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Objective: The pyrolysis transfer rate of aglycones from 7 kinds of glucosides added to cigarette paper in mainstream and sidestream smoke was studied. Methods: 5-methylfurfuryl alcohol glucoside, menthol glucoside, anisyl alcohol glucoside, leaf alcohol glucoside, phenylethanol glucoside, ethyl vanillin glucoside and vanillin glucoside were applied to the surface of cigarette paper and inject into cigarette according to the 0.01% of the weight of cut tobacco respectively. The transfer rates of aglycones in mainstream smoke and side stream smoke were determined under two kinds of flavoring methods. On this basis, the transfer rules of seven aglycones in mainstream smoke and sidestream smoke were studied when the concentration of 0.001%, 0.010% and 0.050% was applied to cigarette paper. Results: In mainstream smoke, the transfer rates of seven aglycones in cut tobacco were higher than those added to cigarette paper, but the opposite was true in sidestream smoke; 5-methylfurfuryl alcohol had the highest transfer rate of aglycones in mainstream smoke and sidestream smoke, and menthol had the lowest transfer rate, followed by leaf alcohol, anisyl alcohol, phenylethanol, ethyl vanillin and vanillin. Under the condition of 0.001% addition, the transfer rates of seven aglycones in mainstream and side stream smoke were 0.27%~1.24% and 0.42%~1.71% respectively, 0.010% addition were 0.38%~1.87% and 0.54%~2.52% respectively, 0.050% addition were 0.31%~1.56% and 0.47%~2.19% respectively. Conclusion: The transfer rates of seven aglycones in side stream smoke were higher than those in mainstream smoke at three additive gradients, the transfer rates of aglycones in mainstream and side stream smoke showed a trend of first increasing and then decreasing with the increase of addition.

The winemaking process generates a large amount of waste which can be profitably converted into a resource. In this work, extracts from stalks, lees, and pomace of Magliocco canino cv (Vitis Vinifera L.) were obtained using ultrasounds. A comprehensive metabolomics profile was carried out by high-resolving power mass spectrometry hyphenated with liquid chromatography. Fifty-nine compounds were annotated and successively verified, bearing different chemical classes. Free amino acids were quantified in the different extracts. Distinction of glycosylated polyphenols vs their aglycones was accomplished by targeted and semi-targeted LC-MS methods; then selected polyphenolic biomarkers were quantified in the studied extracts. The antioxidant activity was evaluated in vitro in a human dermal fibroblasts assay, and the best antioxidant extract was used for the synthesis of an antioxidant DX conjugate by a grafting reaction, to obtain an innovative food ingredient endowed with improved antioxidant activity. The in - vitro endothelium-dependent vasorelaxation, recorded for both stalk and lees extracts could be exploited for the development of new antihypertensive nutraceuticals. [Display omitted] • Targeted and semi-targeted HRMS discriminate glycosylated polyphenols vs free ones. • Stalks and Lees ethanolic extracts exert valuable vasorelaxant activity. • Stalk extract showed remarkable antioxidant power in human dermal fibroblasts assay. • A biopolymer Dextran-based/stalk extract is a novel antioxidant food ingredient. [ABSTRACT FROM AUTHOR]

• A novel method for the isolation of oleuropein from olive leaves has been set up. • Lamellar solids provides a mean for the preservation of oleuropein. • A novel method to obtain elenolic acid from pure oleuropein has been set up. • Characterization of elenolic acid has been achieved by GC–MS analysis. Several processes have been developed in the past to selectively extract oleuropein and its aglycones from olive derived materials. In the present manuscript, we outline a novel approach for processing olive leaves aqueous extracts. This allowed first to select microwave irradiation as the methodology able to provide a large enrichment in oleuropein. Subsequently, the use of lamellar solids led to the selective and high yield concentration of the same. Adsorption on solids also largely contributed to the long term chemical stability of oleuropein. Finally, an eco-friendly, readily available, and reusable catalyst like H 2 SO 4 supported on silica was applied for the hydrolysis of oleuropein into hydroxytyrosol and elenolic acid. This latter was in turn selectively isolated by an acid-base work-up providing its monoaldehydic dihydropyran form (7.8 % extractive yield), that was unequivocally characterized by GC–MS. The isolation of elenolic acid in pure form is described herein for the first time. [ABSTRACT FROM AUTHOR]

• Preparation of the anthocyanins and the aglycone from Purple-heart Radish by integrating MAE, MRP and UAAH. • Pelargonins were identified as the only anthocyanin species in Purple-heart Radish by UHPLC-Q-Orbitrap/MS. • Pelargonins exhibited the higher physicochemical stability than pelargonidin by glycosylation. • Pelargonins and pelargonidin had a dose–effect relationship of the inhibitory effect on pancreatic lipase. • Exploration of the PL inhibitory mechanism of two anthocyanins by kinetic analysis and molecular docking. In this study, an efficient approach to preparation of different anthocyanins from Purple-heart Radish was developed by combining microwave-assisted extraction (MAE), macroporous resin purification (MRP) and ultrasound-assisted acid hydrolysis (UAAH) for evaluation of physicochemical stability and pancreatic lipase (PL) inhibitory activity. By optimization of MAE, MRP and UAAH processes, the anthocyanins reached the yield of 6.081 ± 0.106 mg/g, the purity of 78.54 ± 0.62 % (w/w) and the content of 76.29 ± 1.31 % (w/w), respectively. With high-resolution UHPLC-Q-Orbitrap/MS, 15 anthocyanins were identified as pelargonins with diverse glucosides and confirmed by pelargonidin standard. By glycosylation, pelargonins exhibited higher stability in different pH, temperature, light, metal ions environments than that of pelargonidin. However, PL inhibitory assay, kinetic analysis and molecular docking demonstrated that pelargonidin had higher PL inhibitory activity than pelargonins even though with similar binding sites and a dose–effect relationship. The above results revealed that the effect of glycosylation and deglycosylation on PL inhibitory activity and physicochemical stability. [ABSTRACT FROM AUTHOR]

This study examined the effects of phase II metabolism and efflux transportation on the bioavailability of naringin, hesperidin, and their aglycones (naringenin and hesperetin) in rats. Results indicated naringin and hesperidin have a lower oral bioavailability than their aglycones. Of all the phase II enzymes tested, UDP-glucuronosyltransferase (UGT) 1A1, UGT1A2, UGT1A3, UGT1A7 and SULT sulfotransferase (SULT) 1B1 were of minor importance regarding the phase II metabolism of naringenin and hesperetin in the small intestine. Naringin, hesperidin, and their aglycones were all extensively metabolised in the liver. Naringin and hesperidin were more extensively transported by efflux transporters compared to their aglycones. Significant correlations between phase II enzymes and efflux transporters were detected. In conclusion, more extensive metabolism of naringin and hesperidin than their aglycones in the small intestine, and the interplay of phase II enzymes and efflux transporters in the small intestine explain the lower relative oral bioavailability of naringin and hesperidin than their aglycones. [ABSTRACT FROM AUTHOR]

In this study, pulsed electric fields (PEFs) were evaluated as extraction-aiding technology during soymilk manufacturing to improve its isoflavone profile. Low-intensity PEFs were applied at different processing conditions in two stages of the soymilk extraction process, hydrated soybeans (HSB) and soybean slurry (SBS), with the soymilk extracted from the conventional process as control (CSM). Overall, resultant soymilk samples from PEF-HSB and PEF-SBS presented lower concentrations of glucosides isoflavones and greater aglycone content than those in CSM. In contrast to genistin (Gin) and daidzin (Din), which decreased around 18.5–52.6% and 10.9–54.6%, respectively, an increase in genistein (Ge, 12.3–64.4%) and daidzein (Da, 9–55.8%) was observed. The total isoflavone content (TIC) of most soymilk samples prepared from PEF-HSB was lower than that of the CSM. Conversely, when PEF-SBS was used, the TIC of resultant soymilk was not significantly affected or slightly decreased. However, PEF treated HSB at 10 kVcm−1/100 pulses and SBS at 6 kVcm−1/10 pulses led to a significant augment in TIC, of up to 109 ± 2.39 and 110 ± 1.26 μg/g, respectively, in the extracted soymilk samples. These results indicated that low-intensity PEF is a potential technology that could be implemented during soymilk manufacturing processing to modify the isoflavone profile and content of soymilk, mainly increasing its aglycone concentration. [ABSTRACT FROM AUTHOR]

While flavanones exist in a variety of chemical forms, their favorable health effects are most prominent in their free form—aglycones. Their concentrations in grapefruit (Citrus × paradisi L.) extracts vary according to the extraction and hydrolysis methods used. The primary aim of this work was to maximize the yields of naringin and naringenin from various parts of fresh grapefruit fruits (flavedo, albedo, and segmental) using different extraction and hydrolysis methods. In addition, we aimed to evaluate the excipient—magnesium aluminometasilicate—and determine its influence on the qualitative composition of grapefruit extracts. Extracts were obtained by heat reflux extraction (HRE), ultrasound-assisted extraction with an ultrasonic homogenizer (UAE*), and ultrasound-assisted extraction with a bath (UAE). Ultrasound-assisted extraction using a bath (UAE) was modulated using acidic, thermal, and alkaline hydrolysis. The highest yield of naringin 8A (17.45 ± 0.872 mg/g) was obtained from an albedo sample under optimal conditions using ultrasound-assisted extraction; a high yield of naringenin 23-SHR (35.80 ± 1.79 µg/g) was produced using the heat reflux method from the segmental part. Meanwhile, ultrasonic combined with thermal hydrolysis significantly increased flavanone extraction from the albedo and segmental parts: naringin from sample 9-A (from 17.45 ± 0.872 mg/g to 25.05 ± 1.25 mg/g) and naringenin from sample 15-S (from 0 to 4.21 ± 0.55 µg/g). Additionally, magnesium aluminometasilicate demonstrated significant increases of naringenin from all treated grapefruit parts. To our knowledge, this is the first report of magnesium aluminometasilicate used as an adsorbent in flavanone extractions. [ABSTRACT FROM AUTHOR]

In the midst of ever increasing molecular docking programs and their inherent capacity to predict efficient binding interaction potential, AutoDock Tools have always been at the top spot in being the most widely used and cited tool amongst all. However, the ADT though being the favorites fails to impress in the condition where the ligand molecules possess multiple torsions. The current study hence focuses on validating this inability of ADT in dealing with ligands with multiple torsions and simultaneous use of Molegro Virtual Docker, another prominent molecular docking tool in driving better results with reference ligand types under consideration. The study involves the molecular interaction studies of standard anti-angiogenic drugs, selected aglycones and tocotrienols using ADT and MVD against EGFR, VEGFR-1 and VEGFR-2 angiogenic targets. The study further proposes the use of tocotrienols, natural analogs of vitamin E as a potential anti-angiogenic leads on the basis of the interaction scores and docking figure analysis obtained with MVD in comparison with standard anti-angiogenic drugs under consideration. [ABSTRACT FROM AUTHOR]

A pyranose ring contraction of 2,3-di- O -silylated O -galactopyranosides with retention of aglycone promoted by anhydrous trifluoroacetic acid (TFA) in CH2 Cl2 was demonstrated for the first time. In addition, TFA-promoted pyranose ring contraction of 2,3-bis- O -(triisopropylsilyl)- d -galactopyranose with formation of the corresponding anomeric triols in furanose form was successfully performed. A representative series of β- d -galactopyranosides with Me, Bn, allyl, or 3-(trifluoroacetamido)propyl aglycones has been investigated. TBDPS protective groups were found to be more stable than TIPS groups under conditions of TFA-promoted pyranose ring contraction. An easy access to 2,3-di- O -TBDPS-substituted allyl and benzyl galactofuranosides and 2,3-bis- O -(triisopropylsilyl)-β- d -galactofuranose may present an advantage in synthesis of selectively protected monosacharide building blocks, useful for the synthesis of biologically important oligosaccharides. [ABSTRACT FROM AUTHOR]

Flavonoids are well known for their extensive health benefits. However, few studies compared the differences between flavonoid O-glycoside and C-glycoside. In this work, flavonoid O-glycoside (isoquercitrin), C-glycoside (orientin), and their aglycones (quercetin and luteolin) were chosen to compare their differences on antioxidant activities and metabolism during in vitro digestion and in vivo. In vitro digestion, the initial antioxidant activity of the two aglycones was very high; however, they both decreased more sharply than their glycosides in the intestinal phase. The glycosidic bond of flavonoid O-glycoside was broken in the gastric and intestinal stage, while the C-glycoside remained unchanged. In vivo, flavonoid O-glycoside in plasma was more elevated than C-glycoside on the antioxidant activity; however, flavonoid C-glycoside in urine was higher than O-glycoside. These results indicate that differences of flavonoid glycosides and their aglycones on antioxidant activity are closely related to their structural characteristics and metabolism in different samples. Aglycones possessed higher activity but unstable structures. On the contrary, the sugar substituents reduced the activity of flavonoids while improving their stability and helping to maintain antioxidant activities after digestion. Especially the C-glycoside was more stable because the stability of the C–C bond is higher than that of the C–O bond, which contributes to the difference between flavonoid O-glycoside and C-glycoside on the absorption and metabolism in vivo. This study provided a new perspective for comparing flavonoid O-glycoside, flavonoid C-glycoside, and their aglycones on their structure–activity relationship and metabolism. [ABSTRACT FROM AUTHOR]

A series of bioinspired transformations that are applied to convert strictosidine aglycones into monoterpenoid indole alkaloids is reported. The highly reactive key intermediates, strictosidine aglycones, were prepared in situ by simple removal of a silyl protecting group from the silyl ether derivatives, and converted selectively via bioinspired transformations under substrate control into heteroyohimbine‐ and corynantheine‐type, and akagerine and naucleaoral related alkaloids. Thus, concise, divergent total syntheses of 13 monoterpenoid indole alkaloids, (−)‐cathenamine, (−)‐tetrahydroalstonine, (+)‐dihydrocorynantheine, (−)‐corynantheidine, (−)‐akagerine, (−)‐dihydrocycloakagerine, (−)‐naucleaoral B, (+)‐naucleidinal, (−)‐naucleofficines D and III, (−)‐nauclefiline, and (−)‐naucleamides A and E, were accomplished in fewer than 13 steps. [ABSTRACT FROM AUTHOR]

In this study, neutral loss scan and high‐resolution MS/MS were used in combination to detect and tentatively identify various flavonoid and limonoid glycosides in navel orange albedo, juice, peel and pulp. These compound classes are of research interest due to their flavour and bioactive properties, and although flavonoid glycosides have been previously studied in other food matrices, to the best of our knowledge, neutral loss scans have not been used for the elucidation of limonoid glycosides. Neutral loss masses of 120, 162 and 308 Da were selected for the detection of hexose, rutinose and neohesperidose‐substituted flavonoids, whereas 197 Da was explored for limonoid glycosides due to their tendency to form ammonium adducts. Fragmentation patterns obtained from targeted MS/MS were then used to differentiate rutinose and neohesperidose substituents as well as flavonoid subclasses of flavones, flavanones and flavonols. Additionally, high‐resolution MS/MS was also used for the identification of aglycones by accurate mass (to four decimal places), allowing for the differentiation of aglycones with similar unit masses but different chemical formulas. In total, 19 flavonoid glycosides and six limonoid glycosides were detected. This workflow allows for a rapid screening of flavonoid and limonoid glycosides in citrus, which can be further extended to other food products such as tea. [ABSTRACT FROM AUTHOR]

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Rhubarb is a widely used herbal medicine. To achieve different effects, rhubarb is usually steamed with rice wine (steamed rhubarb). This steaming treatment increases the blood‐activating and stasis‐removing effects of rhubarb. A specific and accurate ultra high performance liquid chromatography with tandem mass spectrometry method was established for simultaneous determination of anthraquinone glycosides, aglycones, and glucuronic acid metabolites in plasma and tissues after administration of raw rhubarb and steamed rhubarb in blood stasis rats. Chromatographic separation was performed on ACQUITY UPLC BEH Shield RP 18 column using the mobile phase consisting of water and acetonitrile both containing 0.1% formic acid. Satisfactory linearity, precision, accuracy, extraction recovery, and matrix effect have been achieved. From pharmacokinetic study, it showed that glucuronic acid metabolites were found abundantly in plasma as bioactive components. The lower area under concentration‐time curve, maximum concentration, and higher apparent volume of distribution (P < 0.01), body clearance (P < 0.01) values in steamed rhubarb showed that most components of steamed rhubarb have lower bioavailability in plasma compared with raw rhubarb. But it found these components were mainly distributed in spleen and liver with large blood flow and perfusion rates. The pharmacokinetics and tissue distribution studies of anthraquinone components will provide helpful information for clinical application of steamed rhubarb and raw rhubarb. [ABSTRACT FROM AUTHOR]

Fusarium oxysporum f. sp. albedinis (Foa) is one of the major soil-borne pathogens that induces vascular wilt on date palm (Phoenix dactylifera L.), known as Bayoud. Although extensive studies have been carried out on the biology of Foa, little is known about the compounds that stimulate or inhibit this fungus. In this study, the effect of flavonic aglycones isolated from date palm leaves on fungal growth, sporulation and fusaric acid (FA) production of Foa was investigated. The flavonic aglycones extract was obtained by acid hydrolysis of the leaves of two date palm cultivars: Takerboucht (TK, a bayoud-resistant cultivar) and Deglet Nour (DN, a susceptible cultivar). The results indicate that the leaflets of TK contain a low amount of flavonic aglycones, estimated at 0.02 mg.g-1 equivalent of quercetin, while the leaflets of DN contain a high amount with approximately 0.21 mg.g-1 equivalent of quercetin. TLC analysis shows the presence of three flavonols: quercetin, isorhamnetin, kaempferol, and three flavones: luteolin, tricine, chrysoeriol. It is well known that Flavonoids are essential in the resistance of plants against pathogenic fungi. Activities of flavonic aglycone from date palm leaves against Foa were evaluated using agar dilution methods. The experimental results demonstrate that TK flavonic aglycone to Foa culture medium stimulated mycelial growth and inhibited conidiogenesis and FA production. The rate of inhibition of these two last processes on the 4th day of incubation was 91.66% and 87.14%, respectively. In addition, DN flavonic aglycones only affect FA production, the reduction rate being 88.17%. Furthermore, activity of flavonic aglycones in date palm leaves depends on incubation time and cultivar type. In addition, it is very interesting to note that leaf extracts could be applied to control fusariosis vascular (Bayoud) in date palm. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: A green and efficient photolabile protecting group (PPG)‐mediated glycosidation approach for the synthesis of 2‐deoxy‐glycosides is reported. By employing ortho‐nitrobenzyl carbonate (oNBC) as PPG, N,N‐dimethylformamide (DMF)‐modulated SPhosAuNTf2‐promoted glycosidation with per‐oNBC‐protected 2‐deoxy‐glycosyl ynenoates affords the 2‐deoxy‐glycosides with moderate to excellent α‐selectivities presumably depending on the reactivities of the acceptor alcohols. Based on the PPG‐mediated glycosidation approach, oligosaccharides with three to six oNBC groups are effectively achieved. The multiple oNBC groups in the 2‐deoxy‐glycosides are completely cleaved by irradiation at 365 nm, resulting in the desired 2‐deoxy‐glycosides in an efficient manner without affecting the common alkyne, alkene, azide functional groups and the traditional protecting groups on the aglycones. [ABSTRACT FROM AUTHOR]

Two new glycosidic acids, evolvulic acids B and C (1 and 2), along with a known one, evolvulic acid A (3), were isolated from the glycosidic acid fraction afforded by alkaline hydrolysis of crude resin glycosides from Evolvulus alsinoides whole plants. Their structures were characterized by the spectroscopic data and chemical evidences. Compounds 1 and 2 are both defined as tetrasaccharides, composed of D-fucose, D-glucose, L-rhamnose or D-galactose units. Their aglycones are identified to be a distinctive 3S,11R,14R-trihydroxyhexadecanoic acid, which is only discovered from E. alsinoides up to now. The cytotoxic and anti-migration activities of compounds 1–3 were also tested. [ABSTRACT FROM AUTHOR]

• The structural impact on anthocyanins' UV–Vis molar absorptivity was studied; • A quantitative strategy based on the molar relative response factors was proposed; • An online database for 617 anthocyanins was developed to support the approach; • Our strategy provided improved quantitative results for anthocyanins in food. The effects of anthocyanin's substitution groups on the UV–Vis molar absorptivity were examined by analyzing a group of 31 anthocyanidin/anthocyanin reference standards with ultra-high performance liquid chromatography-diode array detector (UHPLC-DAD). The substitution groups on aglycones were found to associate with molar absorptivity variations, often neglected in anthocyanin quantitation, resulting in significant analytical errors. A simple yet comprehensive strategy based on the molar relative response factors (MRRFs) and a single master reference calibration (i.e., cyanidin-3-glucoside) was proposed to quantify anthocyanins in red cabbage, blueberry, and strawberry samples with improved analytical accuracy. The results indicate this approach provides an effective, inexpensive, and accurate analytical method for anthocyanins in food materials without using individual reference standards. MRRFs of 617 anthocyanins/anthocyanidins were calculated, and the information is freely available at https://BotanicalDC.online/anthocyanin/. This study could be critical to developing new reference methods for anthocyanin analysis and harmonizing results and data from various sources. [ABSTRACT FROM AUTHOR]

In this study, we conducted a comprehensive investigation into a GH3 family β-glucosidase (BGL) from the wild-type strain of Oenococcus oeni and its mutated counterpart from the acid-tolerant mutant strain. Our analysis revealed the mutant BGL's remarkable capacity to adapt to wine-related stress conditions, including heightened tolerance to low pH, elevated ethanol concentrations, and metal ions. Additionally, the mutant BGL exhibited superior hydrolytic activity towards various substrates. Through de novo modeling, we identified specific amino acid mutations responsible for its resilience to low pH and high ethanol environments. In simulated wine conditions, the mutant BGL outperformed both wild-type and commercial BGLs, efficiently releasing terpene and phenolic aglycones from glycosides in wine grapes. These findings not only expand our understanding of O. oeni BGLs but also highlight their potential in enhancing wine production. The mutant BGL's enhanced adaptation to wine stress conditions opens promising avenue for improving wine quality and flavor. [Display omitted] • Mutant BGL showed superior low-pH and high-ethanol tolerance than wild-type BGL. • Mutant BGL had better hydrolysis abilities to various substrates than wild-type BGL. • Mutant BGL showed higher activity in presence of some reagents than wild-type BGL. • Enhanced pH/ethanol tolerance may be related to BGL mutation-induced stability. • Mutated BGL exhibits superior ability to release terpene aglycones under wine stress. [ABSTRACT FROM AUTHOR]

Virgin olive oil (VOO) phenols are valued for their health and organoleptic properties. The phenolic content of VOO is influenced by several factors, with particular emphasis on cultivar. However, the cultivar influence is a combination of several variables, including genotype, fatty acid (FA) profile, and fruit moisture; the last two variables condition the polarity of the extraction phases. Here, we evaluated the phenolic variability by extracting the effect of the fruit moisture and the FA profile from the cultivar factor. In a set of 40 cultivars monitored for three crop seasons, the cultivar effect was represented by differences in the conversion from oleuropein and ligstroside aglycones to oleacein and oleocanthal. Complementary, the fruit moisture positively favored the enrichment of VOOs in oleocanthal (285 mg/kg vs 380 mg/kg in the low and high moisture groups, respectively) while oleic acid showed a positive effect on the enrichment of VOOs in aglycone isomers of oleuropein (181 mg/kg vs 233 mg/kg in the low and high C18:1 content groups, respectively) and ligstroside (178 mg/kg vs 217 mg/kg in the low and high C18:1 content groups, respectively). • Methylesterase activity is a relevant factor which explain the cultivar effect. • High fruit moisture was associated with a high oleacein and oleocanthal content. • VOOs with a moderate C18:1 content were enriched in oleacein and oleocanthal. • The polarity conditions the distribution of phenols between pomace and VOO. • Enzymatic activity was favoured by medium with high polarity. [ABSTRACT FROM AUTHOR]

Steam explosion has gained much attention in the food industry. This study aimed to investigate if steam explosion could change the composition of phenolic compounds and antioxidant feature of a Chinese indigenous herb "Hangbaiju" (HBJ). Results showed that the color attributes, microstructure, and composition of phenolic compounds of HBJ were altered after the pretreatment. With the increasing pressure and duration, the contents of 3‐ and 4‐O‐caffeoylquinic acid increased. Meanwhile, some flavone aglycones, such as apigenin, luteolin, and acacetin, showed content increases, whereas apigenin‐7‐O‐glucoside, luteolin‐7‐O‐glucoside, and diosmetin‐7‐O‐glucoside showed content increases and then decreases. Furthermore, 3,5‐O‐caffeoylquinic acid and 5‐O‐caffeoylquinic acid exhibited content reduction. Some caffeoylquinic acids exhibited the structural rearrangement and degradation during the steam explosion, which also hydrolyze flavone glycosides to flavone aglycones. Hence, steam explosion pretreatment is suitable for the extraction of 3‐O‐caffeoylquinic acid, 4‐O‐caffeoylquinic acid, and some flavone aglycones, as well as the modification of HBJ samples. Novelty impact statement: Steam explosion altered the appearance of "Hangbaiju" and disrupted its microstructure. Different pressure and duration of steam explosion showed different effect on phenolic compounds composition and antioxidant capacities of "Hangbaiju." Furthermore, steam explosion pretreatment increased flavone aglycones content in "Hangbaiju." [ABSTRACT FROM AUTHOR]

In grape berries (Vitis vinifera L.), sesquiterpenes are mainly accumulated as hydrocarbons in the epicuticular wax layer of grapes, whereas monoterpenes, which are predominantly present as alcohols, are glycosylated and are stored as glycosides in the vacuoles of grape berry cells. In this study, extensive analysis of grape berry hydrolysates by means of comprehensive two-dimensional gas chromatography–time-of-flight–mass spectrometry demonstrated that glycosylated sesquiterpene alcohols show very little structural diversity when compared to the sesquiterpene hydrocarbon fraction in the cuticle and are glycosylated to a rather low extent when compared to monoterpenols. Twenty-four enzymatically released terpenols were found in hydrolysates of the aromatic white wine variety Gewürztraminer (V. vinifera subsp. vinifera) after previous solid-phase extraction and headspace solid-phase microextraction. The detection of only three sesquiterpene alcohols, namely farnesol, nerolidol and drimenol, shows that most sesquiterpene hydrocarbons do not have a related hydroxylated structure in grapes. Nevertheless, the presence of the acyclic aglycone farnesol and nerolidol may be of importance for the wine aroma, since these structural isomers can be converted into numerous sesquiterpenes by nonenzymatic acid-catalyzed reactions during wine production. Grape-derived glycosidically bound sesquiterpene alcohols, therefore, represent, in addition to free sesquiterpene hydrocarbons, another pool of compounds that may influence the aroma profile of wines. [ABSTRACT FROM AUTHOR]

The a1,6-fucosyltransferase, FUT8, is the sole enzyme catalyzing the core-fucosylation of N-glycoproteins in mammalian systems. Previous studies using free N-glycans as acceptor substrates indicated that a terminal ß1,2-GlcNAc moiety on the Man-a1,3-Man arm of N-glycan substrates is required for efficient FUT8-catalyzed core-fucosylation. In contrast, we recently demonstrated that, in a proper protein context, FUT8 could also fucosylate Man5GlcNAc2 without a GlcNAc at the non-reducing end. We describe here a further study of the substrate specificity of FUT8 using a range of N-glycans containing different aglycones. We found that FUT8 could fucosylate most of high-mannose and complex-type N-glycans, including highly branched N-glycans from chicken ovalbumin, when the aglycone moiety is modified with a 9-fluorenylmethyloxycarbonyl (Fmoc) moiety or in a suitable peptide/protein context, even if they lack the terminal GlcNAc moiety on the Man-a1,3-Man arm. FUT8 could also fucosylate paucimannose structures when they are on glycoprotein substrates. Such core-fucosylated paucimannosylation is a prominent feature of lysosomal proteins of human neutrophils and several types of cancers. We also found that sialylation of N-glycans significantly reduced their activity as a substrate of FUT8. Kinetic analysis demonstrated that Fmoc aglycone modification could either improve the turnover rate or decrease the KM value depending on the nature of the substrates, thus significantly enhancing the overall efficiency of FUT8 catalyzed fucosylation. Our results indicate that an appropriate aglycone context of N-glycans could significantly broaden the acceptor substrate specificity of FUT8 beyond what has previously been thought. [ABSTRACT FROM AUTHOR]

Swiss chard is a vegetable valued not only for the taste of its leaves but also because of its health-promoting properties. To date, nothing is known regarding the occurrence of saponins in the Swiss chard plant, even though they could be at least partially responsible for the nutraceutical activities of this plant. This research aimed to describe saponins from the leaves of four Swiss chard (Beta vulgaris L.) cultivars. Saponin structures were analyzed by UHPLC-CAD/QTOF-MS/MS. Based on the fragmentation patterns, we tentatively identified 16 triterpene saponins in B. vulgaris, including two that had not been detected previously. The observed compounds were glycosides of five different, tentatively identified aglycones, i.e., oleanolic acid, hederagenin, gypsogenin, akebonoic acid, and serjanic acid. Moreover, the structure of four saponins detected in Swiss chard leaves included dioxolane-type and six acetal-type substituents. Eleven, eight, eleven, and eight saponins were observed in saponin fractions obtained from Rhubarb, Bulls Blood, Perpetual Spinach, and White Silver cultivars, respectively. Furthermore, the content of all identified triterpene derivatives in the investigated cultivars was estimated using a method based on the UHPLC coupled with QTOF-MS/MS and charged aerosol detector (CAD). The analyzed cultivars differed in the total and individual saponin content. The total saponin content ranged from 125.53 to 397.09 µg/g DW. [ABSTRACT FROM AUTHOR]

While flavanones exist in a variety of chemical forms, their favorable health effects are most prominent in their free form—aglycones. Their concentrations in grapefruit (Citrus × paradisi L.) extracts vary according to the extraction and hydrolysis methods used. The primary aim of this work was to maximize the yields of naringin and naringenin from various parts of fresh grapefruit fruits (flavedo, albedo, and segmental) using different extraction and hydrolysis methods. In addition, we aimed to evaluate the excipient—magnesium aluminometasilicate—and determine its influence on the qualitative composition of grapefruit extracts. Extracts were obtained by heat reflux extraction (HRE), ultrasound-assisted extraction with an ultrasonic homogenizer (UAE*), and ultrasound-assisted extraction with a bath (UAE). Ultrasound-assisted extraction using a bath (UAE) was modulated using acidic, thermal, and alkaline hydrolysis. The highest yield of naringin 8A (17.45 ± 0.872 mg/g) was obtained from an albedo sample under optimal conditions using ultrasound-assisted extraction; a high yield of naringenin 23-SHR (35.80 ± 1.79 µg/g) was produced using the heat reflux method from the segmental part. Meanwhile, ultrasonic combined with thermal hydrolysis significantly increased flavanone extraction from the albedo and segmental parts: naringin from sample 9-A (from 17.45 ± 0.872 mg/g to 25.05 ± 1.25 mg/g) and naringenin from sample 15-S (from 0 to 4.21 ± 0.55 µg/g). Additionally, magnesium aluminometasilicate demonstrated significant increases of naringenin from all treated grapefruit parts. To our knowledge, this is the first report of magnesium aluminometasilicate used as an adsorbent in flavanone extractions.

In many plants, isoflavones are the main secondary metabolites that have various pharmacological activities, but the low water solubility of aglycones limits their usage. The O-glycosylation of (iso)flavones is a promising way to overcome this barrier. O-glycosyltransferases (UGTs) are key enzymes in the biosynthesis of (iso)flavonoid O-glycosides in plants. However, limited investigations on isoflavonoid O-UGTs have been reported, and they mainly focused on legumes. Iris domestica (L.) Goldblatt et Mabberley is a non-legume plant rich in various isoflavonoid glycosides. However, there are no reports regarding its glycosylation mechanism, despite the I. domestica transcriptome previously being annotated as having non-active isoflavone 7-O-UGTs. Our previous experiments indicated that isoflavonoid glycosides were induced by CuCl2 in I. domestica calli; therefore, we hypothesized that isoflavone O-UGTs may be induced by Cu2+. Thus, a comparative transcriptome analysis was performed using I. domestica seedlings treated with CuCl2, and eight new active BcUGTs were obtained. Biochemical analyses showed that most of the active BcUGTs had broad substrate spectra; however, substrates lacking 5-OH were rarely catalyzed. Real-time quantitative PCR results further indicated that the transcriptional levels of BcUGTs were remarkably induced by Cu2+. Our study increases the understanding of UGTs and isoflavone biosynthesis in non-legume plants. [ABSTRACT FROM AUTHOR]

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Bidens pilosa plant has been shown to produce okanin flavanone glycoside and its chalcone derivative. In most other plants, due to chalcone isomerase enzyme, the flavanone tends to exist in higher proportions than their chalcone precursors. Herein we have utilized liquid chromatography–mass spectrometry approach and shown that within the leaves of Bidens pilosa plant the two okanin glycosides exist in unusual equal proportional distribution, which indicates that Bidens pilosa plant is an alternative rich source of these highly sought-after antioxidant molecules. The aglycone okanin chalcone (ONC) and okanin flavanone (ONF) have experimentally been shown to exhibit antioxidant activity. However, experimental findings have not conclusively determined which of the two compounds is a more potent antiradical than the other. Herein, the density functional theory (DFT) method is utilized to establish, from structural and thermodynamic energetic considerations, the preferred antioxidant molecule between the two aglycone okanins. A theoretical study on the antioxidant properties of ONC and ONF has been performed by considering their radical scavenging and metal cation (Mn+, where M = Cu(II) or Fe (III)) chelation ability. The study has been performed using B3LYP/6-31 + G(d,p) method. In the case of the metal chelation mechanism, the LANL2DZ pseudo-potential was selected to describe the selected Mn+ cations. The results of the study suggest that ONC is a better radical scavenger than ONF because of the extended electron delocalization on its neutral radical, which is due to the presence of conjugation within the ONC neutral radical after hydrogen atom abstraction. In the metal chelation mechanism, it is noted that the binding energies depend on the media, the nature of the ligand and the cation and the cation coordination site on the ligand. The charge and the spin density on Mn+ decrease on coordination to the ligand. The ability of the ligands to reduce Mn+ cations, coupled with the strong Mn+ binding properties, has significant implication on the antioxidant ability of both okanins. However, since ONC⋅⋅⋅M+n interaction results in higher binding energy than ONF⋅⋅⋅M+n interaction, the implication is that ONC is a preferred free metal ion chelator than ONF. [ABSTRACT FROM AUTHOR]

Soybean milk or soya milk is a popular soy beverage widely consumed in Asia. The growing interest for studying content of isoflavone aglycones in soybean products was related to the biological activities of soy products towards human health. Hence, it was important to develop a validated analytical method to quantify content of aglycone isoflavones from soybean milk sample. In this study, a reversed-phase HPLC (RP-HPLC) method was validated and applied for determining content of genistein, daidzein, and glycitein in soybean milk. The developed RP-HPLC method was met the requirement of selectivity and sensitivity. Calibration curve formulas of genistein, daidzein, and glycitein were y = 99996x-9713.6 (r=0.9996), y = 71095x+8039.1 (r=0.9994), and y = 37116x -45855 (r=0.9994) in the range of 4.9136-29.4816, 5.0405-30.2430, and 4.2812-25.6872 μg/mL, respectively. Accuracy and intermediate precision were assessed on both standard solution and soybean milk samples spiked with standard solution of genistein, daidzein, and glycitein. It was found that both standard solution and the spiked samples solution were met the requirement of recovery of 85-110% and RSD of less than 4% for intraday and interday analysis. Content of genistein, daidzein, and glycitein in soybean milk sample (n=6) were 4.5420.124, 6.8130.224, and 2.0380.070 μg/mL, respectively. It can be concluded that the RP-HPLC method was successfully validated and applied in the determination of genistein, daidzein, and glycitein in soybean milk. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to evaluate the effects of the germination conditions of 'BRS 216' soybean (Glycine max) on the length, yield, and isoflavone contents of sprouts. A 23 factorial arrangement was used to evaluate the variables soaking time, irrigation frequency, and germination time. Sprouts that showed better length and yield and higher isoflavone contents were evaluated for their chemical composition and vitamin C content. Soaking and germination time of soybean showed a positive and significant linear effect on sprout length. However, only germination time showed a significant positive linear effect on yield, and a significant negative linear effect on the content of malonylglycosides, aglycones, and total isoflavones. Soybean germination conditions were established at 6 hours of soaking, three days of germination, and 8 hours of irrigation frequency. Under these conditions, the obtained sprouts show a more preserved chemical composition, besides higher contents of β-glycosides, malonylglycosides, aglycones, total isoflavones, and vitamin C than the nongerminated soybean. Under suitable germination conditions, it is possible to produce soybean sprouts with better physical characteristics, higher yield, and higher contents of isoflavones, aglycones, and vitamin C.

In this study, pulsed electric fields (PEFs) were evaluated as extraction-aiding technology during soymilk manufacturing to improve its isoflavone profile. Low-intensity PEFs were applied at different processing conditions in two stages of the soymilk extraction process, hydrated soybeans (HSB) and soybean slurry (SBS), with the soymilk extracted from the conventional process as control (CSM). Overall, resultant soymilk samples from PEF-HSB and PEF-SBS presented lower concentrations of glucosides isoflavones and greater aglycone content than those in CSM. In contrast to genistin (Gin) and daidzin (Din), which decreased around 18.5–52.6% and 10.9–54.6%, respectively, an increase in genistein (Ge, 12.3–64.4%) and daidzein (Da, 9–55.8%) was observed. The total isoflavone content (TIC) of most soymilk samples prepared from PEF-HSB was lower than that of the CSM. Conversely, when PEF-SBS was used, the TIC of resultant soymilk was not significantly affected or slightly decreased. However, PEF treated HSB at 10 kVcm−1/100 pulses and SBS at 6 kVcm−1/10 pulses led to a significant augment in TIC, of up to 109 ± 2.39 and 110 ± 1.26 μg/g, respectively, in the extracted soymilk samples. These results indicated that low-intensity PEF is a potential technology that could be implemented during soymilk manufacturing processing to modify the isoflavone profile and content of soymilk, mainly increasing its aglycone concentration.

Flavonoids are well known for their extensive health benefits. However, few studies compared the differences between flavonoid O-glycoside and C-glycoside. In this work, flavonoid O-glycoside (isoquercitrin), C-glycoside (orientin), and their aglycones (quercetin and luteolin) were chosen to compare their differences on antioxidant activities and metabolism during in vitro digestion and in vivo. In vitro digestion, the initial antioxidant activity of the two aglycones was very high; however, they both decreased more sharply than their glycosides in the intestinal phase. The glycosidic bond of flavonoid O-glycoside was broken in the gastric and intestinal stage, while the C-glycoside remained unchanged. In vivo, flavonoid O-glycoside in plasma was more elevated than C-glycoside on the antioxidant activity; however, flavonoid C-glycoside in urine was higher than O-glycoside. These results indicate that differences of flavonoid glycosides and their aglycones on antioxidant activity are closely related to their structural characteristics and metabolism in different samples. Aglycones possessed higher activity but unstable structures. On the contrary, the sugar substituents reduced the activity of flavonoids while improving their stability and helping to maintain antioxidant activities after digestion. Especially the C-glycoside was more stable because the stability of the C–C bond is higher than that of the C–O bond, which contributes to the difference between flavonoid O-glycoside and C-glycoside on the absorption and metabolism in vivo. This study provided a new perspective for comparing flavonoid O-glycoside, flavonoid C-glycoside, and their aglycones on their structure–activity relationship and metabolism.

This work is designed to reveal the varietal characteristics of terpene glycosides (TGs) in ripe Meili grapes. TGs in grape skins were extracted using three ethanol/water solvents, purified and enriched using XAD-2 resin, and collected using ethyl acetate/methanol (9:1, v/v). The aglycones released from TGs were analyzed by headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME–GC–MS). TGs were detected by ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC–Q-TOF-MS), the identification was conducted by both mass fragmentation and TGs database, and the quantitation was realized by octyl-β-d-glucopyranoside. Results showed that 19 aglycones for TGs were found in grape skins by GC–MS, which was mainly monoterpenol with molecular formula C10H18O (linalool, l-α-terpineol, geraniol, nerol, etc.), C10H20O (citronellol), and C10H18O2 (pyranoid/furanoid linalool oxide, etc.). C10H18O aglycones may be the most stable ones, and linalool was the most abundant, occupying 44.88–47.99% of the total content. Forty-nine TGs were detected by UPLC–Q-TOF-MS. Monoterpenol pentosyl-glucosides were the main TGs, especially C10H18O2 pentosyl-glucoside, which constituted 51.94–52.72% of the total concentration. [ABSTRACT FROM AUTHOR]

The study examined the relationship between the contents of principal flavones of Scutellaria baicalensis Georgi and the activity of endogenous b-glucuronidase (sGUS) in differentiated and undifferentiated in vitro cultures grown on solid and liquid medium. Using RP-HPLC, it was shown that sGUS activity did not correlate with the increase in biomass of cultures, but depended on tissue differentiation. In hairy roots cultured both on liquid and solid medium, it was ten times higher than in undifferentiated cultures. At the same time, the share of aglycone forms in the total content of flavones during the culture cycle depended on the growing conditions. It was significantly higher on agar medium than on liquid medium. A correlation between sGUS activity and total aglycone content, as well as wogonin content, was observed only in hairy roots grown in the liquid medium. [ABSTRACT FROM AUTHOR]

Soybean is one of the most important commodities in the world, being applied in feed crops and food, pharmaceutical industries in different ways. Soy is rich in isoflavones that in aglycone forms have exhibited significant anti-obesity and anti-lipogenic effects. Obesity is a global problem as several diseases have been related to this worldwide epidemic. The aim of this work was to verify the effect of free and immobilized β-glucosidase, testing Lentikats, and sol–gel as carriers. Moreover, we wanted to examine if the different types of hydrolysis would generate extracts with distinct biological activity concerning lipid accumulation, PPAR-α regulation, and TNF-α, IL-6, and IL-10 concentrations using in vitro assays. Our results show that all formulations of β-glucosidase could hydrolyze soy isoflavones. Thus, after 24 h of incubation, daidzein content increased 2.6-, 10.8-, and 12.2-fold; and genistein content increased 11.7, 11.4, and 11.4 times with the use of free enzyme, Lentikats®, and sol–gel immobilized enzyme, respectively. Moreover, both methodologies for enzyme immobilization led to promising forms of biocatalysts for application in the production of soy extracts rich in isoflavones aglycones, which are expected to bring about health benefits. A mild lipogenic effect was observed for some concentrations of extracts, as well as a slight inhibition in PPAR-α expression, although no significant differences were noticeable in the cytokines TNF-α, IL-10, and IL-6 as compared with the control. [ABSTRACT FROM AUTHOR]

Flavonoids possess diverse bioactivity and potential medicinal values. Glycosylation of flavonoids, coupling flavonoid aglycones and glycosyl groups in conjugated form, can change the biological activity of flavonoids, increase water solubility, reduce toxic and side effects, and improve specific targeting. Therefore, it is desirable to synthesize various flavonoid glycosides for further investigation on their medicinal values. Compared with chemical glycosylations, biotransformations catalyzed by uridine diphospho-glycosyltransferases provide an environmentally friendly way to construct glycosidic bonds without repetitive chemical synthetic steps of protection, activation, coupling, and deprotection. In this review, we will summarize the existing knowledge on the biotechnological glycosylation reactions either in vitro or in vivo for the synthesis of flavonoid O- and C-glycosides and other rare analogs. Key points • Flavonoid glycosides usually show improved properties compared with their flavonoid aglycones. • Chemical glycosylation requires repetitive synthetic steps and purifications. • Biotechnological glycosylation reactions either in vitro or in vivo were discussed. • Provides representative synthetic examples in detail. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department 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.)

Summary: Flaxseed and soybean are an important source of phytochemical compounds, mainly lignans and isoflavones, but also of flavones, flavanones and flavonols. These compounds appear mainly glycosylated in plant food and are converted into aglycones by the intestinal microbiota, increasing their bioavailability. In this work, we analyse the ability of Bifidobacterium strains (n = 25) to produce lignan and flavonoids aglycones from flaxseed and soybean extracts. Most of the Bifidobacterium strains increased the concentrations of secoisolariciresinol, daidzein, genistein, naringenin, eriodyctiol, luteolin and apigenin. Moreover, Bifidobacterium pseudocatenulatum and Bifidobacterium breve strains showed high production of herbacetin, increased the kaempferol concentration and produced quercetin and quercetagetin. B. pseudocatenulatum INIA P815 and B. breve INIA P367 produced 32.37 ± 2.81 and 28.64 ± 3.36 mg respectively of herbacetin g−1 of lignan extract. Bifidobacterium strains transformed the glycosides of a wide range of flavonoids into their aglycones, increasing the antioxidant activity and improving their bioavailability. [ABSTRACT FROM AUTHOR]

BACKGROUND Urinary excretion of isoflavones and their metabolites after the consumption of soybean meal (SBM) and fermented soybean meal (FSBM) biscuits was investigated in humans in a randomized double‐blinded crossover clinical trial. RESULTS: Aglycones were the most abundant metabolites in urine in both treatments. After FSBM consumption, total urinary excretion of aglycones and metabolites was 54% higher when compared to SBM biscuits. All metabolites were more rapidly excreted after FSBM biscuit consumption when compared to SBM biscuits. Urinary recovery of isoflavones was higher after FSBM biscuit consumption, reaching 67%. Women excreted higher amounts of colonic metabolites and lower amounts of aglycones than men. The prevalence of O‐demethylangolensin‐producer, equol‐producer and nonproducer metabotypes was 56%, 11% and 36% after SBM consumption and 72%, 11% and 17% after FSBM consumption, respectively. CONCLUSIONS: Together, our findings indicate that fermentation improves isoflavone bioavailability and possibly reduces the impact of gut microbiota on the metabolism of isoflavones. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The aim of this study was to produce cereal bars (CB) added with tempeh flour (TF) and evaluate the nutritional composition, fatty acids profile, isoflavone content and sensory acceptance. Tempeh was produced from organic soya beans cotyledons fermented by Rhizophus oligosporus followed by freeze‐drying and milling in order to obtain the TF. The addition of 10%, 15% and 20% TF to CB resulted in both protein and lipid content increase and a higher polyunsaturated/saturated fatty acids ratio. The content of isoflavone aglycones, the forms considered to have higher biological activity, was higher in TF than in soya bean, which was also reflected in the CB chemical composition. An acceptance test showed that CB added with TF (up to 15%) were sensory accepted. Overall results suggest that the addition of TF as an ingredient in cereal bars allows improving the chemical and functional characteristics of this type of ready‐to‐eat foods. [ABSTRACT FROM AUTHOR]

Aim: Consumption of aglycones-rich fermented soy has been positively associated with the recuperation of systemic inflammation. As oral conditions have an impact on overall health and diseases, the reestablishment of bacteria particularly by indigenous oral probiotic is believed to be able to reverse oral inflammation by antagonize oral pathogen and thus maintaining good oral health. Streptococcus salivarius can be combined with bioactive isoflavone aglycones to further improve oral healthiness. This study aimed to explore decent advantages by indigenous source of Streptococcus isolated from healthy periodontal to ferment soy while maintaining probiotic properties before delivering in product targeting oral health. Materials and Methods: Putative probiotic properties of isolated strains were explored through antibiotic susceptibility ensuring safe strain consumption. S. salivarius from Taylor's University Culture Collection (TUCC) 1254 was selected for probiotic properties evaluation, in comparison with the type strain. Both strains were evaluated for fermentation ability in soy through growth, ß-glucosidase assay, and isoflavone bioconversion. Results: The antagonistic ability of S. salivarius TUCC 1254 was better under anaerobic than microaerobic condition; the strain also showed higher colonizing ability to epithelial tissue than the tooth surface resemblance. The strain showed vast cell growth accompanied by organic acid production and higher ß-glucosidase enzyme to bioconvert isoflavone glucosides to bioactive aglycones that could reduce oral inflammation than K12. Soy improved auto-aggregation ability of S. salivarius, which could promote biofilm formation and thus could achieve enhanced oral pathogen-eradicating intention. Conclusion: This study suggested that indigenous bacteria could serve as a better source of oral probiotics and coupling with fermented soy bioactive isoflavone aglycones, become a deliverable platform for improving oral health. [ABSTRACT FROM AUTHOR]

Stereocontrolled synthesis of rare sugar derivatives, namely α- d -allulofuranosides, was achieved using d -fructose, one of the most abundant carbohydrates in nature. The following are the key steps of the α- d -allulofuranosides' synthesis. (1) An α-selective glycosidation reaction of 1,3,4,6-tetra- O -benzoylated d -fructofuranosyl donor to obtain α- d -fructofuranosides with 98 %–75 % isolated yields. (2) A regioselective 1,4,6-tri-O-pivaloylation reaction of the tetraol of α- d -fructofuranosides with the C3-hydroxy group remaining intact. (3) The oxidation of the C3-hydroxy group followed by the stereoselective reduction of the C3-carbonyl group. Primary and secondary alcohols and sugars can be used as glycosyl acceptors and aglycones for the following pivaloylation and stereoinversion reactions to obtain α- d -allulofuranosides. [Display omitted] • Rare sugar derivative, α- d -allulofuranoside, has been synthesized from d -fructose. • Glycosidation of d -fructofuranosyl donor produces α- d -fructofuranoside selectively. • Regioselective 1,4,6-tri- O -pivaloylation of α- d -fructofuranoside has been achieved. • Stereoinversion at C3–OH of α- d -fructofuranoside provides α- d -allulofuranoside. [ABSTRACT FROM AUTHOR]

Isoflavones can be found in different chemical forms, but the health beneficial effects mainly appear in their free forms—aglycones. Their yield in red clover (Trifolium pratensis L.) extracts differs due to different extraction and hydrolysis methodologies. The main aim of this study was to obtain the highest yields of daidzein and genistein from red clover blossoms through the various extraction and hydrolysis methods and to increase their quantities using additional excipients. Extracts were obtained by ultrasound-assisted, heat-reflux and maceration methods combining them with acidic, alkaline, and thermal hydrolysis. Using ultrasound-assisted extraction with optimal conditions and heat-reflux method highest yields of isoflavones were obtained in UTE510 (393.23 ± 19.66 µg/g daidzein and 171.57 ± 8.58 µg/g genistein); UTE530 (415.07 ± 20.75 µg/g daidzein and 150.57 ± 7.53 µg/g genistein) and HNE5 (432.30 ± 21.61 µg/g daidzein and 154.50 ± 7.72 µg/g genistein) samples. These conditions were used with excipients: magnesium aluminometasilicate, croscarmellose sodium, sodium carboxymethyl starch and vinylpyrrolidone-vinyl acetate copolymer. This is the first study reporting the ability of the vinylpyrrolidone-vinyl acetate copolymer to promote solubilization and availability of active compounds from a herbal extract, resulting in enhanced isoflavones yield. The results of the present study showing increased solubility and availability provided by the vinylpyrrolidone-vinyl acetate copolymer suggest that this preparation could in principle also reduce variability due to limited water solubility of isoflavones.

Trifolium pratense L. is receiving increasing attention due to the isoflavones it contains, which have been studied for their benefits to human health. A common problem with isoflavone aglycones is a rather low water solubility and limited pharmaceutical applications. The use of excipients, such as cyclodextrins in the production of isoflavone rich extracts, could become one of the new strategies for the extraction of target compounds. The aim of this study was to evaluate an eco-friendly method using the effects of α-, β- and γ-cyclodextrins for isoflavone solubilization in plant extracts in comparison to a standard extract without excipients. Extractions of red clover were prepared using ultrasound-assisted combined with thermal hydrolysis and heat reflux. It was determined that cyclodextrins significantly increased the isoflavones aglycone yields. By increasing cyclodextrins in the extraction media from 1 to 5%, the daidzin concentration increased on average by 1.06 (α-cyclodextrins), 1.4 (β-cyclodextrins) and 1.25 (γ-cyclodextrins) times. Genistein concentration increased using α- and γ-cyclodextrins (1.28 and 1.12 times, α- and γ-cyclodextrins, respectively), but decreased using β-cyclodextrins. The results showed that the cyclodextrin-assisted extraction enhanced the yields of isoflavones from red clover, which suggests using cyclodextrins as a green alternative and a cost-effective method to increase its pharmaceutical application.

The objective of this work was to determine the main antioxidant aglycones of flavonoids and tannins in antioxidant extracts from Melastoma dodecandrum Lour. (MD), based on its extraction and purification process optimization and component identification by UPLC-ESI-MS/MS. Firstly, the ultrasound-assisted extraction (UAE) process for antioxidants was established by using single factor tests and response surface optimization. Evaluating by DPPH radical scavenging assay, the antioxidant capacity of MD could reach 2742.27 ± 93.86 (μmol Trolox/g) under the optimized conditions including methanol concentration (61%, v/v), extraction time (45 min), liquid-solid ratio (0.46 ml/mg), and extraction temperature (25°C). Then, the antioxidants in the solution were enriched by using macroporous resins. Because of the highest adsorption capacity and desorption ratio, HPD 500 was selected out of 14 macroporous resins for further study based on the static adsorption and desorption tests. The adsorption mechanism of the HPD 500 resin presented that pseudo-first-order kinetics model and Freundlich isotherm model could adequately explain the adsorption process. After the antioxidants were dynamically saturated by HPD 500, the column was eluted with different concentrations of ethanol (0, 25, 50, 75, and 100%, v/v). Among the above five ethanol fractions, 50% ethanol fraction showed the strongest antioxidant activity and more than 95% antioxidants adsorbed in HPD500 could be eluted by 75% ethanol. Guided by analysis results of UPLC-ESI-MS/MS, main antioxidant aglycones of flavonoids and tannins in each ethanol elution fraction were quantitatively detected. Finally, according to the correlation analysis between the antioxidant capacity of each ethanol elution fraction and its content of 10 main flavonoids and phenolic acids, the antioxidant activities of MD could mainly contribute to tannins containing phenolic units such as ellagic acid and/or gallic acid. The results of this work would provide useful information for the production of antioxidants from MD. Thus, the analysis methods could also be a quality control tool for material or products related with MD. [ABSTRACT FROM AUTHOR]

Background: HIV continues to be a major global public health issue, having claimed more than 35 million lives so far. In 2016, 1 million people died from HIV-related causes globally. HIV-1 reverse transcriptase is one of HIV's vital enzymes for virus reproduction. If the enzyme is inhibited, the virus multiplication could be significantly decreased. There are currently many treatments for HIV, but more effective treatment is always needed because of the possibility of drug resistance and side effects for long-term use. Based on the previous study, there are some natural compounds with high affinity to the HIV-1 reverse transcriptase enzyme. Some of these compounds are flavonoid glycosides. Aims and Method: This study was aimed to learn more about in silico HIV-1 reverse transcriptase inhibitory activities of flavonoid glycosides using docking method. Results: The results showed that the most recommended flavonoid glycosides are those with the lowest binding energy, which were kaempferol-3-O-rhamnoside, myricetin-3-O-rhamnoside and quercetin-3-O-rhamnoside. This was due to the interactions of all three flavonoid rings and sugar moiety with key amino acid residues, which were Leu100, Lys101, Glu138, Tyr181, His235 and Tyr318. Conclusion: Flavonoid glycosides with rhamnose as glycone showed lower binding energy on HIV-1 reverse transcriptase. [ABSTRACT FROM AUTHOR]

• Subcritical water extraction of isoflavones from okara byproducts was optimized. • Conjugated isoflavones were less stable to hydrolysis as compared to aglycones. • Prolonged extraction time enhanced maximum aglycone recovery up to 213.5 ± 8.7 min. • Kinetic models for isoflavone degradation and conversion reactions were developed. In this study, the soybean milk and tofu byproduct okara was subjected to subcritical water extraction with the intention of recovering isoflavones with minimal degradation. Response Surface Methodology (RSM) of the extraction variables indicated that optimized conditions would be T = 146.23 °C, P = 3.98 MPa, and α = 20 mg (solid)/mL (extractant). Mathematical models for the conversion and degradation of isoflavones were solved as a set of simultaneous equations leading to rate constants and time-dependent concentration profiles for each genistein- and daidzein-based compound. These kinetic analyses suggested that an optimum extraction time, under RSM-optimized conditions, would be 213.5 ± 8.7 min. The results of our study suggest that okara byproducts could be valorized efficiently, as a source of bioactive isoflavone aglycones, using subcritical water. The mathematical models and optimized extraction conditions that we established in this study could be employed, as process control-optimized variables, in the exploitation of okara, specifically in the isolation of genistein and daidzein. [ABSTRACT FROM AUTHOR]