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《林业工程学报》2017,(4)
原花色素是最有效的自由基清除剂之一,具有非常强的清除自由基和抗氧化的能力。以云南地区滇橄榄树为原料,采用超声波提取法,对其树皮、树芯、树枝、树叶的原花色素质量浓度进行了研究,并对树枝原花色素的提取条件进行优化。其次,对树皮原花色素抗氧化能力及与维生素C(vitamin C,VC)的抗氧化协同作用进行了比较。结果表明:树枝的原花色素质量浓度最高,其次是树皮、树叶、芯材。同时,树枝中原花色素提取的最佳条件为:以质量分数为60%的乙醇为提取剂,料液比1∶7,提取温度60℃,提取时间30 min,在此条件下原花色素的提取率能达到3.85%。滇橄榄树皮提取物具有很强的抗氧化性,清除DPPH自由基的能力最佳,原花色素质量浓度为10μg/m L时,自由基清除率高达88.55%,且抗氧化有效成分主要集中在乙酸乙酯层,水层仍然含有部分抗氧化成分。原花色素和VC以质量比为3∶1,1∶1,1∶3进行复配后的自由基最高清除率分别为88.84%,91.27%,91.05%,协同作用强弱顺序为1∶11∶33∶1。 相似文献
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黑荆树原花色素二聚体的分离制备及抗氧化活性研究 总被引：1，自引：0，他引：1
《林产化学与工业》2017,(2)
以黑荆树皮为原料,采用超声波辅助提取技术提取原花色素,并利用溶剂萃取法得到低聚原花色素含量较高的乙酸乙酯萃取物;进一步通过葡聚糖凝胶Sephadex LH-20柱和快速蛋白液相色谱(FPLC)分离纯化制备黑荆树原花色素二聚体,并采用HPLC-MS对产物结构进行了鉴定。结果表明:超声波辅助提取原花色素的粗提物得率高达50.21%,其中含原花色素为40.75%,乙酸乙酯萃取物经葡聚糖凝胶Sephadex LH-20柱可得液相纯度约为60%的组分I(得率约为5%);组分I经FPLC分离,水-甲醇为流动相,得到纯度为91.72%的原花色素二聚体(得率约为13%);HPLC-MS分析表明,原花色素二聚体相对分子质量为578,可能是由原花青定的C-4键与原刺槐定的C-8键相连。黑荆树原花色素二聚体对DPPH自由基的清除率分析表明:原花色素二聚体的抗氧化活性总体高于儿茶素以及表没食子儿茶素没食子酸酯(EGCG)标样,当二聚体浓度为60μmol/L时对DPPH清除率大于80%,高于EGCG(约为68%)和儿茶素(约为50%)。 相似文献
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《林产化学与工业》2017,(3)
用70%乙醇从大血藤中提取原花色素,并对粗提物进行纯化和分离,采用香草醛-盐酸比色法测定各样品中原花色素含量,并测定各样品抗氧化活性和酶抑制活性。结果表明:大血藤乙醇粗提物(CE)、石油醚萃取物(PE)、乙酸乙酯与水两相不溶物(EIF)、乙酸乙酯萃取物(EF)、正丁醇萃取物(BF)和水相留余物(WR)中含原花色素分别为(36.03±0.40)%、(1.19±0.11)%、(57.99±0.22)%、(32.40±0.07)%、(25.03±0.08)%和(41.32±0.37)%。大血藤乙醇粗提物经葡聚糖凝胶LH-20纯化后,含原花色素(98.35±0.72)%,约为粗提物的2.73倍;大血藤纯化物(PT)对二苯基苦基肼自由基(DPPH·)的半数抑制质量浓度(IC_(50))为(70.70±1.38)mg/L,是L-抗坏血酸的1.12倍;对α-葡萄糖苷酶的IC_(50)为(4.37±0.17)mg/L是阿卡波糖的120.71倍。说明大血藤含有丰富的原花色素,大血藤原花色素具有较强的体外抗氧化活性和酶抑制活性。 相似文献
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《林业工程学报》2016,(6)
原花色素的提取通常采取用传统外加热方式的溶剂浸渍法,存在提取时间长、提取效率低等缺点,而微波辅助提取技术具有加热效率高、提取时间短和提取率高等优点,成为传统提取技术的一种替代方式。笔者以兴安落叶松和日本落叶松树皮为研究对象,对比研究了微波辅助提取法和常规水浴浸渍法在不同提取时间下对原花色素提取得率的影响,并利用紫外光谱仪和红外光谱仪对树皮提取物的结构进行了表征。结果表明,和常规浸渍法相比,利用微波辅助提取法可显著缩短提取时间,提高原花色素的提取得率,并且不会引起原花色素结构的破坏。兴安落叶松和日本落叶松树皮中原花色素的微波辅助提取适宜工艺条件为:微波功率200 W,提取时间10 min,温度60℃,溶剂为50%乙醇,溶剂和树皮的体积与质量比(mL∶g)为10∶1。在此条件下,兴安落叶松和日本落叶松树皮中原花色素的提取得率分别为239%和278%。两者树皮中的原花色素均以原花青素结构为主,仅含有少量原翠雀素。相同条件下,兴安落叶松树皮比日本落叶松树皮的原花色素提取得率稍低。微波辅助提取法适用于落叶松树皮中原花色素的提取,是一种快速、有效和安全的方法。 相似文献
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毛杨梅树皮提取物抗氧化及清除自由基活性初步研究 总被引：1，自引：5，他引：1
毛杨梅树皮提取物中的主要成分为局部棓酰化的聚原翠雀定,具有比原花青定抗氧化活性更强的化学结构特征.本研究以水为提取剂,通过强化提取、絮凝沉降、溶剂萃取、吸附分离等手段从树皮中提取分离得到产物,并经花色素反应定性和IR谱图鉴别.用凝胶渗透色谱法(GPC)和蒸汽渗透压法(VPO)测定产物的相对分子质量(Mr)及其分布,产物中95%以上组分的数均相对分子质量(Mn)为1 705(相当于聚合度4～5),其余组分的Mn为798.用化学法测定目标产物分子中C-3的棓酰化度为38%.生物活性功能测定结果表明,目标产物能明显抑制油脂过氧化;络合Fe2 金属离子能力为181 mg/g;1 mg目标产物对1,1-二苯基-2-苦基肼(DPPH)自由基的清除速率为0.23 mg/min,清除率为92%(试验浓度:产物与DPPH质量比为1:1.8),强于马尾松树皮原花色素试样.初步研究结果表明,毛杨梅树皮提取物可望进一步开发成为新型天然抗氧化及自由基清除剂. 相似文献
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枳实类黄酮体外抗氧化作用研究 总被引：2，自引：0，他引：2
用70%乙醇微波中火提取干燥的脱脂枳实粉1.5min,浓缩干燥得枳实粗提物.提取液过D101大孔树脂,将洗脱液浓缩干燥得枳实纯化物,经测定总黄酮达到92.78%,HPLC测其黄烷酮含量,并测定各提取物的抗氧化活性.结果显示,枳实粗提物、纯化物及黄酮单体均对羟自由基(·OH)、2,2-二苯代苦味酰基自由基(DPPH·)有清除效果,并随着浓度的增加,其对自由基的清除作用呈正相关.提取物对超氧阴离子自由基(·O-2)的清除效果在一定范围内上下波动.枳实提取物具有较强的抗氧化作用,单体之间存在协同作用. 相似文献
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由中国林业科学研究院科技发展基金资助、中国林科院林产化学工业研究所承担的黑荆树树皮低分子及高分子单宁的研究课题,已通过了同行专家的评审。黑荆树树皮是我国近年来大力发展的优质栲胶原料,目前正在大力营造黑荆树林。因此,开展黑荆树皮单宁的化学研究是十分必要的。研究结果,已公开发表了(1)单宁提取分级和黄烷-3-醇的分离鉴定;(2)多聚原花色素 相似文献
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采用分段浸取新工艺是黑荆树皮单宁提取的关键技术。即以平转型连续最提为常压段、以水平渗滤（进、出）垂直釜为加压段，经生产考核，其工艺先进、运行可靠、经济合理、操作简便，产品质量稳定。 相似文献
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通过松树皮原花青素的超声提取、膜分离纯化技术中试试验,考察了超声波提取温度、料液比、提取时间等单因素对原花青素得率的影响,试验得到了超滤膜工作压力、截留分子量的最佳工艺参数。结果表明,采用超声波强化逆流提取松树皮原花青素的最佳参数为：料液比1：12,超声温度60℃,提取时间30min;超滤膜分离纯化工艺参数为：膜工作压力0．2MPa,截留分子量5000。试验获得的松树皮原花青素经检测含量可达95％以上。 相似文献
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油茶叶乙醇提取物清除DPPH自由基作用的研究 总被引：3，自引：0，他引：3
用二苯基苦基肼自由基(DPPH·)法测定了油茶叶乙醇提取物的抗氧化活性,并与芦丁、二丁基羟基甲苯(BHT)进行了比较,在波长517 nm、反应时间40 min的条件下测定了DPPH·的清除率为50%时抗氧化剂的质量浓度(EC50)值.结果表明,油茶叶乙醇提取物时DPPH·具有明显的清除作用,且随着油茶叶乙醇提取物纯化程度的提高,其清除能力也相应增强.测得油茶叶粗提物、油茶叶精提物、芦丁和BHT清除DPPH·的EC50值分别为12.19、6.765、9.481和37.53 mg/L,清除DPPH·能力的大小顺序依次为油茶叶精提物＞芦丁＞油茶叶粗提物＞BHT. 相似文献
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Summary Based on the fact that bark is an almost perfect water barrier and assuming that bark is impregnated with materials which aid in rendering it impermeable to water, the hydrophobic and water-repellent properties of several bark extractives were investigated. Products obtained after extraction with polar and non-polar solvents showed widely different properties. Some were extremely hydrophobic and water-repellent with a water-solid-air contact angle higher than 100°. These were the products obtained from extraction with benzene and mineral turpentine. Alcohol and acetone extractives had contact angles as low as 23° but coatings from some of these materials nevertheless had a high efficiency as water barriers. The efficiency of the various extractives as water repellents or water barriers was determined by coating wood with 10 per cent solutions of the extractives in different solvents and determining the extent to which water could be prevented from being absorbed and causing swelling of the wood and thereby reduce the dimensional changes of the wood. The extractives obtained with nonpolar solvents were extremely efficient as true water repellents while the polar aleohol extracts were far better than could be expected from their almost hydrophilic properties. Nature has therefore provided for hydrophilic film-formers combined with hydrophobic materials which act as a double line of defence against water absorption. The hydrophilic extractives, in addition, act as a bridging agent between the strongly hydrophobic extractives and the hydrophilic cell wall material.Since some of the extractives from wattle bark have excellent hydrophobic properties, and since this bark is available in large quantities as a waste product after tannins have been extracted, the utilization of certain wattle bark extractives as water repellents could be economically attractive. 相似文献
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South Africa has c. 110 000 ha planted to Acacia mearnsii (black wattle) with 85% of the revenue from the species obtained from the timber and 15% from the bark. From 2012/13 a wattle rust disease has spread throughout the black wattle plantation area in KwaZulu-Natal and from 2015 it was recorded in southern Mpumalanga. The pathogen affects trees of all age classes, causing a reduction in growth, as well as mortality with severe infection. No fungicides are currently registered in South Africa for the control of wattle rust. In October/November 2014, three black wattle trials were initiated in the KwaZulu-Natal Midlands and south-eastern Mpumulanga where fungicides were tested at varying rates for the control of wattle rust. The same trial design was used for all three trials and consisted of a 3 × 3 factorial with one additional control, replicated three times and laid out as a randomised complete block design. The factorial combination consisted of three fungicides (azoxystrobin + difenoconazole; azoxystrobin + cyproconazole; azoxystrobin) applied at three rates (×, 2× and ½ ×). The additional control was not treated with fungicides. Wattle rust had a significant and negative impact on tree growth, irrespective of site and/or previous infection. All fungicides tested, and at all rates applied, proved effective for the control of wattle rust. The optimum rate selected, timing and frequency of application will be based on a combination of prevention of resistance as well as optimisation of growth. For the most effective control of wattle rust, fungicides should be applied as a preventative, rather than corrective, measure. However, in cases of severe infestation, a corrective application could also be used to aid the management of wattle rust. 相似文献
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