Showing papers on "Glucoside published in 2023"

Phytochemical Study on Seeds of Paeonia clusii subsp. rhodia—Antioxidant and Anti-Tyrosinase Properties

Abstract: In this study, the black fertile (BSs) and the red unfertile seeds (RSs) of the Greek endemic Paeonia clusii subsp. rhodia (Stearn) Tzanoud were studied for the first time. Nine phenolic derivatives, trans-resveratol, trans-resveratrol-4′-O-β-d-glucopyranoside, trans-ε-viniferin, trans-gnetin H, luteolin, luteolin 3′-O-β-d-glucoside, luteolin 3′,4′-di-O-β-d-glucopyranoside, and benzoic acid, along with the monoterpene glycoside paeoniflorin, have been isolated and structurally elucidated. Furthermore, 33 metabolites have been identified from BSs through UHPLC-HRMS, including 6 monoterpene glycosides of the paeoniflorin type with the characteristic cage-like terpenic skeleton found only in plants of the genus Paeonia, 6 gallic acid derivatives, 10 oligostilbene compounds, and 11 flavonoid derivatives. From the RSs, through HS-SPME and GC-MS, 19 metabolites were identified, among which nopinone, myrtanal, and cis-myrtanol have been reported only in peonies’ roots and flowers to date. The total phenolic content of both seed extracts (BS and RS) was extremely high (up to 289.97 mg GAE/g) and, moreover, they showed interesting antioxidative activity and anti-tyrosinase properties. The isolated compounds were also biologically evaluated. Especially in the case of trans-gnetin H, the expressed anti-tyrosinase activity was higher than that of kojic acid, which is a well-known whitening agent standard.

Curcumins from <em>Curcuma longa </em>Potential Inhibit PTP1B and α-Glucosidase: Experimental and Computational Study

Abstract: Curcuma longa is only a rich source of curcumin (1) and its major analogues demethoxycurcumin (2) and bisdemethoxycurcumin (3) among the Curcuma species. The content ratio of these three curcumins in turmeric is depended on the varieties and growing environment. Recently, curcumin (1) has been reported as potential inhibitor of hepatic and enzymatic protein tyrosine phosphatase 1B (PTP1B) and its related disorders such as hypertriglyceridemia, hyperlipidemia and liver steatosis. Thus, we further purified curcumins (1–3) from C. longa and investigated their inhibitory effects against PTP1B and α-glucosidase enzymes. As the result, curcumins (1–3) exhibited potential PTP1B inhibition with IC50 values of 37.8 ± 1.4, 45.3 ± 0.7, and 72.6 ± 1.1 μM, respectively, and α-glucosidase inhibition with similar manner (IC50 values of 78.2 ± 0.2, 82.4 ± 0.6, and 90.6 ± 1.0 μM, respectively). These results reveal a key role of methoxylation in the variation of PTP1B and α-glucosidase inhibitory activity for these curcumins. In addition, density functional theory (DFT) was used accompanying with molecular docking (MD) to analyze the ligand stability and the interaction of curcumins (1–3) with PTP1B and glucoside hydrolase proteins. Assay-based results and the MD data obtained are highly correlation suggesting that the deterioration of the enzyme activity caused by the distortion of structural conformation of PTP1B and glucoside hydrolase may be related to the arrangement of amino acids in protein structure. This reported for the first time that inhibitory effects of curcumins (1–3) against PTP1B and glucoside hydrolase have been examined in vitro and in silico as well.

Identification of lignans and quality assessment in Dendrobium officinale under different cultivation modes.

Abstract: RATIONALE Lignans have attracted much attention from researchers because of their wide distribution and industrial applications in plants, as well as their remarkable diversity of their biological activities. As literature mainly focused on the extraction and identification of monomeric compounds of lignans, most lignans in Dendrobium officinale, a traditional Chinese medicine with a long cultivation history and rich sources, have not been detected using quality control methods. The aim of this study was to identify the lignans in D. officinale. METHODS HPLC coupled with diode array detection (DAD) and HPLC multiple-stage tandem mass spectrometry (HPLC/MSn ) was used to identify the chemical constituents of D. officinale. Simultaneously, the characteristic chromatograms of D. officinale were established. Additionally, a method was established to determine the content of syringaresinol-4,4'-di-O-β-D-glucoside, syringaresinol-4-O-β-D-glucoside and syringaresinol. RESULTS Thirty-three lignans, including 17 tetrahydrofuran lignans, two dibenzylbutane lignans, three aryl tetrahydronaphthalene lignans, and 11 8-O-4' neolignans, were tentatively identified from the methanol extract of the stems of D. officinale. It was the first time to report 8-O-4' neolignans from D. officinale. In addition, a total of eight characteristic peaks were marked in the characteristic chromatograms, which were identified as lyoniresinol-9'-O-β-D-glucoside, syringaresinol-4,4'-di-O-β-D-glucoside, 8-hydroxy-syringaresinol-4-O-β-D-glucoside, 5,5'-di-methoxy-lariciresinol-4-O-β-D-glucoside, syringaresinol-4-O-β-D-glucoside, 4-hydroxy-3,3',5,5'-tetramethoxy-8,4'-oxyneoligna-7'-ene-9,9'-diol-9-O-β-D-glucoside, 4-hydroxy-3,3',5,5'-tetramethoxy-8,4'-oxyneoligna-7'-ene-9,9'-diol-4-O-β-D-glucoside and syringaresinol. Our results showed that no significant difference occurred in lignan composition among the ninety-nine batches of D. officinale from different sources. However, the peak areas of the lignans of D. officinale planted under simulated wild culture were generally higher than those in greenhouses, and showed an upward trend with the increase in growth years. The average contents of syringaresinol-4,4'-di-O-β-D-glucoside, syringaresinol-4-O-β-D-glucoside and syringaresinol were 10.112-179.873 μg/g, 51.227-222.294 μg/g, 6.368-120.341 μg/g, respectively. CONCLUSIONS This study provided a basis for improving the quality control of D. officinale and could provide references for the identification of lignans in other Dendrobium species.

UGT76F1 glycosylates an isomer of the C7-necic acid component of pyrrolizidine alkaloids in Arabidopsis thaliana.

Abstract: Identification of unknown metabolites and their biosynthetic genes is an active research area in plant specialized metabolism. By following a gene-metabolite association from a genome-wide association study of Arabidopsis stem metabolites, we discovered a previously unknown metabolite, 2-hydroxy-2-(1-hydroxyethyl)pentanoic acid glucoside, and demonstrated that UGT76F1 is responsible for its production in Arabidopsis. The chemical structure of the glucoside was determined by a series of analyses including tandem mass spectrometry, acid and base hydrolysis, and NMR spectrometry. T-DNA knockout mutants of UGT76F1 are devoid of the glucoside but accumulate increased levels of the aglycone. 2-hydroxy-2-(1-hydroxyethyl)pentanoic acid is structurally related to the C7-necic acid component of lycopsamine-type pyrrolizidine alkaloids such as trachelantic acid and viridifloric acid. Feeding norvaline greatly enhances the accumulation of 2-hydroxy-2-(1-hydroxyethyl)pentanoic acid glucoside in wild type but not the UGT76F1 knockout mutant plants, providing evidence for an orthologous C7-necic acid biosynthetic pathway in Arabidopsis despite the apparent lack of pyrrolizidine alkaloids.

Increased bioavailability of diosmetin-7-glucoside-γ-cyclodextrin inclusion complex compared with diosmin in Sprague-Dawley rats.

Abstract: Diosmin (DSN) is found mainly in citrus fruits, and has potent antioxidant effects. This study aimed to evaluate pharmacokinetics of diosmetin-7-glucoside-γ-cyclodextrin (DIOSG-CD) inclusion complex. The area under the curve values from AUC0-24 of DIOSG-CD, prepared by reacting DSN and naringinase with γ-CD, were approximately 800-fold higher than those of DSN following their administration in Sprague-Dawley rats.

Production of Four Flavonoid C-Glucosides in Escherichia coli.

Abstract: Flavonoid C-glucosides, which are found in several plant families, are characterized by several biological properties, including antioxidant, anticancer, anti-inflammatory, neuroprotective, hepatoprotective, cardioprotective, antibacterial, antihyperalgesic, antiviral, and antinociceptive activities. The biosynthetic pathway of flavonoid C-glucosides in plants has been elucidated. In the present study, a pathway was introduced to Escherichia coli to synthesize four flavonoid C-glucosides, namely, isovitexin, vitexin, kaempferol 6-C-glucoside, and kaempferol 8-C-glucoside. A five- or six-step metabolic pathway for synthesizing flavonoid aglycones from tyrosine was constructed and two regioselective flavonoid C-glycosyltransferases from Wasabia japonica (WjGT1) and Trollius chinensis (TcCGT) were used. Additionally, the best shikimate gene module construct was selected to maximize the titer of each C-glucoside flavonoid. Isovitexin (30.2 mg/L), vitexin (93.9 mg/L), kaempferol 6-C-glucoside (14.4 mg/L), and kaempferol 8-C-glucoside (38.6 mg/L) were synthesized using these approaches. The flavonoid C-glucosides synthesized in this study provide a basis for investigating and unraveling their novel biological properties.

Characterization of phenolic constituents in hazelnut kernels.

Abstract: Hazelnuts contain biologically active phenolic compounds and are widely used for their nutritional value. In this study, the phenolic compounds contained in hazelnuts were isolated from the kernels of Corylus avellana L. and investigated. Spectral analyses revealed two new acetophenone glycosides, characterized as 2',4',6'-trihydroxyacetophenone 4'-O-(2-O-β-D-apiosyl)-β-D-glucoside and 2',4',6'-trihydroxyacetophenone 4'-O-(2-O-β-D-apiosyl-6-O-α-L-arabinosyl)-β-D-glucoside, and four known compounds. Four high-molecular mass condensed tannin fractions were detected in the water-soluble fraction of the extract, characterized as B-type procyanidin consisting of extension and terminal units. Gel permeation chromatography analyses revealed that the average molecular mass, based on the polystyrene standard, was approximately 15 000-113 000. These high-molecular mass condensed tannin fractions were chemically characterized and exhibited different molecular weights. The fractions of high-molecular mass condensed tannins were obtained from hazelnuts and tested for 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. The EC50 values indicated significant activity for all the fractions.

Enzymatic synthesis, characterization and molecular docking of a new functionalized polyphenol: Resveratrol-3,4’-⍺-diglucoside

Abstract: Transglucosylation of resveratrol by the Q345F variant of sucrose phosphorylase from Bifidobacterium adolescentis (BaSP) was extensively studied during the last decade. Indeed, Q345F is able to catalyze the synthesis of resveratrol-3-O-⍺-D-glucoside (RES-3) with yield up to 97% using a cost-effective glucosyl donor, sucrose (Kraus et al., Chemical Communications, 53(90), 12182–12184 (2017)). Despite the fact that two further products were detectable in low amounts after glucoside synthesis, they were never identified. Here, we isolated and fully characterized one of those two minor products: resveratrol-3,4′-O-⍺-D-diglucoside (RES-3,4′). This original compound had never been described before. Using bioinformatics models, we successfully explained the formation of this diglucosylated product. Indeed, with RES-3 as acceptor substrate, Q345F is able to transfer a glucosyl moiety in position 4′-OH, what had been reported as impossible in the literature. The low yield observed is due to the steric hindrance into the catalytic site between RES-3 and residues Tyr132 and Tyr344. Nevertheless, the substrate orientation in the active site is favored by stabilizing interactions. Ring A of RES-3 bearing the diol moiety is stabilized by hydrogen bonds with residues Asp50, Arg135, Asn347 and Arg399. Hydroxyl group OH-4′ shares hydrogen bonds with the catalytic residues Asp192 and Glu232. Multiple hydrophobic contacts complete the stabilization of the substrate to favor the glucosylation at position 4′. Understanding of the mechanisms allowing the glucosylation at position 4′ of resveratrol will help the development of enzymatic tools to target and control the enzymatic synthesis of original ⍺-glucosylated polyphenols with high added value and better biodisponibility.

Two New Cytotoxic Sesquiterpene-Amino Acid Conjugates and a Coumarin-Glucoside from Crossostephium chinense

Abstract: The Asteraceae family is a promising source of bioactive compounds, such as the famous Asteraceae plants Tanacetum cinerariifolium (pyrethrin) and Artemisia annua (artemisinin). As a result of our series of phytochemical studies of the subtropical plants, two novel sesquiterpenes, named crossoseamines A and B in this study (1 and 2, respectively), one undescribed coumarin-glucoside (3), and eighteen known compounds (4–21) were isolated from the aerial part of Crossostephium chinense (Asteraceae). The structures of isolated compounds were elucidated by spectroscopic methods, including 1D and 2D NMR experiments (1H, 13C, DEPT, COSY, HSQC, HMBC, and NOESY), IR spectrum, circular dichroism spectrum (CD), and high-resolution electrospray ionization–mass spectrometry (HR-ESI–MS). All isolated compounds were evaluated for their cytotoxic activities against Leishmania major, Plasmodium falciparum, Trypanosoma brucei (gambiense and rhodesiense), and human lung cancer cell line A549 because of the high demand for the discovery of new drug leads to overcome the present side effects and emerging drug-resistant strains. As a result, the new compounds (1 and 2) showed significant activities against A549 (IC50, 1: 3.3 ± 0.3; 2: 12.3 ± 1.0 μg/mL), L. major (IC50, 1: 6.9 ± 0.6; 2: 24.9 ± 2.2 μg/mL), and P. falciparum (IC50, 1: 12.1 ± 1.1; 2: 15.6 ± 1.2 μg/mL).

Ultrasound-Assisted Extraction of Verbascoside from Clerodendrum glandulosum Leaves for Analysis of Antioxidant and Antidiabetic Activities

Abstract: Verbascoside (VER) is a phenylethanoid glycoside compound found in Clerodendrum species and is an important part of traditional medicine. It is found in the leaves of Clerodendrum glandulosum, which is taken as a soup or vegetable and also utilized in traditional medicine by the people of Northeast India, especially against hypertension and diabetes. In the present study, VER was extracted from C. glandulosum leaves using ultrasound-assisted extraction through the solvent extraction method (ethanol–water, ethanol, and water). The ethanol extract had the highest phenolic and flavonoid contents, viz., 110.55 mg GAE/g and 87.60 mg QE/g, respectively. HPLC and LC–MS were used to identify the active phenolic compound, and VER was found to be the main component present in the extraction with a molecular weight of 624.59 g/mol. NMR (1H, 2D-COSY) analysis showed the presence of hydroxytyrosol, caffeic acid, glucose, and rhamnose in the VER backbone. Further, different antioxidant activities and antidiabetic and antihyperlipidemia enzyme markers’ inhibition against VER-enriched ethanol extract were evaluated. The results showed that ultrasound extraction of polyphenols using ethanol from C. glandulosum could be a promising technique for the extraction of bioactive compounds.

Molecular Docking of Secondary Metabolite Compounds of Andrographis Paniculata Plant as Potential Covid-19 Drug Candidate

Abstract: The aim of this research was to investigate the interaction between secondary metabolite compounds and the Mpro receptor, which was the main protein in Covid-19. Ligand-receptor interactions were studied using the Molecular Docking method. The validation results indicated that the test ligand Andrographolide had a higher affinity value compared to the standard ligand, with a value of -6.6 kcal/mol compared to the standard ligand's -7.5 kcal/mol. Additionally, the compound 14-Acetyl-3,19-isopropylideneandrographolide, 5,4 dihydroxy-7,8,2',3'-tetramethoxyflavone-5-glucoside had an affinity of -7.5 kcal/mol, Andrographidin A had -7.6 kcal/mol, Andrographiside had -7.7 kcal/mol, Skullcapflavone I had 7.7 kcal/mol, 5-Hydroxy-7,8,2'-trimethoxyflavone-5-glucoside had -7.7 kcal/mol, Apigenin had 7.7 kcal/mol, 5-Hydroxy-7,8-dimethoxyflavone-5-glucoside had -7.8 kcal/mol, Neoandrographolide had -7.8 kcal/mol, Andropanoside had -7.9 kcal/mol, Wogonin-5 glucoside had -8.1 kcal/mol, 5,2',3'-Trihydroxy-7,8-dimethoxyflavone-3'-glucoside had -8.4 kcal/mol, and Bisandrographolide had -8.5 kcal/mol. From the molecular docking results, the secondary metabolite compounds from the Andrographis paniculata plant exhibited significant interactions surpassing the standard ligand N3. Active residue interactions observed included Phe140, Leu141, Asn142, Gly143, His163, Glu166, Gln189, and Thr190.

Some Bioactivities of Isolated Apigenin-7-O-glucoside and Luteolin-7-O-glucoside

Abstract: In this study, we aimed to isolate compounds from Stachys lavandulifolia (Lamiaceae) by chromatographic methods and perform tyrosinase, acetylcholinesterase, butyrylcholinesterase enzyme-inhibition and antimicrobial activity studies of these compounds by in vitro methods. In addition, a molecular docking study was planned for the molecule with the highest effect. Two flavone glycosides, apigenin-7-O-glucoside and luteolin-7-O-glucoside, were isolated from S. lavandulifolia. Both compounds were observed to be effective against Enterococcus faecalis, Klebsiella pneumoniae, and Staphylococcus aureus. The compounds showed weak tyrosinase and butyrylcholine esterase inhibition, while only luteolin-7-O-glucoside showed a more significant inhibitory effect against acetylcholinesterase (65 ± 2%). Therefore, molecular interactions between acetylcholinesterase and luteolin-7-O-glucoside were evaluated. In the docking study, it was observed that the molecule was bound to the enzyme with a low amount of free binding energy (Glide score: −8.31). As a result, the antibacterial effect of apigenin-7-O-glucoside and both antibacterial and acetylcholinesterase-inhibitory effects of luteolin-7-O-glucoside were determined.

Enzymatic Hydrolysis of Rutin: Evaluation of Kinetic Parameters and Anti-Proliferative, Mutagenic and Anti-Mutagenic Effects

Abstract: The bioavailability of glucoside flavonoids is influenced by the nature of the sugar, glucosides being absorbed faster than rhamnoglucosides, for example. One strategy to enhance the bioavailability is enzymatic hydrolysis. In this study, some kinetic parameters of hesperidinase-mediated hydrolysis of rutin were evaluated using an UHPLC/QTOF-MSE analysis of the products of a bioconversion reaction. The resulting hydrolyzed rutins (after 4, 8 and 12 h of reaction) were submitted to anti-proliferative and Cytokinesis-Block Micronucleus (CBMN) assays in CHO-K1 cells. In the hesperidinase-mediated hydrolysis, the final concentration of quercetin-3-O-glucoside (Q3G) was directly proportional to the rutin concentration and inversely proportional to the reaction time. At an anti-proliferative concentration (2.5 μg/mL), hydrolyzed rutin derivatives did not show a mutagenic effect, except for the sample with a higher content of Q3G (after 4 h of the enzymatic hydrolysis of rutin). Moreover, the higher Q3G content in hydrolyzed rutin protected the CHO-K1 cells 92% of the time against methyl methanesulfonate-induced mutagenic damage. These results suggested that the anti-mutagenic effect of hydrolyzed rutin might be related to antioxidant and cell death induction. Presenting a good lipophilicity/hydrophilicity ratio, together with antioxidant and anti-mutagenic activities, the hesperidinase-mediated hydrolyzed rutin seemed to be a promisor raw material for the development of food supplements.

Glucosylation of Isoeugenol and Monoterpenes in Corynebacterium glutamicum by YdhE from Bacillus lichenformis

Abstract: Corynebacterium glutamicum has been regarded as a food-grade microorganism. In recent years, the research to improve the activities of beneficial therapeutics and pharmaceutical substances has resulted in the engineering of the therapeutically favorable cell factory system of C. glutamicum. In this study, we successfully glucosylated isoeugenol and other monoterpene derivatives in C. glutamicum using a promiscuous YdhE, which is a glycosyltransferase from Bacillus lichenformis. For efficient glucosylation, cultivation conditions such as the production time, substrate concentration, carbon source, and culture medium were optimized. Our system successfully converted about 93% of the isoeugenol to glucosylated compounds in the culture. The glucoside compounds were then purified, analyzed, and identified as isoeugenol-1-O-β-d-glucoside and isoeugenol-1-O-β-d-(2″-acetyl)-glucoside.

Polysaccharides and Bioactive Phenolics from Aconitum septentrionale Roots

Abstract: Aconitum septentrionale is known to contain toxic diterpene alkaloids, while other bioactive compounds in the plant remain unclear. The aim of this study was to explore the phenolic compounds and polysaccharides from the water extract of A. septentrionale roots. Fifteen phenolic compounds were isolated and identified by NMR and MS, including fourteen known and one new dianthramide glucoside (2-[[2-(β-D-glucopyranosyloxy)-5-hydroxybenzoyl]amino]-4,5-dihydroxybenzoic acid methyl ester, 14). One neutral (complex of glucans with minor amounts of mannans) and two acidic polysaccharide fractions (complexes of pectic polysaccharides and glucans) were also obtained. Hydroxytyrosol (1), hydroxytyrosol-1-O-β-glucoside (2) and bracteanolide A (7) inhibited the release of nitric oxide by dendritic cells. Magnoflorine (8) and 2-[[2-(β-D-glucopyranosyloxy)-5-hydroxybenzoyl]amino]-5-hydroxybenzoic acid methyl ester (12) inhibited 15-lipoxygenase, and bracteanolide A (7) was a moderate inhibitor of xanthine oxidase. This study is the first to describe the diversity of phenolics and polysaccharides from A. septentrionale and their anti-inflammatory and anti-oxidant activities.