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Find video protocols related to scientific articles indexed in Pubmed.
Practical application of flavonoid-poor menu meals to the study of the bioavailability of bilberry anthocyanins in human subjects.
Biosci. Biotechnol. Biochem.
PUBLISHED: 07-07-2014
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Practical application of flavonoid-poor menus was evaluated on the bioavailability of anthocyanins as model flavonoids. Detectable amounts of flavonoids were not found in plasma and urine collected from 13 participants, who took the menus. After ingesting bilberry anthocyanins (919 ?mol), average plasma AUC0-6h, Cmax, Tmax values and urinary recovery were 386.0 nmol h/mL, 139.1 nM, 1.31 h and 0.21%, respectively.
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Korean propolis suppresses angiogenesis through inhibition of tube formation and endothelial cell proliferation.
Nat Prod Commun
PUBLISHED: 05-30-2014
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Propolis, a sticky material that honeybees collect from living plants, has been used for its pharmaceutical properties since ancient times. In this study, we examined the effects of ethanol extracts of Korean propolis (EEKP) from various geographic regions on the inhibition of angiogenesis, both in vitro and in vivo. The effects of EEKP were tested on in vitro models of angiogenesis, that is, tube formation and proliferation of human umbilical vein endothelial cells (HUVECs). All EEKP samples exhibited significant inhibitory effects on tube formation of HUVECs in a concentration-dependent manner (6.25-25 microg/mL). In addition, two EEKP samples, prepared from Uijeongbu and Pyoseon propolis, significantly suppressed the proliferation of HUVECs in a concentration-dependent manner (3.13-25 microg/mL). Furthermore, in an in vivo angiogenesis assay using the chick embryo chorioallantoic membrane (CAM) system, we found that the two EEKP samples significantly reduced the number of newly formed vessels. These results indicate that Korean propolis may have potential applications in the prevention and treatment of angiogenesis-related diseases such as cancer.
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Identification of the phenolic compounds contributing to antibacterial activity in ethanol extracts of Brazilian red propolis.
Nat. Prod. Res.
PUBLISHED: 03-25-2014
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The purpose of this study is to identify the quantity and antibacterial activity of the individual phenolic compounds in Brazilian red propolis. Quantitative analysis of the 12 phenolic compounds in Brazilian red propolis was carried out using reversed-phase high-performance liquid chromatography. The main phenolic compounds in Brazilian red propolis were found to be (3S)-vestitol (1), (3S)-neovestitol (2) and (6aS,11aS)-medicarpin (4) with quantities of 72.9, 66.9 and 30.8 mg g of ethanol extracts(- 1), respectively. Moreover, the antibacterial activities of each compound against Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa were evaluated by measuring the minimum inhibitory concentrations. In particular, compound 4 exhibited the most potent antibacterial activity among all the assayed compounds against selected bacteria, indicating that 4 is the most active compound in Brazilian red propolis extracts. Thus, Brazilian red propolis may be used as food additives and pharmaceuticals to protect against bacteria.
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Epigallocatechin gallate decreases the micellar solubility of cholesterol via specific interaction with phosphatidylcholine.
J. Agric. Food Chem.
PUBLISHED: 03-24-2014
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The mechanisms underlying the effect of epigallocatechin gallate (EGCG) on the micellar solubility of cholesterol were examined. EGCG eliminated both cholesterol and phosphatidylcholine (PC) from bile salt micelles in a dose-dependent manner in vitro. When the bile salt micelles contained a phospholipid other than PC, neither cholesterol nor the phospholipid was eliminated following the addition of EGCG. When vesicles comprised of various phospholipids were prepared and, EGCG was added to the vesicles, EGCG effectively and exclusively eliminated only PC. An intermolecular nuclear Overhauser effect (NOE) was observed between PC and EGCG in bile salt micelles with EGCG added, but not between cholesterol and EGCG, by using a NOE-correlated spectroscopy nuclear magnetic resonance method. The results of binding analyses using surface plasmon resonance (SPR) showed that EGCG did not bind to cholesterol. These observations strongly suggest that EGCG decreases the micellar solubility of cholesterol via specific interaction with PC.
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Analysis of antioxidant prenylflavonoids in different parts of Macaranga tanarius, the plant origin of Okinawan propolis.
Asian Pac J Trop Med
PUBLISHED: 01-15-2014
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To analyze the antioxidant prenylflavonoids in different parts of Macaranga tanarius (M. tanarius) (Euphorbiaceae) including the leaf, petiole, stem, leaflet, flower and fruit (only in female plant), and to evaluate their antioxidant properties.
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Chemical and functional characterisation of propolis collected from East Andalusia (southern Spain).
Phytochem Anal
PUBLISHED: 02-27-2013
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Propolis is a complex mixture of natural sticky, gummy and resinous components produced by honeybees (Apis mellifera L.) from plant materials. However, phytochemical data of the Andalusian (southern Spain) propolis are scant.
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A heteroallelic Drosophila insulin-like receptor mutant and its use in validating physiological activities of food constituents.
Biochem. Biophys. Res. Commun.
PUBLISHED: 02-13-2013
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Here we report an additional Drosophila transheterozygote InR(GS15311)/InR(GS50346) carrying two different P-element-inducible alleles of insulin-like receptor gene (InR). InR(GS15311)/InR(GS50346) flies exhibit the following phenotypes previously reported in InR and insulin/IGF-1 signaling (IIS) pathway-related gene mutants: small bodies, developmental delay, shortened lifespan, and increased fasting resistance. All of these characteristics are shared among flies carrying mutated genes implicated in the pathway. This heteroallelic combination exhibited fertility but resulted in male semilethality, while females were viable and grew into adults. Furthermore, an experimental model employing the InR(GS15311)/InR(GS50346) strain confirmed negligible involvement of royal jelly in IIS. Thus, the heteroallelic InR mutant, discovered in this study, will serve as a good model for multiple purposes: investigating the IIS mechanisms; identifying and validating the ingredients that prevent type II diabetes; and screening of food constituents associated with IIS.
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Nymphaeol-A Isolated from Okinawan Propolis Suppresses Angiogenesis and Induces Caspase-Dependent Apoptosis via Inactivation of Survival Signals.
Evid Based Complement Alternat Med
PUBLISHED: 01-10-2013
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Propolis, a resinous substance that honeybees collect to protect their beehive from enemies, is reported to have various biological activities. In our screening program to search for antiangiogenic compounds from propolis, the ethanol extracts of Okinawan propolis (EEOP) showed significant antiangiogenic activities in a tube formation assay with human umbilical vein endothelial cells (HUVECs) in vitro at 3.13? ? g/mL and chorioallantoic membrane (CAM) assay in vivo at 25? ? g/egg. To elucidate the active compounds of EEOP and their mode of action, we isolated some prenylated flavonoids from EEOP and found that nymphaeol-A had the strongest antiangiogenic activity among them. Nymphaeol-A significantly reduced in vivo neovessel formation in the CAM assay at 25? ? g/egg. At the molecular level, nymphaeol-A markedly inactivated mitogen-activated protein kinase/ERK kinase 1/2 (MEK1/2) and extracellular signal-regulated kinase 1/2 (ERK1/2), whose molecular activations signal new vessel formation in HUVECs. In addition, nymphaeol-A dose- and time-dependently induced caspase-dependent apoptosis in tube-forming HUVECs. Taken together, nymphaeol-A was shown to inhibit angiogenesis at least in part via inactivation of MEK1/2-ERK1/2 signaling and induction of caspase-dependent apoptosis. Okinawan propolis and its major component, nymphaeol-A, may be useful agents for preventing tumor-induced angiogenesis.
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Brazilian propolis-derived components inhibit TNF-?-mediated downregulation of adiponectin expression via different mechanisms in 3T3-L1 adipocytes.
Biochim. Biophys. Acta
PUBLISHED: 01-27-2011
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Previous reports suggest that Brazilian propolis has multiple biological functions and may help to restore adiponectin expression and insulin sensitivity. However, little is known about the molecular mechanisms by which these compounds inhibit the downregulation of adiponectin.
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Interaction of epicatechin gallate with phospholipid membranes as revealed by solid-state NMR spectroscopy.
Biochim. Biophys. Acta
PUBLISHED: 01-27-2011
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Epicatechin gallate (ECg), a green tea polyphenol, has various physiological effects. Our previous nuclear Overhauser effect spectroscopy (NOESY) study using solution NMR spectroscopy demonstrated that ECg strongly interacts with the surface of phospholipid bilayers. However, the dynamic behavior of ECg in the phospholipid bilayers has not been clarified, especially the dynamics and molecular arrangement of the galloyl moiety, which supposedly has an important interactive role. In this study, we synthesized [13C]-ECg, in which the carbonyl carbon of the galloyl moiety was labeled by 13C isotope, and analyzed it by solid-state NMR spectroscopy. Solid-state 31P NMR analysis indicated that ECg changes the gel-to-liquid-crystalline phase transition temperature of DMPC bilayers as well as the dynamics and mobility of the phospholipids. In the solid-state 13C NMR analysis under static conditions, the carbonyl carbon signal of the [13C]-ECg exhibited an axially symmetric powder pattern. This indicates that the ECg molecules rotate about an axis tilting at a constant angle to the bilayer normal. The accurate intermolecular-interatomic distance between the labeled carbonyl carbon of [13C]-ECg and the phosphorus of the phospholipid was determined to be 5.3±0.1 Å by 13C-(31)P rotational echo double resonance (REDOR) measurements. These results suggest that the galloyl moiety contributes to increasing the hydrophobicity of catechin molecules, and consequently to high affinity of galloyl-type catechins for phospholipid membranes, as well as to stabilization of catechin molecules in the phospholipid membranes by cation-? interaction between the galloyl ring and quaternary amine of the phospholipid head-group.
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(-)-Epigallocatechin-3-gallate suppresses growth of AZ521 human gastric cancer cells by targeting the DEAD-box RNA helicase p68.
Free Radic. Biol. Med.
PUBLISHED: 01-17-2011
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(-)-Epigallocatechin-3-gallate (EGCG), the most abundant and biologically active polyphenol in green tea, induces apoptosis and suppresses proliferation of cancer cells by modulating multiple signal transduction pathways. However, the fundamental mechanisms responsible for these cancer-preventive effects have not been clearly elucidated. Recently, we found that EGCG can covalently bind to cysteine residues in proteins through autoxidation and subsequently modulate protein function. In this study, we demonstrate the direct binding of EGCG to cellular proteins in AZ521 human gastric cancer cells by redox-cycle staining. We comprehensively explored the binding targets of EGCG from EGCG-treated AZ521 cells by proteomics techniques combined with the boronate-affinity pull-down method. The DEAD-box RNA helicase p68, which is overexpressed in a variety of tumor cells and plays an important role in cancer development and progression, was identified as a novel EGCG-binding target. Exposure of AZ521 cells to EGCG lowered the p68 level dose dependently. The present findings show that EGCG inhibits AZ521 cell proliferation by preventing ?-catenin oncogenic signaling through proteasomal degradation of p68 and provide a new perspective on the molecular mechanism of EGCG action.
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Radical-scavenging activity and phenolic constituents of propolis from different regions of Argentina.
Nat. Prod. Res.
PUBLISHED: 05-13-2010
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Propolis is a resinous substance collected by honeybees from various plant sources. The composition of propolis depends on the type of vegetation and the area of collection. We examined the radical-scavenging activity of propolis from the following regions of Argentina: Mendoza, Rio Negro, La Pampa, and Entre Rios. Ethanol extracts of propolis (EEP) were prepared and their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities were evaluated. Furthermore, the major constituents in EEP were identified by HPLC with photodiode array (PDA) detection, and each component was quantitatively analysed. Almost all of the propolis samples, except La Pampa, had radical-scavenging activity. Propolis with strong radical-scavenging activity contained large amounts of antioxidative compounds, such as caffeic acid, ferulic acid and caffeic acid phenethyl ester.
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Pro-oxidant action of pyrroloquinoline quinone: characterization of protein oxidative modifications.
Biosci. Biotechnol. Biochem.
PUBLISHED: 03-07-2010
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Pyrroloquinoline quinone (PQQ), a putative essential nutrient, is a redox modulator in cell and animal models. Here we characterized PQQ-induced protein oxidative modifications in a model peptide and protein, and we propose that the mechanism of protein modification by PQQ is redox cycling-mediated oxidation. PQQ may contribute to the regulation of intracellular protein functions through its prooxidant action.
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Distribution and excretion of bilberry anthocyanins [corrected] in mice.
J. Agric. Food Chem.
PUBLISHED: 08-12-2009
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The physiology and tissue distribution of bilberry anthocyanins were studied in mice. After oral administration of bilberry extract (100 mg/kg body weight), both unmodified and methylated anthocyanins appeared in the plasma. The plasma concentration of total anthocyanins reached a maximum of 1.18 +/- 0.3 microM after 15 min and then sharply decreased. Their urinary excretion was highest between 0 and 6 h after administration and had ceased by 24 h. The total quantities of bilberry anthocyanins excreted into urine represented 1.88% (range, 0.62% to 2.45%) of consumed anthocyanins. Thirteen anthocyanins were identified in bilberry extracts. Of these, malvidin-3-glucoside and -3-galactoside were the principal anthocyanins in the plasma 60 min after administration. When mice were maintained for 2 weeks on a diet containing 0.5% of bilberry extracts, the plasma concentration of anthocyanins reached a maximum of 0.26 muM. Anthocyanins were detected only in the liver, kidney, testes, and lung, with maximum tissue concentrations of 605, 207, 149, and 116 pmol/g, respectively. In these organs, malvidin-3-glucoside and -3-galactoside were the predominant anthocyanins. Anthocyanins were not detectable in the spleen, thymus, heart, muscle, brain, white fat, or eyes. We conclude that bilberry anthocyanins were absorbed into the body and distributed in specific organs, particularly the liver, kidney, and testis. The most common anthocyanins in tissues were malvidin glycosides.
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Quercetin metabolites and protection against peroxynitrite-induced oxidative hepatic injury in rats.
Free Radic. Res.
PUBLISHED: 08-06-2009
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Quercetin has strong antioxidant potency. Quercetin-3-O-sulphate (Q3S) and quercetin-3-O-glucuronide (Q3GA) are the main circulating metabolites after consumption of quercetin-O-glucoside-rich diets by humans. However, information about how these quercetin metabolites function in vivo is limited. Hence, this study evaluated the efficacy of Q3S and Q3GA for the protection of oxidative injury using in vitro and in vivo experiments. Peroxynitrite-mediated hepatic injury in rats was induced by administration of galactosamine/lipopolysaccharide (GalN/LPS). Twenty-four hours after GalN/LPS treatment, plasma ALT and AST levels delta increased significantly. However, pretreatment with 4(G)-alpha-D-glucopyranosyl rutin, a quercetin glycoside (30 mg/kg body weight), prevented these increases and reduced nitrotyrosine formation, indicating that consumption of quercetin glycosides prevent oxidative hepatotoxicity. Moreover, physiological levels of Q3S and Q3GA (1 microM) effectively prevented peroxynitrite-induced nitrotyrosine formation in human serum albumin in in vitro experiments. These findings indicate peroxynitrite-induced oxidative hepatotoxicity is protected by the in vivo metabolites of quercetin, Q3S and Q3GA.
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Correlation between antiangiogenic activity and antioxidant activity of various components from propolis.
Mol Nutr Food Res
PUBLISHED: 07-16-2009
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Propolis possesses various physiological activities. In this study, we examined the antiangiogenic and antioxidant activities of various components from propolis: acacetin, apigenin, artepillin C, caffeic acid phenethyl ester, chrysin, p-coumaric acid, galangin, kaempferol, pinocembrin, and quercetin. The effects of these components were tested on in vitro models of angiogenesis, tube formation and growth of human umbilical vein endothelial cells (HUVECs). Furthermore, these components were evaluated for their antioxidant activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging and ferric reducing/antioxidant power (FRAP) assays. Two propolis components, caffeic acid phenethyl ester, and quercetin, possessed strong inhibitory effects on tube formation and on endothelial cell proliferation and, coincidentally, showed strong antioxidant activity. Artepillin C, galangin, and kaempferol also possessed strong antiangiogenic and antioxidant activities to a slightly less degree. In contrast, acacetin, apigenin, and pinocembrin possessed a considerable degree of antiangiogenic activities, although they showed very low antioxidant activities. From these results, we propose that components from propolis such as artepillin C, caffeic acid phenethyl ester, galangin, kaempferol, and quercetin might represent a new class of dietary-derived antioxidative compounds with antiangiogenic activities. These propolis components may have the potential to be developed into pharmaceutical drugs for the treatment of angiogenesis-dependent human diseases such as tumors.
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Fingerprinting of propolis by easy ambient sonic-spray ionization mass spectrometry.
Talanta
PUBLISHED: 06-30-2009
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Chemical profiles of a representative set of 49 propolis ethanolic extracts collected worldwide (North and South America, Europe, Asia and Oceania) were obtained via easy ambient sonic-spray ionization mass spectrometry (EASI-MS). This simple and easily implemented fingerprinting technique analyses directly (without any pre-separation or sample manipulation) a tiny droplet of the ethanolic extract placed on a inert surface under ambient conditions. Data acquisition took about a minute per sample with no substantial sample carry-over. Extraction of propolis with ethanol by using an ultrasonic bath method gave EASI-MS data similar to the traditional maceration method, reducing total analysis time for the crude propolis resin from a week to just ca 1h. Principal component analysis of the EASI-MS data is shown to group samples according to the plant sources of their resins, which characterizes their geographical origin.
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Artepillin C (ARC) in Brazilian green propolis selectively blocks oncogenic PAK1 signaling and suppresses the growth of NF tumors in mice.
Phytother Res
PUBLISHED: 03-31-2009
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There are mainly three types of propolis whose major anticancer ingredients are entirely different: (1) CAPE (caffeic acid phenethyl ester)-based propolis in Europe, Far East and New Zealand, (2) artepillin C (ARC)-based Brazilian green propolis and (3) Brazilian red propolis. It was shown previously that NF (neurofibromatosis)-associated tumors require the kinase PAK1 for their growth, and CAPE-based propolis extracts such as Bio 30 suppress completely the growth of NF tumors in vivo by blocking PAK1 signaling. Also it was demonstrated that ARC suppresses angiogenesis, suggesting the possibility that ARC also blocks oncogenic PAK1 signaling. Here it is shown for the first time that both ARC and green propolis extract (GPE) indeed block the PAK1 signaling selectively, without affecting another kinase known as AKT. Furthermore, it was confirmed that ARC as well as GPE suppress almost completely the growth of human NF tumor xenografts in mice, as does Bio 30. These results suggest that both CAPE-based and ARC-based propolis extracts are natural anti-PAK1 remedies and could be among the first effective NF therapeutics available on the market. Since more than 70% of human cancers such as breast and prostate cancers require the kinase PAK1 for their growth, it is quite possible that GPE could be potentially useful for the treatment of these cancers, as is Bio 30.
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Identification of the plant origin of propolis from Jeju Island, Korea, by observation of honeybee behavior and phytochemical analysis.
Biosci. Biotechnol. Biochem.
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Propolis collected on Jeju Island, Korea, contains characteristic components not present in propolis from other regions. Hence, the plant origin of the propolis from Jeju Island can be expected to be a novel plant. To identify the plant origin of this propolis, first we observed honeybee behavior, and found them collecting the resin from Angelica keiskei. Then comparative analyses of chemical and biological properties of the resin from the plant and propolis from hives of nearby apiaries were performed. Alcoholic extracts showed entirely identical HPLC profiles and closely similar antioxidant activities. These results indicate that A. keiskei is the plant origin of the propolis from Jeju Island, Korea.
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Freeze-dried royal jelly maintains its developmental and physiological bioactivity in Drosophila melanogaster.
Biosci. Biotechnol. Biochem.
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Royal jelly (RJ), a honeybee-derived product, has been found to possess developmental and physiological bioactivity in the fruit fly, Drosophila melanogaster, but little is known about the in vivo bioactivity of freeze-dried RJ (FDRJ) powder, which is another form of RJ processed for human use. To address this, we used Drosophila as a model animal to examine the effects of FDRJ in multicellular organisms. When flies were reared on food supplemented with FDRJ, the developmental time from larva to adult was shortened, the adult male lifespan was prolonged, and female fecundity was increased without any significant morphological alterations. Moreover, the expression of dilp5, an insulin-like peptide, its receptor InR, and the nutrient sensing molecule TOR, the target of rapamycin, was significantly increased in FDRJ-fed female flies as compared with ones reared on standard and on protein-enriched food. These findings suggest that like RJ, FDRJ maintains its bioactivity even after processing from RJ, what is expected to have bioactivity for multicellular organisms, including humans.
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Solophenols B-D and solomonin: new prenylated polyphenols isolated from propolis collected from the Solomon Islands and their antibacterial activity.
J. Agric. Food Chem.
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Three new prenylated flavonoids, namely, solophenols B (1), C (2), and D (3), as well as a new prenylated stilbene, solomonin (4), were isolated from propolis collected from the Solomon Islands. In addition, 17 known compounds were identified. The structures of the new compounds were determined by a combination of methods, including mass spectrometry and NMR. These new compounds and several known compounds were tested for antibacterial activity against Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa. Most of them exhibited potent antibacterial activity. These findings may indicate that propolis from the Solomon Islands has potential applications as an ingredient in food additives or pharmaceuticals.
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A new prenylflavonoid isolated from propolis collected in the Solomon Islands.
Biosci. Biotechnol. Biochem.
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The new prenylflavonoid, solophenol A (1), together with three known compounds, bonannione A (2), sophoraflavanone A (3) and (2S)-5,7-dihydroxy-4-methoxy-8-prenylflavanone (4), were isolated from propolis collected from Malaita Island in The Solomon Islands. The structure of each compound was determined by spectroscopic methods, including mass spectrometry and 2D NMR. Compound 1 exhibited potent 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity.
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Component analysis of propolis collected on Jeju Island, Korea.
Phytochemistry
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A study of propolis from Jeju Island, located off the southern tip of Korea, led to the isolation and identification of eight chalcones: (±)-(E)-4-methoxy-4,2-dihydroxy-3-(2?,3?-dihydroxy-3?-methylbutyl)-chalcone, (E,E,E)-4,2,4-trihydroxy-3-(7?-hydroxy-3?,7?-dimethyloct-2?,5?-dienyl)-chalcone, (±)-(E,E)-4,2,4-trihydroxy-3-(5?-hydroxy-3?,7?-dimethyloct-2?,6?-dienyl)-chalcone, (±)-(E)-4-methoxy-4,3?,4?-trihydroxy-2?,2?-dimethyldihydropyrano-(2,3)-chalcone, (±)-(E)-4-methoxy-4,3?-dihydroxy-2?-(1?-hydroxyisopropyl)-dihydrofurano-(2,3)-chalcone, (-)-(E)-4,4-dihydroxy-2?-(1?-hydroxy-1?,5?-dimethylhex-4?-enyl)-dihydrofurano-(2,3)-chalcone, (+)-(E)-4,2-dihydroxy-2?-methyl-2?-(3?,4?-dihydroxy-4?-methylpentanyl)-2H-pyrano-(3,4)-chalcone and (-)-(E)-4,2-dihydroxy-2?-methyl-2?-(3?,4?-dihydroxy-4?-methylpentanyl)-2H-pyrano-(3,4)-chalcone. Nineteen other known compounds were also isolated. Their structures were determined by spectroscopic analyses and comparison with literature data. The propolis from Jeju Island contained compounds not present in propolis from other regions.
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