共查询到18条相似文献,搜索用时 234 毫秒
1.
2.
3.
4.
采用超临界CO2萃取技术获得沙棘果油,通过超高效液相色谱-质谱联用技术和Peakview色谱工作站拟合、二级质谱解析和紫外光谱及质谱数据比对,确定有关化合物的组成和分子结构。共鉴定出沙棘果超临界CO2萃取物中含有18?种黄酮类化合物,其中包括8?种黄酮醇苷元及黄酮醇苷,3?种二氢黄酮醇苷元及二氢黄酮醇苷,5?种黄酮苷元及黄酮苷,1?种二氢黄酮苷元和1?种黄烷醇苷,其中芹菜素-6-C-葡萄糖苷-8-C-木糖苷、儿茶素-7-吡喃葡萄糖苷、苜蓿素、紫罗兰素、刺槐黄素这5?种黄酮首次被发现存在于沙棘中。 相似文献
5.
为明确银杏黄酮的有效活性形态,为银杏黄酮作为天然抗氧化剂提供实验依据,本研究将苷元型和糖苷型银杏黄酮分别添加到大豆油和鼠脑组织匀浆中,考察它们对高温下大豆油氧化的抑制效果和对由FeCl_2-H_2O_2诱导产生的丙二醛(MDA)的抑制效果。结果表明,苷元型和糖苷型的黄酮均能有效地抑制脂质氧化,且在相同浓度下苷元型比糖苷型银杏黄酮有更强的抑制脂质氧化的能力(p0.05);作为天然的抗氧化剂,苷元型银杏黄酮有更好的抗氧化效果。 相似文献
6.
采用超声波辅助法提取沙棘果实中的总黄酮,采用单因素实验和响应面试验优化提取工艺,采用优化的工艺提取不同成熟度、不同地区沙棘果实黄酮,采用高效液相色谱法分析4种主要黄酮苷元的分布及含量,同时比较这些沙棘黄酮提取物的抗氧化活性。结果表明:乙醇体积分数55%、料液比1∶45(g/mL)、超声功率210 W时,沙棘A的总黄酮提取率最高可达3.241%。沙棘果实中主要的黄酮苷元为异鼠李素、槲皮素、山奈酚、杨梅素,而3种沙棘果实黄酮苷元的含量有差异。抗氧化活性测定结果表明,沙棘C的黄酮提取物具有更强的1,1-二苯基-2-三硝基苯肼自由基清除率、2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除率和还原能力,总黄酮苷元含量与DPPH自由基清除率、还原能力呈显著正相关。本研究结果为沙棘黄酮的综合利用开发提供数据支持。 相似文献
7.
8.
9.
10.
该研究以沙棘原果汁为原料,利用乳酸菌进行发酵,筛选出转化黄酮苷元含量高的菌株以及发酵工艺。以发酵后的黄酮苷元含量(以异鼠李素计)的变化为筛选标准,先利用26株单菌进行筛选,再进行复配,得到植物乳植物杆菌L23、戊糖片球菌P27和植物乳植物杆菌L21复配效果最好。并利用正交试验对pH值、温度、碳源添加量以及接种比例进行发酵工艺条件的优化。优化后得到的3株乳酸菌在pH值为4,温度30 ℃,添加碳源6%(m/V),接菌比例为1:2:1时发酵得到的黄酮苷元含量较高,同时检测沙棘原果汁发酵前后总黄酮、总酚酸、有机酸以及粗多糖含量。发酵后的黄酮苷元含量提升约90%,总黄酮提升约108%,粗多糖、有机酸和总酚酸含量与沙棘原果汁相比,具有显著性差异。该研究得出3株乳酸菌发酵沙棘黄酮,黄酮苷元含量明显提升,其他基本指标的含量显著增加,为研究黄酮苷转化为黄酮苷元的机制提供数据参考,为中国沙棘工业产业化深加工提供指导。 相似文献
11.
Hoda M. Eid Louis C. Martineau Ammar Saleem Asim Muhammad Diane Vallerand Ali Benhaddou‐Andaloussi Lidia Nistor Arvind Afshar John T. Arnason Pierre S. Haddad 《Molecular nutrition & food research》2010,54(7):991-1003
Several medicinal plants that stimulate glucose uptake in skeletal muscle cells were identified from among species used by the Cree of Eeyou Istchee of northern Quebec to treat symptoms of diabetes. This study aimed to elucidate the mechanism of action of one of these products, the berries of Vaccinium vitis idaea, as well as to isolate and identify its active constituents using a classical bioassay‐guided fractionation approach. Western immunoblot analysis in C2C12 muscle cells revealed that the ethanol extract of the berries stimulated the insulin‐independent AMP‐activated protein kinase (AMPK) pathway. The extract mildly inhibited ADP‐stimulated oxygen consumption in isolated mitochondria, an effect consistent with metabolic stress and the ensuing stimulation of AMPK. This mechanism is highly analogous to that of Metformin. Fractionation guided by glucose uptake activity resulted in the isolation of ten compounds. The two most active, quercetin‐3‐O‐glycosides, enhanced glucose uptake by 38–59% (50 μM; 18 h treatment) in the absence of insulin. Quercetin aglycone, a minor constituent, stimulated uptake by 37%. The quercetin glycosides and the aglycone stimulated the AMPK pathway at concentrations of 25–100 μM, but only the aglycone inhibited ATP synthase in isolated mitochondria (by 34 and 79% at 25 and 100 μM, respectively). This discrepancy suggests that the activity of the glycosides may require hydrolysis to the aglycone form. These findings indicate that quercetin and quercetin 3‐O‐glycosides are responsible for the antidiabetic activity of V. vitis crude berry extract mediated by AMPK. These common plant products may thus have potential applications for the prevention and treatment of insulin resistance and other metabolic diseases. 相似文献
12.
Xueying Ma Wei Yang Alexis Marsol-Vall Oskar Laaksonen Baoru Yang 《International Journal of Food Science & Technology》2020,55(4):1705-1715
The aim of this study was to investigate sugars, organic acids, flavonol glycosides (FGs), proanthocyanidins and volatiles as flavour compounds in sea buckthorn (SB) berries of five cultivars and to predict the sensory properties of berries. The profiles of flavour compounds in SB berries varied significantly among the cultivars. Total proanthocyanidins and FGs were highest in ‘Pertsik’ and ‘Raisa’, respectively. Total volatiles were highest in ‘Vorobyevskaya’ and lowest in ‘Raisa’. A previously established PLS model was used to predict the sensory properties of SB berries based on the non-volatile flavour compounds. The mouth-drying astringency can be predicted the most reliably, which has the highest regression coefficients with quinic acid, isorhamnetin-3-O-sophoroside-7-O-rhamnoside and total proanthocyanidins. Bitterness cannot be predicted using the model. ‘Pertsik’ berries were predicted to be more mouth-drying astringency and sour than those of ‘Raisa’. The research supports the cultivar selection in cultivation and industry of SB berries. 相似文献
13.
以油菜蜂花粉黄酮醇苷组分为原料,以还原力和DPPH 自由基清除率为指标研究黄酮醇苷在化学模拟体系中的抗氧化活性。结果表明,油菜蜂花粉黄酮醇苷的抗氧化活性不及其苷元成分。以CCl4 制备小鼠脂质过氧化损伤模型,通过体内自由基发生体系进一步研究花粉黄酮醇苷的抗氧化作用,并对可能的作用机制进行探讨。结果显示:油菜蜂花粉黄酮醇苷组分能够显著地降低脂质过氧化小鼠肝匀浆和血清中MDA 含量,提高小鼠SOD 活性和总抗氧化能力(T-AOC),对脂质过氧化损伤有很好的保护作用,原因可能是体内有关酶系可将黄酮醇苷水解使其游离出酚羟基而发挥作用。本研究进一步肯定了油菜蜂花粉黄酮醇苷对机体氧化损伤的保护作用。 相似文献
14.
《Journal of the Institute of Brewing》2017,123(2):185-191
Previous studies show that the complexity of hop aroma in beer can be partly attributed to the hydrolysis of glycosidically bound monoterpene alcohols extracted from hops during the brewing process to release volatile aglycones. However, fundamental studies that examine the extraction of glycosides during brewing and their subsequent hydrolysis by yeast have not been performed. Furthermore, extraction of other hop‐derived compounds into beer shows a strong dependency on the hop cultivar being used and the point at which it is added. This study focused on the extent of glycoside extraction owing to hopping regime and cultivar, and their hydrolysis by yeast β‐glucosidase activity. Glycoside concentrations of wort made with three different hopping regimes and three cultivars were measured by the difference in volatile aglycone concentrations between samples treated with purified β‐glucosidase and untreated samples. Aglycone concentrations were measured by solid‐phase microextraction gas chromatography–mass spectrometry. Additionally, β‐glucosidase activities for 80 different yeast strains and their effect on aglycone concentration in wort were determined. Results showed that yeast have a wide range of abilities to hydrolyse glycosides with a maximum hydrolysis occurring after 3 days of fermentation regardless of yeast activity. Although it was shown that yeast are capable of glycoside hydrolysis, glycoside concentrations in wort are low and make small contributions to hop aroma. These results help explain the extent to which different brewing yeasts and hopping regimes contribute to hoppy beer aroma through the hydrolysis of non‐volatile hop‐derived compounds. Copyright © 2017 The Institute of Brewing & Distilling 相似文献
15.
16.
17.
ABSTRACT: Soymilk (SM) lacks lactose; hence supplementation of SM with lactose is likely to enhance the growth of probiotic bacteria and biotransformation of isoflavone glycosides to isoflavone aglycones. In this study, 11 strains of probiotic bacteria including Lactobacillus rhamnosus, L. salivarius, L. plantarum, L. acidophilus, L. paracasei, HOWARU L. rhamnosus, L. delbrueckii subsp. bulgaricus, Bifidobacterium lactis type Bi-07, B. longum, HOWARU B. bifidum, and B lactis type Bi-04 were inoculated individually or as mixed cultures into SM and soymilk supplemented with lactose (SML). A total of 2% of lactose was added to 1 L of SM with the aim of improving the growth of probiotic organisms and promoting the biotransformation of isoflavone isomers to bioactive isoflavone aglycomes. Samples of SM were incubated at 37 °C and 10 mL aliquots of SM were taken at 0, 24, 48, and 72 h to monitor the growth of probiotic bacteria and changes in isoflavone contents using high-performance liquid chromatography (HPLC). Results indicated that SML fermented with probiotics had higher viable counts by >2.4 log CFU/mL than that in SM at the end of the 72 h fermentation period. Mixed cultures grew at different rates and in general Lactobacilius spp. had >1.02 log CFU/mL more cells than Bifidobacterium spp. at the end of the fermentation period. The total aglycone content in SM at 72 h of fermentation was 0.924 mg/100 mL, whereas that in SML was 1.623 mg/100 mL. Addition of lactose not only improved the growth of probiotic bacteria in SM but also enhanced the biotransformation of isoflavone glucosides to the more bioactive isoflavone aglycones. Mixed cultures did not improve the biotransformation of bioactive isoflavones when compared to single cultures. 相似文献
18.
C. M. Francis 《Journal of the science of food and agriculture》1973,24(10):1235-1240
Four variants of subterranean clover cultivar Geraldton were fed to sheep. One variant, whose flavonoid glycosides were stable due to absence of glucosidase activity in the leaves, was more distasteful to the sheep than were the other clovers. These results suggest that flavonoid glycosides may be unpalatable to the sheep whilst the products of hydrolysis (glucose and aglycone) are not. Taste testing by human subjects of seven purified isoflavone glycosides indicated a slight but distinctive astringent–bitter taste in contrast to the lack of taste of the aglycones. 相似文献