Xian Li

Zhejiang University, Hangzhou, Zhejiang Sheng, China

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Publications (27)52.49 Total impact

  • Article: Biological Activities of Extracts from Chinese Bayberry (Myrica rubra Sieb. et Zucc.): A Review.
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    ABSTRACT: Chinese bayberry (Myrica rubra Sieb. et Zucc.) is a subtropical fruit tree native to China and other Asian countries, and culture of this Myricaceae plant has been recorded in Chinese history for more than 2000 years. Bayberry fruit is delicious with attractive color, flavor, and high economic value. Compared with other berries, bayberry fruit is a rich source of cyanidin-3-glucoside (C3G, e.g., 64.8 mg/100 g fresh weight in 'Biqi' cultivar), which accounts for at least 85 % of the anthocyanins in the fruit. Bayberry is also a plant with high medicinal value since different organs have been used historically as folk medicines. Research efforts suggest bayberry extracts contain antioxidants that exhibit bioactivities counteracting inflammation, allergens, diabetes, cancer, bacterial infection, diarrhea and other health issues. Bayberry compounds have been isolated and characterized to provide a better understanding of the chemical mechanisms underlying the biological activities of bayberry extracts and to elaborate the structure-activity relationships. As the identification of compounds progresses, studies investigating the in vivo metabolism and bioavailability as well as potential toxicity of bayberry extracts in animal models are receiving more attention. In addition, breeding and genetic studies of bayberry with high accumulation of health-benefiting compounds may provide new insight for the bayberry research and industry. This review is focused on the main medicinal properties reported and the possible pharmaceutically active compounds identified in different bayberry extracts.
    Materiae Vegetabiles 04/2013; · 2.51 Impact Factor
  • Article: Characterization, Purification of Poncirin from Edible Citrus Ougan (Citrus reticulate cv. Suavissima) and Its Growth Inhibitory Effect on Human Gastric Cancer Cells SGC-7901.
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    ABSTRACT: Poncirin is a bitter flavanone glycoside with various biological activities. Poncirin was isolated from four different tissues (flavedo, albedo, segment membrane, and juice sac) of Ougan fruit (Citrus reticulate cv. Suavissima). The highest content of poncirin was found in the albedo of Ougan fruit (1.37 mg/g DW). High speed counter-current chromatography (HSCCC) combined with D101 resin chromatography was utilized for the separation and purification of poncirin from the albedo of Ougan fruit. After this two-step purification, poncirin purity increased from 0.14% to 96.56%. The chemical structure of the purified poncirin was identified by both HPLC-PDA and LC-MS. Poncirin showed a significant in vitro inhibitory effect on the growth of the human gastric cancer cells, SGC-7901, in a dose-dependent manner. Thus, poncirin from Ougan fruit, may be beneficial for gastric cancer prevention. The purification method demonstrated here will be useful for further studies on the pharmacological mechanism of poncirin activity, as well as for guiding the consumption of Ougan fruit.
    International Journal of Molecular Sciences 01/2013; 14(5):8684-97. · 2.60 Impact Factor
  • Article: Analysis of Expressed Sequence Tags from Chinese Bayberry Fruit (Myrica rubra Sieb. and Zucc.) at Different Ripening Stages and Their Association with Fruit Quality Development.
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    ABSTRACT: A total of 2000 EST sequences were produced from cDNA libraries generated from Chinese bayberry fruit (Myrica rubra Sieb. and Zucc. cv. "Biqi") at four different ripening stages. After cluster and assembly analysis of the datasets by UniProt, 395 unigenes were identified, and their presumed functions were assigned to 14 putative cellular roles. Furthermore, a sequence BLAST was done for the top ten highly expressed genes in the ESTs, and genes associated with disease/defense and anthocyanin accumulation were analyzed. Gene-encoding elements associated with ethylene biosynthesis and signal transductions, in addition to other senescence-regulating proteins, as well as those associated with quality formation during fruit ripening, were also identified. Their possible roles were subsequently discussed.
    International Journal of Molecular Sciences 01/2013; 14(2):3110-23. · 2.60 Impact Factor
  • Article: Purification of naringin and neohesperidin from Huyou (Citrus changshanensis) fruit and their effects on glucose consumption in human HepG2 cells.
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    ABSTRACT: Huyou (Citrus changshanensis) is rich in naringin and neohesperidin, which are natural flavanone glycosides with a range of biological activities. Among the different fruit parts, i.e. flavedo, albedo, segment membrane (SM), and juice sacs (JS), albedo showed the highest contents of both compounds, with 27.00 and 19.09mg/g DW for naringin and neohesperidin, respectively. Efficient simultaneous purification of naringin and neohesperidin from Huyou albedo was established by the combination of macroporous D101 resin chromatography and high-speed counter-current chromatography (HSCCC). Purified naringin and neohesperidin were identified by both HPLC and LC-MS, and their effects on glucose consumption were investigated in HepG2 cells. Cells treated with naringin and neohesperidin showed increased consumption of glucose, and this was associated with increased phosphorylation of AMP-activated protein kinase (AMPK). Therefore, naringin and neohesperidin from Huyou may act as potential hypoglycaemic agents through regulation of glucose metabolism.
    Food Chemistry 12/2012; 135(3):1471-8. · 3.65 Impact Factor
  • Article: Development and characterization of 109 polymorphic EST-SSRs derived from the Chinese bayberry (Myrica rubra, Myricaceae) transcriptome.
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    ABSTRACT: • Premise of the study: In Chinese bayberry (Myrica rubra), the available simple sequence repeat (SSR) markers are insufficient to meet the developing demand for genetic and molecular breeding research. This study was aimed at developing a large number of polymorphic expressed sequence tag (EST)-SSRs from the transcriptome of Chinese bayberry.• Methods and Results: Five hundred ninety-four compound EST-SSRs and 5557 noncompound ones were identified from 41239 unigene sequences generated from the transcriptome of M. rubra cv. Biqi. Using 10 Chinese bayberry cultivars, 109 polymorphic EST-SSRs were screened from 412 selected. In total, they generated 389 alleles, with a polymorphism ratio of 93.8%. In addition, it was observed that the polymorphism levels of compound EST-SSRs were somewhat lower than those of noncompound ones.• Conclusions: The 109 polymorphic EST-SSRs developed from the Chinese bayberry transcriptome should greatly promote the development of genetic and molecular breeding studies in this as well as other Myricaceae species.
    American Journal of Botany 11/2012; · 2.66 Impact Factor
  • Article: Quantification and Purification of Mangiferin from Chinese Mango (Mangifera indica L.) Cultivars and Its Protective Effect on Human Umbilical Vein Endothelial Cells under H(2)O(2)-induced Stress.
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    ABSTRACT: Mangiferin is a natural xanthonoid with various biological activities. Quantification of mangiferin in fruit peel, pulp, and seed kernel was carried out in 11 Chinese mango (Mangifera indica L.) cultivars. The highest mangiferin content was found in the peel of Lvpimang (LPM) fruit (7.49 mg/g DW). Efficient purification of mangiferin from mango fruit peel was then established for the first time by combination of macroporous HPD100 resin chromatography with optimized high-speed counter-current chromatography (HSCCC). Purified mangiferin was identified by both HPLC and LC-MS, and it showed higher DPPH(•) free-radical scavenging capacities and ferric reducing ability of plasma (FRAP) than by l-ascorbic acid (Vc) or Trolox. In addition, it showed significant protective effects on human umbilical vein endothelial cells (HUVEC) under H(2)O(2)-induced stress. Cells treated with mangiferin resulted in significant enhanced cell survival under of H(2)O(2) stress. Therefore, mangiferin from mango fruit provides a promising perspective for the prevention of oxidative stress-associated diseases.
    International Journal of Molecular Sciences 01/2012; 13(9):11260-74. · 2.60 Impact Factor
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    Article: Transcriptomic analysis of Chinese bayberry (Myrica rubra) fruit development and ripening using RNA-Seq.
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    ABSTRACT: Chinese bayberry (Myrica rubra Sieb. and Zucc.) is an important subtropical fruit crop and an ideal species for fruit quality research due to the rapid and substantial changes that occur during development and ripening, including changes in fruit color and taste. However, research at the molecular level is limited by a lack of sequence data. The present study was designed to obtain transcript sequence data and examine gene expression in bayberry developing fruit based on RNA-Seq and bioinformatic analysis, to provide a foundation for understanding the molecular mechanisms controlling fruit quality changes during ripening. RNA-Seq generated 1.92 G raw data, which was then de novo assembled into 41,239 UniGenes with a mean length of 531 bp. Approximately 80% of the UniGenes (32,805) were annotated against public protein databases, and coding sequences (CDS) of 31,665 UniGenes were determined. Over 3,600 UniGenes were differentially expressed during fruit ripening, with 826 up-regulated and 1,407 down-regulated. GO comparisons between the UniGenes of these two types and interactive pathways (Ipath) analysis found that energy-related metabolism was enhanced, and catalytic activity was increased. All genes involved in anthocyanin biosynthesis were up-regulated during the fruit ripening processes, concurrent with color change. Important changes in carbohydrate and acid metabolism in the ripening fruit are likely associated with expression of sucrose phosphate synthase (SPS) and glutamate decarboxylase (GAD). Mass sequence data of Chinese bayberry was obtained and the expression profiles were examined during fruit ripening. The UniGenes were annotated, providing a platform for functional genomic research with this species. Using pathway mapping and expression profiles, the molecular mechanisms for changes in fruit color and taste during ripening were examined. This provides a reference for the study of complicated metabolism in non-model perennial species.
    BMC Genomics 01/2012; 13:19. · 4.07 Impact Factor
  • Article: Cyanidin-3-glucoside-rich extract from Chinese bayberry fruit protects pancreatic β cells and ameliorates hyperglycemia in streptozotocin-induced diabetic mice.
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    ABSTRACT: Chinese bayberry fruit is a rich source of anthocyanins, especially cyanidin-3-glucoside (C3G). The present study investigated the protective effects of C3G-rich bayberry fruit extract (CRBFE) against pancreatic β cells against oxidative stress-induced injury as well as its hypoglycemic effect in diabetic mice. Bayberry extract from "Biqi" was used for both in vitro and in vivo testing because of its high C3G content and high antioxidant capacity. Pretreatment of β cells with CRBFE (containing 0.5 μmol/L C3G) prevented cell death, increased cellular viability, and decreased mitochondrial reactive oxygen species production and cell necrosis induced by 800 or 1,200 μmol/L H₂O₂. CRBFE dose-dependently up-regulated pancreatic duodenal homeobox 1 gene expression, contributing to increased insulin-like growth factor II gene transcript levels and insulin protein in INS-1 cells. In addition, administration of CRBFE (150 μg of C3G/10 g of body weight twice per day) significantly reduced blood glucose in streptozotocin-induced diabetic ICR mice and increased the glucose tolerance in an oral glucose tolerance test (P<.05). Such results indicated that CRBFE might be useful in prevention and control of diabetes mellitus and diabetes-associated complications.
    Journal of medicinal food 12/2011; 15(3):288-98. · 1.39 Impact Factor
  • Article: Physical changes and physiological characteristics of red and green peel during nectarine (cv. Hu018) maturation.
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    ABSTRACT: The aim of this study was to determine physical changes in nectarine and distinctive physiological characteristics related to red and green peel under stresses occurring during fruit maturation, information on which is currently not available. Fruit firmness increased from 4 to 6 weeks after blooming (WAB) then decreased from 6 WAB until ripening. Anthocyanins in red and green peel during nectarine maturation were identified by high-performance liquid chromatography as cyanidin 3-glucoside together and, at a much lower level, cyanidin 3-rutinoside. Cyanidins in red and green peel decreased from 4 to 8 WAB then increased from 8 to 12 WAB. Anthocyanin contents were positively correlated with PAL, POD, A*, MDA and O2(·-) values and inversely correlated with L* and B* values. Red and green peel during maturation could be separated by hierarchical cluster analysis of the tested data. This study has provided an overview of red and green peel characteristics during nectarine (cv. Hu018) maturation. Values of A*, anthocyanins, O2(·-), MDA, PAL, PPO and POD in red peel were higher than those in green peel, while values of L*, B* and chroma in red peel were lower than those in green peel throughout fruit maturation.
    Journal of the Science of Food and Agriculture 12/2011; 92(7):1448-54. · 1.44 Impact Factor
  • Article: Separation and purification of neohesperidin from the albedo of Citrus reticulata cv. Suavissima by combination of macroporous resin and high-speed counter-current chromatography.
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    ABSTRACT: In this article, a simple and efficient protocol for rapid preparation and separation of neohesperidin from the albedo of Citrus reticulata cv. Suavissima was established by the combination of macroporous resin column chromatography and high-speed counter-current chromatography (HSCCC). Six types of resin were investigated by adsorption and desorption tests, and D101 macroporous resin was selected for the first cleaning-up procedure, in which 55% aqueous ethanol was used to elute neohesperidin. After treatment with D101 resin, the neohesperidin purity increased 11.83-fold from 4.92% in the crude extract to 58.22% in the resin-refined sample, with a recovery of 68.97%. The resin-refined sample was directly subjected to HSCCC purification with a two-phase solvent system composed of ethyl acetate-n-butanol-water (4:1:5, v/v), and 23.6 mg neohesperidin with 97.47% purity was obtained from 60 mg sample in only one run. The recovery of neohesperidin in HSCCC separation procedure was 65.85%. The chemical structure of the purified neohesperidin was identified by both HPLC and LC-MS. The established purification process will be helpful for further characterization and utilization of Citrus neohesperidin.
    Journal of Separation Science 11/2011; 35(1):128-36. · 2.73 Impact Factor
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    Article: Oleanolic and ursolic acid in the fruit of Eriobotrya japonica Lindl.
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    ABSTRACT: High performance liquid chromatography (HPLC) method was applied to determine the content of oleanolic acid (OA) and ursolic acid (UA) in different tissues of 'Ruantiaobaisha' and 'Dayeyangdun' loquat (Eriobotrya japonica Lindl.) fruits in this research. The results demonstrated that peel contained higher OA and UA contents, while flesh and kernel contained very lower amounts of OA and UA. On the basis of above results, the OA and UA contents in the peel of different developmental stages and different cultivars of loquat fruits were analyzed and compared. It is found that OA and UA contents in the peel varied with different developmental stages and cultivars. The OA and UA content in the peel of ripe fruit of different cultivars were in the range of 0.59-1.68 and 2.82-8.20 mg/g DW, respectively. These results can provide a theoretical basis for the comprehensive utilization of loquat fruit in the future.
    Journal of Medicinal Plants Research. 04/2011; 5:1735-1740.
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    Article: Flavonoids, Phenolics, and Antioxidant Capacity in the Flower of Eriobotrya japonica Lindl.
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    ABSTRACT: Flavonoids and phenolics are abundant in loquat flowers. Methanol had the highest extraction efficiency among five solvents, followed by ethanol. Considering the safety and residue, ethanol is better as extraction solvent. The average content of flavonoids and phenolics of loquat flower of five cultivars were 1.59 ± 0.24 and 7.86 ± 0.87 mg/g DW, respectively, when using ethanol as extraction solvent. The contents of both bioactive components in flowers at different developmental stages and in the various flower tissues clearly differed, with the highest flavonoids and phenolics content in flowers of stage 3 (flower fully open) and petal, respectively. The antioxidant capacity was measured using FRAP, DPPH, and ABTS methods. The values of ABTS method was highest, followed by DPPH, the lowest was FRAP, when using vitamin C equivalent antioxidant capacity (VCEAC) as unit. Correlation analysis showed that the ABTS method showed the highest correlation coefficients with flavonoids and phenolics, i.e., 0.886 and 0.973, respectively.
    International Journal of Molecular Sciences 01/2011; 12(5):2935-45. · 2.60 Impact Factor
  • Article: Coordinated regulation of anthocyanin biosynthesis in Chinese bayberry (Myrica rubra) fruit by a R2R3 MYB transcription factor.
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    ABSTRACT: Chinese bayberry (Myrica rubra) is a fruit crop with cultivars producing fruit ranging from white (Shuijing, SJ) to red (Dongkui, DK) and dark red-purple (Biqi, BQ), as a result of different levels of anthocyanin accumulation. Genes encoding the anthocyanin biosynthesis enzymes chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS) and UDPglucose: flavonoid 3-O-glucosyltransferase (UFGT), as well as MrMYB1, a R2R3 MYB transcription factor homologous to known activators of anthocyanin biosynthesis, were isolated from ripe fruit of BQ. Differences in mRNA abundance of MrF3H, MrF3'H, MrDFR1, MrANS and MrUFGT were highly correlated with differential accumulation of anthocyanins between cultivars, suggesting coordinated regulation by transcription factors. The transcript level of MrMYB1 was strongly associated with the anthocyanin content in ripe fruit of the three cultivars, as well as different anthocyanin containing tissues of BQ fruit. Fruit bagging strongly inhibited anthocyanin accumulation in fruit as well as the expression of all anthocyanin biosynthetic genes and MrMYB1. Overexpression of MrMYB1 stimulated both anthocyanin accumulation and activated an Arabidopsis-DFR promoter in tobacco (Nicotiana tabacum). MrMYB1d, an allele with a 1 bp deletion at nucleotide 30 of coding sequence, was observed in SJ and DK fruit, suggesting that a nonsense mutation of the MYB1 protein may be responsible for no or low expression of MYB1 in the white and red fruit. These results show that coordinated expression of multiple biosynthetic genes is involved in anthocyanin accumulation in Chinese bayberry fruit, and this is regulated by MrMYB1.
    Planta 03/2010; 231(4):887-99. · 3.00 Impact Factor
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    Article: Ethylene signal transduction elements involved in chilling injury in non-climacteric loquat fruit.
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    ABSTRACT: Loquat (Eriobotrya japonica Lindl.) is a subtropical fruit, with some cultivars such as 'Luoyangqing' (LYQ) susceptible to chilling injury (CI), while others such as 'Baisha' (BS) are resistant. Although loquats are non-climacteric, modulation of ethylene has an effect on ripening-related post-harvest CI. Therefore the role of ethylene signalling in the development of CI was investigated in fruit of both the LYQ and BS cultivars. Three ethylene receptor genes, one CTR1-like gene, and one EIN3-like gene were isolated and characterized in ripening fruit. All of these genes were expressed differentially within and between fruit of the two cultivars. Transcripts either declined over fruit development (EjERS1a in both cultivars and EjEIL1 in LYQ) or showed an increase in the middle stages of fruit development before declining (EjETR1, EjERS1b, and EjCTR1 in both cultivars and EjEIL1 in BS). The main cultivar differences were in levels rather than in patterns of expression during post-harvest storage. EjETR1, EjCTR1, and EjEIL1 genes showed increased expression in response to low temperature and this was particularly notable for EjETR1, and EjEIL1 during CI development in LYQ fruit. The genes were also differentially responsive to ethylene treatment, 1-methycyclopropene (1-MCP) and low temperature conditioning, confirming a role for ethylene in regulation of CI in loquat fruit.
    Journal of Experimental Botany 10/2009; 61(1):179-90. · 5.36 Impact Factor
  • Article: Lipoxygenase gene expression in ripening kiwifruit in relation to ethylene and aroma production.
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    ABSTRACT: During postharvest ripening of kiwifruit [ Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson var. deliciosa cv. Bruno] at 20 degrees C, six lipoxygenase (LOX) genes exhibited different expression patterns. AdLox1 and AdLox5 were up-regulated during ripening, and transcript accumulation was delayed by 1-methylcyclopropene (1-MCP), whereas AdLox2, AdLox3, AdLox4, and AdLox6 were down-regulated with ripening. Levels of two volatiles arising from the LOX pathway, that is, n-hexanal and (E)-2-hexenal, were highest after harvest and declined during ripening at 20 degrees C, whereas the characteristic kiwifruit esters ethyl and methyl butanoate levels increased late in the ripening process. Individual fatty acid concentrations underwent little change during ripening, with linoleic (LA) and linolenic (LeA) acids constituting about 40% of the total. Application of LA and LeA to kiwifruit flesh disks promoted LOX activity and n-hexanal and (E)-2-hexenal generation, whereas inhibitors of LOX, n-propyl gallate (n-PG) and nordihydroguariaretic acid (NDGA), caused a parallel reduction in enzyme activity and in the production of C6 aldehydes. The six LOX genes showed different sensitivities to the LOX substrates and inhibitors. The ethylene up-regulated genes AdLox1 and AdLox5 were induced by LA and LeA and inhibited by n-PG and NDGA. Of the LOX genes that were down-regulated by ethylene, only AdLox4 and AdLox6 were stimulated in response to the substrates and retarded by the inhibitors. The possible roles of the six LOX genes in kiwifruit ripening and aroma development are discussed.
    Journal of Agricultural and Food Chemistry 05/2009; 57(7):2875-81. · 2.82 Impact Factor
  • Article: Bioactive components and antioxidant capacity of Chinese bayberry ( Myrica rubra Sieb. and Zucc.) fruit in relation to fruit maturity and postharvest storage
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    ABSTRACT: Total phenolics, flavonoids, anthocyanins, cyanidin-3-O-glucoside (Cy-3-glu) and antioxidant capacity of Chinese bayberry fruit (Myrica rubra Sieb. and Zucc.) differed among the four cultivars “Baizhong” (white), “Fenhong” (pink), “Wuzhong” (red) and “Biqi” (dark red). Antioxidant capacity determined by both the ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-2-picrylhydrazyl (DPPH.) radical scavenging capacity was significantly correlated with the antioxidant components in the fruit, and directly related to fruit color. Cy-3-glu accounted for at least 82, 38, and 12% of the total antioxidant capacity in “Biqi”, “Wuzhong” and “Fenhong” fruits, respectively. No detectable Cy-3-glu was found in “Baizhong” fruit. Greater fruit maturity was associated with higher levels of all the bioactive components and antioxidant capacity. Significant increases were also found during postharvest storage of “Biqi” fruit held at either 20 °C for 2days or 0 °C for 5days. However, these levels decreased during a 2-day shelf-life at 20 °C after 5days at 0 °C. These results show that storage and shelf-life conditions are important if health-based bioactive components of bayberry fruit are to be maintained after harvest.
    European Food Research and Technology 07/2008; 227(4):1091-1097. · 1.57 Impact Factor
  • Article: Characterization of cDNAs associated with lignification and their expression profiles in loquat fruit with different lignin accumulation.
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    ABSTRACT: The ripening fruit of two loquat (Eriobotrya japonica Lindl.) cultivars with different levels of lignin accumulation provide an intriguing example of lignification in flesh tissue. Increase in firmness as a result of lignification in ripening red-fleshed Luoyangqing (LYQ) fruit was confirmed, whereas white-fleshed Baisha (BS) fruit softened without lignification. Six cDNAs associated with the lignification pathway, i.e. EjPAL1, EjPAL2 (phenylalanine ammonia lyase, PAL, EC 4.3.1.5), Ej4CL (4-coumarate: coenzyme A ligase, 4CL, EC 6.2.1.12), EjCAD1, EjCAD2 (cinnamyl alcohol dehydrogenase, CAD, EC 1.1.1.195) and EjPOD (peroxidase, POD), were cloned from flesh tissue of LYQ fruit. Expression profiles of the six corresponding genes differed greatly in different tissues, and during fruit development and ripening in both LYQ and BS cultivars. Associated activities of PAL, 4CL, CAD, and POD enzymes were also measured. CAD and POD enzyme activities and the expression of EjCAD1 and EjPOD genes were most closely associated temporally with lignification of loquat flesh tissue. Levels of EjCAD1 transcripts were particularly aligned with changes in lignification during ripening as modified either by ethylene treatment or low temperature conditioning. The two PAL genes showed different expression patterns during fruit development, with EjPAL1 strongly expressed in mature fruit and EjPAL2 only expressed in early stages of development. In addition, EjCAD1 expression was stimulated by low temperature and may contribute to low temperature injury in the fruit. Our integrated data on lignin, monolignol precursors, and associated enzymes and genes, provide a consistent model of fruit lignification.
    Planta 06/2008; 227(6):1243-54. · 3.00 Impact Factor
  • Article: Carotenoids in white- and red-fleshed loquat fruits.
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    ABSTRACT: Fruits of 23 loquat ( Eriobotrya japonica Lindl.) cultivars, of which 11 were white-fleshed and 12 red-fleshed, were analyzed for color, carotenoid content, and vitamin A values. Color differences between two loquat groups were observed in the peel as well as in the flesh. beta-Carotene and lutein were the major carotenoids in the peel, which accounted for about 60% of the total colored carotenoids in both red- and white-fleshed cultivars. beta-Cryptoxanthin and, in some red-fleshed cultivars, beta-carotene were the most abundant carotenoids in the flesh, and in total, they accounted for over half of the colored carotenoids. Neoxanthin, violaxanthin, luteoxanthin, 9- cis-violaxanthin, phytoene, phytofluene, and zeta-carotene were also identified, while zeaxanthin, alpha-carotene, and lycopene were undetectable. Xanthophylls were highly esterified. On average, 1.3- and 10.8-fold higher levels of colored carotenoids were observed in the peel and flesh tissue of red-fleshed cultivars, respectively. The percentage of beta-carotene among colored carotenoids was higher in both the peel and the flesh of red-fleshed cultivars. Correlations between the levels of total colored carotenoids and the color indices were analyzed. The a* and the ratio of a*/ b* were positively correlated with the total content of colored carotenoids, while L*, b*, and H degrees correlated negatively. Vitamin A values, as retinol equivalents (RE), of loquat flesh were 0.49 and 8.77 microg/g DW (8.46 and 136.41 microg/100 g FW) on average for white- and red-fleshed cultivars, respectively. The RE values for the red-fleshed fruits were higher than fruits such as mango, red watermelon, papaya, and orange as reported in the literature, suggesting that loquat is an excellent source of provitamin A.
    Journal of Agricultural and Food Chemistry 10/2007; 55(19):7822-30. · 2.82 Impact Factor
  • Article: Determination of oleanolic acid, ursolic acid and amygdalin in the flower of Eriobotrya japonica Lindl. by HPLC.
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    ABSTRACT: Simple and accurate HPLC methods were developed for the determination of oleanolic acid (OA), ursolic acid (UA) and amygdalin in loquat (Eriobotrya japonica Lindl.) flower, which is commonly used for the treatment of various diseases as a traditional Chinese medicine. HPLC assay was performed on a reversed-phase C(18) column and all three compounds were detected at 210 nm with a flow rate of 1.0 mL/min. The mobile phase consisted of methanol (A) and 0.03 mol/L phosphate buffer (pH 2.8) (B) with a ratio of 88:12 (A:B, v/v) for simultaneous detection of OA and UA, and 25:75 (A:B, v/v) for detection of amygdalin. The established methods showed good precision and accuracy with overall intra-day and inter-day variation of 0.99-3.55 and 1.05-4.05%, respectively, and overall recoveries of 97.37-99.32% for the three compounds. Application of these methods to determine the OA, UA and amygdalin contents in loquat flower showed that cultivar had a minor effect on the contents of all three compounds, with average amounts of 0.38-0.51 mg OA/g dry weight (DW), 2.15-2.68 mg UA/g DW and 1.23-1.56 mg amygdalin/g DW among five loquat cultivars tested. However, developmental stages and flower tissues showed significant effect on the contents of all three bioactive components.
    Biomedical Chromatography 08/2007; 21(7):755-61. · 1.97 Impact Factor
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    Article: Acetylsalicylic acid alleviates chilling injury of postharvest loquat ( Eriobotrya japonica Lindl.) fruit
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    ABSTRACT: Loquat (Eriobotrya japonica Lindl. cv. Luoyangqing) is a chilling-sensitive fruit and therefore has a limited postharvest life. While fruit stored at 5°C retained its acceptable quality after 39 days, fruit stored at 0°C had chilling injury with the symptoms of tissue browning and lignification, decrease in percentage juice, increase in superoxide free radical production, electric conductivity and lignification enzyme activities, including phenylalanine ammonia lyase (PAL), cinnamyl alcohol dehydrogenase (CAD), and guaiacol-peroxidase (G-POD). Such chilling injury symptoms became more severe after fruit were moved to 20°C shelf life. A postharvest application of 1mmol/L aqueous acetylsalicylic acid (ASA, a derivative of salicylic acid) to loquat fruit significantly alleviated chilling injury symptoms, inhibited accumulation of superoxide free radical, and reduced PAL, CAD, and G-POD activities. ASA treatment impairing the accumulation of superoxide free radical may prevent chilling injury and lignification in loquat.
    European Food Research and Technology 01/2006; 223(4):533-539. · 1.57 Impact Factor