食用天然色素的提取及其稳定性研究

研究了食用天然色素的一般提取工艺及其理化性质,并实验分析了光、热、酸碱、防腐剂、氧化还原剂对萝卜红色素、郁金香红色素、郁金香黄色素的稳定性影响。     

Nontroglobitic Fishes in Bruffey-Hills Creek Cave, West Virginia, and other Caves Worldwide

Six species of fishes were tagged and released in September and November 1995 and on five dates between November 1998 and October 1999 inside Bruffey-Hills Creek Cave. Most of the tagged fishes were creek chub, Semotilus atromaculatus, and green sunfish, Lepomis cyanellus. The overall recapture rate was 2.6% as only three of 117 fishes were recaptured. Forty-nine days was the longest time of residence by two L. cyanellus and one S. atromaculatus, and movement of 83.4 m was observed only for the creek chub. Tag loss was confirmed as one factor in the low recapture rate. Nine species of fishes were collected in the cave, including Phoxinus oreas and Pimephales promelas, two species never collected in a cave. Most of the fishes were pigmented normally, but many creek chubs were depigmented and appeared white or pigmentless when first observed in the cave stream. Four species, Phoxinus oreas, Pimephales promelas, Ameiurus nebulosus, and Lepomis macrochirus, were collected for the first time in Bruffey-Hills Creek Cave and in the Bruffey and Hills creeks drainage. Although data from this study did not shed light on residence time of fishes in the cave, the consistent occurrence of epigean fishes in this cave was shown. A list of epigean fishes from caves worldwide was included along with a discussion of aspects of the ecology of epigean fishes in caves and of evolution of troglobitic fishes.     

小麦紫色素的提取工艺、抗氧化活性及其在毛发染色中的应用

以紫粒小麦麦麸为原料,通过碱水裂解初提、大孔吸附树脂纯化、钠滤膜浓缩和蒸发浓缩等技术手段从中提取天然紫色素。采用单因素实验对其提取条件进行优化,在室温条件（25~30℃）下,确定最佳提取条件为：提取时间60 min,料液比1∶4(g/mL),提取3次。经体外抗氧化实验证明,提取的小麦紫色素具有较高的抗氧化活性。此外,小麦紫色素与不同金属离子作用后可将羊毛染成不同的颜色。上述实验结果表明,利用优化后的工艺提取的小麦紫色素纯度高、抗氧化活性高,具有较大的开发潜力和实用价值。     

从87（341）的培育成功分析硬粒小麦品质性状的选择研究

根据通心面的商品外观、加工品质和蒸煮品质对硬粒小麦原料提出的主要品质要求,在优质硬粒小麦８７（３４１）品系的选育过程中,品质性状的选择以蛋白质、面筋和黄色素为主。Ｆ３代面筋的质量、含量和黄色素含量的分离相当大,为不错失优质品系,应从Ｆ３代起就开始分析。Ｆ４代在农艺性状选择的基础上,为品质测试和品质上择优汰劣的关键世代。Ｆ５代及其后代的选择则继续兼顾产量和品质指标,以达到高产优质的选育目的。     

Novel pigments and copigmentation in the blue marguerite daisy

The blue colour of the petals of the blue marguerite daisy, Felicia amelloides, has been found to arise from copigmentation between a novel malonylated delphinidin triglycoside, delphinidin 3-O-neohesperidoside 7-O- (6-O-malonyl-glucoside), and a new flavone C-glycoside, swertisin 2″-O-rhamnoside-4′-O-glucoside. Recombination, in vitro, of these two petal components at pH 6 recreates the blue petal colour.     

Evidence for spatially separate bacteriochlorophyll c and bacteriochlorophyll d pools within the chlorosomal aggregate of the green sulfur bacterium Chlorobium limicola

We have studied the organization of the bacteriochlorophylls (BChl) in isolated chlorosomes of the green sulfur bacterium Chlorobium limicola UdG6040 containing about 50% BChl d and BChl c each. When the chlorosomes are treated in acidic buffer (pH 3.0) two phases in the conversion from BChl to bacteriopheophytin (BPhe) are observed as evidenced by the changes in the absorption spectrum. In the early phase the pheophytinization of BChl d occurs much faster than that of BChl c. In the later phase BChl c and BChl d are converted at similar rates. The delayed BChl c conversion observed in intact chlorosomes is interpreted in terms of spatial separation within the same chlorosome that makes BChl d more accessible to reaction with acid than BChl c. This was supported by acid treatment of in vitro pigment-lipid aggregates which showed that the pheophytinization of aggregates consisting of only BChl c or BChl d takes place with the same rate. Moreover in mixed in vitro aggrega tes where BChl d and BChl c are supposed to be scrambled the two pigments are converted to BPhe simultaneously. Acid treatment of hexanol exposed chlorosomes indicates that the spatial separation of BChl d and BChl c within the chlorosomes is maintained even if the excitonic interaction between BChls has been disturbed by hexanol. Based on these findings it is suggested that BChl d and BChl c in the chlorosome are located distal and proximal, respectively, relative to the chlorosome baseplate.     

铜胁迫下链格孢菌对白车轴草生理生态的影响

通过盆栽实验研究了Cu胁迫下接种病原菌链格孢菌(Alternaria tenuis Nees)对白车轴草(Trifolium repens L.)生理生态指标的影响.结果表明:在未接种的对照组中,随着Cu浓度的增大(0~3000mg.kg-1),植株叶片失绿,生物量下降,叶绿素a、b、a b和类胡萝卜素及叶片可溶性蛋白质含量下降;植物体内丙二醛(MDA)高度积累,细胞膜结构遭到损坏,电导率增大;植株活性氧清除系统受损,不能保持原有平衡,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性显著降低,过氧化物酶(POD)活性升高.接种链格孢菌后,植株叶片色素、膜系统及保护酶系统的损伤均加重,与不接种对照组相比,相同浓度Cu处理的叶绿素a、b、a b和类胡萝卜素、可溶性蛋白质含量、SOD和CAT活性均呈不同程度的下降,而电导率、MDA含量和POD活性则有所上升.     

MEK mediates in vitro neural transdifferentiation of the adult newt retinal pigment epithelium cells: Is FGF2 an induction factor?

Adult newts can regenerate their entire retinas through transdifferentiation of the retinal pigment epithelium (RPE) cells. As yet, however, underlying molecular mechanisms remain virtually unknown. On the other hand, in embryonic/larval vertebrates, an MEK [mitogen‐activated protein kinase (MAPK)/extracellular signal‐regulated kinase (ERK) kinase] pathway activated by fibroblast growth factor‐2 (FGF2) is suggested to be involved in the induction of transdifferentiation of the RPE into a neural retina. Therefore, we examined using culture systems whether the FGF2/MEK pathway is also involved in the adult newt RPE transdifferentiation. Here we show that the adult newt RPE cells can switch to neural cells expressing pan‐retinal‐neuron (PRN) markers such as acetylated tubulin, and that an MEK pathway is essential for the induction of this process, whereas FGF2 seems an unlikely primary induction factor. In addition, we show by immunohistochemistry that the PRN markers are not expressed until the 1–3 cells thick regenerating retina, which contains retinal progenitor cells, appears. Our current results suggest that the activation of an MEK pathway in RPE cells might be involved in the induction process of retinal regeneration in the adult newt, however if this is the case, we must assume complementary mechanisms that repress the MEK‐mediated misexpression of PRN markers in the initial process of transdifferentiation.     

龙须菜及其色素突变体藻胆蛋白的光谱及分子特征的比较

对龙须菜(Gracilaria lemaneiformis Greville)及其色素突变体藻胆蛋白吸收光谱进行了比较研究,结果显示不同藻株藻红蛋白的吸收光谱有显著的变化,而藻蓝蛋白和别藻蓝蛋白的基本相同.我们克隆了龙须菜及其色素突变体的藻红蛋白亚基的部分基因序列,用该基因序列推导出的氨基酸序列进行分析以揭示这一变化的分子机理,结果显示除几个氨基酸残基的替换外,几株藻间的藻红蛋白的氨基酸序列十分相似,一些氨基酸的替换发生在决定藻红蛋白二级结构及亚基间相互作用的区域,可能会影响藻胆蛋白的构型及相互作用,导致光谱性质的变化.