RP-HPLC法测定桑叶中的芦丁和异槲皮苷含量

目的：建立HPLC法测定桑叶中芦丁、异槲皮苷含量的定量分析方法。方法：HPLC外标法。采用色谱柱：Agilent TC-C18柱（250mm×4．6mm,5μm）;流动相：乙腈．甲醇．水．磷酸（100：10：340：0．3,V／V）;检测波长365nm;流速1．0ml／min;进样量20u1;柱温：室温。结果：在上述色谱条件下,芦丁、异槲皮苷获良好分离,浓度分别在7．5～150μg／ml（R2=0．9995）、7．1～142μg／ml（R2=0．9998）范围内呈良好的线性关系,平均加样回收率为98．79％、99．01％,RSD分别为3．37％、2．43％,重复性实验RSD分别为0．0133％和0．0214％。结论：该方法分离度好,简便快速,为桑叶生药及其制剂的质量控制提供可借鉴的分析方法。     

辣椒中辣椒红素稳定性的研究

研究光照、温度、pH值、金属离子4个因素对辣椒红素稳定性的影响。结果表明,辣椒红素在pH为3～12,温度在25～70℃时较为稳定,金属离子K+、Ca2+、Na+、Mg2+、Zn2+对其无影响,而Al3+、Fe3+对其影响不大,Cu2+、Fe2+对其有显著影响。     

辣椒红色素的分离及光稳定性研究

利用硅胶柱层析法分离辣椒红色素，得到黄色素酯和辣椒红素二酯，比较它们的光稳定性。结果表明，在光照条件下，辣椒红素二酯稳定性较高，4d后仍有50％未被降解；避光存放3个月，辣椒红素二酯最稳定，降解率不到0．5％，而混合色素的稳定性降低。     

响应面分析法优化黄蜀葵花中金丝桃苷、异槲皮苷、槲皮素提取工艺的研究

采用响应面优化黄蜀葵花中金丝桃苷、异槲皮苷、槲皮素的提取工艺。在超声功率、提取时间、乙醇浓度、提取温度、料液比的单因素实验基础上,固定提取温度50℃、料液比0.1∶15 g/m L,利用响应面分析法优化,建立二次多项式回归方程模型,确定最佳提取工艺为:超声功率340 W、提取时间60 min、乙醇浓度为60%。经工艺验证,金丝桃苷得率为4.97 mg/g,异槲皮苷得率为4.84 mg/g、槲皮素得率为2.02 mg/g,与理论值的相对误差分别为2.5%、4.5%、6.9%。采用响应面设计分析得到最佳提取工艺条件具有较高的实用价值,可为工业化提取提供理论参考。      

苦荞异槲皮苷对人胃癌细胞SGC-7901增殖及凋亡的影响

从苦荞中提取制备异槲皮苷,研究其对人胃癌细胞SGC-7901增殖、凋亡、迁移和细胞周期的影响。将异槲皮苷作用于人胃癌SGC-7901细胞和人肾上皮细胞系293T,通过噻唑蓝法检测异槲皮苷对其增殖的影响;4’,6-二脒基-2-苯基吲哚(4’,6-diamino-2-phenyl indole,DAPI) 荧光染色法观察细胞核的形态学变化;划痕擦伤迁移实验检测异槲皮苷对SGC-7901细胞迁移能力的影响;流式细胞术检测异槲皮苷对SGC-7901细胞凋亡及细胞周期的影响。结果表明：苦荞异槲皮苷可以抑制SGC-7901细胞的增殖,并呈时间和剂量依赖性,当用100 μmol/L异槲皮苷作用细胞48 h后,对SGC-7901细胞的增殖抑制率达到35.92%, 而对人肾上皮细胞系293T的增殖抑制率仅为 3.15%;DAPI荧光染色法观察异槲皮苷处理细胞后,染色体凝聚,有凋亡小体产生;划痕擦伤实验显示,异槲皮苷能抑制SGC-7901细胞的迁移;流式细胞术检测结果表明,异槲皮苷可使G1和S期细胞减少,G2/M期细胞增多,且细胞凋亡率明显增加。综上所述,苦荞麦异槲皮苷能够诱导SGC-7901细胞发生凋亡,阻断细胞周期并抑制细胞增殖和迁移。     

HPLC法同时测定甘薯叶中5种酚酸和异槲皮苷

咖啡酸、绿原酸、3,4-二咖啡酰奎宁酸、3,5-二咖啡酰奎宁酸、4,5-二咖啡酰奎宁酸和异槲皮苷是甘薯叶中的主要活性成分,本研究建立高效液相色谱（high performance liquid chromatography, HPLC）同时测定这6种成分的方法。通过对检测波长、色谱柱、洗脱溶剂、洗脱流速等参数优化得到的最佳分析条件为:ZORBAX SB-C₁₈（4.6 mm×250 mm,5 μm）为分析柱,以0.1%甲酸水溶液（A）和乙腈（B）为流动相,采用梯度洗脱:0～12 min,10%~25% B;12～18 min,25% B,流速0.8 mL/min,检测波长326 nm,柱温30 ℃。咖啡酸、绿原酸、3,4-二咖啡酰奎宁酸、3,5-二咖啡酰奎宁酸、4,5-二咖啡酰奎宁酸和异槲皮苷的线性范围分别为0.25~25.0、0.5~50.0、5.0~100.0、10.0~200.0、5.0~100.0和0.5~50.0 μg/mL。该方法分析时间短（18 min）,线性度（R2≥0.998）、稳定性（RSD≤1.97%）、精密度（RSD≤1.56%）和加标回收率（95.14%~103.22%）好。对江西10个不同产地甘薯叶目标成分分析发现,宜春丰城的甘薯叶具有最高的总酚含量。     

HPLC法测定不同种源辣木叶花茎中异槲皮苷和新绿原酸的含量

采用高效液相色谱法同时测定不同种源辣木叶、花、茎中的异槲皮苷及新绿原酸的含量,并进行多重比较分析和聚类分析。结果表明,辣木叶花茎中均存在异槲皮苷及新绿原酸,2种活性成分含量分布特征均为:叶花茎(叶中含量显著高于花及茎)。异槲皮苷在辣木花(2.43 mg/g～0.70 mg/g)和茎(1.89 mg/g～0.64 mg/g)中的含量高于新绿原酸(分别为1.28 mg/g～0.69 mg/g、0.68 mg/g～0.26 mg/g),特别是在辣木茎中表现尤为明显。17份辣木样品依据异槲皮苷及新绿原酸的含量特征聚类为5种类群。不同来源地的辣木样品中,来源于古巴的YLM-3叶、花、茎3个部位异槲皮苷和新绿原酸含量均较高(异槲皮苷含量分别为5.94、1.61、1.92 mg/g,新绿原酸含量分别为5.28、1.06、0.49 mg/g),YLM-3的叶片可作为辣木产品开发及利用的理想材料。     

超高效液相色谱法测定山楂原料、提取物和相关食品中金丝桃苷和异槲皮苷的含量

目的 建立超高效液相色谱法测定山楂原料、提取物和相关食品中金丝桃苷和异槲皮苷的分析方法。方法 采用ACQUITY UPLC BEH C18柱, 以甲酸乙腈-甲酸水为流动相进行梯度洗脱分离金丝桃苷和异槲皮苷, 在紫外检测波长360 nm下进行检测, 外标法定量。结果 金丝桃苷和异槲皮苷的检出限(limit of detections, LODs, S/N=3)均为2 mg/kg, 定量限(limit of quantifications, LOQs, S/N=10)均为5 mg/kg; 在0.5~10.0 mg/L的浓度范围内线性关系良好, 相关系数均为0.999; 在原料、提取物和相关食品中, 金丝桃苷和异槲皮苷的平均回收率分别为83.0%~108.0%和86.2%~105.0%, 相对标准偏差(relative standard deviations, RSDs)分别为1.6%~5.7%和1.1%~3.9%。结论 本方法操作简便、快速、分离度和准确度高, 可用于山楂原料、提取物和相关食品的质量控制。     

荨麻中槲皮苷提取工艺的研究

对荨麻中槲皮苷的乙醇提取工艺进行了研究。用HPLC法测定槲皮苷含量,通过L9(34)正交试验,优选了工业参数。结果表明:对提取效果影响因素依次为乙醇体积分数>料液比>浸提温度>浸提时间。最佳提取工艺条件是:体积分数70%乙醇、料液比1:30、浸提温度80℃,浸提时间3h,提取率为211mg/kg。     

HPLC法测定荨麻中槲皮苷的含量

目的:建立食药两用植物荨麻中槲皮苷含量的测定方法。方法:色谱柱:C18柱(150mm×4.6mm,5μm);流动相:甲醇-0.2%磷酸(体积比50:50);流速:1.0ml/min;柱温:室温;检测波长:360nm。结果:槲皮苷进样量在0.40～2.00μg范围内与峰面积线性关系良好(r=0.9996),回收率96.88%,RSD1.68%。结论:本法简便,结果可靠,可用于荨麻质量控制。     

Antioxidant effects of flavonoids used as food additives (purple corn color, enzymatically modified isoquercitrin, and isoquercitrin) on liver carcinogenesis in a rat medium-term bioassay

To clarify the effects of purple corn color, enzymatically modified isoquercitrin (EMIQ), and isoquercitrin (IQ), registered as natural food additives in Japan, on liver carcinogenesis in vivo, a medium-term bioassay was employed. A total of 100 male F344 rats were divided into 5 groups; groups 1 to 4 were given a single intraperitoneal injection of diethylnitrosamine (200 mg/kg b.w.) on day 1. From weeks 2 to 8, they were administered basal diet purple corn color, EMIQ, or IQ as containing test chemicals at doses of 1.0% (groups 1 and 5), 0.1% (group 2), 0.01% (group 3), or 0% (group 4) (experiments 1, 4, and 5). All rats were subjected to two-thirds partial hepatectomy at week 3 and were sacrificed at week 8. Purple corn color exerted no significant modifying effects on GST-P positive foci, preneoplastic foci, development in the liver. However, serum of rats treated with purple corn color provided evidence of antioxidant power significantly by potential antioxidant (PAO) test in vivo (experiment 2). And microarray analyses showed purple corn color to induce RNA expression such as P450 (cytochrome) oxidoreductase, phosphatidylinositol 3-kinase, and phospholipase A2 (experiment 3). Higher doses of EMIQ or IQ with strong antioxidant power in vivo by PAO test treated groups were correlated with smaller numbers of GST-P positive foci, with Spearman's rank correlation coefficients of P= 0.002 and P= 0.049, respectively (experiments 4 and 5). Therefore, the tested food additives may be effective as antioxidants in vivo and have chemopreventive potential against liver preneoplastic lesion development.     

各类载体对红曲红色素光稳定性的影响

水溶性蛋白类载体为目前市场销售红曲红产品中主要载体，可使红曲红色素光稳定性由35．6％提高到54．6％，海藻酸钠、明胶和β-环状糊精作载体可使红曲红色素光稳定性由35．6％分别提高到66．5％、66．3％和60．6％。     

苯并三唑结构紫外线吸收剂对蚕丝耐光稳定性能的影响

为提升蚕丝织物的耐光稳定性能,采用苯并三唑结构紫外线吸收剂UV-FAST W（简称UVFW）对其进行处理,并将处理蚕丝进行紫外光照实验,测试了蚕丝的光照黄变历程,分析了UVFW浓度对蚕丝光黄变与光脆损的影响,探讨了UVFW处理蚕丝的湿牢度问题,同时还研究了UVFW对染色蚕丝颜色指标与光色牢度的影响。结果表明：经1%浓度UVFW处理的蚕丝,光稳定性能得到较大程度的提升,继续增加UVFW浓度,蚕丝的光稳定性能提升不明显,且UVFW浓度增加将降低蚕丝的初始白度;UVFW处理蚕丝的湿处理牢度需进一步提升,水洗后蚕丝光稳定性能明显下降;UVFW对染色蚕丝的颜色指标与光色牢度均产生影响,但影响程度与染料有关。     

Stabilization of grape skin anthocyanins by copigmentation with enzymatically modified isoquercitrin (EMIQ) as a copigment

The thermal and light stability of grape skin anthocyanins with enzymatically modified isoquercitrin (EMIQ) as a copigment was investigated at different pH levels of 3, 4 and 5. The ratios of anthocyanins to EMIQ were 2:1, 1:1, and 1:2 (w/w), respectively, in the thermal experiments at 90 °C, and EMIQ concentrations (0.25, 0.5, and 1%, w/w) were evaluated respectively in the light experiments. Results revealed that the degradation of anthocyanins copigmented with EMIQ followed first-order reaction kinetics. The half life of anthocyanins extended significantly with the increase of EMIQ concentration (p < 0.05), moreover, the color stability increased due to the addition of EMIQ as the total color difference values ΔE* were smaller for the copigmented anthocyanins. The magnitude of the bathochromic (λ_max) shifted to the longest wavelength absorption band with the increasing copigment concentration for all pH levels. Results demonstrated that EMIQ was an effective copigment to stabilize grape skin anthocyanins.     

两种荧光染料的光稳定性研究

采用标准氙灯分别光照自制的苯乙烯吡啶盐阳离子荧光橘红DHEASPBr-C2和市售的阳离子荧光黄X-10GFF染色腈纶织物,探究两种染料光稳定性。在染料0.05%（omf）条件下,阳离子荧光黄X-10GFF染色腈纶织物的荧光强度大于阳离子荧光橘红DHEASPBr-C2;在标准氙灯光照条件下,两只染料均发生不同程度的光褪色,前者略好于后者。采用量子化学中的密度泛函方法(DFT),揭示两种染料光降解机理。阳离子荧光橘红DHEASPBr-C2因具有较多的活泼位点,更易在空气中发生光褪色。     

溶胶-凝胶法改善芳纶织物的耐光性

针对高性能纤维耐光性较差的现状,采用TiO2溶胶-凝胶涂层方法改善芳纶织物的耐光性.利用动态光散射激光粒度分析仪Nano ZS分析发现,制备的TiO2水溶胶粒子尺寸和分布都很均匀.利用U-4100紫外/可见/近红外分光光度计表征,对比涂层前后织物对光的透射、反射和吸收量,发现涂层后织物耐光性提高.同时,通过扫描电镜观察,涂层后在织物表面形成TiO2水溶胶一凝胶的连续膜结构,对光辐照有较好的屏蔽作用.     

In vitro assessment of sunscreen photostability: the effect of radiation source, sunscreen application thickness and substrate

The photostabilities of four sunscreen products have been assessed in vitro by applying sunscreen to a substrate and measuring the spectral transmission prior to, and after exposure to a source of ultraviolet (UV) radiation. Results were independent of whether an application thickness of 1 or 2 mg/cm ; 2 was used, and whether the UV source was natural sunlight or a xenon arc solar-simulator. There were significant differences, however, between results obtained on a roughened quartz substrate and those obtained on excised human epidermis. It is unlikely that any substrate will give an exact representation of the in vivo situation and, indeed, both quartz and excised human epidermis have disadvantages associated with their use. However, the ranking of the four products in terms of their photostability was the same for both substrates. This implies that transmission spectroscopy, with either a quartz or a human epidermis substrate, can be used successfully to compare the photostabilities of different sunscreen products.     

抗紫外线整理改善漂白羊绒的耐光稳定性

为改善漂白羊绒织物的耐光稳定性,对其进行抗紫外线整理,优化的工艺为:整理剂质量分数5％、整理温度60℃、整理时间30 min.整理后羊绒织物的UPF值达90以上,白度略有下降.在人造光源下连续辐照40 h,或者UVA光源下连续辐照168 h,羊绒织物白度变化很小,表明抗紫外线整理可以明显改善漂白羊绒的耐光稳定性.     

半花菁荧光染料光稳定性的量子化学计算

针对纺织品用荧光染料光稳定性较差的问题,应用已合成的2种半花菁荧光染料进行研究。对染料染色腈纶织物进行光老化试验,比较2种染料的日晒牢度;进行染料水溶液的光降解试验,得到量化的染料降解速率常数。采用量子化学理论中的密度泛函方法,对2种染料阳离子进行构型优化和频率计算,并对得到的稳定构型进行分子轨道计算;通过研究各形态氧与染料阳离子前线分子轨道的相互作用,在理论上比较2种染料阳离子的活泼位点及其稳定性差异。结果表明,半花菁荧光染料1,3,3-三甲基-反式-2-[对-（N,N-二乙基）-氨基-苯乙烯基]-N-甲基吲哚氯化盐的光稳定性优于反式-4-[对-（N,N-二乙基）-氨基-苯乙烯基]-N-乙基吡啶溴化盐,计算结果与实验结果有很好的一致性,可作为判断此类染料光稳定性的理论参考。