茶饮料中微量色素物质的HPLC分析方法研究

以含乙腈的流动相作为洗脱剂,对茶饮料中微量色素物质的HPLC分析方法进行了研究。结果显示,在色谱柱长为15cm、柱温为35℃、总流量为1ml、检测波长450nm条件下,最佳的洗脱参数为:①以3/0.5/96.5(v/v/v)的乙腈、乙酸和水的混合液为流动相A,以75/15/10(v/v/v)的乙腈、甲醇和氯仿混合液为B相;②梯度洗脱,即前20min内B相由80%上升到100%,并保持15min。在该条件下新黄质、紫黄质、叶黄素、叶绿素b、叶绿素a、脱镁叶绿素b、β-胡萝卜素和脱镁叶绿素a等色素物质均可获得基线分离。同时研究还显示,该方法重复性较好,检测限低,可满足绿茶饮料中微量色素物质的分析。     

红茶色素的形成与降解作用的初步研究

在红茶制造中,用铜酶抑制剂二乙基二硫代氨基甲酸钠能抑制多酚氧化酶活性24%左右,从而部分的抑制了茶叶发酵,特别是茶黄素的形成受到了抑制。采用茶叶匀浆发酵法,结果表明,非酶性氧化产物中茶黄素约为酶促氧化形成量的6.8%,茶红素约为20.6%。用茶黄素单没食子酯在纯过氧化物酶作用下,研究其降解作用,其产物用双向纸层析和紫外光谱进行分析鉴定,结果鉴别出3,4-二羟苯甲酸、咖啡酸、没食子酸和邻苯二酚等4种成分。     

Metabolie Engineering of Flower Color in Ornamental Plants

Abstract

Advances in the knowledge of plant pigment pathways at genetic, biochemical and molecular levels, and the establishment of genetic transformation methods for an increasing number of plant species have paved the way to genetic engineering of flower and plant color for ornamental purposes. From trial-and-error approaches based on the available few genes, the trend is now to comprehensively study the target species, genotypes and pigment pathways to precisely address specific breeding goals. This review examines the state of the art in this field, from the pioneering stages to fundamental and applied research on flavonoids, which is being extended to carotenoids and is also likely to involve other pigments in the near future.     

渍水对冬油菜苗期生长及生理的影响

以中双9号油菜为材料,通过盆栽试验研究了苗期不同渍水时间对冬油菜生长和生理指标的影响。结果发现,光合色素含量在整个试验期间一直下降。其它生长及生理指标均表现为先升高后降低的趋势,其中相对生长率、根系活力、可溶性糖、根系丙二醛（MDA）含量、叶片超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性在渍水第13d时达到最高,而叶片MDA含量则在渍水胁迫24d时达到最大值。说明渍水胁迫对冬油菜幼苗地上部和根系生长产生显著影响。短期渍水胁迫下,油菜幼苗能够通过调节自身的生理代谢活动,维持一定的生长量;但是随着胁迫时间的延长,植株生理活动受到严重影响,油菜幼苗生长受抑制,相对生长率显著降低。     

新鲜烟叶不同处理对质体色素含量的影响

以K326为材料,利用高效液相色谱法测定了杀青与液氮研磨两种处理后烟叶4种质体色素叶绿素a,叶绿素b,β-胡萝卜素和叶黄素的含量。结果显示,虽然液氮研磨与新鲜烟叶质体色素含量存在极显著差异,但与杀青相比,液氮研磨烟叶更接近新鲜烟叶中质体色素的含量。可见对于新鲜烟叶质体色素含童的测定,液氮研磨要比杀青处理结果更接近真实磕。     

Marennine,Promising Blue Pigments from a Widespread Haslea Diatom Species Complex

In diatoms, the main photosynthetic pigments are chlorophylls a and c, fucoxanthin, diadinoxanthin and diatoxanthin. The marine pennate diatom Haslea ostrearia has long been known for producing, in addition to these generic pigments, a water-soluble blue pigment, marennine. This pigment, responsible for the greening of oysters in western France, presents different biological activities: allelopathic, antioxidant, antibacterial, antiviral, and growth-inhibiting. A method to extract and purify marennine has been developed, but its chemical structure could hitherto not be resolved. For decades, H. ostrearia was the only organism known to produce marennine, and can be found worldwide. Our knowledge about H. ostrearia-like diatom biodiversity has recently been extended with the discovery of several new species of blue diatoms, the recently described H. karadagensis, H. silbo sp. inedit. and H. provincialis sp. inedit. These blue diatoms produce different marennine-like pigments, which belong to the same chemical family and present similar biological activities. Aside from being a potential source of natural blue pigments, H. ostrearia-like diatoms thus present a commercial potential for aquaculture, cosmetics, food and health industries.     

钝裂银莲花花色素成分及其稳定性

以黄色和浅黄色钝裂银莲花(Anemone obtusiloba)花瓣为研究材料,对其色素进行特征显色反应和紫外-可见光谱扫描分析,并对其色素的成分及其稳定性进行研究。结果显示,两种花色钝裂银莲花花瓣均含有叶绿素和类胡萝卜素,主要色素为黄酮类化合物(花色素苷、黄酮、黄酮醇和异黄酮),不含橙酮和二氢黄酮,其黄酮类化合物均表现为酚羟基结构,可能具有4-酮基、3-OH或4-酮基、5-OH结构的特征;pH值对花色素具有一定影响,避光保存花色苷的稳定性强于光照,Fe3+和Cu2+对花色素稳定性影响比较大。     

Increase in DNA fragmentation and the role of ethylene and reactive oxygen species in petal senescence of Osmanthus fragrans

In sweet osmanthus (Osmanthus fragrans Lour.) flowers, petal browning, partial abscission and wilting are the visible symptoms of senescence, 4–5 days after flowering, which seriously affect its ornamental and economic value. In the present study, DNA fragmentation was used as a marker to investigate the role of ethylene and reactive oxygen species (ROS) in flower senescence of O. fragrans ‘Liuye Jingui’. In intact plants, nuclear shrinkage and DNA fragmentation occurred at the late full flowering stage when senescence symptoms became visible. This coincided with a rapid increase in ethylene production, ROS generation and lipid peroxidation. To further determine the role of ethylene and ROS in flower senescence, cut flowers were treated with ethephon, silver thiosulphate (STS), hydrogen peroxide (H₂O₂), and vitamin C (Vc). The vase life of cut flowers was significantly prolonged by 0.2 mM STS and 2.5 mM Vc treatments, but reduced by 0.03% H₂O₂ and 500 mg L⁻¹ ethephon treatments, compared to distilled water. The percentage of DNA fragmentation was dramatically increased by ethephon but reduced by STS treatment throughout vase life. In contrast, the dramatic increase of DNA fragmentation in the H₂O₂ treated samples was only observed at day three, and clear petal abscission and rapid petal wilting occurred only with ethephon. Compared with the distinguishable nuclei and complete vacuoles in both STS treatment and distilled water, ethephon treatment caused substantial damage to large central vacuoles and other organelles, and many petal cells twisted out of shape due to a loss of cytoplasm, resulting in rapid petal wilting. Thus, it is concluded that ethylene plays an important role in flower senescence of sweet osmanthus, enhancing DNA fragmentation, damaging cellular structure, and leading to petal abscission and wilting. In addition, ROS is also involved in the regulation of late DNA degradation and lipid peroxidation.     

紫叶李在高温高湿条件下色素含量及光合速率的研究

用分光光度法和CI-340便携式光合测定系统,测定了紫叶李在不同温湿度条件下光合色素含量变化和光合速率日变化.结果表明:(1)紫叶李叶片中叶绿素a、叶绿素b和类胡萝卜素的含量随着温度的升高而增加,随湿度的增加而减少,花青素含量在高温高湿条件下逐渐降低.(2)紫叶李的光合速率在大田自然条件下呈不对称双峰日变化曲线,而在高温高湿条件下午休现象消失,光合速率随温度的升高而增强.     

红曲色素的基本性质和快速分离技术

红曲色素是天然食用色素之一,在285、400和500nm 处有3个吸收峰,在强酸性、酸性和中性的条件下相当稳定;温度、金属离子、氧化剂、还原剂和络合剂对红曲色素的影响较小。从红曲色素中分离出一种黄色红曲色素,在285和398nm 处有吸收峰。其极性小于紫色红曲色素和橙色红曲色素。用针筒层析分离柱可快速将3种红曲色素分离。