Synthesis of a New Glycoconjugate with Di-á´ -Psicose Anhydride Structure.

Demand for healthy diets has led researchers to explore new saccharide as sucrose alternatives. ᴅ-Psicose, the C-3 epimer of ᴅ-fructose, has a similar sweetness intensity to sucrose but contributes fewer calories. This study proposes a disaccharide with a stable structure derived from ᴅ-psicose. The compound with a spiro-tricyclic core was generated at 32% conversion via caramelization of ᴅ-psicose under acidic anhydrous conditions. The compound was identified by high-resolution mass spectrometry and multi-dimensional nuclear magnetic resonance (NMR). The molecular formula was established as C12H20O10 from the molecular weight of m/z 324.1055. Twelve signals were observed by the 13C NMR spectrum. This compound, denoted di-ᴅ-psicose anhydride (DPA), exhibited a lower water solubility (40 g/L) and higher thermal stability (peak temperature = 194.7 °C) than that of ᴅ-psicose (peak temperature = 126.5 °C). The quantitatively evaluated metal ion scavenging ability of DPA was the best in magnesium (average 98.6 ± 1.1%). This synthesis methodology can provide disaccharides with high stability-reducing heavy metals.

Aurones and Flavonols from Coreopsis lanceolata L. Flowers and Their Anti-Oxidant, Pro-Inflammatory Inhibition Effects, and Recovery Effects on Alloxan-Induced Pancreatic Islets in Zebrafish.

(1) Background: Many flavonoids have been reported to exhibit pharmacological activity; a preparatory study confirmed that Coreopsis lanceolata flowers (CLFs) contained high flavonoid structure content; (2) Methods: CLFs were extracted in aqueous methanol (MeOH:H2O = 4:1) and fractionated into acetic ester (EtOAc), normal butanol (n-BuOH), and H2O fractions. Repeated column chromatographies for two fractions led to the isolation of two aurones and two flavonols; (3) Results: Four flavonoids were identified based on a variety of spectroscopic data analyses to be leptosidin (1), leptosin (2), isoquercetin (3), and astragalin (4), respectively. This is the first report for isolation of 2-4 from CLFs. High-performance liquid chromatography (HPLC) analysis determined the content levels of compounds 1-4 in the MeOH extract to be 2.8 ± 0.3 mg/g (1), 17.9 ± 0.9 mg/g (2), 3.0 ± 0.2 mg/g (3), and 10.9 ± 0.9 mg/g (4), respectively. All isolated compounds showed radical scavenging activities and recovery activities in Caco-2, RAW264.7, PC-12, and HepG2 cells against reactive oxygen species. MeOH extract, EtOAc fraction, and 1-3 suppressed NO formation in LPS-stimulated RAW 264.7 cells and decreased iNOS and COX-2 expression. Furthermore, all compounds recovered the pancreatic islets damaged by alloxan treatment in zebrafish; (4) Conclusions: The outcome proposes 1-4 to serve as components of CLFs in standardizing anti-oxidant, pro-inflammatory inhibition, and potential anti-diabetic agents.

Optimization and validation for quantification for allulose of jelly candies using response surface methodology.

A simple, rapid and reliable extraction method for allulose content in jelly were optimized using response surface methodology. The extraction method was selected based on preliminary experiments, with a three-factor, three-level central complex design including 20 experimental runs to optimize the extraction parameters. The optimum extraction factors predicted were temperature of 66 °C, solvent of 74% (v/v) ethanol, and extraction time of 24 min under shaking water bath extraction. The measured parameters were in accordance with the predicted values. The developed analytical method was validated with regard to linearity, accuracy and precision presenting recovery level from 90.79 to 95.18% and detection limits varying from 0.53 to 1.62 mg/mL. Finally, the method will be potentially applicable to a commercial jelly food using optimum extraction.

Enrichment of Polyglucosylated Isoflavones from Soybean Isoflavone Aglycones Using Optimized Amylosucrase Transglycosylation.

Isoflavones in soybeans are well-known phytoestrogens. Soy isoflavones present in conjugated forms are converted to aglycone forms during processing and storage. Isoflavone aglycones (IFAs) of soybeans in human diets have poor solubility in water, resulting in low bioavailability and bioactivity. Enzyme-mediated glycosylation is an efficient and environmentally friendly way to modify the physicochemical properties of soy IFAs. In this study, we determined the optimal reaction conditions for Deinococcus geothermalis amylosucrase-mediated α-1,4 glycosylation of IFA-rich soybean extract to improve the bioaccessibility of IFAs. The conversion yields of soy IFAs were in decreasing order as follows: genistein > daidzein > glycitein. An enzyme quantity of 5 U and donor:acceptor ratios of 1000:1 (glycitein) and 400:1 (daidzein and genistein) resulted in high conversion yield (average 95.7%). These optimal reaction conditions for transglycosylation can be used to obtain transglycosylated IFA-rich functional ingredients from soybeans.

Stability and Fermentability of Green Tea Flavonols in In-Vitro-Simulated Gastrointestinal Digestion and Human Fecal Fermentation.

Flavonols, the second most abundant flavonoids in green tea, exist mainly in the form of glycosides. Flavonols are known to have a variety of beneficial health effects; however, limited information is available on their fate in the digestive system. We investigated the digestive stability of flavonol aglycones and glycosides from green tea under simulated digestion and anaerobic human fecal fermentation. Green tea fractions rich in flavonol glycosides and aglycones, termed flavonol-glycoside-rich fraction (FLG) and flavonol-aglycone-rich fraction (FLA) hereafter, were obtained after treatment with cellulase and tannase, respectively. Kaempferol and its glycosides were found to be more stable in simulated gastric and intestinal fluids than the derivatives of quercetin and myricetin. Anaerobic human fecal fermentation with FLG and FLA increased the populations of Lactobacilli spp. and Bifidobacteria spp. and generated various organic acids, such as acetate, butyrate, propionate, and lactate, among which butyrate was produced in the highest amount. Our findings indicate that some stable polyphenols have higher bioaccessibilities in the gastrointestinal tract and that their health-modulating effects result from their interactions with microbes in the gut.

Development and validation of QuEChERS-based LC-MS/MS method for simultaneous quantification of eleven N-nitrosamines in processed fish meat, processed meat, and salted fish products.

N-Nitrosamines (NAs) pose a threat to food safety due to their carcinogenic and mutagenic properties. In this study, we developed and validated a QuEChERS-based LC-MS/MS method for the simultaneous analysis of 11 NAs in 74 processed fish meat, processed meat, and salted fish products. Sample preparation was optimized by screening two versions of QuEChERS buffer, four extraction methods, and eight purification methods. The optimal analytical approach was validated for three product categories in terms of linearity, matrix effects, accuracy, and precision. Satisfactory precision and accuracy were demonstrated, with relative recoveries of 70-120% for the 11 NAs. The limits of detection for fish meat, processed meat, and salted fish products were 0.12-7.50, 0.12-4.14, and 0.10-7.81 ng·g-1, respectively. Among the 11 NAs, nine were detected in all 74 samples. This methodology could be applied to monitor NA levels to ensure the safety and quality of food products.

Modulating intestinal health: Impact of chitooligosaccharide molecular weight on suppressing RAGE expression and inflammatory response in methylglyoxal-induced advanced glycation end-products.

The accumulation of methylglyoxal (MGO) produced in high-temperature processed foods and excessive production in the body contributes to intestinal barrier dysfunction. In this study, we investigated the effects of chitooligosaccharides (COSs) of different molecular weights (<1 kDa, 1-3 kDa, 3-5 kDa, 5-10 kDa, and >10 kDa) on MGO-induced intestinal barrier dysfunction. We investigated the effect of COSs on inhibiting intracellular MGO accumulation/MGO-derived AGEs production and regulating the receptor for AGE (RAGE)-mediated downstream protein expression, including proteins related to apoptosis and inflammation, intestinal barrier integrity, and paracellular permeability. Pretreatment with COSs ameliorated MGO-induced increased RAGE protein expression, activation of apoptotic cascade/inflammatory response, loss of intestinal epithelial barrier integrity, and increased paracellular permeability, ameliorating intestinal dysfunction through MGO scavenging. 1-3 kDa COSs most effectively ameliorated MGO-induced intestinal dysfunction. Our results suggest the potential of COSs in improving intestinal health by ameliorating intestinal barrier dysfunction by acting as an MGO scavenger and highlighting the need for the optimization of the molecular weight of COSs to optimize its protective effects.

Trapping mechanism by di-d-psicose anhydride with methylglyoxal for prevention of diabetic nephropathy.

Di-d-psicose anhydride (DPA), derived from functional rare saccharide as d-psicose, is investigated for its strong chelating ability. Methylglyoxal (MGO), an important precursor of advanced glycation end-products (AGEs), promotes obesity, and causes complications such as diabetic nephropathy. On mesangial cells, DPA can substantially reduce the negative effects of MGO. DPA effectively trapping MGO in mesangial cells. The bonding properties of the DPA-MGO adduct were discussed by mass spectrometry and nuclear magnetic resonance (NMR). The NMR spectra of the DPA-MGO adduct provide evidence for chelation bonding. The inhibition of AGE formation and the mass spectrometry results of the DPA-MGO adduct indicate that DPA can scavenge MGO at a molar ratio of 1:1. DPA suppressed 330 % of the up-regulated receptor for an AGEs protein expression to a normal level and restored the suppressed glyoxalase 1 level to 86 % of the normal group. This research provides important evidence and theoretical basis for the development of AGE inhibitors derived from rare saccharide.

Aralia continentalis Root Enhances Non-Rapid Eye Movement Sleep by Activating GABAA Receptors.

Aralia continentalis exhibits various biological activities; however, their sleep-promoting effects have not been previously reported. In this study, we evaluated the hypnotic effects and sleep-wake profiles of A. continentalis root (KS-126) using a pentobarbital-induced sleep-acceleration test and polysomnographic recordings. Additionally, we investigated the molecular mechanism of KS-126 through patch-clamp electrophysiology. Our polysomnographic recordings revealed that KS-126 not only accelerated the onset of non-rapid eye movement sleep (NREMS) but also extends its duration. Considering the temporal dynamics of the sleep-wake stages, during the initial and subsequent periods KS-126 extended NREMS duration and decreased wakefulness, thereby enhancing sleep-promoting effects. Furthermore, the assessment of sleep quality via analysis of electroencephalogram power density indicated that KS-126 did not significantly alter sleep intensity. Finally, we found that KS-126 enhanced GABAA receptor-mediated synaptic responses in primary hippocampal neurons, leading to an increase in the percentage of the GABA current. This effect was not affected by the selective benzodiazepine receptor antagonist flumazenil, but was entirely inhibited by the GABAA receptor antagonist bicuculline. In conclusion, KS-126 extends the duration of NREMS without altering its intensity by prolonging GABAergic synaptic transmission, which modulates GABAA receptor function.

Synthesis of Alpha-Linked Glucosides from Soybean Isoflavone Aglycones Using Amylosucrase from Deinococcus geothermalis.

Soybean isoflavone aglycones (SIAs) have many biological activities but are poorly water-soluble in the human body. Glycosylation provides structural diversity to SIAs and can alter their physicochemical properties, including water solubility. An alpha-linked glucosylation of SIA was achieved using amylosucrase from Deinococcus geothermalis. A total of 13 alpha-linked glucosyl SIAs were obtained, and their colors in solution were confirmed. The structures of the isolated compounds were identified by mass spectrometry and multidimensional nuclear magnetic resonance spectroscopy. The amylosucrase transglycosylation formed new isoflavone glycosides with alpha glycosidic bonds at C-7 and/or C-4' of SIAs, followed by the production of isoflavone glycosides with alpha (1 → 6) glycosidic bonds. The products with a glucosyl moiety attached to the C-4' of SIAs were found to be more water-soluble than their counterparts attached to the C-7 and/or beta-linkages. This study suggests a strategy for the synthesis of bioactive compounds with enhanced water solubility through alpha-linked glucosylation.

Rosa gallica and its active compound, cyanidin-3,5-O-diglucoside, improve skin hydration via the GLK signaling pathway.

Rosa gallica has been previously reported to display anti-inflammatory, anti-oxidative, and anti-skin wrinkle activities. However, the effect of Rosa gallica on skin hydration and its active components are largely unknown. Herein, we aimed to investigate the skin hydration effect of rose petal extract (RPE) in humans and elucidate the underlying molecular mechanism. A double-blinded clinical study was performed to investigate the effect of RPE on skin hydration. Stratum corneum moisture analysis demonstrated that RPE treatment significantly improved hydration levels in human skin. Furthermore, HAS2 and hyaluronic acid levels were notably increased by RPE in keratinocytes and 3D human skin equivalent model. By comparing the modulatory effect on HAS2 expression, cyanidin-3,5-O-diglucoside (CDG) was identified as the most potent compound in RPE likely responsible for skin hydration. The kinase activity of GLK, an upstream regulator of MAPK signaling, was increased by CDG in a dose-dependent manner. Importantly, silencing GLK reversed CDG-mediated HAS2 upregulation, further supporting the involvement of GLK in the CDG-mediated effects. Binding of CDG to GLK was confirmed by pull-down assay and computer modeling. These findings suggest that RPE and its active component CDG increases skin hydration by upregulating HAS2 expression through modulating the GLK-MAP2K-MAPK signaling pathway.

Anti-Inflammatory Effects and Macrophage Activation Induced by Bioavailable Cinnamon Polyphenols in Mice.

SCOPE: Cinnamon is a commonly used spice and herb that is rich in polyphenols. Due to the limited bioavailability of oral polyphenols, it remains unclear to which extent they can reach cells and exert a biological effect. This study aims to investigate the impact of bioavailable cinnamon polyphenols on lipopolysaccharide (LPS)-stimulated macrophages. METHODS AND RESULTS: A polyphenol fraction is prepared from cinnamon (Cinnamomi ramulus) (CRPF) by boiling cinnamon in water and adsorbing the extract onto a hydrophobic resin. Mice are orally administered CRPF for 7 days and then subjected to three independent experiments: endotoxemia, serum collection, and macrophage isolation. Upon intraperitoneal lipopolysaccharide challenge, CRPF decreases serum levels of inflammatory cytokines, involving suppression of liver and spleen macrophages. When normal macrophages are cultured in serum obtained from CRPF-treated mice, they exhibit an anti-inflammatory phenotype. However, macrophages from CRPF-treated mice show an increased production of inflammatory cytokines when cultured in fetal bovine serum and stimulated with LPS. CONCLUSION: The study provides evidence for the presence of bioavailable cinnamon polyphenols with anti-inflammatory properties and macrophage activation. These findings suggest that cinnamon polyphenols have the potential to modulate macrophage function, which could have implications for reducing inflammation and improving immune function.

Identification and quantification of multi-class veterinary drugs and their metabolites in beef using LC-MS/MS.

The practice of abusing antibiotics to improve livestock growth poses a threat to food safety. To prevent and regulate this, accurate monitoring of residual veterinary drugs (VDs) is required. A method based on QuEChERS with dispersive solid-phase extraction for the determination of multi-class VDs was investigated using selected product ions under optimized multiple reaction monitoring conditions. During the clean-up procedure, chitosan, octadecyl silica, primary-secondary amine, and enhanced matrix removal (EMR)-lipid were evaluated for simultaneous analysis of multi-class VDs in beef matrix. The EMR sorbent was most advantageous (113/115) compared to others, and showed a satisfactory recovery range (70.7-117.9%) except cefquinome (67.3%) and cefalonium (69.8%). This methodology can be used to detect oxolinic acid and ractopamine (27.4% and 88.0% of maximum residue limit, respectively) in real beef samples. We thus study propose a simple and fast analytical method for multi-class VDs for the future health of humans and animals.

Simultaneous determination of trichothecene mycotoxins in cereals by LC-MS/MS.

This study was designed to determine the residual trichothecene mycotoxins in cereal samples. The optimal solvent for extraction was 84% (v/v) aqueous acetonitrile with 1% (v/v) formic acid. The best performing clean-up method was dispersive-solid phase with a mixture octadecyl silica and primary-secondary amine. The recoveries for the studied mycotoxins ranged from 83.3 to 92.8%. The methodology was successfully applied for monitoring 100 cereal samples obtained from a Korean market. The bean sample were found to be co-contamination with deoxynivalenol and HT-2 toxin. Deoxynivalenol possessed the highest detection freauency (4/100) and amount (727.38 µg/kg) among the trichothecene mycotoxins. The hazard index was less than 1.0 for all the observed mycotoxins in all cereal samples except one white rice sample (1.2681). This results indicated that periodic risk assessments of trichothecene mycotoxin through cereal intake are necessary for the health and safety.

Evaluation of various clean-up sorbents in kale followed by LC-MS/MS analysis of pesticides.

Chlorophyll-rich samples, such as kale, interfere with the analysis of residual pesticides and adversely affect the integrity of tandem mass spectrometers. Dispersed solid-phase (d-SPE) extraction using graphitized carbon black effectively removes pigments from kale extracts; however, it also reduces the recoveries of 30 pesticides. To overcome this, alternative sorbents, including ENVI-Carb, ChloroFiltr, and Z-Sep+, were evaluated in this study. A sorbent combination based on 50 mg of Z-Sep+ was most advantageous (21/30), good precision (< 15%), excellent pigment removal capacity, and low matrix effect. The limit of quantification (0.0001-0.0040 mg/kg) was lower than the Korean maximum residue limits levels. The proposed method was validated according to international guidelines and applied to real kale samples. The results demonstrated that d-SPE using Z-Sep+ provides an effective strategy for ensuring mass spectrometry system integrity and improving the analytical accuracy in chlorophyll-rich samples. Supplementary information: The online version contains supplementary material available at 10.1007/s10068-022-01101-3.

Antioxidant capacity of 12 major soybean isoflavones and their bioavailability under simulated digestion and in human intestinal Caco-2 cells.

Soy isoflavones (SIs) show various health benefits, such as antioxidant and estrogenic effects. It is important to understand the bioaccessibility and bioavailability of SIs due to the close relation to their bioactivities. In this study, the antioxidant capacity, bioaccessibility, and bioavailability of 12 SIs were evaluated using radical-scavenging methods, simulations of human digestion, and Caco-2 cells in Transwell, respectively. All SIs were stable (91.1-99.2%) under gastric digestion conditions compared with the control (100%), whereas acetyl and malonyl conjugates were unstable (38.5% and 65.5%, respectively) under small intestinal digestion conditions. SI aglycones showed higher permeability (7-15 times) and cellular accumulation (8.8 times) than their glucosides. A small amount of SI conjugates was intact in the cell and in the basolateral side of each Transwell. These results suggest that SI conjugates, especially malonyl and acetyl forms, have incidental bioactivity after being metabolized to aglycones inside the cell.

Stability of Enzyme-Modified Flavonoid C- and O-Glycosides from Common Buckwheat Sprout Extracts during In Vitro Digestion and Colonic Fermentation.

Common buckwheat sprout (CBS) contains more flavone C-glycosides (FCGs) and flavonol O-glycosides (FOGs) than does common buckwheat seed. Both flavonoids in CBS are well known for providing benefits to human health. However, they are relatively less bioaccessible and more directly degradable to aglycone during digestion than are multiglycosylated flavonoids. To overcome such limitations, the water solubility and digestion stability of FCGs and FOGs were enhanced by transglycosylation using cyclodextrin glycosyltransferase. Gastric conditions had little effect on the stability of FCGs and FOGs and their enzyme-modified compounds. In contrast, under intestinal conditions, transglycosylated FCGs lost a glucose moiety and reverted to their parent compounds before transglycosylation. Under colonic fermentation using human fecal samples, the different profiles and concentrations of short-chain fatty acids were suggested to be mainly due to the presence of transglycosylated FCGs and FOGs. These findings indicate that the process of transglycosylation changes the bioaccessibility of flavonoids in CBS.

Influence of production systems on phenolic characteristics and antioxidant capacity of highbush blueberry cultivars.

Blueberry is a crop grown worldwide due to the excellent quality and high polyphenol content of its fruit and tolerance to cold conditions. We investigated the influence of three production systems, namely an open field, heated greenhouse, and non-heated (plastic) greenhouse, on the phenolic characteristics (total phenolic, flavonoid, and anthocyanin content) and antioxidant capacities of "Spartan" (northern highbush), "Sharpblue" (southern highbush), and "O'Neal" (southern highbush) blueberry cultivars. The non-heated production system showed the highest phenolic characteristics and antioxidant capacity in "Spartan" and "O'Neal," while the open field production system showed the highest phenolic characteristics and antioxidant capacity in "Sharpblue." Derivatives of delphinidin and malvidin were two of the most abundant anthocyanins. The heated greenhouse production system resulted in larger amounts of delphinidin derivatives compared with the other production systems, while the blueberry grown in the non-heated greenhouse produced larger amount of malvidin derivatives. The anthocyanin profiles varied according to production system and blueberry cultivars. The principal component analysis loading plot of blueberries for individual anthocyanins explained over 95% of the total variance. In summary, the results of this study suggest that a strategic approach to blueberry production could elevate the phenolic content and antioxidant capacity of cultivated blueberry. PRACTICAL APPLICATION: The highbush blueberry, a rich source of bioactive polyphenols, is a popular fruit. The microclimate of the production system of highbush blueberries affects the concentrations of antioxidative phenolic compounds such as anthocyanins. Therefore, discovering and applying the appropriate method of production for each blueberry cultivar could facilitate production of high-quality blueberries rich in phenolic antioxidants.

Oral Administration of Rosa gallica Prevents UVB-Induced Skin Aging through Targeting the c-Raf Signaling Axis.

Rosa gallica is a widely used Rosa species for medicinal and culinary purposes. Rosa gallica has been reported to display antioxidant, anti-inflammatory, and antibacterial activities. However, the effect of Rosa gallica against skin aging in vivo is unknown and its active components have not been fully understood. Oral administration of Rosa gallica prevented UVB-mediated skin wrinkle formation and loss of collagen/keratin fibers in the dorsal skin of mice. Examination of biomarkers at the molecular level showed that Rosa gallica downregulates UVB-induced COX-2 and MMP-1 expression in the skin. Through a direct comparison of major compounds identified using the UHPLC-MS/MS system, we discovered gallic acid as the primary component contributing to the anti-skin aging effect exhibited by Rosa gallica. Examination of the molecular mechanism revealed that gallic acid can potently and selectively target the c-Raf/MEK/ERK/c-Fos signaling axis. In addition, both gallic acid and MEK inhibitor blocked UVB-induced MMP-1 expression and restored collagen levels in a reconstructed 3D human skin model. Collectively, Rosa gallica could be used as a functional ingredient in the development of nutraceuticals against skin aging.

Neuroprotective effects of ethanolic extract from dry Rhodiola rosea L. rhizomes.

Rhodiola rosea L. rhizome has been used as a traditional medicine to treat fatigue, depression, and cognitive dysfunction. We aimed to authenticate R. rosea L. rhizome using the DNA barcoding technique and to quantify its main compounds, total phenolics, total flavonoids, and antioxidant capacity, and then to investigate their neuroprotective effects. The sequences of internal transcribed spacer and trnH-psbA of R. rosea L. rhizomes showed a 99% identity with those of NCBI GenBank database according to BLAST searches. Analysis using reversed-phase HPLC revealed five main compounds in R. rosea L. rhizome. Rhodiola rosea L. rhizome and two bioactive compounds, salidroside and tyrosol, showed free radical scavenging activity. Rhodiola rosea L. rhizome and its identified compounds protected neuronal PC-12 cells against oxidative stress and showed moderate acetylcholinesterase inhibition. Taken together, these results suggest that R. rosea L. rhizomes with bioactives can be used as a functional ingredient with potential for neuroprotection. SUPPLEMENTARY INFORMATION: The online version of this article (doi:10.1007/s10068-020-00868-7) contains supplementary material, which is available to authorized users.