GC - MS法对不同产地大米的快速鉴定

采用GC - MS对4种不同产地大米中的脂溶性成分进行分析,并利用NIST标准质谱库和质谱图搜索程序进行检索.结果表明,大米中主要的脂溶性成分为棕榈酸、亚油酸、油酸、角鲨烯和谷甾醇.不同产地大米中脂溶性化合物的指纹谱图存在显著差异,通过主成分分析和聚类分析,建立了一种对不同产地大米进行快速鉴定的方法.     

Pentacyclic Triterpenoids from Sabia discolor Dunn and Their α-Glycosidase Inhibitory Activities

Four new pentacyclic triterpenoids named Sabiadiscolor A–D (1 and 7–9) together with eleven known ones were isolated by repeated column chromatography. Their structures were identified and characterized by NMR and MS spectral data as 6 oleanane-type pentacyclic triterpenoids (1–6), 7 ursane-type ones (7–13), and 2 lupanane-type ones (14–15). Except for compound 15, all other compounds were isolated from Sabia discolor Dunn for the first time. Their α-glycosidase inhibitory activities were evaluated, which showed that compounds 1, 3, 8, 9, 13, and 15 implied remarkable activities with IC₅₀ values ranging from 0.09 to 0.27 μM, and the preliminary structure–activity relationship was discussed.     

Synthesis,characterization and α‐amylase and α‐glucosidase inhibition studies of novel vanadyl chalcone complexes

A series of chalcone ligands and their corresponding vanadyl complexes of composition [VO (L^I–IV)₂(H₂O)₂]SO₄ (where L^I = 1,3‐Diphenylprop‐2‐en‐1‐one, L^II = 3‐(2‐Hydroxy‐phenyl)‐1‐phenyl‐propenone, L^III = 3‐(3‐Nitro‐phenyl)‐1‐phenyl‐propenone, L^IV = 3‐(4‐Methoxy‐phenyl)‐1‐phenyl‐propenone) have been synthesized and characterized using various spectroscopic (Fourier‐transform infrared, electrospray ionization mass, nuclear magnetic resonance, electron paramagnetic resonance, thermogravimetric analysis, vibrating sample magnetometer) and physico‐analytic techniques. Antidiabetic activities of synthesized complexes along with chalcones were evaluated by performing in vitro and in silico α‐amylase and α‐glucosidase inhibition studies. The obtained results displayed moderate to significant inhibition activity against both the enzymes by vanadyl chalcone complexes. The most potent complexes were further investigated for the enzyme kinetic studies and displayed the mixed inhibition for both the enzymes. Further, antioxidant activity of vanadyl chalcone complexes was evaluated for their efficiency to release oxidative stress using 2,2‐diphenyl‐1‐picryl‐hydrazyl‐hydrate assay, and two complexes (Complexes 2 and 4 ) have demonstrated remarkable antioxidant activity. All the complexes were found to possess promising antidiabetic and antioxidant potential.     

Characterization of the Influence of Thermal Sterilization on the Volatiles in Flat Peach Juice

This study characterized the effect of thermal sterilization on the volatiles in flat peach juice. In three independent trials, juice samples prepared with flat peaches from Shihezi, Xinjiang, China were divided into groups sterilized at 65, 75, and 85°C for 30?min. The chemical compositions were identified by gas chromatography–mass spectrometry combined with headspace solid-phase microextraction and analyzed by hierarchical clustering and principal component analysis. Fourteen volatiles (seven esters, four alcohols, two aldehydes, and one ketone) were identified as characteristic in fresh peach juice. Esters of thermally treated samples were significantly decreased by threefold (P?相似文献   

Phytochemical Composition,Antioxidant Activity,and Enzyme Inhibitory Activities (α-Glucosidase,Xanthine Oxidase,and Acetylcholinesterase) of Musella lasiocarpa

In this study, we aimed to investigate the chemical components and biological activities of Musella lasiocarpa, a special flower that is edible and has functional properties. The crude methanol extract and its four fractions (petroleum ether, ethyl acetate, n-butanol, and aqueous fractions) were tested for their total antioxidant capacity, followed by their α-glucosidase, acetylcholinesterase, and xanthine oxidase inhibitory activities. Among the samples, the highest total phenolic and total flavonoid contents were found in the ethyl acetate (EtOAc) fraction (224.99 mg GAE/g DE) and crude methanol extract (187.81 mg QE/g DE), respectively. The EtOAc fraction of Musella lasiocarpa exhibited the strongest DPPH· scavenging ability, ABTS·⁺ scavenging ability, and α-glucosidase inhibitory activity with the IC₅₀ values of 22.17, 12.10, and 125.66 μg/mL, respectively. The EtOAc fraction also showed the strongest ferric reducing antioxidant power (1513.89 mg FeSO₄/g DE) and oxygen radical absorbance capacity ability (524.11 mg Trolox/g DE), which were higher than those of the control BHT. In contrast, the aqueous fraction demonstrated the highest acetylcholinesterase inhibitory activity (IC₅₀ = 10.11 μg/mL), and the best xanthine oxidase inhibitory ability (IC₅₀ = 5.23 μg/mL) was observed from the crude methanol extract as compared with allopurinol (24.85 μg/mL). The HPLC-MS/MS and GC-MS analyses further revealed an impressive arsenal of compounds, including phenolic acids, fatty acids, esters, terpenoids, and flavonoids, in the most biologically active EtOAc fraction. Taken together, this is the first report indicating the potential of Musella lasiocarpa as an excellent natural source of antioxidants with possible therapeutic, nutraceutical, and functional food applications.     

Phytochemical Profile,Antioxidant Capacity, α-Amylase and α-Glucosidase Inhibitory Potential of Wild Moroccan Inula viscosa (L.) Aiton Leaves

Medicinal plants offer imperative sources of innovative chemical substances with important potential therapeutic effects. Among them, the members of the genus Inula have been widely used in traditional medicine for the treatment of several diseases. The present study investigated the antioxidant (DPPH, ABTS and FRAP assays) and the in vitro anti-hyperglycemic potential of aerial parts of Inula viscosa (L.) Aiton (I. viscosa) extracts through the inhibition of digestive enzymes (α-amylase and α-glucosidase), responsible of the digestion of poly and oligosaccharides. The polyphenolic profile of the Inula viscosa (L.) Aiton EtOAc extract was also investigated using HPLC-DAD/ESI-MS analysis, whereas the volatile composition was elucidated by GC-MS. The chemical analysis resulted in the detection of twenty-one polyphenolic compounds, whereas the volatile profile highlighted the occurrence of forty-eight different compounds. Inula viscosa (L.) Aiton presented values as high as 87.2 ± 0.50 mg GAE/g and 78.6 ± 0.55mg CE/g, for gallic acid and catechin, respectively. The EtOAc extract exhibited the higher antioxidant activity compared to methanol and chloroform extracts in different tests with (IC₅₀ = 0.6 ± 0.03 µg/mL; IC₅₀ = 8.6 ± 0.08 µg/mL; 634.8 mg ± 1.45 AAE/g extract) in DPPH, ABTS and FRAP tests. Moreover, Inula viscosa (L.) Aiton leaves did show an important inhibitory effect against α-amylase and α-glucosidase. On the basis of the results achieved, such a species represents a promising traditional medicine, thanks to its remarkable content of functional bioactive compounds, thus opening new prospects for research and innovative phytopharmaceuticals developments.     

Multitarget Action of Xanthones from Garcinia mangostana against α-Amylase, α-Glucosidase and Pancreatic Lipase

Digestive enzymes such α-amylase (AA), α-glucosidase (AG) and pancreatic lipase (PL), play an important role in the metabolism of carbohydrates and lipids, being attractive therapeutic targets for the treatment of type 2 diabetes and obesity. Garcinia mangostana is an interesting species because there have been identified xanthones with the potential to inhibit these enzymes. In this study, the multitarget inhibitory potential of xanthones from G. mangostana against AA, AG and PL was assessed. The methodology included the isolation and identification of bioactive xanthones, the synthesis of some derivatives and a molecular docking study. The chemical study allowed the isolation of five xanthones (1–5). Six derivatives (6–11) were synthesized from the major compound, highlighting the proposal of a new solvent-free methodology with microwave irradiation for obtaining aromatic compounds with tetrahydropyran cycle. Compounds with multitarget activity correspond to 2, 4, 5, 6 and 9, highlighting 6 with IC₅₀ values of 33.3 µM on AA, 69.2 µM on AG and 164.4 µM on PL. Enzymatic kinetics and molecular docking studies showed that the bioactive xanthones are mainly competitive inhibitors on AA, mixed inhibitors on AG and non-competitive inhibitors on PL. The molecular coupling study established that the presence of methoxy, hydroxyl and carbonyl groups are important in the activity and interaction of polyfunctional xanthones, highlighting their importance depending on the mode of inhibition.     

The Application of Ultrasound in Honey: Antioxidant Activity,Inhibitory Effect on α-amylase and α-glucosidase,and In Vitro Digestibility Assessment

In the present study, the effects of ultrasound (10, 20, and 30 min) on the bioactive compounds, antioxidant capacity, enzymatic inhibition, and in vitro digestion of six honey extracts from the Oaxaca state, Mexico, were analyzed. Significant differences were found in each honey extract with respect to the ultrasonic treatment applied (p < 0.05). In the honey extract P-A1 treated with 20 min of ultrasound, the phenols reached a maximum concentration of 29.91 ± 1.56 mg EQ/100 g, and the flavonoids of 1.92 ± 0.01 mg EQ/100 g; in addition, an inhibition of α-amylase of 37.14 ± 0.09% was noted. There were also differences in the phases of intestinal and gastric digestion, presenting a decrease in phenols (3.92 ± 0.042 mg EQ/100 g), flavonoids (0.61 ± 0.17 mg EAG/100 mg), antioxidant capacity (8.89 ± 0.56 mg EAG/100 mg), and amylase inhibition (9.59 ± 1.38%). The results obtained from this study indicate that, in some honeys, the processing method could increase the concentration of bioactive compounds, the antioxidant capacity, and the enzymatic inhibition; however, when subjected to in vitro digestion, the properties of honey are modified. The results obtained could aid in the development of these compounds for use in traditional medicine as a natural source of bioactive compounds.     

Thioether and Ether Furofuran Lignans: Semisynthesis,Reaction Mechanism,and Inhibitory Effect against α-Glucosidase and Free Radicals

The transformation of sesame lignans is interesting because the derived products possess enhanced bioactivity and a wide range of potential applications. In this study, the semisynthesis of 28 furofuran lignans using samin (5) as the starting material is described. Our methodology involved the protonation of samin (5) to generate an oxocarbenium ion followed by the attack from two different nucleophiles, namely, thiols (RSH) and alcohols (ROH). The highly diastereoselective thioether and ether furofuran lignans were obtained, and their configurations were confirmed by 2D NMR and X-ray crystallography. The mechanism underlying the reaction was studied by monitoring ¹H NMR and computational calculations, that is, the diastereomeric α- and β-products were equally formed through the S_N1-like mechanism, while the β-product was gradually transformed via an S_N2-like mechanism to the α-congener in the late step. Upon evaluation of the inhibitory effect of the synthesized lignans against α-glucosidases and free radicals, the lignans 7f and 7o of the phenolic hydroxyl group were the most potent inhibitors. Additionally, the mechanisms underlying the α-glucosidase inhibition of 7f and 7o were verified to be of a mixed manner and noncompetitive inhibition, respectively. The results indicated that both 7f and 7o possessed promising antidiabetic activity, while simultaneously inhibiting α-glucosidases and free radicals.     

α-Amyrin and β-Amyrin Isolated from Celastrus hindsii Leaves and Their Antioxidant,Anti-Xanthine Oxidase,and Anti-Tyrosinase Potentials

Celastrus hindsii is a popular medicinal plant in Vietnam and Southeast Asian countries as well as in South America. In this study, an amount of 12.05 g of an α-amyrin and β-amyrin mixture was isolated from C. hindsii (10.75 g/kg dry weight) by column chromatography applying different solvent systems to obtain maximum efficiency. α-Amyrin and β-amyrin were then confirmed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR). The antioxidant activities of the α-amyrin and β-amyrin mixture were determined via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,20-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays with IC₅₀ of 125.55 and 155.28 µg/mL, respectively. The mixture exhibited a high potential for preventing gout by inhibiting a relevant key enzyme, xanthine oxidase (XO) (IC₅₀ = 258.22 µg/mL). Additionally, an important enzyme in skin hyperpigmentation, tyrosinase, was suppressed by the α-amyrin and β-amyrin mixture (IC₅₀ = 178.85 µg/mL). This study showed that C. hindsii is an abundant source for the isolation of α-amyrin and β-amyrin. Furthermore, this was the first study indicating that α-amyrin and β-amyrin mixture are promising in future therapies for gout and skin hyperpigmentation.     

Elucidation of Analytical–Compositional Fingerprinting of Three Different Species of Chili Pepper by Using Headspace Solid-Phase Microextraction Coupled with Gas Chromatography–Mass Spectrometry Analysis,and Sensory Profile Evaluation

The aim of the present study was to determine the volatile compounds of three different species of chili peppers, using solid-phase microextraction (SPME) methods in combination with gas chromatography–mass spectrometry (GC-MS). The detection of marker aroma compounds could be used as a parameter to differentiate between species of chili peppers for their detection and traceability in chili pepper food. The sensorial contribution was also investigated to identify the predominant notes in each species and to evaluate how they can influence the overall aroma. Three different pepper species belonging to the Capsicum genus were analyzed: Chinense, Annuum, and Baccatum. A total of 269 volatile compounds were identified in these species of chili peppers. The Capsicum annum species were characterized by a high number of acids and ketones, while the Capsicum chinense and Capsicum baccatum were characterized by esters and aldehydes, respectively. The volatile profile of extra virgin olive oils (EVOOs) flavored with chili peppers was also investigated, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the volatile profiles were demonstrated to be a powerful analytical strategy for building a model that highlights the potential of a volatile characterization approach for use in evaluating food traceability and authenticity.     

The Effect of α-, β- and γ-Cyclodextrin on Wheat Dough and Bread Properties

Cyclodextrins (CDs) are cyclic oligosaccharides that have found widespread application in numerous fields. CDs have revealed a number of various health benefits, making them potentially useful food supplements and nutraceuticals. In this study, the impact of α-, β-, and γ-CD at different concentrations (up to 8% of the flour weight) on the wheat dough and bread properties were investigated. The impact on dough properties was assessed by alveograph analysis, and it was found that especially β-CD affected the viscoelastic properties. This behavior correlates well with a direct interaction of the CDs with the proteins of the gluten network. The impact on bread volume and bread staling was also assessed. The bread volume was in general not significantly affected by the addition of up to 4% CD, except for 4% α-CD, which slightly increased the bread volume. Larger concentrations of CDs lead to decreasing bread volumes. Bread staling was investigated by texture analysis and low field nuclear magnetic resonance spectroscopy (LF-NMR) measurements, and no effect of the addition of CDs on the staling was observed. Up to 4% CD can, therefore, be added to wheat bread with only minor effects on the dough and bread properties.     

Chemical Composition,Enantiomeric Distribution,Antimicrobial and Antioxidant Activities of Origanum majorana L. Essential Oil from Nepal

This study was conducted to examine the chemical constituents of Origanum majorana L. essential oils (EOs) that originate in Nepal, as well as their biological activities, antioxidant properties, and enantiomeric compositions. The EOs were extracted by the hydro-distillation method using a Clevenger-type apparatus and their chemical compositions were determined through gas chromatography and mass spectrometry (GC-MS). Chiral GC-MS was used to evaluate the enantiomeric compositions of EOs. The minimum inhibitory concentrations (MICs) of the essential oils were determined by the micro-broth dilution method, and the antioxidant activity was evaluated by the 2,2-diphenyl-1-picrylhydrazyl scavenging assay and ferric-reducing antioxidant power (FRAP). GC-MS analysis showed the presence of 50 and 41 compounds in the EO samples, (S₁) and (S₂), respectively, representing the Kathmandu and Bhaktapur districts. The oxygenated monoterpenoids, along with terpinen-4-ol, were predominant constituents in both EO samples. However, the EOs from two locations showed some variations in their major components. The chiral terpenoids for two EO samples of marjoram have also been reported in this study in an elaborative way for the first time in accordance with the literature review. A hierarchical cluster analysis based on the compositions of EOs with 50 compositions reported in the literature revealed at least 5 different chemotypes of marjoram oil. The antioxidant activity for the sample (S₂) was found to be relatively moderate, with an IC₅₀ value of 225.61 ± 0.05 μg/mL and an EC₅₀ value of 372.72 ± 0.84 µg/mL, as compared to the standard used. Furthermore, with an MIC value of 78.1 µg/mL, the EO from sample (S₂) demonstrated effective antifungal activity against Aspergillus niger and Candida albicans. Moreover, both samples displayed considerable antimicrobial activity. The results suggest that EOs of Origanum majorana possess some noteworthy antimicrobial properties as well as antioxidant activity, and hence can be used as a natural preservative ingredient in the food and pharmaceutical industries.     

α-Glucosidase, α-Amylase and Antioxidant Evaluations of Isolated Bioactives from Wild Strawberry

Diabetes mellitus is a metabolic disorder and is a global challenge to the current medicinal chemists and pharmacologists. This research has been designed to isolate and evaluate antidiabetic bioactives from Fragaria indica. The crude extracts, semi-purified and pure bioactives have been used in all in vitro assays. The in vitro α-glucosidase, α-amylase and DPPH free radical activities have been performed on all plant samples. The initial activities showed that ethyl acetate (Fi.EtAc) was the potent fraction in all the assays. This fraction was initially semi-purified to obtain Fi.EtAc 1–3. Among the semi-purified fractions, Fi.EtAc 2 was dominant, exhibiting potent IC₅₀ values in all the in vitro assays. Based on the potency and availability of materials, Fi.EtAc 2 was subjected to further purification to obtain compounds 1 (2,4-dichloro-6-hydroxy-3,5-dimethoxytoluene) and 2 (2-methyl-6-(4-methylphenyl)-2-hepten-4-one). The two isolated compounds were characterized by mass and NMR analyses. The compounds 1 and 2 showed excellent inhibitions against α-glucosidase (21.45 for 1 and 15.03 for 2 μg/mL), α-amylase (17.65 and 16.56 μg/mL) and DPPH free radicals (7.62 and 14.30 μg/mL). Our study provides baseline research for the antidiabetic bioactives exploration from Fragaria indica. The bioactive compounds can be evaluated in animals-based antidiabetic activity in future.     

Design,Synthesis, and Antifungal Activities of New β‐Methoxyacrylate Analogues

Strobilurins have become one of the most important classes of agricultural fungicides. To search for new strobilurin derivatives with high activity against resistant pathogens, a series of new β‐methoxyacrylate analogues containing substituted pyrimidine in the side chain with strobilurin pharmacophore were synthesized and their biological activities were tested. The compounds were confirmed and characterized by ¹H‐NMR, elemental analysis and mass spectroscopy. The bioassays indicated that most of the compounds 1 exhibited potent antifungal activities against Colletotrichum orbiculare, Botrytis cinerea Pers and Phytophthora capsici Leonian at a concentration of 50 μg mL^?1. Notably, compound 1b (R = 2,5‐dimethylphenyl) showed better antifungal activity against all the tested fungi than the commercial strobilurin fungicide azoxystrobin.     

Phytochemical Composition,Antioxidant Activity, α-Glucosidase and Acetylcholinesterase Inhibitory Activity of Quinoa Extract and Its Fractions

This study is aimed to evaluate the chemical compositions and biological activities of quinoa, a novel and excellent food crop. Quinoa extract and its fractions were prepared by ethanol extraction and liquid-liquid extraction, including ethanol crude extract, and petroleum ether, chloroform, ethyl acetate (EAF), and n-butanol and water fractions. The total phenolic and flavonoid contents, antioxidant activities, α-glucosidase and acetylcholinesterase inhibitory abilities of the extract and fractions were further determined. Based on these foundations, the chemical composition of the EAF fraction exhibiting the strongest functional activity was analyzed by ultra-performance liquid chromatography-mass spectrometry. The results showed the EAF fraction had the highest phenolic and flavonoid contents, and the highest antioxidant activities, as well as the strongest α-glucosidase and acetylcholinesterase inhibitory abilities, which is even better than the positive control. The phytochemical composition of the EAF fraction indicated that 661 and 243 metabolites were identified in positive and negative ion modes, which were classified into superclass, class and subclass levels, respectively. Phenolic acids and flavonoids were the major bioactive compounds in the EAF fraction. This study found that quinoa, especially its ethyl acetate fraction, had the potential for the development of natural antioxidants, acetylcholinesterase inhibitors, and hypoglycemic agents.     

Biological Activity of Extracts of Red and Yellow Fruits of Cornus mas L.—An In Vitro Evaluation of Antioxidant Activity,Inhibitory Activity against α-Glucosidase,Acetylcholinesterase, and Binding Capacity to Human Serum Albumin

Although extracts are broadly used in order to support the treatment of numerous diseases, only in a limited number of cases is the process of applying and establishing their mechanisms of action scientifically analyzed. Fruits of Cornelian cherry are an abundant source of iridoids, anthocyanins, flavonols and phenolic acids. The aim of the present study was to evaluate the in vitro bioactivity of red and yellow Cornelian cherry fruits’ extracts. The biological potential of extracts, in a broad sense, involved antioxidant activity in relation to phosphatidylcholine liposomes, inhibitory ability against α-glucosidase and acetylcholinesterase enzymes, as well as interactions with human serum albumin. Studies showed that both extracts were more effective in protecting liposome membranes against free radicals produced by AAPH in an aqueous environment due to the fact that they can be better eliminated by the hydrophilic components of the extracts than those produced by UVB radiation. Extracts exhibited inhibitory activity against acetylcholinesterase and α-glucosidase, wherein loganic acid extract showed noncompetitive inhibition of the enzyme. Moreover, extracts binded to albumin mainly through hydrogen bonds and van der Waals forces. Taken together, red and yellow cherry fruits’ extracts exhibit diverse biological properties and can be exploited as a source of natural therapeutic agents.     

Umbu Fruit Peel as Source of Antioxidant,Antimicrobial and α-Amylase Inhibitor Compounds

Herein, the extraction of bioactive compounds from umbu fruit peel was optimized using thermal-assisted solid–liquid extraction. In parallel, antioxidant, antimicrobial, and inhibitory effects against α-amylase of optimized extract were also evaluated. The combination of operational conditions including the temperature (32–74 °C), ethanol concentration (13–97%), and solid/liquid ratio (1:10–1:60; w/v) was employed using a rotational central composite design for optimization. The extracts were evaluated for total phenolic compounds (TPC), total flavonoid compounds (TFC) and antioxidant capacity by ABTS^•+, DPPH^• and FRAP assays. The bioactive profile of the optimized extract was obtained by ultra-performance liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry in electrospray ionization in both negative and positive modes. The statistically evaluated results showed that the optimal operational conditions for the recovery of bioactive compounds from umbu fruit peel included 74 °C, 37% ethanol, and a solid–liquid ratio of 1:38. Under these conditions, the obtained values were 1985 mg GAE/100 g, 1364 mg RE/100 g, 122 µmol TE/g, 174 µmol/TE g and 468 µmol Fe²⁺/g for TPC, TFC, ABTS^•+, DPPH^•, and FRAP assays, respectively. In addition, the optimized extract was effective against Gram-positive and Gram-negative bacteria (MBC ranged from 0.060 to 0.24 mg GAE/mL), as well as it was effective to inhibit α-amylase (IC₅₀ value of 0.076 mg GAE/mL). The optimized extract showed to be mainly constituted by phenolic acids and flavonoids.     

Production and Digestibility Studies of β-Galactosyl Xylitol Derivatives Using Heterogeneous Catalysts of LacA β-Galactosidase from Lactobacillus Plantarum WCFS1

The synthesis of β-galactosyl xylitol derivatives using immobilized LacA β-galactosidase from Lactobacillus plantarum WCFS1 is presented. These compounds have the potential to replace traditional sugars by their properties as sweetener and taking the advantages of a low digestibility. The enzyme was immobilized on different supports, obtaining immobilized preparations with different activity and stability. The immobilization on agarose-IDA-Zn-CHO in the presence of galactose allowed for the conserving of 78% of the offered activity. This preparation was 3.8 times more stable than soluble. Since the enzyme has polyhistidine tags, this support allowed the immobilization, purification and stabilization in one step. The immobilized preparation was used in synthesis obtaining two main products and a total of around 68 g/L of β-galactosyl xylitol derivatives and improving the synthesis/hydrolysis ratio by around 30% compared to that of the soluble enzyme. The catalyst was recycled 10 times, preserving an activity higher than 50%. The in vitro intestinal digestibility of the main β-galactosyl xylitol derivatives was lower than that of lactose, being around 6 and 15% for the galacto-xylitol derivatives compared to 55% of lactose after 120 min of digestion. The optimal amount immobilized constitutes a very useful tool to synthetize β-galactosyl xylitol derivatives since it can be used as a catalyst with high yield and being recycled for at least 10 more cycles.     

Screening of Carbonic Anhydrase,Acetylcholinesterase, Butyrylcholinesterase,and α-Glycosidase Enzyme Inhibition Effects and Antioxidant Activity of Coumestrol

Coumestrol (3,9-dihydroxy-6-benzofuran [3,2-c] chromenone) as a phytoestrogen and polyphenolic compound is a member of the Coumestans family and is quite common in plants. In this study, antiglaucoma, antidiabetic, anticholinergic, and antioxidant effects of Coumestrol were evaluated and compared with standards. To determine the antioxidant activity of coumestrol, several methods—namely N,N-dimethyl-p-phenylenediamine dihydrochloride radical (DMPD^•+)-scavenging activity, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS^•+)-scavenging activity, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^•)-scavenging activity, potassium ferric cyanide reduction ability, and cupric ion (Cu²⁺)-reducing activity—were performed. Butylated hydroxyanisole (BHA), Trolox, α-Tocopherol, and butylated hydroxytoluene (BHT) were used as the reference antioxidants for comparison. Coumestrol scavenged the DPPH radical with an IC₅₀ value of 25.95 μg/mL (r²: 0.9005) while BHA, BHT, Trolox, and α-Tocopherol demonstrated IC₅₀ values of 10.10, 25.95, 7.059, and 11.31 μg/mL, respectively. When these results evaluated, Coumestrol had similar DPPH^•-scavenging effect to BHT and lower better than Trolox, BHA and α-tocopherol. In addition, the inhibition effects of Coumestrol were tested against the metabolic enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase II (CA II), and α-glycosidase, which are associated with some global diseases such as Alzheimer’s disease (AD), glaucoma, and diabetes. Coumestrol exhibited K_i values of 10.25 ± 1.94, 5.99 ± 1.79, 25.41 ± 1.10, and 30.56 ± 3.36 nM towards these enzymes, respectively.