沙棘籽中原花青素的提取工艺

对沙棘籽中原花青素的提取工艺进行了初步研究。结果表明,沙棘籽脱脂后,粉碎度为90目,按液料比为4∶1加入85%(V/V)丙酮,在35℃的条件下提取14 h,对其中原花青素的提取效果达到最佳,产物经正丁醇-盐酸法显色,比色法测定其质量含量可达80%以上。     

葡萄籽原花色素对超氧阴离子的清除作用

研究了葡萄籽原花色素不同浓度(0.01～25 mg/ml)对超氧阴离子的清除作用.结果表明,在高浓度条件下,葡萄籽原花色素对邻苯三酚自氧化具有显著的抑制作用,而在低浓度条件下的抑制作用较弱.在试验浓度范围,葡萄籽原花色素对邻苯三酚自氧化的最大抑制率为91.5%,且在同浓度条件下与维生素C的抑制作用相当.在光照核黄素体系中,不同浓度的葡萄籽原花色素对超氧阴离子均具有显著的清除作用,并明显优于同浓度的维生素C.这说明葡萄籽原花色素具有良好的自由基清除能力.     

砧木对‘赤霞珠9’葡萄果实发育及隐色花色素还原酶基因表达的影响

以‘赤霞珠’嫁接苗和自根苗果实为试材,用Trizol法,对果皮和果肉RNA进行提取和纯化,利用RT-PCR技术对果实隐色花色素还原酶(LAR)转录水平进行研究。结果表明:‘5BB’‘SO4’和‘101-14MG’均增加了‘赤霞珠’葡萄枝条N素质量分数,‘SO4’增加了P素质量分数,‘101-14MG’增加了K素质量分数;‘5BB’和‘SO4’增大了‘赤霞珠’葡萄果粒,‘5BB’使‘赤霞珠’葡萄提前8d转色,‘SO4’拉长了果蒂长度,增加了果穗松散度;在整个‘赤霞珠’果实发育期,各处理果实隐色花色素还原酶活性呈现逐渐下降的趋势,‘101-14MG’和‘SO4’嫁接‘赤霞珠’果实LAR活性始终大于‘赤霞珠’自根苗果实,‘101-14MG’嫁接‘赤霞珠’果实LAR活性最强;果皮和果肉中LAR相对表达量总体呈现下降趋势,果肉中LAR相对表达量极小,果皮中LAR表达量显著高于果肉,‘101-14MG’和‘SO4’嫁接‘赤霞珠’果皮和果肉中LAR相对表达量均大于‘赤霞珠’自根苗和‘5BB’嫁接‘赤霞珠’,其中‘101-14MG’嫁接苗显著大于自根苗。     

Polyphenols in Acacia mangium and Acacia auriculiformis heartwood with reference to heart rot susceptibility

The heartwood of Acacia mangium is vulnerable to heart rot and this is the first study to investigate the role of heartwood extractives in its susceptibility. Acacia auriculiformis was compared with A. mangium because it is rarely associated with heart rot. The heartwood extracts of both species were dominated by three flavonoids (2,3-trans-3,4′,7,8-tetrahydroxyflavanone, teracacidin, and 4′,7,8,-trihydroxyflavanone), which were purified and identified by nuclear magnetic resonance spectroscopy. The latter compound has not been previously reported in A. mangium and evidence for melacacidin is also newly reported. The mass spectrometric (MS) behavior of these compounds is given, for example teracacidin does not form molecular ions by either electrospray ionization or atmospheric-pressure chemical ionization. The nature of Acacia tannins was compared to quebracho tannin (composed of profisetinidins) using oxidative cleavage to enable MS detection but a negative reaction was obtained for both, which suggests the Acacia tannins may also be of the 5-deoxy proanthocyanidin type. The concentration of flavanones was less when A. mangium heartwood was decayed but the amount of proanthocyanidins was only slightly reduced and therefore these compounds may be more resistant to degradation by heart rot fungi. We found that the total phenol content of A. auriculiformis was about fivefold that of A. mangium, and, while preliminary, this provides evidence for a role played by phenolic extractives in heart rot resistance of these Acacia species.     

原花青素在防控分泌性腹泻中的研究进展

原花青素具有抗氧化、抗分泌性腹泻等功能,可作为防控断奶仔猪腹泻的重要物质.本文综述了原花青素的结构与活性、分泌性腹泻的发生机制及原花青素抗分泌性腹泻的作用机理,为原花青素在防控断奶仔猪腹泻上的应用和研究提供理论依据.     

Proanthocyanidins and a phloroglucinol derivative from Rumex acetosa L.

From the ethyl acetate soluble fraction of an acetone–water extract of the aerial parts of Rumex acetosa L. (Polygonaceae), a variety of monomeric flavan-3-ols (catechin, epicatechin, epicatechin-3-O-gallate), A- and B-type procyanidins and propelargonidins (15 dimers, 7 trimers, 2 tetramers) were isolated with 5 so far unknown natural products. Dimers: procyanidin B1, B2, B3, B4, B5, B7, A2, epiafzelechin-(4β→8)-epicatechin, epiafzelechin-(4β→8)-epicatechin-3-O-gallate (new natural product), epiafzelechin-(4β→6)-epicatechin-3-O-gallate (new natural product), epiafzelechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate, B2-3′-O-gallate, B2-3,3′-di-O-gallate, B5-3′-O-gallate, and B5-3,3′-di-O-gallate. Trimers: procyanidin C1, epiafzelechin-(4β→8)-epicatechin-(4β→8)-epicatechin (new natural product), epicatechin-(4β→8)-epicatechin-(4β→8)-catechin, cinnamtannin B1, cinnamtannin B1-3-O-gallate (new natural product), tentatively epicatechin-(2β→7, 4β→8)-epiafzelechin-(4α→8)-epicatechin (new natural product), and epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate.Tetramers: procyanidin D1 and parameritannin A1. All compounds were elucidated by ESI-MS, CD spectra, 1D- and 2D-NMR experiments as free phenols or peracetylated derivatives and, in part, after partial acid-catalysed degradation with phloroglucinol.A more abundant proanthocyanidin polymer was also isolated, purified and its chemical composition studied by ¹³C NMR.In addition a so far unknown phloroglucinolglycoside (1-O-β-d-(2,4-dihydroxy-6-methoxyphenyl)-6-O-(4-hydroxy-3,5-dimethoxybenzoyl)-glucopyranoside) was isolated.     

植物多酚(英文)

从普遍存在的绿原酸到分子量在500—20000范围之间的多酚组分(即植物单宁)植物多酚的变化是很复杂的。从广义上讲,多酚主要可分为两类,即原花色素和以倍酸和(或)六羟基联苯甲酸和它们的衍生物为基础的聚酯化合物。如早期文献报道的,前者相当于凝缩类单宁,而后者则是水解单宁。作为植物的二次代谢物它们具有一些不同的分子特性。它们不仅具有多种多样酚基,而且还有一种和各种天然大分子即蛋白、多糖和核酸以及代谢物如生物碱结合成可逆复合物的倾向。根据这些性质,历史上按“伞”命名法称之为植物单宁。文中还讨论了植物多酚结构的变化因素,以及它们与其它物质的结合。     

Effects of log storage and drying on birch (<Emphasis Type="Italic">Betula pendula</Emphasis>) wood proanthocyanidin concentration and discoloration

In conventional drying, sawn birch (Betula sp.) timber darkens and reddens from the inside while the layer a few millimetres under the yellowish surface remains light in color. Lack of information concerning the chemical basis of the discoloration hinders the development of a reliable solution for this problem. In this study, the role of soluble proanthocyanidins in discoloration of birch wood was investigated because the polymerization and oxidation of these compounds are known to yield insoluble reddish compounds. Different periods of log storage affected the synthesis of soluble proanthocyanidins during conventional drying. Concentration of proanthocyanidins also correlated with changes in the color of birch wood. Discoloration appeared differently in conventionally dried and vacuum-dried wood, which indicates that the discoloration mechanism in these drying methods may differ chemically, and/or the compounds that take part in discoloration may be different at different drying temperatures.     

原花青素对脂多糖诱导的环氧合酶-2表达的抑制作用

以脂多糖(LPS)诱导的RAW264.7细胞为模型,研究原花青素对LPS诱导的小鼠RAW264.7细胞中环氧合酶-2(COX-2)mRNA转录的抑制机制。采用RT-PCR法测定原花青素对LPS诱导的RAW264.7细胞中COX-2mRNA转录的影响,采用Western blot和免疫组化法考察原花青素对LPS诱导的RAW264.7细胞核转录因子κB(NF-κB)亚基p65(NF-κB/p65)及NF-κB结合蛋白(I-κB)表达的影响。结果发现LPS处理RAW264.7细胞可以明显上调COX-2 mRNA的表达,同时降低胞质蛋白I-κB的表达水平,增加NF-κB的水平。原花青素对RAW264.7细胞中COX-2 mRNA的转录有较强抑制作用,抑制NF-κB/p65的表达及I-κB的降解,原花青素可能是通过抑制NF-κB/p65的表达及I-κB/p65的降解而抑制COX-2的表达。     

葡萄籽中原花青素提取和测量方法研究

以赤霞珠葡萄籽为原料,对原花青素的提取方法和含量测定进行了探索.结果表明: 葡萄籽粉料液比为1:10( w /v ),在PH6.0、60℃条件下用80 %甲醇提取3次,每次提取时间为90min时原花青素提取效果最佳,赤霞珠葡萄籽中原花青素含量为8.79%.