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https://www.readbyqxmd.com/read/30011063/circular-permutation-of-a-bacterial-tyrosinase-enables-efficient-polyphenol-specific-oxidation-and-quantitative-preparation-of-orobol
#1
Pyung-Gang Lee, Sang-Hyuk Lee, Eun Young Hong, Stefan Lutz, Byung-Gee Kim
Tyrosinase is a type-3 copper oxygenase that catalyzes a phenol moiety into ortho-diphenol, and subsequently to ortho-quinone. Diverse tyrosinases have been observed across the kingdom including Animalia, Bacteria, Plantae, and Fungi. Among the tyrosinases, bacterial and mushroom tyrosinases have been extensively exploited to prepare melanin, ortho-hydroxy-polyphenols or novel plant secondary metabolites during the past decade. And their use as a biocatalyst to prepare various functional bio-compounds have drawn great attention worldwide...
July 16, 2018: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/29737209/inhibitory-effects-of-amentoflavone-and-orobol-on-daclatasvir-induced-resistance-associated-variants-of-hepatitis-c-virus
#2
Wei-Ping Lee, Keng-Li Lan, Shi-Xian Liao, Yi-Hsiang Huang, Ming-Chih Hou, Keng-Hsin Lan
Hepatitis C virus (HCV) is recognized as a major causative agent of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Despite rapid progress in the development of direct-acting antivirals (DAA) against HCV infection in recent years, cost-effective antiviral drugs with more affordable prices still need to be developed. In this study, we screened a library of natural compounds to identify natural HCV inhibitors. The library of the pure compounds extracted from Chinese herbs deposited in the chemical bank of National Research Institute of Chinese Medicine (NRICM), Taiwan was screened in the cell culture-derived HCV (HCVcc) system...
2018: American Journal of Chinese Medicine
https://www.readbyqxmd.com/read/29381070/probing-the-antiallergic-and-anti-inflammatory-activity-of-biflavonoids-and-dihydroflavonols-from-dietes-bicolor
#3
Iriny M Ayoub, Michal Korinek, Tsong-Long Hwang, Bing-Hung Chen, Fang-Rong Chang, Mohamed El-Shazly, Abdel Nasser B Singab
Dietes bicolor (Iridaceae) is an ornamental plant used by African local healers to treat diarrhea and dysentery. A new dihydroflavonol, (2R,3R)-3,5,7-trihydroxy-8-methoxyflavanone (1); two known dihydroflavonols, trans-3-hydroxy-5-methoxy-6,7-methylenedioxyflavanone (2) and trans-3-hydroxy-5,7-dimethoxyflavanone (3); the known isoflavone orobol 7,3'-di-O-methyl ether (4); the known biflavones lanaroflavone (5), robustaflavone (6), and amentoflavone (7); and β-sitosterol (8) were isolated from the CH2 Cl2 fraction of D...
February 23, 2018: Journal of Natural Products
https://www.readbyqxmd.com/read/28958517/antioxidant-phenolic-compounds-isolated-from-wild-pyrus-ussuriensis-maxim-fruit-peels-and-leaves
#4
Daren Qiu, Jie Guo, Huimei Yu, Jiao Yan, Shengxiang Yang, Xiang Li, Yamei Zhang, Jinzhu Sun, Jie Cong, Shuliang He, Dongsheng Wei, Jian-Chun Qin
Thirteen phenolic compounds were isolated from pear (Pyrus ussuriensis Maxim.) peels and leaves extracts by using various column chromatography techniques with a guided DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging assay, the result of antioxidant activity of phenolic compounds is then verified by measurement of ROS (reactive oxygen species). The isolated compounds were identified as rutin (1), (-)-catechin (2), orobol (3), daidzein (4), tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl)-glyceryl] ether (5), tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl-9″-O-acetyl)-glyceryl] ether (6), 5,7,3',5'-tetrahydroxyflavanone (7), artselaeroside A (8), trilobatin (9), 3-(2,4,6-trihydroxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one (10), quercetin-3-O-(3″-O-galloyl)-α-l-rhamnopyranoside (11), apigenin (12) and quercetin (13) on the basis of nuclear magnetic resonance spectroscopy along with comparison with literature data...
February 15, 2018: Food Chemistry
https://www.readbyqxmd.com/read/28357634/bioactive-flavonoids-from-flos-sophorae
#5
Wenzhong Shi, Lili Liu, Jian Li, Lu Qu, Xu Pang, Haiyang Yu, Yi Zhang, Tao Wang
Three new flavonoid glycosides-soyaflavonosides A (1), B (2), and C (3)-together with 23 known ones were obtained from the 70% EtOH extract of Flos Sophorae (Sophora japonica, Leguminosae). Their structures were elucidated by chemical and spectroscopic methods. Among the known isolates, 14, 18, 20, 22, and 26 were isolated from the Sophora genus for the first time; 12, 19, 24, and 25 were obtained from the species firstly. Moreover, NMR data for compounds 18 and 26 are reported for the first time here. Meanwhile, compounds 4, 8-13, 15, 16, 19, 21, and 22 presented obvious inhibitory effects on TG accumulation in HepG2 cells...
July 2017: Journal of Natural Medicines
https://www.readbyqxmd.com/read/26461518/using-tyrosinase-as-a-monophenol-monooxygenase-a-combined-strategy-for-effective-inhibition-of-melanin-formation
#6
Sang-Hyuk Lee, Kiheon Baek, Ju-Eun Lee, Byung-Gee Kim
Tyrosinase is a binuclear copper-containing metalloprotein that leads the fast and regio-selective o-hydroxylation of monophenols to o-diphenols. However, the subsequent second oxidation to produce o-quinones, i.e., melanin precursors, from the o-diphenols has restricted its use to the production of functional o-diphenol derivatives. Herein, we present a combined strategy for the effective inhibition of melanin formation in tyrosinase reaction, which allows the use of tyrosinase as a monophenol monooxygenase...
April 2016: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/26423042/antineuroinflammatory-and-antiproliferative-activities-of-constituents-from-tilia-amurensis
#7
Ki Hyun Kim, Eunjung Moon, Joon Min Cha, Seulah Lee, Jae Sik Yu, Chung Sub Kim, Sun Yeou Kim, Sang Un Choi, Kang Ro Lee
As part of our ongoing search for bioactive constituents of natural Korean medicinal resources, we found in a preliminary study that the methanol (MeOH) extract from the trunks of Tilia amurensis RUPR. showed an inhibitory effect on nitric oxide (NO) production in an activated murine microglial cell line. A bioassay-guided fractionation and chemical investigation of the MeOH extract resulted in the isolation and identification of a new isoflavonoid glycoside, orobol 4'-O-β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside (1) and 16 known compounds (2-17)...
2015: Chemical & Pharmaceutical Bulletin
https://www.readbyqxmd.com/read/25880257/evaluation-of-leishmanicidal-and-trypanocidal-activities-of-phenolic-compounds-from-calea-uniflora-less
#8
Tamires C Lima, Rafaela J Souza, Alan D C Santos, Milene H Moraes, Nicole E Biondo, Andersson Barison, Mário Steindel, Maique W Biavatti
The phytochemical study of Calea uniflora led to the isolation of nine phenolic compounds identified as noreugenin (1), ethyl caffeate (2), a mixture of butein (3) + orobol (4), α-hydroxy-butein (5), caffeic acid (6), butein 4'-O-glucopyranosyl (7), quercetin 3-O-glucopyranosyl (8) and 3,5-di-O-caffeoylquinic acid (9). The chemical identity of the isolates was established on the basis of NMR and physical data. The chemical shifts of 5 and 7 have been reassigned and all the isolates were tested against Leishmania amazonensis and Trypanosoma cruzi amastigotes...
2016: Natural Product Research
https://www.readbyqxmd.com/read/23698223/on-the-radical-scavenging-activity-of-isoflavones-thermodynamics-of-o-h-bond-cleavage
#9
Jozef Lengyel, Ján Rimarčík, Adam Vagánek, Erik Klein
We have performed Density Functional Theory B3LYP/6-311++G** calculations of reaction enthalpies of antioxidant action mechanisms for nine isoflavones. O-H bond dissociation enthalpies, ionization potentials, proton dissociation enthalpies, proton affinities and electron transfer enthalpies related to Hydrogen Atom Transfer (HAT), Single Electron Transfer-Proton Transfer (SET-PT) and Sequential Proton-Loss Electron-Transfer (SPLET) mechanisms were investigated in gas- and solution-phases. Studies on the radical scavenging ability of isoflavones, contrary to various flavonoids, are still scarce...
July 14, 2013: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/21312307/antiinflammatory-constituents-from-eclipta-prostrata-using-raw264-7-macrophage-cells
#10
Supinya Tewtrakul, Sanan Subhadhirasakul, Pimpimon Tansakul, Sarot Cheenpracha, Chatchanok Karalai
The whole plant extract of Eclipta prostrata and its isolated compounds were tested for their antiinflammatory effects against lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E2 (PGE2 ) and tumor necrosis factor-alpha (TNF-α) release in RAW264.7 cells, as well as for the antiinflammatory mechanism of the active compound on mRNA expression. Among the isolated compounds, orobol (5) exhibited the highest activity against NO release with an IC50 value of 4.6 μm, followed by compounds 1, 2 and 4 with IC50 values of 12...
September 2011: Phytotherapy Research: PTR
https://www.readbyqxmd.com/read/20506821/-chemical-constituents-in-flos-sophorae-carbonisatus
#11
Raorao Li, Caifang Wang, Peilin Lei, Lanlan Huang, Sitong Yuan
OBJECTIVE: To investigate the chemical constituents of lipid-soluble and water-soluble extracts in Flos Sophorae Carbonisatus. METHOD: The compounds were isolated by means of solvent extraction and column chromatography, and their structures were determined by spectral analysis. RESULT: Two compounds from petroleum ether extract and ten from n-BuOH extract were isolated and identified as sophoradiol (1), beta-sitosterol (2), 3 beta, 22 beta, 24-trihydroxy-olean-12-ene (soyasapogenol B) (3), daucosterol (4), kaikasaponin I (5), quercetin (6), isorhamnetin (7), 2-O-methyl-insitol (8), isorhamnetin-3-O-rutinoside (9), isoquercitrin (10), orobol-7-O-beta-D-glucoside (11), rutin (12), respectively...
March 2010: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/20497313/inhibitory-effects-of-orobol-7-o-d-glucoside-from-banaba-lagerstroemia-speciosa-l-on-human-rhinoviruses-replication
#12
H J Choi, E Y Bae, J H Song, S H Baek, D H Kwon
AIMS: The anti-human rhinovirus (HRV) activity of orobol 7-O-d-glucoside (O7G) from Lagerstroemia speciosa L. (Lythraceae) was evaluated in Hela cells. METHODS AND RESULTS: We tested anti-HRV activity of O7G using a cytopathic effect (CPE) reduction method, which exhibited broad-spectrum anti-HRVs activity with a 50% inhibitory concentration (IC(50)) ranging from 0.58 to 8.80 microg ml(-1). The 50% cytotoxicity concentration (CC(50)) of O7G is more than 100 microg ml(-1), and the derived therapeutic indices are more than 12...
July 2010: Letters in Applied Microbiology
https://www.readbyqxmd.com/read/19685745/-studies-on-chemical-constituents-from-stems-of-cudrania-tricuspidata
#13
Yuzhen Guan, Zhiqi Yin, Lian Guo, Xiaojun Huang, Wencai Ye, Wenbin Shen
OBJECTIVE: To study the chemical constituents from the stems of Cudrania tricuspidata. METHOD: The chemical constituents from the ethanol extract of C. tricuspidata were isolated and purified by silica gel, Sephadex LH-20 column chromatographic methods. Their structures were identified on the basis of spectroscopic data and physico-chemical properties. RESULT: Thirteen compounds were isolated and identified as butyrospermyl acetate (1), glutinol (2), taraxerone (3), quercetin (4), kaempferol (5), isorhamnetin (6), orobol (7), 3'-O-methyorobol (8), taxifolin (9), naringenin (10), steppogenin (11), 1,3,6,7-tetrahydroxyx-anthone (12), 5,7-dihydroxy chromone (13)...
May 2009: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/17696192/hiv-1-protease-and-hiv-1-integrase-inhibitory-substances-from-eclipta-prostrata
#14
Supinya Tewtrakul, Sanan Subhadhirasakul, Sarot Cheenpracha, Chatchanok Karalai
The bioassay-guided fractionation for anti-HIV-1 integrase activity led to the isolation of six compounds from the whole plant extract of Eclipta prostrata extract. They were identified as 5-hydroxymethyl-(2,2':5',2'')-terthienyl tiglate (1), 5-hydroxymethyl-(2,2':5',2'')-terthienyl agelate (2), 5-hydroxymethyl-(2,2':5',2'')-terthienyl acetate (3), ecliptal (4), orobol (5) and wedelolactone (6). Of these, compound 6 showed the highest activity against HIV-1 integrase (IN) with an IC50 value of 4.0+/-0.2 microm, followed by compound 5 (IC50=8...
November 2007: Phytotherapy Research: PTR
https://www.readbyqxmd.com/read/17549368/differential-regulation-of-the-cytotoxicity-activity-of-paclitaxel-by-orobol-and-platelet-derived-growth-factor-in-human-ovarian-carcinoma-cells
#15
Seiji Isonishi, Motoaki Saitou, Misato Saitou, Makoto Yasuda, Tadao Tanaka
Paclitaxel (PX) binds to and stabilizes tubulin, preventing depolymerization, and resulting in cell death. Based on a previous report showing the activity of phosphatidylinositol kinase (PIK) on tubulin, we investigated the effect of the PI4K inhibitor orobol and the PI3K activator platelet derived growth factor (PDGF) on PX sensitivity. Drug sensitivity was examined by classical colony forming assay. Tubulin isotype expression was determined by semi-quantitative RT-PCR. Microtubule texture was observed by laser confocal microscope using anti-beta-tubulin antibody...
July 2007: Oncology Reports
https://www.readbyqxmd.com/read/17097654/disposition-of-genistein-in-rainbow-trout-oncorhynchus-mykiss-and-siberian-sturgeon-acipenser-baeri
#16
K Gontier-Latonnelle, J P Cravedi, M Laurentie, E Perdu, V Lamothe, F Le Menn, C Bennetau-Pelissero
Genistein (G) is a xenoestrogen from soy present in fish diet. In vivo, a 50-fold difference in sensitivity to genistein on vitellogenin (VTG) synthesis was found when comparing trout and sturgeon. This difference was not linked to the estrogen receptor affinity nor to the sensitivity of induction of the VTG pathway. The study was performed to check if differences in the G disposition in the two species could explain their difference of sensitivity to G. A pharmacokinetic analysis of radiolabeled G was performed to determine its bioavailability and metabolism in both species...
January 15, 2007: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/16881680/isoflavone-profiles-of-red-clovers-and-their-distribution-in-different-parts-harvested-at-different-growing-stages
#17
COMPARATIVE STUDY
Rong Tsao, Yousef Papadopoulos, Raymond Yang, J Chris Young, Ken McRae
The isoflavone compositions and concentrations in the leaf, flower, petiole, and stem of 13 red clover cultivars were studied using high-performance liquid chromatography coupled with a diode array and a mass spectrometric detector with negative electrospray ionization. Different cultivars showed significantly different concentrations of individual and total isoflavones. The leaf contained the highest overall concentration, followed by the stem, petiole, and flower. Biochanin A and formononetin were the predominant isoflavones in all cultivars and all parts, along with eight other minor aglycones, daidzein, genistein, glycitein, irilone, orobol, pratensein, pseudobaptigenin, and prunetin, and four minor malonylglycosides, genistein-7-glucoside-6' '-malonate, orobol-7-glucoside-6' '-malonate, formononetin-7-glucoside-6' '-malonate, and biochanin A-7-glucoside-6' '-malonate...
August 9, 2006: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/16643874/total-synthesis-of-two-isoflavone-c-glycosides-genistein-and-orobol-8-c-beta-d-glucopyranosides
#18
Shingo Sato, Kaoru Hiroe, Toshihiro Kumazawa, Onodera Jun-ichi
Genistein and orobol 8-C-beta-D-glucopyranosides (1 and 3) were firstly synthesized in overall yields of 39% and 41% from 2,4-di-O-benzylphloroacetophenone (4), as follows: (1) the formation of the chalcone (6, 7) by aldol condensation of the benzyl-protected C-glycosylphloroacetophenone (5), a key intermediate of the total synthesis of 1 and 3 and synthesized by a C-glycosylation method involving the O-->C glycoside rearrangement of 4 in 96% yield; (2) the formation of isoflavones (10, 11 and 12, 13) by the formation of acetals by oxidative rearrangement of the protected chalcones (8 and 9) using Tl(NO3)3, followed by acid-catalyzed cyclization; (3) a final debenzylation by hydrogenolysis...
July 3, 2006: Carbohydrate Research
https://www.readbyqxmd.com/read/16346840/degradation-of-the-isoflavone-biochanin-a-and-its-glucoside-conjugates-by-ascochyta-rabiei
#19
B Kraft, W Barz
Strains of Ascochyta rabiei which are pathogenic to chickpea (Cicer arietinum L.) readily catabolized the main chickpea isoflavone biochanin A (5,7-dihydroxy-4'-methoxyisoflavone). 3'-Hydroxylation and O-demethylation reactions led to the isoflavones pratensein, genistein, and orobol, which were rapidly further degraded. Dihydrogenistein and p-hydroxyphenylacetic acid were also identified as catabolites. Biochanin A-7-O-glucoside was degraded, leading to aglycone and pratensein. Biochanin A-7-O-glucoside-6''-O-malonate, the main phenolic constituent of chickpea, was very slowly degraded without subsequent accumulation of catabolites...
July 1985: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/16276966/a-phenolic-glucoside-isolated-from-prunus-serrulata-var-spontanea-and-its-peroxynitrite-scavenging-activity
#20
Hyun Ah Jung, Hae Young Chung, Sam Sik Kang, Sook Kyung Hyun, Hye Sook Kang, Jae Sue Choi
A new phenolic glucoside (1), pursargentoside, was isolated from the leaves of Prunus serrulata var. spontanea, along with three other known compounds, orobol 7-omicron-glucoside (2), 1beta, 2alpha, 3alpha, 24-tetrahydroxy-urs-12-en-28-oic acid (3), and chlorogenic acid (4). The structure of pursargentoside (1) was identified by spectroscopic data analysis including 1D and 2D NMR spectroscopy, as 2-omicron-beta-(6'-benzoyl)-glucopyranosyl omicron-(Z)-coumaric acid. Compounds 1, 2, and 4 exhibited ONOO scavenging activity, whereas compound 3 was determined to be virtually inactive...
October 2005: Archives of Pharmacal Research
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