共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
竹叶总黄酮提取纯化工艺研究 总被引:3,自引:0,他引:3
以芦丁为对照,竹叶总黄酮得率为考察指标,通过正交试验法优选破碎提取竹叶总黄酮的最佳工艺.在此基础上,采用真空薄膜浓缩,超声波脱色,大孔树脂Diaion HP-20吸附分离纯化竹叶总黄酮提取物.结果表明,20 g竹叶粗粉最佳提取工艺为用80%(体积分数)乙醇做溶剂,液固比为10:1(mL:g)提取1次,5 min.最佳分离纯化工艺为:采用大孔树脂Diaion HP-20进行分离富集,以不同浓度的乙醇进行梯度洗脱,洗脱流速为5mL/min,收集并减压浓缩各洗脱部分的总黄酮提取物,精制后的总黄酮纯度可达76%. 相似文献
3.
4.
MuJun UeharaTohru LiJianzhang FurunoTakeshi 《中国林学(英文版)》2004,6(2):1-5
The antioxidant activity of solvent extracts from two main bamboo species, moso bamboo (Phyllostachys pubescens) and madake bamboo (P bambusoides) in Japan, was first evaluated by scavenging free radical of 1,1-diphenyl-2-picrylhydrazyl (DPPH), the inhibition activity for peroxidation of linoleic acid, and the reduction power. The methanol-extracts of moso bamboo culms and madake bamboo leaves presented stronger antioxidant activity compared with DPPH scavenging activity. Methanol-extract of moso bamboo culms was further fractionated by different solvents and n-butanol soluble fraction exhibited the most significant activity in the DPPH scavenging assay. The fractionation of n-butanol soluble extract was isolated by silica gel column with gradient mixture solvent of chloroform and methanol. The isolated fractions were directed by the antioxidant activity measured by scavenging the stable DPPH free radical. It was observed that most of the eluted fractions showed the antioxidative activity. Fractions acquired from elution with the mixture solvent of chloroform and methanol (10:1-5:1) showed stronger antioxidant activity than the other fractions. 相似文献
5.
6.
万寿菊花中叶黄素提取及分离提纯的研究 总被引:1,自引:0,他引:1
研究了利用正己烷和乙醇混合溶剂,或石油醚溶剂,从万寿菊花粉提取、分离、提纯叶黄素的方法.最适工艺参数:正己烷(为提取剂)和95%乙醇(体积比3:2),提取温度60℃,提取时间4~5h,提取次数5~6次,液料比15:1(mL:g);皂化温度55~60℃,皂化时间6h.按本工艺条件操作,万寿菊花中叶黄素得率为7.5%~7.9%. 相似文献
7.
为寻找天然胰蛋白酶抑制剂,经过葡聚糖凝胶G25、G50柱、二乙二胺乙基纤维素-葡聚糖凝胶A50分离纯化从竹笋中获得了竹笋胰蛋白酶抑制剂(BSTI),纯化后浓度比粗提物提高了1200倍,SDS-PAGE显示纯化胰蛋白酶抑制剂为单一条带。其性质研究表明:经100℃热变性15 min后,BSTI仍保持50%的抑制活性,表明BSTI有较强的热稳定性;BSTI的等电点为4.4左右; BSTI在CoCl2溶液中还有94.7%的活性,但是在FeSO4溶液中活性却完全被压制;BSTI在氧化剂中活性不高;几种还原剂对其活性有一定的抑制,但是维生素C不仅不会抑制其活性反而能够提高它的活力;螯合剂KCN能大幅提高BSTI的活性,EDTA和喔星会抑制其活性。 相似文献
8.
Radical scavenging activity and composition of raspberry (Rubus idaeus) leaves from different locations in Lithuania 总被引:1,自引:0,他引:1
Raspberry (Rubus idaeus) leaves, collected in different locations of Lithuania were extracted with ethanol and the extracts were tested for their antioxidant activity (AA) by using ABTS(.)(+) decolourisation and DPPH(.) scavenging methods. All extracts were active, with radical scavenging capacity at the used concentrations from 20.5 to 82.5% in DPPH(.) reaction system and from 8.0 to 42.7% in ABTS(.)(+) reaction. The total amount of phenolic compounds in the leaves varied from 4.8 to 12.0 mg of gallic acid equivalents (GAE) in 1 g of plant extract. Quercetin glucuronide, quercetin-3-O-glucoside and rutin were identified in the extracts. 相似文献
9.
10.
11.
This study investigated the liquefaction of bamboo in phenol, which involved the effects of weight ratios of phenol to bamboo,
amount of catalyst, temperature, etc. The study showed that liquefaction could be accomplished with a phenol to bamboo weight
ratio of 2–1: 1, a 5% catalyst of HCl or BF3, and a temperature of 115°C. Liquefied bamboo formaldehyde (BLF) resin adhesive for exterior use could be obtained with a
phenol to formaldehyde molar ratio of 1:1.6–2.0. The curing behavior of BLF resin adhesive, studied by TG-DSC and IR analyses,
showed that BLF resin adhesives had a lower curing temperature than PF adhesives but had the same characteristic trough in
IR spectra as PF adhesives.
__________
Translated from Chemistry and Industry of Forest Products, 2004, 24(3) [译自: 林产化学与工业, 2004, 24(3)] 相似文献
12.
13.
14.
The Argyreia cymosa bark extracts were subjected to in vitro antioxidant activity with different methods. The petroleum ether extract has shown antioxidant activity in ABTS, nitric oxide, hydroxyl radical (by p-NDA) and lipid peroxidation methods. The ethyl acetate extract has shown antioxidant activity in DPPH, H(2)O(2) and hydroxyl radical (by deoxyribose) scavenging methods. 相似文献
15.
16.
17.
目的 建立快速、简便、重复性好、得率高的杜仲胶颗粒提取技术,为进一步分析胶颗粒膜蛋白、脂肪酸、糖脂等组成及杜仲橡胶分子量奠定基础。 方法 以杜仲叶片和翅果为材料,利用不同离心条件及研磨次数探究杜仲胶颗粒得率,并结合光镜与电镜观察结果,探讨适合从不同杜仲组织器官中提取胶颗粒的最优条件。 结果 杜仲组织(叶片或翅果)液氮经速冻、反复研磨捣碎6次过滤10次,在4℃条件下以5 000 g离心力,45度定角离心10 min,并反复漂洗8次得到的杜仲胶颗粒含量最高。在此条件下,以10月采摘的杜仲叶和翅果为材料,提取的杜仲胶颗粒含量可分别达3.70 g·kg-1叶片、5.37 g·kg-1翅果。进一步观察发现,不论是杜仲叶片或翅果随着其发育的成熟,组织中胶颗粒粒径大小和积累量均呈现先增加后稳定的变化趋势。杜仲胶颗粒在光镜和电镜下呈球形,胶颗粒间粒径大小差异较大。以10月杜仲叶、翅果及树皮为例,小胶颗粒(1~4 μm)分别占39%,53%,98.38%,中等胶颗粒(4~7 μm)分别占38%,34%,0.12%,大胶颗粒(7~11 μm)分别占23%,13%,0.05%。 结论 本研究建立的杜仲胶颗粒提取技术较为快捷,得率高,可快速对不同时期不同组织器官的杜仲胶颗粒进行提取。 相似文献
18.
竹笋水溶性多糖提取工艺研究 总被引:4,自引:0,他引:4
采用单因素试验和正交试验设计,探索了毛竹笋水溶性多糖提取的最佳工艺条件.结果表明,影响竹笋水溶性多糖得率的因素主次关系依次是乙醇体积分数>提取温度>提取时间>水料比;多糖的最佳提取工艺条件为:水料比10:1(mL:g),提取时间4h,提取温度100℃,95%乙醇醇析.在此最佳工艺条件下,竹笋水溶性多糖的得率为0.32%. 相似文献
19.
以水竹叶为原料,采用水浴和超声波两种提取方法,通过单因素与正交试验确定了水竹叶总黄酮提取的最佳条件,并筛选了不同树脂对总黄酮的吸附和解吸附特性。实验结果表明:水浴提取最佳条件为:温度50℃,提取时间2.0h,乙醇体积分数60%,固液比1:20(g:mL,下同);总黄酮得率1.65%。影响得率的因素为:固液比〉乙醇体积分数〉提取温度〉提取时间。超声波提取最佳条件为:2.0g水竹叶,超声波作用时间30min,乙醇体积分数60%,固液比1:15;总黄酮得率为1.27%。影响得率的因素为:超声波作用时间〉乙醇体积分数〉固液比。AB-8树脂对总黄酮纯化具有较好效果,体积分数为70%的乙醇是较好的解吸剂。 相似文献
20.
采用热水浸提、醇沉法提取绞股蓝多糖,对绞股蓝多糖提取工艺和一般理化性质进行了研究。选择浸提固液比、温度、时间和浸提次数作为单因素进行梯度实验,确定其条件范围,再通过正交实验L9(3^4)进一步确定绞股蓝水溶性多糖最佳提取工艺条件。结果表明最佳提取工艺为:固液比1:40、浸提温度85℃、浸提时间2h、反复浸提2次。理化性质结果表明提取的绞股蓝多糖中含有多肽和AA,为蛋白质复合多糖。 相似文献