共查询到20条相似文献，搜索用时 768 毫秒
1.
羊栖菜中多酚的提取制备及体外抗氧化活性研究 总被引：2，自引：0，他引：2
为研究羊栖菜多酚的提取工艺及其体外抗氧化活性,在单因素试验的基础上,以多酚浸出率为响应值,采用响应面法优化羊栖菜多酚提取工艺,并考察其对DPPH自由基、超氧阴离子自由基、羟自由基的清除能力以及总抗氧化能力。结果表明:在温度为70℃,乙醇浓度为40%,浸提时间46 min,液料比20:1,羊栖菜多酚的浸出率为4.048%;粗提液经XDA-7大孔树脂柱层析分离纯化其纯度为61.86%;羊栖菜多酚对DPPH自由基、超氧阴离子自由基、羟自由基清除作用的IC50分别为6.65、6000、125.42μg/m L,总抗氧化能力为65.04 U/mg。该结果表明:羊栖菜多酚是一种极具开发潜力的天然抗氧化剂。 相似文献
2.
3.
以玉米须为原料,以多糖提取率为考察指标,在单因素试验的基础上,通过正交试验优化水提醇沉法提取玉米须多糖的工艺条件,并就玉米须多糖对羟基自由基(·OH)和超氧阴离子自由基(O_2~-·)的清除能力进行了研究。结果表明,玉米须多糖的最佳提取工艺参数为:提取时间2 h,提取温度60℃,料液比1∶19(g/m L),乙醇浓度75%。该工艺条件下,玉米须多糖平均提取率为4.47%。玉米须多糖浓度为5 mg/m L时,对·OH和O_2~-·的清除率分别为82.31%和77.56%,说明玉米须多糖具有较强的抗氧化性。 相似文献
4.
罗勒叶黄酮的提取及其清除自由基作用 总被引：4，自引：0，他引：4
采用微波法提取罗勒叶中黄酮类物质,并研究提取物清除自由基的作用。通过单因素实验,确定微波功率、时间、料液比等为罗勒叶黄酮提取的关键影响因素,在此基础上,优化出罗勒叶抗氧化性成分的最佳提取条件。实验结果表明,罗勒叶中抗氧化物的最佳提取工艺条件为:微波功率420W,提取时间60s,料液比1∶40时,提取液中黄酮的质量浓度达到最大值1.1479mg/mL,提取液对羟自由基的清除率为61.34%。罗勒叶提取物具有良好的清除羟自由基的能力,同时对小鼠肝脏自发性脂质过氧化作用和脂质过氧化物具有较好的抑制效果。 相似文献
5.
以柚子皮为原料,采用超声辅助酶法提取柚子皮中水溶性膳食纤维,探讨料液比、加酶量、超声时间对提取率的影响。在单因素试验的基础上,通过正交试验优化工艺条件,并对其抗氧化活性进行研究。结果表明,超声辅助酶法提取柚子皮水溶性膳食纤维的最佳工艺条件为:加酶量400μL,料液比1∶16(g/m L),超声时间25 min,在该工艺条件下的平均提取率为4.67%。浓度为2 mg/m L的柚子皮水溶性膳食纤维对超氧阴离子自由基和羟自由基的清除率分别为(11.72±1.41)%和(40.79±4.06)%,对铁的还原能力为(0.128 3±0.004 7)mmol/g,表现出较好的抗氧化活性。 相似文献
6.
7.
以野生蛤蒌为原料,以黄酮类化合物提取率为考察指标,在单因素试验的基础上,通过正交试验优化超声-微波提取野生蛤蒌中黄酮类化合物的最佳工艺条件。通过颜色和荧光反应鉴定蛤蒌黄酮提取液中黄酮类化合物种类,并测定其总抗氧化性、还原能力和对1,1-二苯基-2-三硝基苯肼(DPPH·)的清除效果。结果表明,超声-微波提取野生蛤蒌中黄酮类化合物的最佳工艺为:提取剂为体积分数50%乙醇,超声时间20 min,微波时间10 min,微波功率为260 W,料液比1∶40(g/m L),在该工艺条件下得到的黄酮类化合物的平均提取率为6.903%。蛤蒌黄酮提取液中黄酮物质的种类可能主要为:双氢黄酮、查尔酮和黄酮醇等。每克蛤蒌黄酮提取物的总抗氧化能力相当于107 mg抗坏血酸的抗氧化能力,其还原能力大于BHT,小于抗坏血酸,清除DPPH·的IC50为0.242 mg/m L。 相似文献
8.
采用碱性蛋白酶酶解鲽鱼鱼皮胶原蛋白制备胶原蛋白肽并对其清除超氧阴离子自由基的能力进行研究。通过单因素试验和响应面法分析不同酶解条件对超氧阴离子自由基清除率的影响,优化得到最佳酶解工艺条件：pH 9.5,加酶量1581 U/g,底物浓度10 mg/mL,酶解时间为6 h,酶解温度60℃,最高清除率为75.51%,半数清除浓度(IC50)为7.98 mg/mL。 相似文献
9.
为了筛选欧李种壳中单宁提取的最佳工艺条件,以欧李种壳为试验材料,乙醇、丙酮为提取剂,采用L9(34)正交试验设计,对固液比、溶剂浓度、浸提时间、浸提温度等提取条件进行研究。在此基础上,采用随机试验设计,对不同提取剂的较好提取条件进行比较分析,同时用二苯基苦基肼自由基(DPPH)法研究了欧李种壳单宁的自由基清除能力。结果表明:从欧李种壳中提取单宁的最佳工艺条件为70%丙酮,浸提时间5 h,浸提温度60℃,固液比1∶12。按此提取工艺,单宁的提取量为0.180%;当单宁酸的浓度达到0.1 mg/mL时,它的自由基清除能力达到85%,半数清除率时,单宁浓度为0.023 mg/mL,欧李种壳单宁具有较高抗氧化活性。 相似文献
10.
首乌藤是传统的药食同源植物,为进一步研究其生物活性成分,以乙醇溶液浸提,结合超声波辅助方法,采用L9(34)正交实验设计研究了首乌藤黄酮的最佳提取工艺,并测定了其对羟自由基(·OH)和1,1-二苯基-2-苦苯肼自由基(DPPH.)的清除结果。结果表明,黄酮最佳提取工艺条件为:提取温度60℃,乙醇体积分数50%,提取时间40 min,超声波功率200 W,料液比1∶15,提取次数2次,该条件下总提取率可达21.35%。在一定范围内,提取物对.OH的清除效果与其浓度呈线性关系(R2=0.994 7),IC50为0.130 mg/mL;对DPPH.有较强的清除能力,其IC50值为0.032 mg/mL。试验表明,首乌藤含有丰富的黄酮类化合物,具有体外抗氧化活性,是天然的自由基清除剂,有很大的开发前景。 相似文献
11.
Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
12.
G. H. Kroon 《Euphytica》1994,76(1-2):125-125
Summary
K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes. 相似文献
13.
Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
14.
Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed. 相似文献
15.
Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed. 相似文献
16.
Mohammed Riyazaddin Polavarapu B. Kavi Kishor Are Ashok Kumar Belum V. S. Reddy Rajendra S. Munghate Hari C. Sharma 《Plant Breeding》2015,134(4):423-436
Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums. 相似文献
17.
Summary
Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases. 相似文献
18.
J. T. Fletcher 《Euphytica》1992,63(1-2):33-49
Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office. 相似文献
19.
Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae 总被引：1，自引：0，他引：1
Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus. 相似文献
20.
Richard N. Lester 《Euphytica》1989,44(1-2):125-132
Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected. 相似文献