Mechanism underlying the influence of humidity on thermal comfort and stress under mimicked working conditions.

Thermal comfort in an office impacts physical health, stress, and productivity. Humidity affects thermal comfort; however, the underlying mechanism remains unclear. This study assessed the influence of humidity on body temperature, thermal comfort, stress, and their relationship in working individuals. Thirteen participants performed three sets of 20-min calculation tasks followed by a 10-min rest in 26 °C or 33 °C with relative humidity (RH) of 30 % or 60 %. Core body temperature (Tcore), mean skin surface temperature (Tskin), and electrocardiogram were continuously recorded. Subjective thermal sensations and comfort were assessed with visual analog scales. Stress level was estimated based on α-amylase activity and immunoglobulin A level in saliva and heart rate variability. Mean Tskin and Tcore elevated at 33 °C with 60 % RH, where warm sensation and thermal discomfort also increased. Heart rate variability reflecting parasympathetic nerve activity decreased. There was a negative linear relationship between weighted body temperature and thermal comfort. However, thermal discomfort was augmented at a given weighted body temperature at 60 % RH. Thus, under indoor working conditions, high humidity may augment thermal discomfort and become a stress factor. Increases in Tskin and Tcore are involved in the mechanism, alongside other factors.

Serum α-amylase correlates with xerostomia in patients with primary Sjögren's disease.

Sjögren's disease is one of the most common systemic autoimmune diseases with hallmark features of sicca (dryness) symptoms of the eyes and mouth. There are a variety of ways to quantify xerostomia. α-Amylase is an enzyme secreted by the pancreas and salivary glands. While not specific to salivary glands, it may be measured as a surrogate marker of their output. Therefore, in this short investigation, we determined if there were any associations of serum α-amylase with subjective and objective markers of xerostomia. This investigation found a correlation between objective and subjective markers of xerostomia and α-amylase which suggests that measuring this analyte is a novel adjunct to qualifying xerostomia in the clinic.

ARTP mutagenesis of Aureobasidium pullulans RM1603 for high pullulan production and transcriptome analysis of mutants.

Pullulan is a microbial exopolysaccharide produced by Aureobasidium spp. with excellent physical and chemical properties, resulting in great application value. In this study, a novel strain RM1603 of Aureobasidium pullulans with high pullulan production of 51.0 ± 1.0 g·L- 1 isolated from rhizosphere soil was subjected to atmospheric and room temperature plasma (ARTP) mutagenesis, followed by selection of mutants to obtain pullulan high-producing strains. Finally, two mutants Mu0816 and Mu1519 were obtained, with polysaccharide productions of 58.7 ± 0.8 and 60.0 ± 0.8 g∙L- 1 after 72-h fermentation, representing 15.1 and 17.6% increases compared with the original strain, respectively. Transcriptome analysis of the two mutants and the original strain revealed that the high expression of α/ß-hydrolase (ABHD), α-amylase (AMY1), and sugar porter family MFS transporters (SPF-MFS) in the mutants may be related to the synthesis and secretion of pullulan. These results demonstrated the effectiveness of ARTP mutagenesis in A. pullulans, providing a basis for the investigation of genes related to pullulan synthesis and secretion.

Insights into free radicals scavenging, α-Amylase inhibition, cytotoxic and antifibrotic activities unveiled by Peganum harmala extracts.

BACKGROUND: Peganum harmala L. is used in traditional medicine to treat several health ailments. Hence, the present work aimed to investigate the DPPH free radical scavenging, α-amylase, cytotoxic, and antifibrotic effects of the hydrophilic extract and fixed oil obtained from P. harmala seeds. METHODS: The hydrophilic extract and fixed oil of P. harmala were assessed for their abilities to scavenge DPPH free radicals and inhibit α-amylase using reference bioassays. The cytotoxicity was assessed on several cancer and normal cell lines, including B16F1, Caco-2, COLO205, HeLa, Hep 3B and Hep G2, MCF-7, and HEK-293 T cells. The MTS assay was used to evaluate the antifibrotic capabilities utilizing the human hepatic stellate (LX-2) cell line. RESULTS: P. harmala plant fixed oil has potent DPPH free radical scavenging activity with an IC50 dose of 79.43 ± 0.08 µg/ml. Besides, the hydrophilic extract has a poor anti-α-amylase effect compared with the antidiabetic drug Acarbose, with IC50 doses of 398 ± 0.59 and 25.11 ± 1.22 µg/ml, respectively. In addition, the growth of MCF-7, Hep3B, HepG2, HeLa, COLO205, CaCo2, B16F1, and HeK293t was inhibited by P. harmala hydrophilic extract with IC50 doses of 121.34 ± 1.71, 268.3 ± 0.75, 297.20 ± 1.00, 155.60 ± 1.14, 150.01 ± 0.51, 308.35 ± 0.53, 597.93 ± 1.36, and 5.38 ± 0.99 µg/ml, respectively. In addition, at 1000 µg/ml, 5-Fluorouracil reduced fibrosis cells by 0.089%, while the hydrophilic extract decreased the number of LX-2 cells by 5.81%. CONCLUSION: P. harmala plant-fixed oil exhibits potential antioxidant properties. While the hydrophilic extract showed limited effectiveness as an anti-α-amylase agent and demonstrated notable cytotoxic effects against various tested cancer cell lines. Furthermore, this extract significantly reduces the number of LX-2 fibrotic cells. These findings emphasize the therapeutic potential of these products in managing various health disorders and warrant further investigation into their mechanisms of action and clinical applications.

Screening of broad-host expression promoters for shuttle expression vectors in non-conventional yeasts and bacteria.

BACKGROUND: Non-conventional yeasts and bacteria gain significance in synthetic biology for their unique metabolic capabilities in converting low-cost renewable feedstocks into valuable products. Improving metabolic pathways and increasing bioproduct yields remain dependent on the strategically use of various promoters in these microbes. The development of broad-spectrum promoter libraries with varying strengths for different hosts is attractive for biosynthetic engineers. RESULTS: In this study, five Yarrowia lipolytica constitutive promoters (yl.hp4d, yl.FBA1in, yl.TEF1, yl.TDH1, yl.EXP1) and five Kluyveromyces marxianus constitutive promoters (km.PDC1, km.FBA1, km.TEF1, km.TDH3, km.ENO1) were selected to construct promoter-reporter vectors, utilizing α-amylase and red fluorescent protein (RFP) as reporter genes. The promoters' strengths were systematically characterized across Y. lipolytica, K. marxianus, Pichia pastoris, Escherichia coli, and Corynebacterium glutamicum. We discovered that five K. marxianus promoters can all express genes in Y. lipolytica and that five Y. lipolytica promoters can all express genes in K. marxianus with variable expression strengths. Significantly, the yl.TEF1 and km.TEF1 yeast promoters exhibited their adaptability in P. pastoris, E. coli, and C. glutamicum. In yeast P. pastoris, the yl.TEF1 promoter exhibited substantial expression of both amylase and RFP. In bacteria E. coli and C. glutamicum, the eukaryotic km.TEF1 promoter demonstrated robust expression of RFP. Significantly, in E. coli, The RFP expression strength of the km.TEF1 promoter reached ∼20% of the T7 promoter. CONCLUSION: Non-conventional yeast promoters with diverse and cross-domain applicability have great potential for developing innovative and dynamic regulated systems that can effectively manage carbon flux and enhance target bioproduct synthesis across diverse microbial hosts.

Antioxidant and Antidiabetic Activity of Cornus mas L. and Crataegus monogyna Fruit Extracts.

The present study evaluated three green extraction methods, accelerated solvent extraction (ASE), ultrasound-assisted extraction (UAE), and laser irradiation extraction (LE), for the polyphenolic compounds and vitamin C extraction of Cornus mas L. and Crataegus monogyna fruit extracts. The polyphenols and vitamin C of extracts were quantified using HPLC-DAD, and the total phenolic content, flavonoid content, antioxidant activity (DPPH and reducing power), and antidiabetic activity were also studied. The antidiabetic activity was examined by the inhibition of α-amylase and α-glucosidase, and in vitro on a beta TC cell line (ß-TC-6). The results showed significant differentiation in the extraction yield between the methods used, with the ASE and LE presenting the highest values. The C. mas fruit extract obtained by ASE exhibited the best antioxidant activity, reaching an IC50 value of 31.82 ± 0.10 µg/mL in the DPPH assay and 33.95 ± 0.20 µg/mL in the reducing power assay. The C. mas fruit extracts obtained by ASE and LE also have the highest inhibitory activity on enzymes associated with metabolic disorders: α-amylase (IC50 = 0.44 ± 0.02 µg/mL for the extract obtained by ASE, and 0.11 ± 0.01 µg/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm) and α-glucosidase (IC50 of 77.1 ± 3.1 µg/mL for the extract obtained by ASE, and 98.2 ± 4.7 µg/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm). The evaluation of in vitro antidiabetic activity demonstrated that the treatment with C. mas and C. monogyna fruit extracts obtained using ASE stimulated the insulin secretion of ß-TC-6 cells, both under normal conditions and hyperglycemic conditions, as well. All results suggest that C. mas and C. monogyna fruit extracts are good sources of bioactive molecules with antioxidant and antidiabetic activity.

Evaluation of Sourdough Bread and Its Potential Use in Support of the Treatment of Chronic Non-Communicable Diseases.

Gastrointestinal disorders dysregulate the biochemical environment of the gastrointestinal tract by altering pH conditions during the gastric phase of digestion or by reducing the secretion of pancreatin during the intestinal part of the process. Ingested functional food could therefore lose some of its health-promoting potential apart from its nutritional value. In this work, we aimed to manufacture bread marked by decreased gluten content, using a commercial or laboratory sourdough, that could be appropriate for patients afflicted with wheat allergy, hypertension and pancreatic malfunctions. A reference sample (no sourdough) was prepared alongside wheat and wheat-rye bread samples-produced with either commercial or laboratory sourdough (L. plantarum BS, L. brevis 1269, L. sanfranciscensis 20663). We measured the QQQPP allergen content (ELISA) in bread extracts digested in vitro and determined how these extracted components affect the level of active angiotensin and alpha amylase (spectrophotometry). We then elucidated how these properties changed when physiological digestion conditions (pH and pancreatin activity) were disturbed to mimic gastric hyperacidity, hypochlorhydria or exocrine pancreatic insufficiency. The key finding was that every tested type of bread produced with laboratory sourdough exhibited pronounced angiotensin-converting enzyme inhibition. The effect was preserved even in dysregulated digestive conditions. The use of laboratory sourdough prevented an increase in allergenicity when pancreatin was restricted as opposed to the commercial sourdough, which surpassed the reference sample reading at 50% pancreatin. No statistically consistent link was reported when the inhibition of alpha amylase was assayed. In conclusion, functional bread manufactured with sourdough composed of L. plantarum BS, L. brevis 1269, and L. sanfranciscensis 20663 was shown to be potentially capable of contributing to the treatment against hypertension as evidenced by in vitro research. It was also moderately safer with regard to its allergenicity.

Ultrasound and enzyme treatments on morphology, structures, and adsorption properties of cassava starch.

Porous starch materials are environmentally friendly and renewable and exhibit high adsorption performances. Ultrasound and compound enzyme (α-amylase and glucoamylase) treatments were applied to prepare modified cassava starch. The granules, crystal morphology, crystal structure, and molecular structure of starch were investigated. The hydrolysis degree, solubility, swelling, and adsorption properties of cassava starch were analyzed. After the cassava starch was modified by ultrasound and enzyme treatments, the granule size of the starch decreased, and the surfaces were eroded to form pits, grooves and cavity structure. The starch spherulites weakened or even disappeared. The functional groups of starch did not change significantly, but the degree of crystal order decreased. The double-helix structure was reduced, and the crystal structure was composed of A + V-type crystals, with a decrease in crystallinity. The gelatinization temperature and thermal degradation temperatures enhanced. The enzymatic hydrolysis degree and solubility of the modified cassava starch increased. The swelling degree decreased, and oil adsorption, water adsorption improved. MB adsorption behavior of modified cassava starch closely followed a pseudo-second-order kinetics model and the Langmuir isotherm equation. These findings could help to understand the relationship between the structure and properties of modified starch, and guide its application in the field of adsorption.

Integrative metabolomics and chemometrics depict the metabolic alterations of differently processed red kidney beans (Phaseolus vulgaris L.) and in relation to in-vitro anti-diabetic efficacy.

Red kidney beans (RKB) serve as a powerhouse packed with a plethora of largely unexplored extraordinary chemical entities with potential significance. However, their nutraceutical applications as a functional hypoglycemic food still lag behind and warrant further investigation. With a scope to optimize chemical and biological traits of RKB, green modification approaches (processing methods) seem inevitable. Accordingly, the current study offered the first integrative workflow to scrutinize dynamic changes in chemical profiles of differently processed RKB and their potential entanglements on diabetes mitigation using Ultra Performance Liquid Chromatography-mass spectrometry (UPLC-MS/MS) coupled with chemometrics. Different physical and biological processing treatments namely germination, fermentation, cooking and dehulling were preliminarily implemented on RKB. Complementarily, the concomitant metabolite alterations among differently processed RKB were monitored and interpreted. Next, an in-vitro α-amylase and α-glycosidase inhibitory testing of the differently processed samples was conducted and integrated with orthogonal projection to latent structures (OPLS) analysis to pinpoint the possible efficacy compounds. A total of 72 compounds spanning fatty acids and their glycerides, flavonoids, phenolic acids, amino acids, dipeptides, phytosterols and betaxanthins were profiled. Given this analysis and compared with raw unprocessed samples, it was found that flavonoids experienced notable accumulation during germination while both fermentation and dehulling approaches sharply intensified the content of amino acids and dipeptides. Comparably, Fatty acids, phytosterols and betaxanthins were unevenly distributed among the comparable samples. Admittedly, OPLS-DA revealed an evident discrimination among the processed samples assuring their quite compositional discrepancies. In a more targeted approach, kaempferol-O-sophoroside, quercetin, carlinoside and betavulgarin emerged as focal discriminators of sprouted samples while citrulline, linoleic acid, linolenoyl-glycerol and stigmasterol were the determining metabolites in cooked samples. Our efficacy experimental findings emphasized that the different RKB samples exerted profound inhibitory actions against both α-amylase and α-glycosidase enzymes with the most promising observations in the case of sprouted and cooked samples. Coincidently, OPLS analysis revealed selective enhancement of possible efficacy constituents primarily citrulline, formononetin, gamabufotalin, kaempferol-O-sophoroside, carlinoside, oleic acid and ergosterol in sprouted and cooked samples rationalizing their noteworthy α-amylase and α-glucosidase inhibitory activities. Taken together, this integrated work provides insightful perspectives beyond the positive impact of different processing protocols on bioactives accumulation and pharmacological traits of RKB expanding their utilization as functional hypoglycemic food to rectify diabetes.

Molecular Characteristics and Functional Identification of a Key Alpha-Amylase-Encoding Gene AMY11 in Musa acuminata.

Alpha-amylase (AMY) plays a significant role in regulating the growth, development, and postharvest quality formation in plants. Nevertheless, little is known about the genome-wide features, expression patterns, subcellular localization, and functional regulation of AMY genes (MaAMYs) in the common starchy banana (Musa acuminata). Twelve MaAMY proteins from the banana genome database were clustered into two groups and contained a conserved catalytic domain. These MaAMYs formed collinear pairs with the AMYs of maize and rice. Three tandem gene pairs were found within the MaAMYs and are indicative of putative gene duplication events. Cis-acting elements of the MaAMY promoters were found to be involved in phytohormone, development, and stress responses. Furthermore, MaAMY02, 08, 09, and 11 were actively expressed during fruit development and ripening. Specifically, MaAMY11 showed the highest expression level at the middle and later stages of banana ripening. Subcellular localization showed that MaAMY02 and 11 were predominately found in the chloroplast, whereas MaAMY08 and 09 were primarily localized in the cytoplasm. Notably, transient attenuation of MaAMY11 expression resulted in an obvious increase in the starch content of banana fruit, while a significant decrease in starch content was confirmed through the transient overexpression of MaAMY11. Together, these results reveal new insights into the structure, evolution, and expression patterns of the MaAMY family, affirming the functional role of MaAMY11 in the starch degradation of banana fruit.

Potential bioaccessibility and bioavailability of polyphenols and functional properties of tiger nut beverage and its by-product during in vitro digestion.

"Horchata de chufa" is a beverage produced from tiger nut tubers, which yields a high amount of by-product. This study explored the functional properties of the Spanish tiger nut beverage (TNB) and its by-product (TNBP) together with the bioaccessibility and bioavailability of polyphenols in vitro. TNB and TNBP were characterized for polyphenols via LC/MS/MS and underwent in vitro digestion (INFOGEST). The total antioxidant capacity (TAC) of all bioaccessible fractions and digestion residues was assessed. Intestinal bioaccessible fractions were tested for the ability to inhibit the activity of digestive enzymes (α-amylase, α-glucosidase, and lipase) and the content of polyphenols, whose bioavailability was assessed in a Caco-2 cell model. Thirteen polyphenols were quantified and found to be more abundant in TNB (603 ± 1.4 µg g-1 DW) than in TNBP (187 ± 1.0 µg g-1 DW). Polyphenol bioaccessibility was higher for TNBP than that for TNB (57% vs. 27%), and despite a similar TAC of the intestinal bioaccessible fractions (10.2 ± 0.1 µmoL vs. 9.2 ± 0.03 µmoL eq. Trolox per g DW for TNB and TNBP, respectively), the different patterns of polyphenols released upon digestion suggested the higher ability of TNBP fraction to inhibit α-glucosidase and lipase. TNBP digestion residue showed higher TAC than TNB. Moreover, TNB polyphenols exhibited over 80% bioavailability, whereas TNBP polyphenols' bioavailability ranged from 62% to 84%. Overall, the findings demonstrated that TNBP maintains a high nutritional value, thus suggesting its possible reuse in innovative, healthy, and sustainable foods.

Boosting resistant starch in rice: Bacterial inulin as a metabolic and glucose uptake modulator.

Bacillus stercoris PSSR12 (B. stercoris PE), an isolate from rice field soils, was identified via 16s rRNA sequencing. The synthesis of the inulin and inulin producing enzyme (IPE) in B. stercoris PE was verified using SDS-PAGE and FTIR. This study aimed to assess the impact of B. stercoris PE treatment on in vitro inhibition of α-amylase and α-glucosidase from traditional and commercial rice varieties of South India. Additionally, the study investigated enzymatic inhibition and mRNA expression of starch synthesis genes (RAmy1a, GBSSIa, SBEIIa, and SBEIIb). Glucose transporter gene expression (GLUT1 and GLUT4) patterns were analyzed in 3T3-L1 adipocytes to evaluate glucose uptake in B. stercoris PE treated rice varieties. The application of B. stercoris PE enhanced grain quality by imparting starch ultra-structural rigidity, inhibiting starch metabolizing enzymes, and inducing molecular changes in starch synthesis genes. This approach holds promise for managing type II diabetes mellitus and potentially reducing insulin dependence.

Inhibition mechanism of different structural polyphenols against α-amylase studied by solid-state NMR and molecular docking.

Polyphenol has the considerable effects for inhibition of digestive enzymes, however, inhibition mechanism of molecular size-dependent polyphenols on enzyme activity is still lacking. Herein, inhibition effect and binding interactions of three different structural polyphenols (catechol, quercetin and hesperidin) on α-amylase were studied. Inhibition assays proved that polyphenols significantly inhibited α-amylase and their effects were increased with their molecular sizes. Hesperidin showed the highest inhibition ability of α-amylase, which was determined as IC50 = 0.43 mg/mL. Fluorescence and FT-IR spectroscopy proved that inter-molecular interactions between polyphenols and α-amylase occurred through non-covalent bonds. Besides, the secondary structure of α-amylase was obviously changed after binding with polyphenols. Inter-molecular interactions were investigated using solid-state NMR and molecular docking. Findings proved that hydrogen bonds and π-π stacking interactions were the mainly inter-molecular interactions. We hope this contribution could provide a theoretical basis for developing some digestive enzyme inhibitors from natural polyphenols.

The Construction of an Environmentally Friendly Super-Secreting Strain of Bacillus subtilis through Systematic Modulation of Its Secretory Pathway Using the CRISPR-Cas9 System.

Achieving commercially significant yields of recombinant proteins in Bacillus subtilis requires the optimization of its protein production pathway, including transcription, translation, folding, and secretion. Therefore, in this study, our aim was to maximize the secretion of a reporter α-amylase by overcoming potential bottlenecks within the secretion process one by one, using a clustered regularly interspaced short palindromic repeat-Cas9 (CRISPR-Cas9) system. The strength of single and tandem promoters was evaluated by measuring the relative α-amylase activity of AmyQ integrated into the B. subtilis chromosome. Once a suitable promoter was selected, the expression levels of amyQ were upregulated through the iterative integration of up to six gene copies, thus boosting the α-amylase activity 20.9-fold in comparison with the strain harboring a single amyQ gene copy. Next, α-amylase secretion was further improved to a 26.4-fold increase through the overexpression of the extracellular chaperone PrsA and the signal peptide peptidase SppA. When the final expression strain was cultivated in a 3 L fermentor for 90 h, the AmyQ production was enhanced 57.9-fold. The proposed strategy allows for the development of robust marker-free plasmid-less super-secreting B. subtilis strains with industrial relevance.

Synthesis, anti-diabetic profiling and molecular docking studies of 2-(2-arylidenehydrazinyl)thiazol-4(5H)-ones.

Aim: To synthesize novel more potent anti-diabetic agents. Methodology: A simple cost effective Hantzsch's synthetic strategy was used to synthesize 2-(2-arylidenehydrazinyl)thiazol-4(5H)-ones. Results: Fifteen new 2-(2-arylidenehydrazinyl)thiazol-4(5H)-ones were established to check their anti-diabetic potential. From alpha(α)-amylase inhibition, anti-glycation and anti-oxidant activities it is revealed that most of the compounds possess good anti-diabetic potential. All tested compounds were found to be more potent anti-diabetic agents via anti-glycation mode. The results of α-amylase and anti-oxidant inhibition revealed that compounds are less active against α-amylase and anti-oxidant assays. Conclusion: This study concludes that introduction of various electron withdrawing groups at the aryl ring and substitution of different functionalities around thiazolone nucleus could help to find out better anti-diabetic drug.

Diabetes is a most spreading chronicle disease effecting millions of peoples across the globe every year and this number increases day by day. To cure the human population from this dilemma, we had synthesized, characterized and evaluated the anti-diabetic behavior of our synthesized compounds. α-Amylase, in vitro anti-glycation and anti-oxidant assays were performed to find out good lead for Diabetes Mellitus. All tested compounds were found to be excellent anti-glycating agents with IC₅₀ values far better than standard amino-guanidine (IC₅₀ = 3.582 ± 0.002 µM). Compound 4m was most efficient glycation inhibitor (IC₅₀ = 1.095 ± 0.002 µM). Cytotoxicity of all compounds was determined with in vitro hemolytic assay and found all compounds safe and bio-compatible to humans at all tested concentrations. The inhibition potential was also examined with theoretical docking studies to support our experimental results against human pancreatic alpha-amylase (HPA) and human serum albumin (HSA) proteins. All compounds showed excellent binding affinity with HSA active pockets however, only compound 4h and 4k binding affinity was good with HPA.

Two newly established and mutually related subfamilies GH13_48 and GH13_49 of the α-amylase family GH13.

Currently, the main α-amylase family GH13 has been divided into 47 subfamilies in CAZy, with new subfamilies regularly emerging. The present in silico study was performed to highlight the groups, represented by the maltogenic amylase from Thermotoga neapolitana and the α-amylase from Haloarcula japonica, which are worth of creating their own new GH13 subfamilies. This enlarges functional annotation and thus allows more precise prediction of the function of putative proteins. Interestingly, those two share certain sequence features, e.g. the highly conserved cysteine in the second conserved sequence region (CSR-II) directly preceding the catalytic nucleophile, or the well-preserved GQ character of the end of CSR-VII. On the other hand, the two groups bear also specific and highly conserved positions that distinguish them not only from each other but also from representatives of remaining GH13 subfamilies established so far. For the T. neapolitana maltogenic amylase group, it is the stretch of residues at the end of CSR-V highly conserved as L-[DN]. The H. japonica α-amylase group can be characterized by a highly conserved [WY]-[GA] sequence at the end of CSR-II. Other specific sequence features include an almost fully conserved aspartic acid located directly preceding the general acid/base in CSR-III or well-preserved glutamic acid in CSR-IV. The assumption that these two groups represent two mutually related, but simultaneously independent GH13 subfamilies has been supported by phylogenetic analysis as well as by comparison of tertiary structures. The main α-amylase family GH13 has thus been expanded by two novel subfamilies GH13_48 and GH13_49. KEY POINTS: • In silico analysis of two groups of family GH13 members with characterized representatives • Identification of certain common, but also some specific sequence features in seven CSRs • Creation of two novel subfamilies-GH13_48 and GH13_49 within the CAZy database.

Structural characterization and hypoglycemic effect of polysaccharides of Polygonatum sibiricum.

Polygonatum sibiricum polysaccharide (PSP) was extracted and purified from raw material obtained from P. sibiricum. The structural features of PSP were investigated by Congo red, circular dichroism spectrum, high-performance gel permeation chromatography, scanning electron microscope, atomic force microscope, ultraviolet spectroscopy, and Fourier transform infrared spectroscopy analysis. In vitro simulations were conducted to investigate the kinetics of PSP enzyme inhibition. Moreover, a type II diabetes mouse model (T2DM) with streptozotocin-induced insulin resistance was established, and the indexes of lipid quadruple, insulin resistance index, oral glucose tolerance (OGTT), organ index, and pancreatic morphology of model mice were measured. The results showed that PSP mainly consists of monosaccharides, such as mannose, glucose, galactose, xylose, and arabinose. It also has a ß-glycosidic bond of a pyranose ring and an irregular reticulated aggregated structure with a triple helix. In vitro enzyme inhibition assays revealed that PSP acts as a reversible competitive inhibitor of α-glucosidase and α-amylase. Furthermore, PSP was found to reduce insulin resistance index, increase OGTT and serum insulin levels, decrease free fatty acid content to improve lipid metabolism, and lower glycated serum protein content to enhance glucose metabolism in T2DM mice, thereby leading to a reduction in blood glucose concentration. Additionally, PSP exhibited reparative effects on the damaged liver tissue cells and pancreatic tissue in T2DM mice. The experiment results provide a preliminary basis for the therapeutic mechanism of PSP about type II diabetes and a theoretical reference for application in food and pharmaceutical development.

Impact of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality based active shooter training drill.

Ingestion of L-theanine and L-tyrosine has been shown to reduce salivary stress biomarkers and improve aspects of cognitive performance in response to stress. However, there have been no studies to concurrently examine the impact of both L-theanine and L-tyrosine ingestion during a mental stress challenge (MSC) involving a brief cognitive challenge and a virtual reality based active shooter training drill. Thus, the purpose of this study was to determine the impact of ingestion of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality active shooter drill and cognitive challenge. The cognitive challenge involved a Stroop challenge and mental arithmetic. Eighty subjects (age = 21 ± 2.6 yrs; male = 46; female = 34) were randomly assigned L-tyrosine (n = 28; 2000 mg), L-theanine (n = 25; 200 mg), or placebo (n = 27) prior to MSC exposure. Saliva samples, state-anxiety inventory (SAI) scales, and heart rate (HR) were collected before and after exposure to the MSC. Saliva was analyzed for stress markers α-amylase (sAA) and secretory immunoglobulin A (SIgA). The MSC resulted in significant increases in sAA, SIgA, HR, and SAI. Ingestion of L-theanine and L-tyrosine did not impact markers of stress. However, the L-tyrosine treatment demonstrated significantly lower missed responses compared to the placebo treatment group during the Stroop challenge. These data demonstrate that ingestion of L-theanine or L-tyrosine does not impact markers of stress in response to a MSC but may impact cognitive performance. This study was pre-registered as a clinical trial ("Impact of supplements on stress markers": NCT05592561).

Biomimetic green synthesis of ZnO nanoflowers using α-amylase: from antimicrobial to toxicological evaluation.

Biologically mediated synthesis of nanomaterials has emerged as an ecologically benign and biocompatible approach. Our study explores enzymatic synthesis, utilizing α-amylase to synthesize ZnO nanoflowers (ZnO-NFs). X-ray diffraction and energy-dispersive X-ray spectroscopy revealed crystal structure and elemental composition. Dynamic light scattering analysis indicates that ZnO-NFs possess a size of 101 nm. Transmission electron microscopy showed a star-shaped morphology of ZnO-NFs with petal-like structures. ZnO-NFs exhibit potent photocatalytic properties, degrading 90% eosin, 87% methylene blue, and 81% reactive red dyes under UV light, with kinetics fitting the Langmuir-Hinshelwood pseudo-first-order rate law. The impact of pH and interfering substances on dye degradation was explored. ZnO-NFs display efficient bacteriocidal activity against different Gram-positive and negative strains, antibiofilm potential (especially with P. aeruginosa), and hemocompatibility up to 600 ppm, suggesting versatile potential in healthcare and environmental remediation applications.

Spectrum-effect relationship between HPLC fingerprint and hypoglycemic of litchi leaves (Litchi chinensis Sonn) in vitro.

Litchi chinensis Sonn (Litchi) has been listed in the Chinese Pharmacopeia, and is an economically and medicinally valuable species within the family Sapindaceae. However, the material basis of its pharmacological action and the pharmacodynamic substances associated with its hypoglycemic effect are still unclear. The predominant objective of this study was to establish the fingerprint profile of litchi leaves and to evaluate the relationship between the components of the high-performance liquid chromatography (HPLC) fingerprint of litchi leaves, assess its hypoglycemic effect by measuring α-glucosidase and α-amylase inhibition, and find the spectrum-effect relationship of litchi leaves by bivariate correlation analysis, Grey relational analysis and partial least squares regression analysis. In this study, the fingerprint of litchi leaves was established by HPLC, and a total of 15 common peaks were identified that clearly calibrated eight components, with P1 being gallic acid, P2 being protocatechuic acid, P3 being catechin, P6 being epicatechin, P12 being rutin, P13 being astragalin, P14 being quercetin and P15 being kaempferol. The similarities between the fingerprints of 11 batches of litchi leaves were 0.766-0.979. Simultaneously, the results of the spectrum-effect relationship showed that the chemical constituents represented by peaks P8, P3, P12, P14, P2, P13, and P11 were relevant to the hypoglycemic effect.