不同大豆种质种皮黄酮类色素的差异分析

为探究大豆种皮中黄酮类色素的含量和分布规律,选取167份大豆种质资源为实验材料,利用高效液相色谱(HPLC)法对大豆种皮黄酮类色素含量进行测定。结果表明：大豆种皮花色苷组分中矢车菊素-3-O-葡萄糖苷含量最多,异黄酮组分中大豆苷含量最高。花色苷组分在野生和半野生大豆种皮中高于栽培大豆。异黄酮组分中染料木苷在野生大豆中最高,黄豆黄苷在半野生大豆中最高,其他组分在栽培大豆中最高。栽培大豆黑色种皮花色苷组分、染料木苷和大豆苷元含量最高,青色种皮大豆苷和黄豆黄苷含量最高,双色种皮黄豆黄素含量最高。相关分析表明3类结合型糖苷内部、3类游离型苷元内部、3种花色苷组分内部两两相关极显著。大豆苷与游离型苷元、矢车菊素-3-O-葡萄糖苷相关显著。聚类分析将大豆材料划分为三大类群,第一类群除黄豆黄苷和飞燕草素-3-O-葡萄糖苷外,其他色素组分含量均最高,为黄酮类色素的研究和利用提供参考。     

Accounting for co‐extractable compounds (blank correction) in spectrophotometric measurement of extractable and total‐bound proanthocyanidin in Leucaena spp

Methods to account for the spectral interference of co‐extractable compounds (blank correction) in the spectrophotometric analysis of both extractable and bound proanthocyanidin (PA) using the proanthocyanidin (butanol/HCl) assay were evaluated. Crude extractable and bound PA sample matrices of PA‐free Leucaena magnifica were used. Extractable PA blanks generated in heated 95% butanol/5% H₂O reagent underestimated the optical density (absorbance) of co‐extractable compounds by 24% (P < 0.01), whereas unheated 95% butanol/5% HCl blanks, incubated at room temperature, accurately measured the absorbance of the background matrix (P < 0.01). Current procedures that estimate bound PA concentrations using the proanthocyanidin assay produce intensely coloured background matrices. Recovery measurements from total‐bound PA extracts spiked with 1071 and 2142 µg anthocyanidin per tube indicated that existing analytical procedures that do not account for the spectral interference of co‐extractable compounds overestimated (P < 0.01) bound PA concentrations by 69 and 38% respectively. An innovative technique that generated an internal correction factor for each sample, using wavelength‐scanning spectrophotometry and non‐linear curve‐fitting computer software, was developed. This procedure recovered 100% of added anthocyanidins from bound PA matrices. © 2002 Society of Chemical Industry     

显齿蛇葡萄种皮中花色苷及多糖体外抗氧化活性评价

研究显齿蛇葡萄种皮中花色苷及多糖的体外抗氧化活性。分别采用p H示差法、紫外可见光分光光度法测定花色苷含量、多糖含量;考察花色苷、多糖对羟基自由基（·OH）、超氧阴离子自由基（O₂^-·）、DPPH自由基（DPPH·）的清除能力。结果显示花色苷和多糖对DPPH自由基的IC₅₀值顺序为多糖（0.06 mg/m L）>花色苷（0.09 mg/m L）>VC（0.15 mg/m L）;·OH、O₂^-·和DPPH·的IC₅₀与花色苷含量之间的相关系数分别为-0.987（p<0.05）、-0.958（p<0.05）和-0.995（p<0.01）,而与多糖含量不显著相关。因此,显齿蛇葡萄种皮花色苷及多糖均具有较好的清除DPPH自由基能力,尤其是多糖的清除能力最强;花色苷含量及其清除DPPH自由基活性之间呈极显著相关性（p<0.01）。      

Changes in the dry matter,sugar, plant fibre and lignin contents of swede,rape and kale roots in response to turnip root fly (Delia floralis) larval damage

Plants from two genotypes of swede (Brassica napus var napobrassica), kale (B oleracea var. acephala) and rape (B napus var napus) were each inoculated at the three to four true leaf stage with 10 eggs of the turnip root fly, Delia floralis. After 8 weeks the damage caused by the resultant larvae significantly reduced the weight of leaves, stems and roots compared with uninoculated plants, with the greatest reduction (26–46%) being found in the roots. Dry matter content, which did not differ between either crop type or cultivar, was unaffected by larval damage. Ethanol-soluble sugar content was reduced in all cases by larval damage, but only significantly in one rape and one swede cultivar. The effect of D floralis damage on the concentrations of individual sugars (glucose, fructose and sucrose) was crop type and cultivar dependent. The neutral detergent fibre and lignin contents of the undamaged swede roots were significantly lower than in either the undamaged kale or rape cultivars studied. In all crop types the neutral detergent fibre and lignin content significantly increased following D floralis damage. The six Brassica genotypes studied fell into two groups on the basis of host status for D floralis. The two kale cultivars and the forage rape Hobson were considered poor hosts for D floralis, with low percent age pupation (38–41%) and low pupae weight (12.5–14.4 mg). The two swedes and the oilseed rape Ariana were considered good host for D floralis, with both higher percentage pupation (51–59%) and pupae weights (19.8–20.0 mg). The possible relationships between the root composition of undamaged and attacked roots, and D floralis resistance are discussed.