh3-3 led to the recovery of β-glucosidase activity in the gluc-1 mutant, as well as normal utilization of cellobiose, the full gene deletion strain Δgh3-3 was found to behave differently than gluc-1 with lower secreted β-glucosidase activity, indicating a dominant role of the amino acid substitution in the point mutated gh3-3 gene of gluc-1. Our results furthermore confirm that GH3-3 is the major extracellular β-glucosidase in N. crassa and demonstrate that the two cellodextrin transporters CDT-1 and CDT-2 are essential for growth on cellobiose when the three main N. crassa β-glucosidases are absent. Overall, these findings provide valuable insight into the mechanisms of cellulose utilization in filamentous fungi, being an essential step in the efficient production of biorefinable sugars from agricultural and forestry plant biomass. [ABSTRACT FROM AUTHOR]

In this work the green synthesis of gold nanoparticles (Au-NPs) using the oxidoreductive enzymes Myriococcum thermophilum cellobiose dehydrogenase (Mt CDH), Glomerella cingulata glucose dehydrogenase (Gc GDH), and Aspergillus niger glucose oxidase (An GOX)) as bioreductants was investigated. The influence of reaction conditions on the synthesis of Au-NPs was examined and optimised. The reaction kinetics and the influence of Au ions on the reaction rate were determined. Based on the kinetic study, the mechanism of Au-NP synthesis was proposed. The Au-NPs were characterized by UV–Vis spectroscopy and transmission electron microscopy (TEM). The surface plasmon resonance (SPR) absorption peaks of the Au-NPs synthesised with Mt CDH and Gc GDH were observed at 535 nm, indicating an average size of around 50 nm. According to the image analysis performed on a TEM micrograph, the Au-NPs synthesized with Gc GDH have a spherical shape with an average size of 2.83 and 6.63 nm after 24 and 48 h of the reaction, respectively. Key points: • The Au NPs were synthesised by the action of enzymes CDH and GDH. • The synthesis of Au-NPs by CDH is related to the oxidation of cellobiose. • The synthesis of Au-NPs by GDH was not driven by the reaction kinetic. [ABSTRACT FROM AUTHOR]

Introduction: β-Glucosidase serves as the pivotal rate-limiting enzyme in the cellulose degradation process, facilitating the hydrolysis of cellobiose and cellooligosaccharides into glucose. However, the widespread application of numerous β-glucosidases is hindered by their limited thermostability and low glucose tolerance, particularly in elevated-temperature and high-glucose environments. Methods: This study presents an analysis of a β-glucosidase gene belonging to the GH1 family, denoted lqbg8, which was isolated from the metagenomic repository of Hehua hot spring located in Tengchong, China. Subsequently, the gene was cloned and heterologously expressed in Escherichia coli BL21(DE3). Post expression, the recombinant β-glucosidase (LQBG8) underwent purification through a Ni affinity chromatography column, thereby enabling the in-depth exploration of its enzymatic properties. Results: LQBG8 had an optimal temperature of 70°C and an optimum pH of 5.6. LQBG8 retained 100 and 70% of its maximum activity after 2-h incubation periods at 65°C and 70°C, respectively. Moreover, even following exposure to pH ranges of 3.0–10.0 for 24 h, LQBG8 retained approximately 80% of its initial activity. Notably, the enzymatic prowess of LQBG8 remained substantial at glucose concentrations of up to 3 M, with a retention of over 60% relative activity. The kinetic parameters of LQBG8 were characterized using cellobiose as substrate, with Km and Vmax values of 28 ± 1.9 mg/mL and 55 ± 3.2 μmol/min/mg, respectively. Furthermore, the introduction of LQBG8 (at a concentration of 0.03 mg/mL) into a conventional cellulase reaction system led to an impressive 43.7% augmentation in glucose yield from corn stover over a 24-h period. Molecular dynamics simulations offered valuable insights into LQBG8’s thermophilic nature, attributing its robust stability to reduced fluctuations, conformational changes, and heightened structural rigidity in comparison to mesophilic β-glucosidases. Discussion: In summation, its thermophilic, thermostable, and glucose-tolerant attributes, render LQBG8 ripe for potential applications across diverse domains encompassing food, feed, and the production of lignocellulosic ethanol. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) is one of the chronic non-communicable diseases and has been rapidly increasing globally. Alpha glucosidase is an important enzyme that hydrolyzes polysaccharides into monosaccharides before being absorbed into the bloodstream. The alpha glucosidase inhibitors, such as acarbose are expensive and have several adverse effects. The use of herbal products to prevent or treatment of disease is becoming popular. There are many herbal products that can reduce blood sugar levels. However, taking herbal products with anti-DM medicines may cause herb-drug interactions that affect either the pharmacokinetics or pharmacodynamics of the drugs, leading to adverse effects or ineffective treatment. The aim of this study is to examine the effect of herbal extracts on alpha-glucosidase activity and the level of cytochrome P450 3A4 (CYP3A4) by using HepaRG as a model. Three herbs that reported blood glucose-lowering activity were selected including Moringa oleifera, Momordica charantia, and Morus alba. All herbs were extracted with 95% ethanol and tested for their in vitro alpha glucosidase inhibitory activity. The results showed that M. alba extract exhibits the highest activity (IC50= 83.75 µg/mL). Then, the extracts were evaluated for their cytotoxicity on the HepaRG cell line. All extracts showed no cytotoxicity at concentrations up to 250 µg/mL. The sub-cytotoxic concentration of each extract was selected to test for the effect on the CYP3A4 enzyme. The results showed that only M. alba extract elevated the level of CYP3A4, while the others slightly reduce the level of CYP3A4. However, this is a preliminary study that the major compounds of each extract must be isolated and evaluated in the future. [ABSTRACT FROM AUTHOR]

Fungi are important contaminants of historic canvas paintings worldwide. They can grow on both sides of the canvas and decompose various components of the paintings. They excrete pigments and acids that change the visual appearance of the paintings and weaken their structure, leading to flaking and cracking. With the aim of recognizing the most dangerous fungal species to the integrity and stability of paintings, we studied 55 recently isolated and identified strains from historic paintings or depositories, including 46 species from 16 genera. The fungi were categorized as xero/halotolerant or xero/halophilic based on their preference for solutes (glycerol or NaCl) that lower the water activity (aw) of the medium. Accordingly, the aw value of all further test media had to be adjusted to allow the growth of xero/halophilic species. The isolates were tested for growth at 15, 24 °C and 37 °C. The biodeterioration potential of the fungi was evaluated by screening their acidification properties, their ability to excrete pigments and their enzymatic activities, which were selected based on the available nutrients in paintings on canvas. A DNase test was performed to determine whether the selected fungi could utilize DNA of dead microbial cells that may be covering surfaces of the painting. The sequestration of Fe, which is made available through the production of siderophores, was also tested. The ability to degrade aromatic and aliphatic substrates was investigated to consider the potential degradation of synthetic restoration materials. Xerotolerant and moderately xerophilic species showed a broader spectrum of enzymatic activities than obligate xerophilic species: urease, β-glucosidase, and esterase predominated, while obligate xerophiles mostly exhibited β-glucosidase, DNase, and urease activity. Xerotolerant and moderately xerophilic species with the highest degradation potential belong to the genus Penicillium, while Aspergillus penicillioides and A. salinicola represent obligately xerophilic species with the most diverse degradation potential in low aw environments. [ABSTRACT FROM AUTHOR]

Metabolic product accumulation exhibited variations among mulberry (Morus alba L.) leaves (MLs) at distinct growth stages, and this assessment was conducted using a combination of analytical techniques including high-performance liquid chromatography (HPLC), gas chromatography–mass spectrometry (GC-MS), and liquid chromatography–mass spectrometry (LC-MS). Multivariate analysis was applied to the data, and the findings were correlated with antioxidant activity and α-glucosidase inhibitory effects in vitro. Statistical analyses divided the 27 batches of MLs at different growth stages into three distinct groups. In vitro assays for antioxidant activity and α-glucosidase inhibition revealed that IC50 values were highest at the Y23 stage, which corresponds to the 'Frost Descends' solar term. In summary, the results of this study indicate that MLs at different growth stages throughout the year can be categorized into three primary growth stages using traditional Chinese solar terms as reference points, based on the observed variations in metabolite content. [ABSTRACT FROM AUTHOR]

Background: Moringa peregrina is widely used in the traditional medicine of the Arabian Peninsula to treat various ailments, because it has many pharmacologically active components with several therapeutic effects. Objective: This study aimed to investigate the inhibitory effect of Moringa peregrina seed ethanolic extract (MPSE) against key enzymes involved in human pathologies, such as angiogenesis (thymidine phosphorylase), diabetes (α-glucosidase), and idiopathic intracranial hypertension (carbonic anhydrase). In addition, the anticancer properties were tested against the SH-SY5Y (human neuroblastoma). Results: MPSE extract significantly inhibited a-glucosidase, thymidine phosphorylase, and carbonic anhydrase with half-maximal inhibitory concentrations (IC50) values of 303.1 ± 1.3, 471.30 ± 0.3, and 271.30 ± 5.1 µg/mL, respectively. Furthermore, the antiproliferative effect of the MPSE was observed on the SH-SY5Y cancer cell line with IC50 values of 55.1 µg/mL. Conclusions: MPSE has interesting inhibitory capacities against key enzymes and human neuroblastoma cancer cell line. [ABSTRACT FROM AUTHOR]

Background: Olax scandens Roxb. (Olacaceae) is a scandent thorny shrub used by many ethnic tribes of Asia to cure stomach ache, diarrhoea, fever, cough, mouth ulcers, anaemia, filaria, joint pains, intestinal and liver diseases and diabetes. Objectives: The present study was undertaken to investigate the in vitro hypoglycemic activity and mechanism of action of O. scandens stem bark extracts in five different in vitro models at different glucose concentrations. Materials and Methods: Various extracts of O. scandens stem bark was studied for their effect on glucose adsorption, glucose diffusion, glucose uptake by yeast cells, alpha glucosidase and alpha amylase inhibition at different glucose concentrations. Results: In the glucose adsorption method, the butanolic extract showed statistically significant increase in glucose bound concentration of 7.35 mM/L at 100 mM glucose concentration used. All extracts showed a significant retardation in glucose diffusion across a dialysis membrane into the external medium, at different time intervals. GDRI of ethyl acetate extract was 84.471 at 30 min whereas the butanolic extract and aqueous ethanolic extract showed highest GDRI of 80.267 and 70.386 at 120 min respectively. In the method of glucose uptake by yeast cells, aqueous ethanolic and butanolic extracts both showed significantly higher uptake of glucose of 65% at 5 mg/mL concentration. The ethyl acetate extract and standard acarbose showed 26.25% and 35% inhibition of alpha glucosidase respectively at 100 µg/mL concentration. Whereas at the same concentration, ethyl acetate extract and acarbose showed 48.922% and 63.093% inhibition of alpha amylase. Conclusion: Significant in vitro hypoglycemic activity was seen in glucose diffusion method suggesting a possible role of fibre which may retard glucose release across the dialysis membrane. This mechanism can be correlated with retardation in the transport of glucose across the intestinal lumen thus causing a reduction in post prandial hyperglycemia. [ABSTRACT FROM AUTHOR]

Zingiber zerumbet affords the essential oil having important application and its rhizomes are the main ingredient in traditional Indian Ayurveda formulation. We report here the impact of enzymes on the isolable yield of oleoresin and essential oil (EO) from Zingiber zerumbet. The impact of enzymes like cellulase, amylase, bio-protease, pectinase, hemi-cellulase and enzyme for herbal extract is evaluated. Viscozyme affords the highest oleoresin (16%) and essential oil (7.1%), a betterment of 138% and 24% respectively. Zerumbone, a principal bioactive component of zerumbet, was afforded in 8.98% and 5.7% from oleoresin and essential oil. Box Behnken Design has been employed to optimize parameters to get the highest oleoresin and EO yield. The EO was tested for its inhibitory activity on α -amylase and α-glucosidase. The EO collected from viscozyme-assisted extraction inhibited α -amylase with IC 50 26 µM while the same from enzyme for herbal extract-assisted extraction inhibited α -glucosidase with IC 50 274 µM. The extraction efficiency of all the enzymes used here is reported. [Display omitted] • Viscozyme treated zerumbet affords high oleoresin & essential oil. • Zerumbone from oleoresin & essential oil was respectively 7.5% & 5.7%. • Zerumbet essential oil showed potent α -amylase and α -glucosidase inhibition. • Optimized the extraction method by RSM. • Quantified zerumbone by Gas Chromatography (GC). [ABSTRACT FROM AUTHOR]

This study characterized a novel intracellular α-glucosidase, produced by Debaryomyces hansenii. The enzyme was purified through ultra-filtration, ammonium sulfate precipitation, chromatography Q-Sepharose and Sephacryl S-200 column. SDS-PAGE analysis confirmed the molecular weight of the purified protein to be 125 kDa. The enzyme exhibited maximum activity at pH 4.5and 50 °C and stability at pH 4.0 – 6.0 at 30 – 60 °C. The optimum isomalto-oligosaccharides (IMOs) bio-synthesis temperature using 400 g/L maltose was evaluated to be 35 °C with an optimum enzyme unit determined as 4.34 U g−1. The enzyme exhibits maximum maltose utilization of 78%, with or without inorganic salts, and was inhibited by ZnCl 2 , CoCl 2 and CuSO 4. Using maltose, the K m and V max values were 7.55 µM and 909 µmol/ml/mg respectively. In 3 L bioreactor, 4.34 U of enzyme produced IMOs with 47% purity utilizing 400 g/L maltose at 35 °C for 14 h. Furthermore, low purity IMOs was passed through cationic ion exchange resins to obtain high purity IMOs by separating glucose and maltose. This pioneering study produced high purity IMOs with 89% purity and 60% yield with greater conversion efficiency using a purified enzyme with a higher concentration of maltose and chromatographic method, which were confirmed by HPLC. [Display omitted] • Highly active α-glucosidase from D.hansenii was homogenized and purified. • Optimization studies enhanced isomaltooligosaccharides (IMOs) purity and yield. • Production of IMOs (47% purity) through biotransformation in a 3 L bioreactor. • High purity IMOs (89%) production using chromatographic separation. • IMOs component distribution confirmed by HPLC-RID. [ABSTRACT FROM AUTHOR]

The importance of bioactive substances from seaweeds has grown as a result of their capacity to promote human disease resistance and enhance human health. Secondary metabolites from brown marine algae could serve as a good source of phytochemicals with rich anti-oxidant ability, as most of the ailments are associated with free radicals. This research is focused on looking into the brown algal species Sargassum myriocystum belonging to the class Phaeophyceae, which has not been investigated for the presence of different bioactive compounds. The efficient extraction of and the qualitative analysis of the phytochemical compounds were performed and characterized. Moreover, the characteristic functional and bioactive molecules in the extract at optimum conditions were evaluated which showed the presence of various bioactive compounds. The antioxidant and anti-inflammatory potential of the extract indicated the potential reduction of free radicals and inflammatory mediators by the seaweed extract. The inhibition of digestive enzymes including α-amylase and α-glucosidase exhibited promising anti-diabetic potential and the antimicrobial property against some gram negative, gram positive bacteria and fungus was evaluated which inhibited the growth of microbes. Hence, the present study may provide the platform for utilizing bioactive compounds from brown seaweed as a promising therapeutic agent from natural source. [ABSTRACT FROM AUTHOR]

Passiflora edulis Var. flavicarpa (passion fruit) generates vast waste (60–70%) in the form of peel and seed after the juice extraction. The study aimed to isolate Scirpusin B (SB) from passion fruit (PF) seed waste collected from Northeast India and to analyse its anti-radical, antibacterial, anti-diabetic, and anti-oral cancer activities. Scirpusin B was isolated following hydro-alcoholic extraction, fractionation, and column chromatography. The isolated fraction was further identified through NMR and mass spectroscopy. SB exhibited significant antiradical activity against six standard antioxidant compounds, indicating its commercial application. SB inhibited α-amylase (IC50 Value: 76.38 ± 0.25 µg/mL) and α-glucosidase digestive enzymes (IC50 Value: 2.32 ± 0.04 µg/mL), signifying its antidiabetic properties. In addition, SB showed profound antibacterial activity against eight gram-positive and gram-negative bacteria reported for the first time. Furthermore, SB inhibited SAS and TTN oral cancer cell proliferation up to 95% and 83%, respectively. SB significantly inhibited colonies of SAS and TTn cells in the clonogenic assay, attributing to its anticancer properties. The PI-FACS assay confirmed the ability of SB (75 µM) to kill SAS and TTn cells by 40.26 and 44.3% in 72 h. The mechanism of SB inhibiting oral cancer cell proliferation was understood through western blot analysis, where SB significantly suppressed different cancer hallmark proteins, such as TNF-α, survivin, COX-2, cyclin D1, and VEGF-A. The present study suggests that SB isolated from PF seed can add noteworthy value to the waste biomass for various industrial and medical applications. [ABSTRACT FROM AUTHOR]

Soil salinization is the main factor that threatens the growth and development of plants and limits the increase of yield. It is of great significance to study the key soil environmental factors affecting plant root traits to reveal the adaptation strategies of plants to saline-alkaline-stressed soil environments. In this study, the root biomass, root morphological parameters and root mineral nutrient content of two alfalfa cultivars with different sensitivities to alkaline stress were analyzed with black soil as the control group and the mixed saline-alkaline soil with a ratio of 7:3 between black soil and saline-alkaline soil as the saline-alkaline treatment group. At the same time, the correlation analysis of soil salinity indexes, soil nutrient indexes and the activities of key enzymes involved in soil carbon, nitrogen and phosphorus cycles was carried out. The results showed that compared with the control group, the pH, EC, and urease (URE) of the soil surrounding the roots of two alfalfa cultivars were significantly increased, while soil total nitrogen (TN), total phosphorus (TP), organic carbon (SOC), and α-glucosidase activity (AGC) were significantly decreased under saline-alkaline stress. There was no significant difference in root biomass and root morphological parameters of saline-alkaline tolerant cultivar GN under saline-alkaline stress. The number of root tips (RT), root surface area (RS) and root volume (RV) of AG were reduced by 61.16%, 44.54%, and 45.31%, respectively, compared with control group. The ratios of K+/Na+, Ca2+/Na+ and Mg2+/Na+ of GN were significantly higher than those of AG (p < 0.05). The root fresh weight (RFW) and dry weight (RDW), root length (RL), RV and RT of alfalfa were positively regulated by soil SOC and TN, but negatively regulated by soil pH, EC, and URE (p < 0.01). Root Ca2+/Na+ ratio was significantly positively correlated with soil TN, TP and SOC (p < 0.01). The absorption of Mg and Ca ions in roots is significantly negatively regulated by soil β-glucosidase activity (BGC) and acid phosphatase activity (APC) (p < 0.05). This study improved knowledge of the relationship between root traits and soil environmental factors and offered a theoretical framework for elucidating how plant roots adapt to saline-alkaline stressed soil environments. [ABSTRACT FROM AUTHOR]

Obesity, a global issue, is linked to cardiometabolic syndrome. Dietary modification is one of the recommended modes for managing cardiometabolic syndrome. Strawberries, a functional food, and kombucha, a fermented tea beverage, have gained attention for their health benefits. This study investigated the bioactive components of strawberry kombucha drink (SKD) and their effects on antioxidant activities and improving metabolic disorder markers. An in vitro experiment was performed to determine the effect of SKD on enzymatic parameters: lipase, α-glucosidase, and α-amylase activities. In addition, antioxidant activity using the DPPH method and quantification of the radical scavenging activity were also measured. Furthermore, untargeted metabolomic profiling of SKD and molecular docking simulation were conducted. The findings suggest that SKD, rich in secondary metabolites, can inhibit lipase, α-glucosidase, and α-amylase activities. It demonstrated in vitro anti-obesity, anti-diabetic, and antioxidant properties, potentially reducing metabolic and inflammatory issues. Thus, SKD could be a therapeutic beverage to alter metabolic issues associated with obesity. Nevertheless, further preclinical study is warranted to determine SKD's potential in vivo. [ABSTRACT FROM AUTHOR]

Two new compounds geobomlin A (1) and geobomlin B (2) were isolated from the roots of Stachys geobombycis C. Y. Wu. Structural determinations were established principally by two-dimensional NMR and MS data analyses. Geobomlin B showed moderate inhibitory activity against α-glucosidase with IC50 = 248.77 μM. We have also determined the mechanism by which geobomlin B elicit its inhibitory effect on α-glucosidase, for which we have established a competitive inhibition mode. Docking studies confirmed our results on geobomlin B α-glucosidase inhibitory properties. [ABSTRACT FROM AUTHOR]

The Penicillium verruculosum filamentous fungus is a highly active producer of cellulolytic complex enzymes, cellobiohydrolases, endoglucanases and β-glucosidases. Using the CRISPR/Cas9 genome editing system, previously adapted to P. verruculosum, a strain with a knockout of the xlnR gene encoding XlnR, one of the main transcription factors of filamentous fungi, has been obtained. The transcription level of cellulolytic genes was determined by quantitative PCR for the P. verruculosum B1-221-151 strain and the new P. verruculosum ΔxlnR strain. The XlnR protein was shown to activate transcription of the cbh1, egl2, and bgl1 genes encoding cellobiohydrolase 1, endoglucanase 2, and β-glucosidase, respectively, in the presence of xylose and xylooligosaccharides in the growth medium. It was found that other factors are also involved in the activation of transcription of these genes by cellobiose, cellotriose, sophorose, and gentiobiose, which has a complex effect on the biosynthesis of the cellulolytic complex of enzymes produced by the P. verruculosum fungus. [ABSTRACT FROM AUTHOR]

Stachys brachyclada de Noé ex Coss. (Lamiaceae) is a quite rare medicinal plant endemic to the Mediterranean basin. In this study, seven secondary metabolites from a methanol extract of its leaves have been isolated and identified by a combination of chromatographic and spectroscopic methods (1D and 2D NMR experiments and ESIMS analysis). They include one ethyl 4-hydroxybenzoate (1), three acylated flavone glycosides (2-4), one diapigenin derivative (5) and two flavone aglycones (6-7). Stachysetin (5) was found the major compound of the extract (74.0 mg/g of dry matter). Moreover, the produced extract showed the ability in inhibiting the α-glucosidase enzyme (IC50 = 13.7 µg/mL), in quenching the radical 1,1-diphenyl-2-picrylhydrazyl (EC50 = 74.6 µg/mL), and in reducing the intracellular oxidative stress level in Human Dermal Fibroblast (64% inhibition at 50 µg/mL). [ABSTRACT FROM AUTHOR]

Marine algae (seaweeds) have emerged as a promising source in the continuing search for antidiabetic compounds because of their medicinal and nutritional properties. The present study evaluated marine red algae, Portieria hornemannii, for its inhibition of diabetic-linked enzymes (α-amylase, α-glucosidase, and DPP-IV) and antioxidant (DPPH) potential using in vitro assays. Among the tested extracts, ethyl acetate and acetone extract exhibited notable inhibition against α-amylase (IC50: 95.30 μg/mL), α-glucosidase (IC50: 632.5 μg/mL), and DPP-IV (IC50: 36.91 μg/mL). However, the antioxidant activity of the extracts was mild to moderate (17%). Furthermore, the half maximal inhibitory concentration (IC50) of the extracts was found to be non-toxic against mouse macrophage cells (J774) and human red blood cells. Chemical profiling by GC-MS analysis revealed the presence of major bioactive compounds such as phytol, z,z-6,28-heptatriactontadien-2-one, hentriacontane, and l-ascorbic acid. Overall, our findings indicate that the extracts of P. hornemannii reduce postprandial hyperglycemia by inhibiting the release of simple sugars through the inhibition of the enzymes (α-amylase, α-glucosidase, and DPP-IV). [ABSTRACT FROM AUTHOR]

β-glucosidase (Bgl) hydrolyzes cellobiose to glucose, thereby releasing non-reducing terminal glucosyl residues. Bgl is an essential enzyme belonging to the biomass-degrading enzyme family, which plays a vital role in enzymatic saccharification during biofuel production. The four loops above the Bgl substrate-binding pocket undergo a conformational change upon substrate recognition. However, the structural dynamism of this loop and how it is conserved among Bgl family members remain unknown. Herein, to better understand the four loops above the substrate-binding pocket of Bgl, four Bgl crystal structures in Thermoanaerobacterium saccharolyticum (TsaBgl) were determined at 1.5–2.1 Å. The L1, L2, and L4 loops of TsaBgl showed a rigid conformation stabilized by their neighboring residues via hydrogen bonds and hydrophobic interactions. The TsaBgl L3 loop showed relatively high flexibility and two different N-terminal region conformations. The conformational change in the TsaBgl L3 loop induced a change in charge and shaped at the substrate-binding pocket entrance. The amino acid sequences and structures of the TsaBgl L1–4 loops were compared with other 45 Bgl proteins, and a diversity of the L2 and L3 loops was observed. Differences in amino acids and lengths of Bgls L2–L3 loop induced differences in the conformation and structure of the Bgls substrate-binding pocket entrance. These findings expand our knowledge on the molecular function of the loops in the Bgl enzyme family. [ABSTRACT FROM AUTHOR]

Chamomile (Matricaria chamomilla L.) is one of the oldest and most widely known medicinal plants belonging to Asteraceae family. An artifact named chamazulene forms from the sesquiterpene structured lactones such as matricin during the hydro-distillation of flowering tops of chamomile. These compounds are associated with the anti-inflammatory potential of chamomile along with flavonoids, other sesquiterpenoids, and essential oil of the plant. However, not all M. chamomilla specimens grown in different regions or species known and used as chamomile contains sesquiterpene lactone components. Thus, chamazulene content of chamomile has become a pharmaceutical interest. A traditional and well-established indication of the plant is diabetes. Protective and beneficial effects of chamomile on diabetic complications and glycemic control have been proposed by several studies. However, the mechanism of action is yet to be elucidated. Flowering tops of chamomile samples were collected from six different localities of Diyarbakır/Türkiye. Essential oils (EOs) were obtained by hydro-distillation. Petroleum ether (PE), ethyl acetate (EA), methanol (Me), and infusion (INF) extracts were prepared. Qualitative analysis of the EOs resulted in no chamazulene content. Bismil district might be eligible for medicinal chamomile culture with its high essential oil yield. In-vitro hypoglycemic potentials of the extracts and EOs were evaluated by α-glucosidase inhibitory assay. All EOs and EA extracts (except M4-Bismil samples) showed the highest inhibitory activities comparable to that of standard acarbose. α-Glucosidase inhibition might be a significant mechanism of action contributing to the antidiabetic effects of chamomile. [ABSTRACT FROM AUTHOR]

α-Glucosidase, an enzyme that plays a crucial role in glucose absorption in the intestine, is a key therapeutic intervention in the management of diabetes mellitus. The inhibition of this enzyme is critical for controlling postprandial hyperglycemia. The present study aims to investigate the stability of phenolic content, total flavonoid content, and α-glucosidase inhibition activities of six Thai folk anti-diabetes remedies by in vitro simulated gastrointestinal digestion methods, as well as to evaluate their synergistic effect with acarbose. The TFD-04 decoction and 90% EtOH extract showed higher total phenolic and flavonoid content (86.83 mg GAE/g extract, 10.00 mg QE/g extract) and (75.32 mg GAE/g extract, 12.45 mg QE/g extract), respectively. The α- glucosidase inhibitory activities (maltase and sucrase) of TFD-04 were found maximum in decoction and GD-decoction with IC50 values of 0.25±0.02 and 0.78±0.04 mg/mL, respectively, when compared with acarbose with statistical significance (P< 0.05). The IC50 values of 0.59±0.02 and 1.59±0.02 mg/mL, respectively. In addition, the decoction extract of TFD-04 showed the most potent synergistic inhibitory effect with acarbose. A kinetic analysis showed that TFD-04 showed uncompetitive inhibition against intestinal maltase. This study suggests that decoction extracts of TFD-04 may serve as effective anti-hyperglycemic remedies in the field of diabetic therapy. [ABSTRACT FROM AUTHOR]

Objective: The present research study was conducted to investigate in vitro anti-diabetic potentials of ethanol extract of leaves of Muntingia calabura for α-glucosidase and α-amylase inhibitory activities. Materials & Methods: The leaves of Muntingia calabura were collected and authenticated. dried and powdered. The powdered drug was defatted using petroleum ether and extracted with ethanol. The ethanol extract of Muntingia calabura was subjected to preliminary phytochemical investigation. The in vitro a-glucosidase inhibitory and α-amylase inhibitory properties were determined for the ethanol extract and concentrations of extract required to inhibit absorbance (IC50 values) EEMC were determined. Results: Significant IC50 values were found in both tests that assessed the inhibitory activity of α-glucosidase and α-amylase, demonstrating the capacity of the ethanol extract of Muntingia calabura to block carbohydrate digesting enzymes and prevent postprandial blood glucose. Conclusion: The results of the presents investigation recommends that ethanol extract of Muntingia calabura possess significant α-glucosidase and a-amylase inhibitory activity. [ABSTRACT FROM AUTHOR]

A novel cellulose microfibril swelling (Cms) gene of Bacillus sp. AY8 was successfully cloned and sequenced using a set of primers designed based on the conserved region of the gene from the genomic database. The molecular cloning of the Cms gene revealed that the gene consisted of 679 bp sequences encoding 225 amino acids. Further in silico analysis unveiled that the Cms gene contained the NlpC/P60 conserved region that exhibited a homology of 98% with the NlpC/P60 family proteins found in both the strains, Burkholderialata sp. and Burkholderia vietnamiensis. The recombinant Cms enzyme had a significant impact on the reduction of crystallinity indices (CrI) of various substrates including a 3%, a 3.97%, a 4.66%, and a substantial 14.07% for filter paper, defatted cotton fiber, avicel, and alpha cellulose, respectively. Additionally, notable changes in the spectral features were observed among the substrates treated with recombinant Cms enzymes compared to the untreated control. Specifically, there was a decrease in band intensities within the spectral regions of 3000–3450 cm−1, 2900 cm−1, 1429 cm−1, and 1371 cm−1 for the treated filter paper, cotton fiber, avicel, and alpha cellulose, respectively. Furthermore, the recombinant Cms enzyme exhibited a maximum cellulose swelling activity at a pH of 7.0 along with a temperature of 40 °C. The molecular docking data revealed that ligand molecules, such as cellobiose, dextrin, maltose 1-phosphate, and feruloyated xyloglucan, effectively bonded to the active site of the Cms enzyme. The molecular dynamics simulations of the Cms enzyme displayed stable interactions with cellobiose and dextrin molecules up to 100 ns. It is noteworthy to mention that the conserved region of the Cms enzyme did not match with those of the bioadditives like expansins and swollenin proteins. This study is the initial report of a bacterial cellulose microfibril swellase enzyme, which could potentially serve as an additive to enhance biofuel production by releasing fermentable sugars from cellulose. [ABSTRACT FROM AUTHOR]

Peyer’s patches (PPs) are specialized gut-associated lymphoid tissues that initiate follicular helper T (Tfh)-mediated immunoglobulin A (IgA) response to luminal antigens derived from commensal symbionts, pathobionts, and dietary sources. IgA-producing B cells migrate from PPs to the small intestinal lamina propria and secrete IgA across the epithelium, modulating the ecological balance of the commensal microbiota and neutralizing pathogenic microorganisms. α-glucosidase inhibitors (α-GIs) are antidiabetic drugs that inhibit carbohydrate digestion in the small intestinal epithelium, leading to alterations in the commensal microbiota composition and metabolic activity. The commensal microbiota and IgA responses exhibit bidirectional interactions that modulate intestinal homeostasis and immunity. However, the effect of α-GIs on the intestinal IgA response remains unclear. We investigated whether α-GIs affect IgA responses by administering voglibose and acarbose to mice via drinking water. We analyzed Tfh cells, germinal center (GC) B cells, and IgA-producing B cells in PPs by flow cytometry. We also assessed pathogen-specific IgA responses. We discovered that voglibose and acarbose induced Tfh cells, GCB cells, and IgA-producing B cells in the PPs of the proximal small intestine in mice. This effect was attributed to the modification of the microbiota rather than a shortage of monosaccharides. Furthermore, voglibose enhanced secretory IgA (S-IgA) production against attenuated Salmonella Typhimurium. Our findings reveal a novel mechanism by which α-GIs augment antigen-specific IgA responses by stimulating Tfh-GCB responses in PPs, and suggest a potential therapeutic application as an adjuvant for augmenting mucosal vaccines. [ABSTRACT FROM AUTHOR]

A series of 24-nor-allobetulin derivatives holding 3β-hydroxy-, oxime, methoxyoxime, lactame and 4-bromobenzylidene substituents have been synthesized and their differences in the NMR spectra were studied in detail. It was revealed that 3-oxo-24-nor-allobetulin loses selectivity in the reaction of oximation and forms a mixture of Z/E oximes (and methoxyoximes) in contract to the related derivatives of native scaffold (that forms only E-isomers). The screening of α-glucosidase inhibitory activity revealed that 24-nor-allobetulins are more active than allobetulins. The lead 3-oxo-24-nor-allobetulin with IC50 0.49 µM was more than 60-fold and 500-fold active than acarbose and 3-oxo-allobetulin, respectively. We can conclude that the removal of the C-24 methyl group significantly increased the antidiabetic effect and 24-nor-allobetulins should be identified as the new and promising scaffolds as α-glucosidase inhibitors on the basis of triterpenoids. [ABSTRACT FROM AUTHOR]

The α-glucosidase inhibitor is of interest to researchers due to its association with type-II diabetes treatment by suppressing postprandial hyperglycemia. Hesperidin is a major flavonoid in orange fruit with diverse biological properties. This paper evaluates the effects of hesperidin on α-glucosidase through inhibitory kinetics, fluorescence quenching, and molecular docking methods for the first time. The inhibition kinetic analysis shows that hesperidin reversibly inhibited the α-glucosidase activity with an IC50 value of 18.52 μM and the inhibition was performed in an uncompetitive type. The fluorescence quenching studies indicate that the intrinsic fluorescence of α-glucosidase was quenched via a static quenching process and only one binding site was present between the hesperidin and α-glucosidase. The interaction between them was spontaneous and mainly driven by hydrogen bonds, as well as hydrophobic forces. Furthermore, the molecular docking results suggest that hesperidin might bond to the entrance or outlet part of the active site of α-glucosidase through a network of five hydrogen bonds formed between hesperidin and the four amino acid residues (Trp709, Arg422, Asn424, and Arg467) of α-glucosidase and the hydrophobic effects. These results provide new insight into the inhibitory mechanisms of hesperidin on α-glucosidase, supporting the potential application of a hesperidin-rich orange product as a hypoglycemic functional food. [ABSTRACT FROM AUTHOR]

In the genome of Cellulomonas flavigena, two genes that potentially encode endoglucanases — Cfla_2912 and Cfla_2913 were identified. We cloned the genes and created Pichia pastoris-based recombinant producers of two proteins that were expressed from the AOX1 promoter. Each of the endoglucanase molecules contains a GH6 catalytic domain, CBM2 carbohydrate-binding module, and TAT signal peptide. The fermentation of the producers was carried out in a 10 L fermenter; Cfla_2912 and Cfla_2913 were purified using affinity chromatography. The yield comprised 10.3 mg/ml (430 U/ml) for Cfla_2913 and 9 mg/ml (370 U/ml) for Cfla_2912. Cfla_2912 and Cfla_2913 were found to have a high activity against barley β-glucan and lichenan, a weak activity against carboxymethyl cellulose (CMC), phosphoric-acid treated cellulose, and no activity against laminarin, xylan, soluble starch, microcrystalline cellulose, cellobiose, and cellotriose. Thus, the proteins exhibited β-glucanase activity. Both proteins had a neutral pH optimum of about 7.0 and were more stable at neutral and slightly alkaline pH ranging from 7.0 to 9.0. Cfla_2912 and Cfla_2913 showed a moderate thermal stability. The products of barley β-glucan hydrolysis by Cfla_2912 and Cfla_2913 were trisaccharide, tetrasaccharide, and cellobiose. Cfla_2912 and Cfla_2913 efficiently hydrolyzed cereal polysaccharides, which indicate that they may have biotechnological potential. [ABSTRACT FROM AUTHOR]

The GH3 β-glucosidase gene of Myceliophthora thermophila (MtBgl3c) has been cloned and heterologously expressed in E. coli for the first time. This study highlights the important characteristics of recombinant MtBgl3c (rMtBgl3c) which make it a promising candidate in industrial applications. Optimization of the production of rMtBgl3c led to 28,000 U L−1. On purification, it has a molecular mass of ∼100 kDa. It is a broad substrate specific thermostable enzyme that exhibits pH and temperature optima at 5.0 and 55 °C, respectively. The amino acid residues Asp287 and Glu514 act as nucleophile and catalytic acid/base, respectively in the enzyme catalysis. Its low Km value (1.28 mM) indicates a high substrate affinity as compared to those previously reported. The rMtBgl3c displays a synergistic action with the commercial enzyme cocktail in the saccharification of sugarcane bagasse suggesting its utility in the cellulose bioconversion. Tolerance to solvents, detergents as well as glucose make this enzyme applicable in wine, detergent, paper and textile industries too. [ABSTRACT FROM AUTHOR]

Although the nutritional demands of animals are known to differ between immature and mature stages and between neonates from different clutches in various organisms, little evidence has been accumulated to examine this possibility in crustacean zooplankters. To this end, we examined the five digestive enzyme activities related to assimilations of carbohydrates, lipids, amino acids and phosphorus in the neonates, immature and mature individuals of panarctic Daphnia pulex. We found that all the enzyme activities were higher at lower food levels, indicating that the activities increased with decreasing supplies of the nutritional substances relative to the demands. As expected, these enzyme activities changed ontogenetically. Beta‐glucosidase activities increased with age, especially at a high food level, while the opposite pattern was found for lipase activities. A decreasing trend with age was also found in the activities of arginine and alanine amino‐peptidase and alkaline phosphatase at a low food level. These results suggest that juvenile individuals require more lipids, amino acids and phosphorus relative to the requirements of adult individuals, while the opposite pattern was true for carbohydrates. We also measured the enzyme activities of the neonates born from the 1st and 2nd clutches of the maternal individuals. The results showed that most digestive enzyme activities differed significantly between the neonates from the first and second clutches depending on the food levels. The present study confirmed that the nutritional demands differ not only between mature and immature individuals in Daphnia pulex and suggests that the mature individuals invest nutrients and energy reserves differently to neonates of the different clutches depending on their nutritional conditions. [ABSTRACT FROM AUTHOR]

Metabolic syndrome (MetS) is a global issue affecting over a billion people, raising the risk of diabetes, cardiovascular disorders, and other ailments. It is often characterized by hypertension, dyslipidemia and/or obesity, and hyperglycemia. Chemical investigation of Aeonium arboreum (L.) Webb & Berthel led to the isolation of six compounds, viz. β-sitosterol, β-sitosterol glucoside, myricetin galactoside, quercetin rhamnoside, kaempferol rhamnoside, and myricetin glucoside. Interestingly, A. arboreum's dichloromethane (DCM), 100 and 50% MeOH Diaion fractions and the isolated compound (quercetin-3-rhamnoside) revealed potent α-glucosidase inhibitory activity, especially 50% Diaion fraction. In addition, they also showed very potent antioxidant potential, especially the polar fractions, using DPPH, ABTS, FRAP, ORAC, and metal chelation assays. Notably, the 50% Diaion fraction had the highest antioxidant potential using DPPH and ORAC assays, while the 100% Diaion fraction and quercetin-3-rhamnoside showed the highest activity using ABTS, FRAP, and metal chelation assays. Also, quercetin-3-rhamnoside showed a good docking score of −5.82 kcal/mol in comparison to acarbose. In addition, molecular dynamic stimulation studies illustrated high stability of compound binding to pocket of protein. Such potent activities present A. arboreum as a complementary safe approach for the management of diabetes mellitus as well as MetS. [ABSTRACT FROM AUTHOR]

BACKGROUND: In goji berries (Lycium barbarum L.), the cell wall properties and ripening environment affect fruit quality and their economic benefits. However, the mechanism underlying the cell wall remains to be fully elucidated. RESULTS: The results showed that total sugar content was higher in Qinghai berries (13.87%, P < 0.01), whereas cellulose content peaked in Zhongning berries (28%, P < 0.05). Arabinose, galactose, and galacturonic acid were the principal components of the cell wall polysaccharides in goji berries. Among them, the content of galactose in Zhongning was significantly the highest (P < 0.05). Interestingly, we found that highly expressed β‐glucosidase and lowly expressed endoglucanase led to cellulose accumulation by RNA‐sequencing analysis. The expression analysis results suggested that pectate lyase and pectinesterase enzymes could be major factors related to higher galactose and galacturonic acid contents in Zhongning compared to in Qinghai and Gansu. The starch and sucrose metabolism pathway, pentose and glucuronate interconversions pathway, and galactose metabolism pathway played a significant role in cell wall polysaccharide synthesis and metabolism. CONCLUSION: In the present study, we aimed to provide some insights into the cell wall on polysaccharide composition, structural features, and gene analysis in goji berries from Zhongning, Qinghai, and Gansu in China. These results might help to clarify the molecular function of the major genes in the cell wall polysaccharides of goji berries and provide a solid foundation for further study. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]