A series of 4-thioflavonols compounds were synthesized by treating flavonols with lawsons reagent with variable substituent groups at A, B, and AB rings. All the synthesized compounds were checked for antibacterial an...A series of 4-thioflavonols compounds were synthesized by treating flavonols with lawsons reagent with variable substituent groups at A, B, and AB rings. All the synthesized compounds were checked for antibacterial and antifungal activity. We report that many compounds were found active against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, bacterial strains and, C. albicans, C. parapsilosisstrains and C. krusei fungal strains. Most of the synthesized 4-thioflavonols compounds were found to show enhanced antimicrobial activity than respective flavonol compounds.展开更多
The cell cycle checkpoint system play a pivotal role in the cellular DNA damage response, and the discovery of checkpoint inhibitors is expected to sensitize current cancer therapies. Checkpoint signaling cascades are...The cell cycle checkpoint system play a pivotal role in the cellular DNA damage response, and the discovery of checkpoint inhibitors is expected to sensitize current cancer therapies. Checkpoint signaling cascades are critically modulated by ATM (ataxia telangiectasia-mutated) and its related molecules. Generally, ATM primarily responds to ionizing irradiation-induced DNA double-strand breaks. Heavy ions from an accelerated carbon ion beam have been used to cure cancer because they are more effective than ionizing irradiation such as X-ray and γ-radiation in terms of biological damage. In a previous study, we demonstrated that a persimmon leaf flavonol (PLF) promoted the cytotoxic effect of chemotherapeutic agents on cancer cells through inhibition of checkpoint activities, especially in the ATM dependent pathway. The present study investigated whether PLF inhibits checkpoint activity during the DNA damage response induced by heavy ion irradiation. Treatment with PLF significantly increased the cytotoxicity of heavy ion irradiation in A549 adenocarcinoma cells. The phosphorylation of checkpoint proteins such as p53, SMC1, and Chk1 was increased by heavy ions. PLF reduced the phosphorylation of checkpoint proteins. Pre-treatment with PLF significantly prevented the decrease of mitotic cells in heavy ion-exposed cells. We further evaluated tumor volume in SCID mice inoculated with human lung adenocarcinoma A549 cells. The combination treatment of PLF and heavy ion resulted in a decrease of tumor volume compared with controls, although PLF itself did not exhibit any effect. These results indicate that PLF inhibits tumor growth through modulation of the DNA damage response. PLF may be useful for clinical application in combination with heavy ion radiotherapy.展开更多
Flavonols were extracted from Acanthopanax Senticosus Harms by Soxhlet extraction（SE）,atmospheric pressure microwave-assisted extraction（AMAE） and pressurized microwave-assisted extraction（PMAE）.The influences o...Flavonols were extracted from Acanthopanax Senticosus Harms by Soxhlet extraction（SE）,atmospheric pressure microwave-assisted extraction（AMAE） and pressurized microwave-assisted extraction（PMAE）.The influences of experimental conditions,such as concentration of ethanol in the eluent,microwave irradiation time,etc.on the extraction yield were studied.Four flavonols（hyperin,rutin,quercitrin and quercetin） in the extracts were determined quantitatively by HPLC method.The experimental results demonstrate the advantages of PMAE and AMAE over those of conventional SE,that is the extraction time is dramatically reduced,and the yields of flavonols are effective improved.Although the yield of flavonols is higher and the extraction time is shorter by PMAE than those of AMAE,flavonols are easy to be decomposed over a certain time.展开更多
The enthalpies of bond dissociations of the hydroxyl groups, the energy of the highest occupied molecular orbitals and the corresponding radicals spin densities of all possible ten isomeric mono-hydroxyl flavones are ...The enthalpies of bond dissociations of the hydroxyl groups, the energy of the highest occupied molecular orbitals and the corresponding radicals spin densities of all possible ten isomeric mono-hydroxyl flavones are calculated by means of 3-parameter Becke, Lee, Yang and Parr functional. The structural factors affecting these descriptors of radical-scavenging activity are outlined. The results obtained show that the hydroxyl groups in ring A and C are more involved in the process of a radical-capturing than recently believed.展开更多
Hsp90 is a major protein involved in the stabilization of various proteins in cancer cells.The present investigation focused on the molecular docking simulation studies of flavanols as inhibitors of Hsp90 at the high ...Hsp90 is a major protein involved in the stabilization of various proteins in cancer cells.The present investigation focused on the molecular docking simulation studies of flavanols as inhibitors of Hsp90 at the high affinity adenosine triphosphate（ATP）binding site and analyzed absorption,distribution,metabolism,excretion and toxicity（ADME-toxicity）.The molecular docking analysis revealed that the flavanols showed competitive inhibition with ATP molecule at the active site and enhanced pharmacological parameters.展开更多
In this study,we designed a convenient method,to total synthesis of fl avonols especially for C-5 substituted ones and derivatives on a large scale.Beginning from the inexpensively available 2,4,6-trihydroxyacetopheno...In this study,we designed a convenient method,to total synthesis of fl avonols especially for C-5 substituted ones and derivatives on a large scale.Beginning from the inexpensively available 2,4,6-trihydroxyacetophenone through Aldol condensation reaction,I2/DMSO cyclization reaction,Oxone“one pot”oxidation,kaempferol(1)and derivative(2)was obtained in an overall yield of 35%.The structures of the target compound and key intermediates were verifi ed by MS,IR,1H-NMR and 13C-NMR techniques,and the structure of 5a was further confi rmed by X-ray diff raction analysis.展开更多
Flavonols, the main flavonoids in plant leaves, have newly been proposed as a H2O2 scavenger in guard cells. However, whether 5-aminolevulinic acid(5-ALA) is involved in regulating stomatal movement of apple(Malus ...Flavonols, the main flavonoids in plant leaves, have newly been proposed as a H2O2 scavenger in guard cells. However, whether 5-aminolevulinic acid(5-ALA) is involved in regulating stomatal movement of apple(Malus × domestica Borkh. ‘Fuji') leaves through flavonol accumulation remains unclear. In this study, using diphenylboric acid 2-amino ethyl ester(DPBA, a flavonol fluorescent dye) and a laser scanning confocal microscope,we observed that 5-ALA pretreatment significantly improved flavonol accumulation in guard cells of apple leaves, especially around the nucleus.Then we demonstrated that 5-ALA pretreatment inhibited ABA-induced stomatal closure via decreasing reaction oxygen species(ROS) accumulation in guard cells. Pretreatment with quercetin or kaempferol, two main kinds of flavonols in plants, also inhibited ABA-induced stomatal closure by decreasing ROS content in the guard cells. Furthermore, exogenous flavonols could suppress H2O2-induced stomatal closure in apple leaves.Taken together, we conclude that ALA-induced flavonol accumulation in guard cells is involved in the inhibitory effect of ALA on ABA-induced ROS accumulation and stomatal closure in apple leaves.展开更多
In this research, supercritical carbon dioxide extraction （SFE） showed better extraction etlect when compared with Solid- liquid extraction （SLE）, Soxhlet extraction （SEt and Ultrasonic extraction （UE）, not onl...In this research, supercritical carbon dioxide extraction （SFE） showed better extraction etlect when compared with Solid- liquid extraction （SLE）, Soxhlet extraction （SEt and Ultrasonic extraction （UE）, not only in the rate but also the time. The comparison among these three extraction modifiers, including acetone, ethanol and methanol demonstrated that ethanol was preferred to SFE due to its high extraction effect and low toxicology. In addition, parameter of SFE, influence of temperature and pressure were investigated, and the best extraction effect was achieved at the optima conditions, temperature of 40℃ and the pressure of 35 MPa. Thus, SFE is a highly effective method for flavonols extraction, requiring minimum energy and producing non-toxic byproduct. SFE-GC system is applied for the evaluation on flavonols that plays a key role in plant resistance to heavy metal, with its content and synthetase gene expression significantly increasing in plant when threatened by heavy metal. Besides, results indicated that flavonols can improve plant resistance to oxidative stress by quenching the redundant ROS in matrix.展开更多
Traditional electrospray ionization tandem mass spectrometry(ESI-MS^(n))has been a powerful tool in diverse research areas,however,it faces great limitations in the study of protein-small molecule interactions.In this...Traditional electrospray ionization tandem mass spectrometry(ESI-MS^(n))has been a powerful tool in diverse research areas,however,it faces great limitations in the study of protein-small molecule interactions.In this article,the state-of-the-art temperature-controlled electrospray ionization tandem mass spectrometry(TC-ESI-MS^(n))is applied to investigate interactions between ubiquitin and two flavonol molecules,respectively.The combination of collision-induced dissociation(CID)and MS solution-melting experiments facilitates the understanding of flavonol-protein interactions in a new dimension across varying temperature ranges.While structural changes of proteins disturbed by small molecules are unseen in ESI-MS^(n),TC-ESI-MS^(n)allows a simultaneous assessment of the stability of the complex in both gas and liquid phases under various temperature conditions,meanwhile investigating the impact on the protein’s structure and tracking changes in thermodynamic data,and the characteristics of structural intermediates.展开更多
Lesion mimic often exhibits leaf disease-like symptoms even in the absence of pathogen infection,and is characterized by a hypersensitive-response(HR)that closely linked to plant disease resistance.Despite this,only a...Lesion mimic often exhibits leaf disease-like symptoms even in the absence of pathogen infection,and is characterized by a hypersensitive-response(HR)that closely linked to plant disease resistance.Despite this,only a few lesion mimic genes have been identified in wheat.In this investigation,a lesion mimic wheat mutant named je0297 was discovered,showing no alteration in yield components when compared to the wild type(WT).Segregation ratio analysis of the F_(2)individuals resulting from the cross between the WT and the mutant revealed that the lesion mimic was governed by a single recessive gene in je0297.Using Bulked segregant analysis(BSA)and exome capture sequencing,we mapped the lesion mimic gene designated as lm6 to chromosome 6BL.Further gene fine mapping using 3315 F_(2)individuals delimited the lm6 within a 1.18 Mb region.Within this region,we identified 16 high-confidence genes,with only two displaying mutations in je0297.Notably,one of the two genes,responsible for encoding flavonol synthase,exhibited altered expression levels.Subsequent phenotype analysis of TILLING mutants confirmed that the gene encoding flavonol synthase was indeed the causal gene for lm6.Transcriptome sequencing analysis revealed that the DEGs between the WT and mutant were significantly enriched in KEGG pathways related to flavonoid biosynthesis,including flavone and flavonol biosynthesis,isoflavonoid biosynthesis,and flavonoid biosynthesis pathways.Furthermore,more than 30 pathogen infection-related(PR)genes exhibited upregulation in the mutant.Corresponding to this expression pattern,the flavonoid content in je0297 showed a significant decrease in the 4^(th)leaf,accompanied by a notable accumulation of reactive oxygen,which likely contributed to the development of lesion mimic in the mutant.This investigation enhances our comprehension of cell death signaling pathways and provides a valuable gene resource for the breeding of disease-resistant wheat.展开更多
Two total synthetic routes for the preparation of myricetin were designed and explored.It was validated that route B presented an efficient approach to synthesizing myricetin,starting from commercially available and i...Two total synthetic routes for the preparation of myricetin were designed and explored.It was validated that route B presented an efficient approach to synthesizing myricetin,starting from commercially available and inexpensive phloroglucinol.Myricetin was synthesized with an overall yield of 60%across three steps without the need of column chromatography separation.The successful preparation of myricetin on a 25-g scale underscored the potential of this approach.展开更多
[Objective]The aim was to identify the composition of pigments from Jujube fruit skin.[Method]Pigments were extracted from＇Lubei Dongzao＇,＇Lajiao Zao＇,＇Chengwu Dongzao＇,＇Dabailing＇and identificated by using hi...[Objective]The aim was to identify the composition of pigments from Jujube fruit skin.[Method]Pigments were extracted from＇Lubei Dongzao＇,＇Lajiao Zao＇,＇Chengwu Dongzao＇,＇Dabailing＇and identificated by using high performance liquid chromatography-mass spectrometry（HPLC-MS）.[Result]The results showed that eight flavanols and four to five flavonols were detected,no anthocyanins was detected.The contents of flavonoids were differnt in four varieties.The contents of flavanols（11 mg/g） and flavonols（1.78 mg/g） in＇Dabailing＇ were one-time higher than other varieties.Quercetin 3 rutinoside was the major flavonol.[Conclusion]The research provided theoretical basis for further study on mechanism of Jujube pigment turnning into the red.展开更多
Abstract： In the present study, we established an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry （UPLC-QTOF-MSE） method to simultaneously quantify 33 components in Ginkgo bilo...Abstract： In the present study, we established an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry （UPLC-QTOF-MSE） method to simultaneously quantify 33 components in Ginkgo biloba leaf extracts （GBEs）, including 17 flavonol glycosides, five terpene trilactones （TTLs）, four polyphenols and seven carboxylic acids. This optimized method was successfully applied to analyze the explicit compositions of GBE samples collected from different places. Furthermore, the data were processed through unsupervised principal component analysis （PCA） and supervised orthogonal partial least squared discrimination analysis （OPLS-DA） to evaluate the quality and compare the differences between the samples according to the contents of the 33 chemical constituents. Bilobalide, protocatechuic acid, shikimic acid, quinic acid, ginkgolide B, ginkgolide J, kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, quercetin-3-O-ct-L-rhamnopyranocyl-2＂-（6＇＂-p-coumaroyl）-β-D-glucoside and rutin were recognized as characteristic chemical markers that contributed most to control the quality of GBEs. Based on the fact that GBEs should be standardized with the characteristic components as quality control chemical markers, it is most important to maintain the quality of GBEs stable and reliable, and this method also provided a good strategy to further rectify and standardize the GBEs market.展开更多
A phytochemical investigation on the leaves of Cistus parviflorus led to the isolation of 18 compounds.The structures of the isolated compounds were elucidated as kaempferol 3-O-（3′′,6′′-di-O-E-p-coumaroyl）-β-D...A phytochemical investigation on the leaves of Cistus parviflorus led to the isolation of 18 compounds.The structures of the isolated compounds were elucidated as kaempferol 3-O-（3′′,6′′-di-O-E-p-coumaroyl）-β-D-glucopyranoside（1）,scopoletin（2）,kaempferol 3-O-（3′′-O-E-p-coumaroyl）-β-D-glucopyranoside（3）,kaempferol 3-O-（6′′-O-E-p-coumaroyl）-β-D-glucopyranoside（4）,kaempferol 3-O-β-D-glucopyranoside（5）,kaempferol 3-O-α-L-rhamnopyranosyl-（1→2）-（6′-O-E-p-coumaroyl）-β-D-glucopyranoside（6）,methyl flavogallonate（7）,quercetin 3-O-β-D-glucopyranoside（8）,quercetin 3-O-β-D-galactopyranoside（9）,hydroquinone（10）,arbutin（11）,methyl β-glucopyranoside（12）,shikimic acid（13）,（S）-1,2-propandiol-1-O-β-D-glucopyranoside（14）,benzyl-O-α-L-rhamnopyranosyl-（1→6）-β-D-glucopyranoside（15）,2-phenethyl-O-α-L-rhamnopyranosyl-（1→6）-β-D-glucopyranoside（16）,corchoionoside C（17）,kaempferol 3-O-α-L-rhamnopyranosyl-（1→2）-β-D-glucopyranoside（18） by the analysis of the MS and NMR spectroscopic data and comparison with the literature.Compounds 1–2,6–7,10–12,and 14–16 were isolated from Cistus genus for the first time.展开更多
This review was based on a literature search of PubM ed and Scielo databases using the keywords "quercetin,rutin,isoquercitrin,isoquercitin(IQ),quercetin-3-glucoside,bioavailability,flavonols and favonoids,and ca...This review was based on a literature search of PubM ed and Scielo databases using the keywords "quercetin,rutin,isoquercitrin,isoquercitin(IQ),quercetin-3-glucoside,bioavailability,flavonols and favonoids,and cancer" and combinations of all the words.We collected relevant scientific publications from 1990 to 2015 about the absorption,bioavailability,chemoprevention activity,and treatment effects as well as the underlying anticancer mechanisms of isoquercitin.Flavonoids are a group of polyphenolic compounds widely distributed throughout the plant kingdom.The subclass of flavonols receives special attention owing to their health benefits.The main components of this class are quercetin,rutin,and IQ,which is a flavonoid and although mostly found as a glycoside,is an aglycone(lacks a glycoside side chain).This compound presents similar therapeutic profiles to quercetin but with superior bioavailability,resulting in increased efficacy compared to the aglycone form.IQ has therapeutic applications owing to its wide range of pharmacological effects including antioxidant,antiproliferative,anti-inflammatory,anti-hypertensive,and anti-diabetic.The protective effects of IQ in cancer may be due to actions on lipid peroxidation.In addition,the antitumor effect of IQ and its underlying mechanism are related to interactions with Wnt signaling pathway,mixed-lineage protein kinase 3,mitogen-activated protein kinase,apoptotic pathways,as well proinflammatory protein signaling.This review contributed to clarifying the mechanisms of absorption,metabolism,and actions of IQ and isoquercitrin in cancer.展开更多
Flavonoids are widely used in industry for the prevention of various diseases. In daily life we are directly in touch with flavonoids due to their presence in different beverages, fruits and vegetables. Flavonoids are...Flavonoids are widely used in industry for the prevention of various diseases. In daily life we are directly in touch with flavonoids due to their presence in different beverages, fruits and vegetables. Flavonoids are mainly used as a coloring agent in plants, antioxidant and nutritional food for human. Flavonoids have explicit role in UV filtration, symbiotic nitrogen fixation and floral pigmentation. Flavonoids have potential for different biological activities like chelation of metals, decreasing platelets aggregation and cell signaling etc.展开更多
The fruits of the Sea buckthorn(Hippophae rhamnoides L.)are a popular plant food and a valuable health product.Cultivating plants produces a lot of leaves with fine branches as an unnecessary residue,which needs valor...The fruits of the Sea buckthorn(Hippophae rhamnoides L.)are a popular plant food and a valuable health product.Cultivating plants produces a lot of leaves with fine branches as an unnecessary residue,which needs valorization.The aim of the study was to estimate(by HPLC-MS/MS)the qualitative and quantitative content of polyphenolic compounds in different parts of H.rhamnoides(HR),and to determine the level of antioxidant activity of leaves and fruits(by DPPH,ABTS methods and ferrozine test).Up to 19 compounds were identified in different parts of HR.The fruits are rich in flavonoids,including various glycosides of flavonols isorhamnetin,quercetin,and kaempferol.Two isorhamnetin glycosides were not identified in the leaves,while isorhamnetin-3-rhamnosylglactosides and the ellagitannins hippophaenin B,stachyurin and casuarinin were present only in the leaves of the plant.The bark and roots contained considerably more catechins,but minimal flavonols than the fruits and leaves of HR.The total phenolics and flavonols were most abundant in water infusions from leaves of HR(especially quercetin-3-O-glucoside-7-O-rhamnoside),compared to methanolic extracts.No significant differences in the quantitative and qualitative content of the fresh and dried leaves were detected.The highest antioxidant activity by all three methods was detected in the leaves of HR.In addition to the fruits,the leaves may have a perspective as a source of biologically active substances of HR.展开更多
Stomach and colorectal cancers are common cancers and leading causes of cancer deaths.Because the alimentary tract can interact directly with dietary components,stomach and colorectal cancer may be closely related to ...Stomach and colorectal cancers are common cancers and leading causes of cancer deaths.Because the alimentary tract can interact directly with dietary components,stomach and colorectal cancer may be closely related to dietary intake.We systematically searched published literature written in English via PubMed by searching for terms related to stomach and colorectal cancer risk and dietary flavonoids up to June 30,2012.Twenty-three studies out of 209 identified articles were finally selected for the analysis.Log point effect estimates and the corresponding standard errors were calculated using covariate-adjusted point effect estimates and 95%CIs from the selected studies.Total dietary flavonoid intake was not associated with a reduced risk of colorectal or stomach cancer [odds ratio(OR)(95%CI) = 1.00(0.90-1.11) and 1.07(0.70-1.61),respectively].Among flavonoid subclasses,the intake of flavonols,flavan-3-ols,anthocyanidins,and proanthocyanidins showed a significant inverse association with colorectal cancer risk [OR(95%CI) = 0.71(0.63-0.81),0.88(0.79-0.97),0.68(0.56-0.82),and 0.72(0.61-0.85),respectively].A significant association was found only between flavonols and stomach cancer risk based on a limited number of selected studies [OR(95%CI) = 0.68(0.46-0.99)].In the summary estimates from casecontrol studies,all flavonoid subclasses except flavones and flavanones were inversely associated with colorectal cancer risk,whereas neither total flavonoids nor any subclasses of flavonoids were associated with colorectal cancer risk in the summary estimates based on the cohort studies.The significant association between flavonoid subclasses and cancer risk might be closely related to bias derived from the case-control design.There was no clear evidence that dietary flavonoids are associated with reduced risk of stomach and colorectal cancer.展开更多
The objectives of this study were to identify the antioxidants in acid hydrolysates of six of Taiwan’s indigenous purple-leaved vegetables (IPLV), including purple-leaved sweet potato (Ipomoea batatas L. Lamark), pur...The objectives of this study were to identify the antioxidants in acid hydrolysates of six of Taiwan’s indigenous purple-leaved vegetables (IPLV), including purple-leaved sweet potato (Ipomoea batatas L. Lamark), purple-leaved gynura line 1 (Gynura bicolor D.C.), purple-leaved gynura line 2 (Gynura bicolor D.C.), purple-leaved perilla line 1 (Perilla frutescents L. Britton), bicolored-leaved perilla line 2 (Perilla frutescens L. Britton), and heartleaf houttuynia (Houttuynia cordata Thumb.). Their antioxidant activity and ability to protect DNA from oxidative damage was also evaluated. The antioxidants identified included flavonoids, anthocyanidins and flavonols. Both purple-leaved perilla line 1 and bicolored-leaved perilla line 2 were found to be abundant in cynidin, malvidin, and myricetin. Moreover, purple-leaved sweet potato and heartleaf houttuynia were found to be abundant in quercetin. Purple-leaved sweet potato and purple-leaved perilla line 1 contained significantly higher inhibition percentages of conjugated diene formation than other vegetables. Purple-leaved sweet potato, heartleaf houttuynia, purple-leaved perilla line 1, and bicolored-leaved perilla line 2 had better inhibition percentages of tail DNA% and tail moment in the study. In conclusion, the abovementioned four indigenous purple-leaved vegetables abounded in antioxidants had strong antioxidant activity for protecting DNA in lymphocytes from oxidative damages.展开更多
A series of novel flavonols were synthesized by cyclizing corresponding hydoxy chalcones using Algar flynn Oyamada reaction (1)The synthesized compounds were characterized by various spectrochemical methods including ...A series of novel flavonols were synthesized by cyclizing corresponding hydoxy chalcones using Algar flynn Oyamada reaction (1)The synthesized compounds were characterized by various spectrochemical methods including IR, MASS, NMR spectroscopy. Out of 13 compounds screened for antibacterial activity [2], compound VMF 12 (a bromo derivative) showed activity with an IC50value at 0.16μM against S. aureus.展开更多
文摘A series of 4-thioflavonols compounds were synthesized by treating flavonols with lawsons reagent with variable substituent groups at A, B, and AB rings. All the synthesized compounds were checked for antibacterial and antifungal activity. We report that many compounds were found active against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, bacterial strains and, C. albicans, C. parapsilosisstrains and C. krusei fungal strains. Most of the synthesized 4-thioflavonols compounds were found to show enhanced antimicrobial activity than respective flavonol compounds.
文摘The cell cycle checkpoint system play a pivotal role in the cellular DNA damage response, and the discovery of checkpoint inhibitors is expected to sensitize current cancer therapies. Checkpoint signaling cascades are critically modulated by ATM (ataxia telangiectasia-mutated) and its related molecules. Generally, ATM primarily responds to ionizing irradiation-induced DNA double-strand breaks. Heavy ions from an accelerated carbon ion beam have been used to cure cancer because they are more effective than ionizing irradiation such as X-ray and γ-radiation in terms of biological damage. In a previous study, we demonstrated that a persimmon leaf flavonol (PLF) promoted the cytotoxic effect of chemotherapeutic agents on cancer cells through inhibition of checkpoint activities, especially in the ATM dependent pathway. The present study investigated whether PLF inhibits checkpoint activity during the DNA damage response induced by heavy ion irradiation. Treatment with PLF significantly increased the cytotoxicity of heavy ion irradiation in A549 adenocarcinoma cells. The phosphorylation of checkpoint proteins such as p53, SMC1, and Chk1 was increased by heavy ions. PLF reduced the phosphorylation of checkpoint proteins. Pre-treatment with PLF significantly prevented the decrease of mitotic cells in heavy ion-exposed cells. We further evaluated tumor volume in SCID mice inoculated with human lung adenocarcinoma A549 cells. The combination treatment of PLF and heavy ion resulted in a decrease of tumor volume compared with controls, although PLF itself did not exhibit any effect. These results indicate that PLF inhibits tumor growth through modulation of the DNA damage response. PLF may be useful for clinical application in combination with heavy ion radiotherapy.
文摘Flavonols were extracted from Acanthopanax Senticosus Harms by Soxhlet extraction（SE）,atmospheric pressure microwave-assisted extraction（AMAE） and pressurized microwave-assisted extraction（PMAE）.The influences of experimental conditions,such as concentration of ethanol in the eluent,microwave irradiation time,etc.on the extraction yield were studied.Four flavonols（hyperin,rutin,quercitrin and quercetin） in the extracts were determined quantitatively by HPLC method.The experimental results demonstrate the advantages of PMAE and AMAE over those of conventional SE,that is the extraction time is dramatically reduced,and the yields of flavonols are effective improved.Although the yield of flavonols is higher and the extraction time is shorter by PMAE than those of AMAE,flavonols are easy to be decomposed over a certain time.
文摘The enthalpies of bond dissociations of the hydroxyl groups, the energy of the highest occupied molecular orbitals and the corresponding radicals spin densities of all possible ten isomeric mono-hydroxyl flavones are calculated by means of 3-parameter Becke, Lee, Yang and Parr functional. The structural factors affecting these descriptors of radical-scavenging activity are outlined. The results obtained show that the hydroxyl groups in ring A and C are more involved in the process of a radical-capturing than recently believed.
文摘Hsp90 is a major protein involved in the stabilization of various proteins in cancer cells.The present investigation focused on the molecular docking simulation studies of flavanols as inhibitors of Hsp90 at the high affinity adenosine triphosphate（ATP）binding site and analyzed absorption,distribution,metabolism,excretion and toxicity（ADME-toxicity）.The molecular docking analysis revealed that the flavanols showed competitive inhibition with ATP molecule at the active site and enhanced pharmacological parameters.
基金Science and Technology Project of Gansu Province(grant No.18YF1NA128)the Natural Science Foundation of Liaoning Province(grant No.201602712).
文摘In this study,we designed a convenient method,to total synthesis of fl avonols especially for C-5 substituted ones and derivatives on a large scale.Beginning from the inexpensively available 2,4,6-trihydroxyacetophenone through Aldol condensation reaction,I2/DMSO cyclization reaction,Oxone“one pot”oxidation,kaempferol(1)and derivative(2)was obtained in an overall yield of 35%.The structures of the target compound and key intermediates were verifi ed by MS,IR,1H-NMR and 13C-NMR techniques,and the structure of 5a was further confi rmed by X-ray diff raction analysis.
基金supported by the National Natural Science Foundation of China (31401820)the Natural Science Foundation of Jiangsu Province, China (BK20140702)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD130809001)the Fundamental Research Funds for the Central Universities (KJQN201538)
文摘Flavonols, the main flavonoids in plant leaves, have newly been proposed as a H2O2 scavenger in guard cells. However, whether 5-aminolevulinic acid(5-ALA) is involved in regulating stomatal movement of apple(Malus × domestica Borkh. ‘Fuji') leaves through flavonol accumulation remains unclear. In this study, using diphenylboric acid 2-amino ethyl ester(DPBA, a flavonol fluorescent dye) and a laser scanning confocal microscope,we observed that 5-ALA pretreatment significantly improved flavonol accumulation in guard cells of apple leaves, especially around the nucleus.Then we demonstrated that 5-ALA pretreatment inhibited ABA-induced stomatal closure via decreasing reaction oxygen species(ROS) accumulation in guard cells. Pretreatment with quercetin or kaempferol, two main kinds of flavonols in plants, also inhibited ABA-induced stomatal closure by decreasing ROS content in the guard cells. Furthermore, exogenous flavonols could suppress H2O2-induced stomatal closure in apple leaves.Taken together, we conclude that ALA-induced flavonol accumulation in guard cells is involved in the inhibitory effect of ALA on ABA-induced ROS accumulation and stomatal closure in apple leaves.
文摘In this research, supercritical carbon dioxide extraction （SFE） showed better extraction etlect when compared with Solid- liquid extraction （SLE）, Soxhlet extraction （SEt and Ultrasonic extraction （UE）, not only in the rate but also the time. The comparison among these three extraction modifiers, including acetone, ethanol and methanol demonstrated that ethanol was preferred to SFE due to its high extraction effect and low toxicology. In addition, parameter of SFE, influence of temperature and pressure were investigated, and the best extraction effect was achieved at the optima conditions, temperature of 40℃ and the pressure of 35 MPa. Thus, SFE is a highly effective method for flavonols extraction, requiring minimum energy and producing non-toxic byproduct. SFE-GC system is applied for the evaluation on flavonols that plays a key role in plant resistance to heavy metal, with its content and synthetase gene expression significantly increasing in plant when threatened by heavy metal. Besides, results indicated that flavonols can improve plant resistance to oxidative stress by quenching the redundant ROS in matrix.
基金supports by the National Natural Science Foundation of China(No.22174037)the Joint Funds of the Hunan Provincial Natural Science Foundation of China(No.2023JJ50255)+1 种基金Changsha Science and Technology Project(No.Z202269490128)National Key Research and Development Program of China(No.2023YFF0613400)are appreciated.
文摘Traditional electrospray ionization tandem mass spectrometry(ESI-MS^(n))has been a powerful tool in diverse research areas,however,it faces great limitations in the study of protein-small molecule interactions.In this article,the state-of-the-art temperature-controlled electrospray ionization tandem mass spectrometry(TC-ESI-MS^(n))is applied to investigate interactions between ubiquitin and two flavonol molecules,respectively.The combination of collision-induced dissociation(CID)and MS solution-melting experiments facilitates the understanding of flavonol-protein interactions in a new dimension across varying temperature ranges.While structural changes of proteins disturbed by small molecules are unseen in ESI-MS^(n),TC-ESI-MS^(n)allows a simultaneous assessment of the stability of the complex in both gas and liquid phases under various temperature conditions,meanwhile investigating the impact on the protein’s structure and tracking changes in thermodynamic data,and the characteristics of structural intermediates.
基金supported by the National Key Research and Development Program of China(2022YFD1200700)the Nuclear Energy Development Research Program of the State Administration of Science,Technology,and Industry for National Defense(Crop Varietal Improvement and Insect Pests Control by Nuclear Radiation)the China Agriculture Research System of MOF and MARA(CARS-03)。
文摘Lesion mimic often exhibits leaf disease-like symptoms even in the absence of pathogen infection,and is characterized by a hypersensitive-response(HR)that closely linked to plant disease resistance.Despite this,only a few lesion mimic genes have been identified in wheat.In this investigation,a lesion mimic wheat mutant named je0297 was discovered,showing no alteration in yield components when compared to the wild type(WT).Segregation ratio analysis of the F_(2)individuals resulting from the cross between the WT and the mutant revealed that the lesion mimic was governed by a single recessive gene in je0297.Using Bulked segregant analysis(BSA)and exome capture sequencing,we mapped the lesion mimic gene designated as lm6 to chromosome 6BL.Further gene fine mapping using 3315 F_(2)individuals delimited the lm6 within a 1.18 Mb region.Within this region,we identified 16 high-confidence genes,with only two displaying mutations in je0297.Notably,one of the two genes,responsible for encoding flavonol synthase,exhibited altered expression levels.Subsequent phenotype analysis of TILLING mutants confirmed that the gene encoding flavonol synthase was indeed the causal gene for lm6.Transcriptome sequencing analysis revealed that the DEGs between the WT and mutant were significantly enriched in KEGG pathways related to flavonoid biosynthesis,including flavone and flavonol biosynthesis,isoflavonoid biosynthesis,and flavonoid biosynthesis pathways.Furthermore,more than 30 pathogen infection-related(PR)genes exhibited upregulation in the mutant.Corresponding to this expression pattern,the flavonoid content in je0297 showed a significant decrease in the 4^(th)leaf,accompanied by a notable accumulation of reactive oxygen,which likely contributed to the development of lesion mimic in the mutant.This investigation enhances our comprehension of cell death signaling pathways and provides a valuable gene resource for the breeding of disease-resistant wheat.
基金The Clinical Medicine Special Project of Nantong University for financial support(Grant No.2022JQ011)。
文摘Two total synthetic routes for the preparation of myricetin were designed and explored.It was validated that route B presented an efficient approach to synthesizing myricetin,starting from commercially available and inexpensive phloroglucinol.Myricetin was synthesized with an overall yield of 60%across three steps without the need of column chromatography separation.The successful preparation of myricetin on a 25-g scale underscored the potential of this approach.
基金Supported by National Key Technology R & D Program 2006BAD01A1701 and 2006BAD18B02Shandong Agriculture Good Cultivar Engineering Project (2008LZ09)~~
文摘[Objective]The aim was to identify the composition of pigments from Jujube fruit skin.[Method]Pigments were extracted from＇Lubei Dongzao＇,＇Lajiao Zao＇,＇Chengwu Dongzao＇,＇Dabailing＇and identificated by using high performance liquid chromatography-mass spectrometry（HPLC-MS）.[Result]The results showed that eight flavanols and four to five flavonols were detected,no anthocyanins was detected.The contents of flavonoids were differnt in four varieties.The contents of flavanols（11 mg/g） and flavonols（1.78 mg/g） in＇Dabailing＇ were one-time higher than other varieties.Quercetin 3 rutinoside was the major flavonol.[Conclusion]The research provided theoretical basis for further study on mechanism of Jujube pigment turnning into the red.
文摘Abstract： In the present study, we established an ultra performance liquid chromatography coupled with time-of-flight mass spectrometry （UPLC-QTOF-MSE） method to simultaneously quantify 33 components in Ginkgo biloba leaf extracts （GBEs）, including 17 flavonol glycosides, five terpene trilactones （TTLs）, four polyphenols and seven carboxylic acids. This optimized method was successfully applied to analyze the explicit compositions of GBE samples collected from different places. Furthermore, the data were processed through unsupervised principal component analysis （PCA） and supervised orthogonal partial least squared discrimination analysis （OPLS-DA） to evaluate the quality and compare the differences between the samples according to the contents of the 33 chemical constituents. Bilobalide, protocatechuic acid, shikimic acid, quinic acid, ginkgolide B, ginkgolide J, kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, quercetin-3-O-ct-L-rhamnopyranocyl-2＂-（6＇＂-p-coumaroyl）-β-D-glucoside and rutin were recognized as characteristic chemical markers that contributed most to control the quality of GBEs. Based on the fact that GBEs should be standardized with the characteristic components as quality control chemical markers, it is most important to maintain the quality of GBEs stable and reliable, and this method also provided a good strategy to further rectify and standardize the GBEs market.
文摘A phytochemical investigation on the leaves of Cistus parviflorus led to the isolation of 18 compounds.The structures of the isolated compounds were elucidated as kaempferol 3-O-（3′′,6′′-di-O-E-p-coumaroyl）-β-D-glucopyranoside（1）,scopoletin（2）,kaempferol 3-O-（3′′-O-E-p-coumaroyl）-β-D-glucopyranoside（3）,kaempferol 3-O-（6′′-O-E-p-coumaroyl）-β-D-glucopyranoside（4）,kaempferol 3-O-β-D-glucopyranoside（5）,kaempferol 3-O-α-L-rhamnopyranosyl-（1→2）-（6′-O-E-p-coumaroyl）-β-D-glucopyranoside（6）,methyl flavogallonate（7）,quercetin 3-O-β-D-glucopyranoside（8）,quercetin 3-O-β-D-galactopyranoside（9）,hydroquinone（10）,arbutin（11）,methyl β-glucopyranoside（12）,shikimic acid（13）,（S）-1,2-propandiol-1-O-β-D-glucopyranoside（14）,benzyl-O-α-L-rhamnopyranosyl-（1→6）-β-D-glucopyranoside（15）,2-phenethyl-O-α-L-rhamnopyranosyl-（1→6）-β-D-glucopyranoside（16）,corchoionoside C（17）,kaempferol 3-O-α-L-rhamnopyranosyl-（1→2）-β-D-glucopyranoside（18） by the analysis of the MS and NMR spectroscopic data and comparison with the literature.Compounds 1–2,6–7,10–12,and 14–16 were isolated from Cistus genus for the first time.
基金Supported by Sao Paulo Research Foundation-FAPESP,No.2012-04634-1
文摘This review was based on a literature search of PubM ed and Scielo databases using the keywords "quercetin,rutin,isoquercitrin,isoquercitin(IQ),quercetin-3-glucoside,bioavailability,flavonols and favonoids,and cancer" and combinations of all the words.We collected relevant scientific publications from 1990 to 2015 about the absorption,bioavailability,chemoprevention activity,and treatment effects as well as the underlying anticancer mechanisms of isoquercitin.Flavonoids are a group of polyphenolic compounds widely distributed throughout the plant kingdom.The subclass of flavonols receives special attention owing to their health benefits.The main components of this class are quercetin,rutin,and IQ,which is a flavonoid and although mostly found as a glycoside,is an aglycone(lacks a glycoside side chain).This compound presents similar therapeutic profiles to quercetin but with superior bioavailability,resulting in increased efficacy compared to the aglycone form.IQ has therapeutic applications owing to its wide range of pharmacological effects including antioxidant,antiproliferative,anti-inflammatory,anti-hypertensive,and anti-diabetic.The protective effects of IQ in cancer may be due to actions on lipid peroxidation.In addition,the antitumor effect of IQ and its underlying mechanism are related to interactions with Wnt signaling pathway,mixed-lineage protein kinase 3,mitogen-activated protein kinase,apoptotic pathways,as well proinflammatory protein signaling.This review contributed to clarifying the mechanisms of absorption,metabolism,and actions of IQ and isoquercitrin in cancer.
文摘Flavonoids are widely used in industry for the prevention of various diseases. In daily life we are directly in touch with flavonoids due to their presence in different beverages, fruits and vegetables. Flavonoids are mainly used as a coloring agent in plants, antioxidant and nutritional food for human. Flavonoids have explicit role in UV filtration, symbiotic nitrogen fixation and floral pigmentation. Flavonoids have potential for different biological activities like chelation of metals, decreasing platelets aggregation and cell signaling etc.
基金supported by the European Union in the MSCA4Ukraine project ID Number 1232466.
文摘The fruits of the Sea buckthorn(Hippophae rhamnoides L.)are a popular plant food and a valuable health product.Cultivating plants produces a lot of leaves with fine branches as an unnecessary residue,which needs valorization.The aim of the study was to estimate(by HPLC-MS/MS)the qualitative and quantitative content of polyphenolic compounds in different parts of H.rhamnoides(HR),and to determine the level of antioxidant activity of leaves and fruits(by DPPH,ABTS methods and ferrozine test).Up to 19 compounds were identified in different parts of HR.The fruits are rich in flavonoids,including various glycosides of flavonols isorhamnetin,quercetin,and kaempferol.Two isorhamnetin glycosides were not identified in the leaves,while isorhamnetin-3-rhamnosylglactosides and the ellagitannins hippophaenin B,stachyurin and casuarinin were present only in the leaves of the plant.The bark and roots contained considerably more catechins,but minimal flavonols than the fruits and leaves of HR.The total phenolics and flavonols were most abundant in water infusions from leaves of HR(especially quercetin-3-O-glucoside-7-O-rhamnoside),compared to methanolic extracts.No significant differences in the quantitative and qualitative content of the fresh and dried leaves were detected.The highest antioxidant activity by all three methods was detected in the leaves of HR.In addition to the fruits,the leaves may have a perspective as a source of biologically active substances of HR.
文摘Stomach and colorectal cancers are common cancers and leading causes of cancer deaths.Because the alimentary tract can interact directly with dietary components,stomach and colorectal cancer may be closely related to dietary intake.We systematically searched published literature written in English via PubMed by searching for terms related to stomach and colorectal cancer risk and dietary flavonoids up to June 30,2012.Twenty-three studies out of 209 identified articles were finally selected for the analysis.Log point effect estimates and the corresponding standard errors were calculated using covariate-adjusted point effect estimates and 95%CIs from the selected studies.Total dietary flavonoid intake was not associated with a reduced risk of colorectal or stomach cancer [odds ratio(OR)(95%CI) = 1.00(0.90-1.11) and 1.07(0.70-1.61),respectively].Among flavonoid subclasses,the intake of flavonols,flavan-3-ols,anthocyanidins,and proanthocyanidins showed a significant inverse association with colorectal cancer risk [OR(95%CI) = 0.71(0.63-0.81),0.88(0.79-0.97),0.68(0.56-0.82),and 0.72(0.61-0.85),respectively].A significant association was found only between flavonols and stomach cancer risk based on a limited number of selected studies [OR(95%CI) = 0.68(0.46-0.99)].In the summary estimates from casecontrol studies,all flavonoid subclasses except flavones and flavanones were inversely associated with colorectal cancer risk,whereas neither total flavonoids nor any subclasses of flavonoids were associated with colorectal cancer risk in the summary estimates based on the cohort studies.The significant association between flavonoid subclasses and cancer risk might be closely related to bias derived from the case-control design.There was no clear evidence that dietary flavonoids are associated with reduced risk of stomach and colorectal cancer.
文摘The objectives of this study were to identify the antioxidants in acid hydrolysates of six of Taiwan’s indigenous purple-leaved vegetables (IPLV), including purple-leaved sweet potato (Ipomoea batatas L. Lamark), purple-leaved gynura line 1 (Gynura bicolor D.C.), purple-leaved gynura line 2 (Gynura bicolor D.C.), purple-leaved perilla line 1 (Perilla frutescents L. Britton), bicolored-leaved perilla line 2 (Perilla frutescens L. Britton), and heartleaf houttuynia (Houttuynia cordata Thumb.). Their antioxidant activity and ability to protect DNA from oxidative damage was also evaluated. The antioxidants identified included flavonoids, anthocyanidins and flavonols. Both purple-leaved perilla line 1 and bicolored-leaved perilla line 2 were found to be abundant in cynidin, malvidin, and myricetin. Moreover, purple-leaved sweet potato and heartleaf houttuynia were found to be abundant in quercetin. Purple-leaved sweet potato and purple-leaved perilla line 1 contained significantly higher inhibition percentages of conjugated diene formation than other vegetables. Purple-leaved sweet potato, heartleaf houttuynia, purple-leaved perilla line 1, and bicolored-leaved perilla line 2 had better inhibition percentages of tail DNA% and tail moment in the study. In conclusion, the abovementioned four indigenous purple-leaved vegetables abounded in antioxidants had strong antioxidant activity for protecting DNA in lymphocytes from oxidative damages.
文摘A series of novel flavonols were synthesized by cyclizing corresponding hydoxy chalcones using Algar flynn Oyamada reaction (1)The synthesized compounds were characterized by various spectrochemical methods including IR, MASS, NMR spectroscopy. Out of 13 compounds screened for antibacterial activity [2], compound VMF 12 (a bromo derivative) showed activity with an IC50value at 0.16μM against S. aureus.
