Showing papers on "Glucoside published in 2019"

In vitro antioxidant activity and phenolic profiles of tropical fruit by‐products

Abstract: Peel and seeds of red-skinned passion fruit, mango, longan, rambutan, white-flesh and red-flesh dragon fruit were screened for their in vitro antioxidant activity, and determination of a detailed profile of phenolic compounds. Rambutan peel and mango seed extracts exhibited the highest total phenolic content and antioxidant activities (DPPH, ABTS and FRAP values). By using UPLC-QTOF-MS/MS analysis, the profiles of soluble and bound phenolics in the fruit by-products were obtained. Ellagic acid, geraniin, quercetin hexoside, gallic and galloyshikimic acid were predominant in rambutan peel, whereas, mangiferin, ellagic acid and galloy(di)glucoside were the major phenolic compounds in mango seed. Main phenolic compounds in longan peel were ellagic acid, galloyldiglucoside, and gallic acid, while in dragon fruit peel this was isorhamnetin glycoside, isorhamnetin glucorhamoside. Meanwhile, rutin and quercetin hexoside were predominant in passion fruit peel. These findings contribute significantly to the database of phenolic profiles of by-products of tropical fruits.

Chemogenic silver nanoparticles enhance lignans and neolignans in cell suspension cultures of Linum usitatissimum L.

Abstract: Cell suspension culture of Linum usitatissimum is a great source of the novel and multipurpose medicinal compounds lignans and neolignans. Conventional culturing practices usually result in low yield of plant secondary metabolites; therefore, we conceived a successful mechanism to elicit production of lignans and neolignans in cell suspension cultures, simply, by addition of chemogenic Ag-NPs into the culture medium. A three stage feeding strategy (day 10, 10 and 15, and 10 and 20, respectively, after inoculation) spanning the log growth phase (day 10–20), was implemented to elicit cell suspension cultures of Linum usitatissimum. Though enhancing effects of Ag-NPs were observed at each stage, feeding Ag-NPs at day 10 resulted in comparatively, highest production of lignans (secoisolariciresinol diglucoside, 252.75 mg/l; lariciresinol diglucoside, 70.70 mg/l), neolignans (dehydrodiconiferyl alcohol glucoside, 248.20 mg/l; guaiacylglycerol-β-coniferyl alcohol ether glucoside, 34.76 mg/l), total phenolic content (23.45 mg GAE/g DW), total flavonoid content (11.85 mg QUE/g DW) and biomass (dry weight: 14.5 g/l), respectively. Furthermore, a linear trend in accumulation of lignans and neolignans was observed throughout log phase as compared to control, wherein growth non-associated trend in biosynthesis of these metabolites was observed. Optimum production of both lignans and neolignans occurred on day 20 of culture; a ten fold increase in secoisolariciresinol diglucoside, 2.8 fold increase in lariciresinol diglucoside, five fold increase in dehydrodiconiferyl alcohol glucoside and 1.75 fold increase in guaiacylglycerol-β-coniferyl alcohol ether glucoside was observed in production levels compared to control treatments, respectively.

Potential Industrial Production of a Well-Soluble, Alkaline-Stable, and Anti-Inflammatory Isoflavone Glucoside from 8-Hydroxydaidzein Glucosylated by Recombinant Amylosucrase of Deinococcus geothermalis.

Abstract: 8-Hydroxydaidzein (8-OHDe), an ortho-hydroxylation derivative of soy isoflavone daidzein isolated from some fermented soybean foods, has been demonstrated to possess potent anti-inflammatory activity. However, the isoflavone aglycone is poorly soluble and unstable in alkaline solutions. To improve the aqueous solubility and stability of the functional isoflavone, 8-OHDe was glucosylated with recombinant amylosucrase of Deinococcus geothermalis (DgAS) with industrial sucrose, instead of expensive uridine diphosphate-glucose (UDP-glucose). One major product was produced from the biotransformation, and identified as 8-OHDe-7-α-glucoside, based on mass and nuclear magnetic resonance spectral analyses. The aqueous solubility and stability of the isoflavone glucoside were determined, and the results showed that the isoflavone glucoside was almost 4-fold more soluble and more than six-fold higher alkaline-stable than 8-OHDe. In addition, the anti-inflammatory activity of 8-OHDe-7-α-glucoside was also determined by the inhibition of lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells. The results showed that 8-OHDe-7-α-glucoside exhibited significant and dose-dependent inhibition on the production of nitric oxide, with an IC50 value of 173.2 µM, which remained 20% of the anti-inflammatory activity of 8-OHDe. In conclusion, the well-soluble and alkaline-stable 8-OHDe-7-α-glucoside produced by recombinant DgAS with a cheap substrate, sucrose, as a sugar donor retains moderate anti-inflammatory activity, and could be used in industrial applications in the future.

Patch testing with alkyl glucosides: Concomitant reactions are common but not ubiquitous.

Abstract: Background Alkyl glucosides contitute a family of mild surfactants that are increasingly being used in a wide range of cosmetics and household products. Contact allergy to alkyl glucosides may be more frequent than previously suspected, especially in atopic patients. Objectives To investigate the frequency of contact allergy to alkyl glucosides, and to identify concomitant reactivity. Method We retrospectively reviewed all cases of suspected allergic contact dermatitis (ACD) in which patients were patch tested with either a cosmetic series that includes five alkyl glucosides (decyl glucoside, lauryl glucoside, coco glucoside, cetearyl glucoside, and caprylyl/capryl glucoside) or a specific alkyl glucoside series from November 2013 to April 2017 in two UK centres. Results A total of 5775 patients were patch tested across the two centres. Twenty-nine (1.04%) of the 2796 patients tested with the cosmetic/alkyl glucoside series had a positive patch test reaction to at least one of the alkyl glucosides. Twenty-three (79.3%) patients were sensitized to multiple alkyl glucosides; 21 patients (72.4%) were female. The mean age was 43.5 years. Twelve patients (41.4%) had a background of atopic dermatitis. Conclusions The prevalence of alkyl glucoside-induced ACD is relatively high, and there are frequent concomitant reactions between different alkyl glucosides. We recommend the inclusion of alkyl glucosides in all cosmetic series.

Amarisolide F, an Acylated Diterpenoid Glucoside and Related Terpenoids from Salvia amarissima

Abstract: Nine terpenoids were isolated from the leaves and flowers of Salvia amarissima, including a new acylated diterpenoid glucoside, amarisolide F (1), a new neo-clerodane diterpenoid, amarissinin D (2), which was isolated as an acetyl derivative (2a), and four known diterpenoids. The structure of amarisolide F (1) was elucidated by NMR and MS data analyses, as well as its methanolysis products 7 and 8, which also constituted new diterpenoids, named amarissinin E and 8- epi-amarissinin E, respectively. The absolute configuration of compound 7 was established by single-crystal X-ray diffraction. The cytotoxicity and anti-MDR effect of 1 in three phenotypes of the MCF-7 cell lines were assayed. Compound 1 was 2-3.6-fold more active than amarissinins A (3) and B (4), but several orders of magnitude less active than teotihuacanin (6) and reserpine.

Synthesis and Biological Evaluation of the Novel Growth Inhibitor Streptol Glucoside, Isolated from an Obligate Plant Symbiont.

Abstract: The plant Psychotria kirkii hosts an obligatory bacterial symbiont, Candidatus Burkholderia kirkii, in nodules on their leaves. Recently, a glucosylated derivative of (+)-streptol, (+)-streptol glucoside, was isolated from the nodulated leaves and was found to possess a plant growth inhibitory activity. To establish a structure-activity relationship study, a convergent strategy was developed to obtain several pseudosugars from a single synthetic precursor. Furthermore, the glucosylation of streptol was investigated in detail and conditions affording specifically the α or β glucosidic anomer were identified. Although (+)-streptol was the most active compound, its concentration in P. kirkii plant leaves extract was approximately ten-fold lower than that of (+)-streptol glucoside. These results provide compelling evidence that the glucosylation of (+)-streptol protects the plant host against the growth inhibitory effect of the compound, which might constitute a molecular cornerstone for this successful plant-bacteria symbiosis.

Chemical Constituents from the Aerial Parts of Agastache rugosa and Their Inhibitory Activities on Prostaglandin E2 Production in Lipopolysaccharide-Treated RAW 264.7 Macrophages.

Abstract: A new flavone glucoside, acacetin-7-O-(3″-O-acetyl-6″-O-malonyl)-β-d-glucopyranoside (1), two new phenolic glucosides, (3R,7R)-tuberonic acid-12-O-[6'-O-(E)-feruloyl]-β-d-glucopyranoside (14) and salicylic acid-2-O-[6'-O-(E)-feruloyl]-β-d-glucopyranoside (15), and two new phenylpropanoid glucosides, chavicol-1-O-(6'-O-methylmalonyl)-β-d-glucopyranoside (17) and chavicol-1-O-(6'-O-acetyl)-β-d-glucopyranoside(18), as well as 26 known compounds, 2-13, 16, and 19-31, were isolated from the aerial parts of Agastache rugose. The structures of the new compounds were established by spectroscopic/spectrometric methods such as HRESIMS, NMR, and ECD. The anti-inflammatory effect of the isolated compounds was evaluated by measuring their inhibitory activities on prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. New compounds 1, 15, 17, and 18 inhibited LPS-induced PGE2 production with IC50 values of 16.8 ± 0.8, 33.9 ± 4.8, 14.3 ± 2.1, and 48.8 ± 4.4 μM, respectively. Compounds 5, 7, 9-11, 13, 19, 20, 22, and 27-30 showed potent inhibitory activities with IC50 values of 1.7-8.4 μM.

Phytochemical and Antioxidant Studies on a Rare Rheum cordatum Losinsk. Species from Kazakhstan.

Abstract: An optimisation of extraction towards an increased antioxidant capacity and the study on the extracts’ composition by HPLC-ESI-Q-TOF-MS were performed on different organs of a rarely studied plant: Rheum cordatum Losinsk (Polygonaceae) growing in Kazakhstan. More than 20 compounds from anthraquinones and phenolics were identified in an optimised method. The plant was proven to contain a wide variety of phenolic compounds (catechins, flavonoids, and their glucosides and phenolic acids) in contrast to the anthraquinone composition, which was mainly represented by emodin and its analogues. The results of the studies could determine the plant as a rich source of pharmacologically precious polyphenols. It was evidenced that the extracting solvents, the time of collection, and the organs tested affected both the chemical content and the antioxidant potential of the extracts. Ethanol : water (50 : 50 ) was selected as the most beneficial extractant for all metabolites, and based on the principal component analysis of raw data, the radical scavenging potential of the plant was strictly related to the presence of epicatechin gallate (ECG), kaempferol glucoside, and epigallocatechin gallate (EGCG) occurring in this extract at the concentration of 1.69-5%, 0.16-0.47%, and 0.001-2.93%, respectively.

A New Triterpenoid Glucoside from a Novel Acidic Glycosylation of Ganoderic Acid A via Recombinant Glycosyltransferase of Bacillus subtilis.

Abstract: Ganoderic acid A (GAA) is a bioactive triterpenoid isolated from the medicinal fungus Ganoderma lucidum. Our previous study showed that the Bacillus subtilis ATCC (American type culture collection) 6633 strain could biotransform GAA into compound (1), GAA-15-O-β-glucoside, and compound (2). Even though we identified two glycosyltransferases (GT) to catalyze the synthesis of GAA-15-O-β-glucoside, the chemical structure of compound (2) and its corresponding enzyme remain elusive. In the present study, we identified BsGT110, a GT from the same B. subtilis strain, for the biotransformation of GAA into compound (2) through acidic glycosylation. BsGT110 showed an optimal glycosylation activity toward GAA at pH 6 but lost most of its activity at pH 8. Through a scaled-up production, compound (2) was successfully isolated using preparative high-performance liquid chromatography and identified to be a new triterpenoid glucoside (GAA-26-O-β-glucoside) by mass and nuclear magnetic resonance spectroscopy. The results of kinetic experiments showed that the turnover number (kcat) of BsGT110 toward GAA at pH 6 (kcat = 11.2 min−1) was 3-fold higher than that at pH 7 (kcat = 3.8 min−1), indicating that the glycosylation activity of BsGT110 toward GAA was more active at acidic pH 6. In short, we determined that BsGT110 is a unique GT that plays a role in the glycosylation of triterpenoid at the C-26 position under acidic conditions, but loses most of this activity under alkaline ones, suggesting that acidic solutions may enhance the catalytic activity of this and similar types of GTs toward triterpenoids.

Isolation of Sesquiterpene-Amino Acid Conjugates, Onopornoids A-D, and a Flavonoid Glucoside from Onopordum alexandrinum.

Abstract: Previous phytochemical investigations have revealed the presence of a variety of compounds such as pyrrolidine derivatives, flavonoids, and megastigmanes in Egyptian plants. Onopordum alexandrinum has been traditionally used by the natives for treatment of skin cancers and leprosy. In this paper the isolation of four new sesquiterpene-amino acid conjugates, onopornoids A-D (1-4), i.e., three elemanes and one germacrane, and a new acylated flavonoid glucoside (5) along with nine known compounds (6-14) from the whole aerial parts of the title plant is discussed. The structures were elucidated based on chemical and spectroscopic/spectrometric data.

Glucoside Derivatives Of Podophyllotoxin: Synthesis, Physicochemical Properties, And Cytotoxicity.

Abstract: Background Widespread concern of the side effects and the broad-spectrum anticancer property of podophyllotoxin as an antitumor agent highlight the need for the development of new podophyllotoxin derivatives. Although some per-butyrylated glucosides of podophyllotoxin and 4β-triazolyl-podophyllotoxin glycosides show good anticancer activity, the per-acetylated/free of podophyllotoxin glucosides and their per-acetylated are not well studied. Methods A few glucoside derivatives of PPT were synthesized and evaluated for their in vitro cytotoxic activities against five human cancer cell lines, HL-60 (leukemia), SMMC-7721 (hepatoma), A-549 (lung cancer), MCF-7 (breast cancer), and SW480 (colon cancer), as well as the normal human pulmonary epithelial cell line (BEAS-2B). In addition, we investigated the structure-activity relationship and the physicochemical property-anticancer activity relationship of these compounds. Results Compound 6b shows the highest cytotoxic potency against all five cancer cell lines tested, with IC50 values ranging from 3.27±0.21 to 11.37±0.52 μM. We have also found that 6b displays higher selectivity than the etoposide except in the case of HL-60 cell line. The active compounds possess similar physicochemical properties: MSA > 900, %PSA 2, MW > 700 Da, and RB > 10. Conclusion We synthesized several glucoside derivatives of PPT and tested their cytotoxicity. Among them, compound 6b showed the highest cytotoxicity. Further studies including selectivity of active compounds have shown that the selectivity indexes of 6b are much greater than the etoposide except in the case of HL-60 cell line. The active compounds possessed similar physicochemical properties. This study indicates that active glucoside analogs of podophyllotoxin have potential as lead compounds for developing novel anticancer agents.

Salicin i derivati salicina

Abstract: Salicin is the first phenolic glucoside found in nature and after oral use it is metabolized to a pharmacologically active form, salicylic acid. There are many salicylic acid derivatives, one of which is the most commonly used drug, acetylsalicylic acid or aspirin. Aspirin is a medicine that has antipyretic and anticoagulant properties and acts by inhibiting activity of the enzyme cyclooxygenase which is responsible for the production of prostaglandins, substances responsible for inflammation and pain. The most known method of aspirin synthesis is esterification of salicylic acid with acetic anhydride with phosphoric or sulfuric acid. The aim of final thesis was to investigate the possibility of aspirin synthesis by conventional method, but with the use of choline chloride (ChCl) eutectic solvents for which a catalytic role in the esterification reaction can be assumed. The results of the experimental work showed that the eutectic solvents ChCl: levulinic acid and ChCl: citric acid can’t be used as catalyst for the acetylsalicylic acid synthesis. However, with the use of eutectic solvent ChCl: urea, acetylsalicylic acid was obtained and for the first time the possibility of using eutectic solvent in the acetylsalicylic acid synthesis was confirmed.

Simultaneous Enhancement of Thermostability and Catalytic Activity of a Metagenome-Derived β-Glucosidase Using Directed Evolution for the Biosynthesis of Butyl Glucoside

Abstract: Butyl glucoside synthesis using bioenzymatic methods at high temperatures has gained increasing interest. Protein engineering using directed evolution of a metagenome-derived β-glucosidase of Bgl1D was performed to identify enzymes with improved activity and thermostability. An interesting mutant Bgl1D187 protein containing five amino acid substitutions (S28T, Y37H, D44E, R91G, and L115N), showed catalytic efficiency (kcat/Km of 561.72 mM−1 s−1) toward ρ-nitrophenyl-β-d-glucopyranoside (ρNPG) that increased by 23-fold, half-life of inactivation by 10-fold, and further retained transglycosidation activity at 50 °C as compared with the wild-type Bgl1D protein. Site-directed mutagenesis also revealed that Asp44 residue was essential to β-glucosidase activity of Bgl1D. This study improved our understanding of the key amino acids of the novel β-glucosidases and presented a raw material with enhanced catalytic activity and thermostability for the synthesis of butyl glucosides.

New Depsides and Neuroactive Phenolic Glucosides from the Flower Buds of Rugosa Rose ( Rosa rugosa).

Abstract: The flower buds of Rosa rugosa Thunb. have been commonly used as a source of rose oil and as an ingredient in tea in eastern Asia, including China, Japan, and Korea. Repeated chromatography of a hot water extract from the flower buds of R. rugosa led to the isolation and characterization of three new depside glucosides, rosarugosides A-C (1-3), along with three phenolic compounds, one ionone glucoside, four flavonoids, and two tannins having known chemical structures. Linarionoside A and 2-phenylethyl-(6- O-galloyl)-β-d-glucopyranoside were isolated from R. rugosa for the first time in this study. The structures of the new compounds 1-3 were elucidated by interpreting one- and two-dimensional nuclear magnetic resonance spectroscopic and mass spectrometric data. Among the isolates, a new depside glucoside (1) and two major phenolic glucosides (4 and 5) improved MK-801-induced sensorimotor gating deficits, which were measured via an acoustic startle response test in mice.

Acylquinic Acids, Flavonoids, and Maltol O-Glucoside from Panax vietnamensis

Abstract: Panax vietnamensis Ha et Grushv. (Araliaceae) is a perennial endemic species of mountainous regions of Vietnam and northern China. A unique feature of the plant is a high content of triterpene glycosides, especially ocotillol derivatives [1]. Its distribution area is alarmingly decreasing because of its broad medicinal use. Therefore, studies on the development of alternate reproduction methods of P. vietnamensis are critical. Previously, root cells of P. vietnamensis were demonstrated by us to be capable of forming callus and suspension cultures that produced triterpene glycosides [2]. Phenolic compounds from the intact plant and its cell cultures have not been characterized although phenolic compounds from subterranean organs of P. vietnamensis and two types of cell cultures (callus and suspension) were studied by us during our research. Aerial organs of P. vietnamensis were collected in 2018 on Ngoc Linh Mountain, Quang Nam Province, Vietnam; 72% moisture. Callus culture of P. vietnamensis cells was produced from roots of intact plants using Murashige−Skoog medium [3] containing 2,4-diphenoxyacetic acid (0.5 mg/mL), α-naphthaleneacetic acid (1 mg/mL), and kinetin (0.05 mg/mL) and cultivation in Petri dishes in the dark at 26°C for three months (seven passages) [2]. Suspension culture of P. vietnamensis cells was produced in a bioreactor (20-L) from virulent calluses in the same medium without adding agar at 26°C in the dark. Column chromatography (CC) used polyamide, reversed (RP-SiO2) and normal-phase silica gel (SiO2), Sephadex LH-20, and cellulose (Sigma-Aldrich, St. Louis, MO, USA). Preparative HPLC used a Summit liquid chromatograph (Dionex, Sunnyvale, CA, USA) [4]; analytical HPLC, an LC-20 Prominence liquid chromatograph (Shimadzu, Columbia, MD, USA) [5]. Spectrophotometric studies used an SF-2000 spectrophotometer (OKB Spectr, St. Petersburg, Russia). Mass spectrometric studies used an LCMS-8050 TQ mass spectrometer (Shimadzu, Columbia, MD, USA) and the previously described conditions [6]. NMR spectra were recorded on a VXR 500S NMR spectrometer (Varian, Palo Alto, CA, USA). Roots of P. vietnamensis (2.5 kg) were ground in a blender. The resulting matter was extracted with EtOH (96%, 10 L, 2×) at 50°C in an ultrasonic bath (100 W, 35 kHz) for 3 h. The EtOH extract was filtered and evaporated to dryness under vacuum at 40°C. The dry solid (161 g) was suspended in H2O (1 L). The resulting suspension was extracted with CHCl3 and n-BuOH. The BuOH fraction (42 g) was placed onto polyamide (600 g) and eluted sequentially with H2O (fraction 1), EtOH (40%, fraction 2), EtOH (90%, fraction 3), and NH4OH solution (0.5%) in EtOH (90%) (fraction 4). Fraction 1 (1.4 g) was separated over RP-SiO2 (CC, 2 × 40 cm, H2O–MeCN eluent, 100:0→50:50) and Sephadex LH-20 (CC, 1 × 80 cm, 50% EtOH eluent) to afford astragalin (kaempferol-3-O-glucoside, 16 mg, 1) [7] and trifolin (kaempferol-3-O-galactoside, 10 mg, 2) [7]. Fraction 2 (0.8 g) was chromatographed over SiO2 (CC, 2 × 30 cm, EtOAc−Me2CO eluent, 90:10→70:30) and Sephadex LH-20 (CC, 1 × 80 cm, 70% EtOH eluent) to isolate dianthoside (maltol O-glucoside, 11 mg, 3) [8]. Fraction 3 (9.4 g) was separated using Sephadex LH-20 (CC, 3 × 80 cm, Me2CO−H2O eluent, 50:50→10:90), RP-SiO2 (CC, 1 × 40 cm, H2O−MeCN eluent, 100:0→30:70) and prep. HPLC [gradient mode (%B), 0−60 min, 5−30%; 60−90 min, 30−70%] to afford 5-O-caffeoylquinic acid (65 mg, 4) [9], 3-O-caffeoylquinic acid (20 mg, 5) [10], 5-O-feruloylquinic acid (15 mg, 6) [11], 3-O-feruloylquinic acid (8 mg, 7) [11], 3-O-feruloyl-5-O-caffeoylquinic acid (11 mg, 8) [12], and a mixture of 9−11 (108 mg). Compounds 9−11 were separated using CC over cellulose (4 × 100 cm, 15% HOAc

Preparation of salidroside with n-butyl β-D-glucoside as the glycone donor via a two-step enzymatic synthesis catalyzed by immobilized β-glucosidase from bitter almonds

Abstract: β-Glucosidase from bitter almonds was immobilized on epoxy group-functionalized beads for catalyzing salidroside synthesis in a two-step process with n-butyl-β-D-glucoside (BG) as the glucosyl dono...