二色补血草不同部位总黄酮含量的测定

采用分光光度法测定了二色补血草花、根、茎、叶总黄酮的含量,分别为35.5869、23.5367、24.7081、30.5378mg/g.RSD为0.1016%-0.1410%,稳定性R＞97.5%,平均回收率96.38%-100.2%.     

三种中草药抗氧化性研究

微波辅助法提取3种中草药中黄酮类化合物,从还原能力、清除羟基自由基和抗油脂氧化方面,研究其抗氧化活性。结果表明：3种中草药中,总黄酮含量从高到低依次为：老鹤草（132.516mg/g）、豨莶草（78.4749mg/g）、白花蛇舌草（35.6519mg/g）。其提取物具有较好的还原能力,且对羟基自由基均有明显的清除作用,其清除效果随提取物浓度的增加而增强。三种中草药提取物也具有一定的抗油脂氧化能力,它们的抗氧化能力存在差异。实验结果为我们更加合理开发利用这些药用植物提供了很好的科学依据。     

珙桐叶总黄酮提取工艺及体外抗氧化性

运用正交试验设计探讨了绵竹白云山珙桐叶黄酮的微波辅助提取工艺条件,并对提取液的抗氧化性能进行了研究。结果表明,珙桐叶总黄酮提取的最佳工艺参数：微波功率700W,料液比（g/mL）1∶40,乙醇质量分数浓度为70%,提取时间为2min,测得每克干叶中总黄酮含量为71.03mg。对提取液的抗氧化性研究表明,珙桐叶总黄酮对超氧阴离子自由基、羟基自由基的清除率较好,在实验所选浓度范围内,总还原能力随浓度增加而增强。     

反相高效液相色谱法同时测定二色补血草茎中芦丁和槲皮素的含量

采用RP-HPLC法同时测定二色补血草茎中芦丁和槲皮素的含量.以Hypersil ODS2色谱柱(4.6mm×250mm,5μm),柱温为室温,以CH3OH-0.5% H3PO4为流动相,流速1mL/min,检测波长为355nm,测定二色补血草茎中芦丁和槲皮素的含量.芦丁在0.12-1.20μg、槲皮素在0.04-0.40μg范围内呈良好的线性关系,相关系数分别为0.9999和0.9997,芦丁回收率为101.42%,RSD为0.98%,槲皮素回收率为102.85%,RSD为1.32%.该方法操作简单,线性关系好.     

药桑不同萃取部位总黄酮与抗氧化活性相关性

采用NaNO2-Al（NO3）3-NaOH显色法测定药桑总黄酮含量,紫外可见分光光度法测定药桑中总黄酮对DPPH·、ABTS·＋的清除率,SPSS统计软件分析黄酮与抗氧化活性之间的相关性,探讨药桑中总黄酮的含量与抗氧化活性的相关性.结果显示药桑不同溶剂萃取部位中总黄酮含量各不相同,其中乙酸乙酯相总黄酮含量最高,水相中总黄酮含量最低.通过SPPS17.0分析,发现总黄酮的含量与抗氧化活性之间的关系是：与DPPH·清除率呈正相关关系,为显著相关关系,与ABTS·＋清除率呈正相关关系,但相关性不显著.本研究初步确定了药桑中总黄酮的含量与其抗氧化化活性的关系.     

超声波法提取贯众总黄酮及其不同极性部位的抗氧化作用

对超声波法提取贯众地下部分总黄酮的工艺条件进行优化,研究其不同极性部位抗氧化作用.采用紫外分光光度法测定提取物总黄酮含量,通过正交试验得到最佳提取工艺为:超声时间30min,料液比1∶40(g/mL),乙醇浓度60％.采用有机溶剂萃取法将贯众地下部分提取物分氯仿相、乙酸乙酯相、水饱和正丁醇相和水相4个不同极性部位,以清除1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、总还原力为评价指标,考察了不同极性部位提取物的的抗氧化作用.结果表明,4个不同极性部位提取物均有抗氧化作用,其中乙酸乙酯相的抗氧化作用最强.贯众根状茎具有较强的抗氧化活性,值得开发利用.     

两个品种猴腿蹄盖蕨总黄酮含量的测定及抗氧化活性研究

初步建立两个品种猴腿蹄盖蕨不同部位总黄酮的HPLC指纹图谱,并测定总黄酮含量,研究其抗氧化活性。采用RP-HPLC法,建立不同部位总黄酮的HPLC指纹图谱;紫外分光光度法测定总黄酮含量及对HO.和O2-.的清除率。两个品种猴腿蹄盖蕨总黄酮含量均较高,HPLC指纹图谱显示地上部分总黄酮成分类似,根总黄酮成分有差异;不同部位总黄酮粗提物对HO.和O2-.均有清除作用。猴腿蹄盖蕨总黄酮具有较强的抗氧化活性,值得深入研究。     

陕西山楂总黄酮的含量测定

为确定陕西产山楂总黄酮的含量,以芦丁为对照,采用NaNO2-Al（NO3）3-NaOH分光光度法510nm波长下测定了陕西产山楂总黄酮含量.回归方程为y=0.0159x＋0.0019,相关系数r=0.9908,陕西产山楂总黄酮含量为（17.52±1.42）mg/g.该试验方法简便灵敏,结果准确可靠,可用于陕西山楂总黄酮的测定.     

高效液相色谱法分析车前草中的黄酮化合物

建立检测车前草中总黄酮含量的高效液相色谱法,探索车前草黄酮苷的水解条件.通过水解车前草黄酮提取物,将黄酮苷水解成苷元,再用HPLC法测定水解后车前草黄酮苷元含量.以Shim-pack VP-ODS (150L×4.6,10μm)为分析柱,流动相为甲醇-0.1％磷酸水溶液梯度洗脱,流速为1.0mL/min,检测波长为360nm,柱温30℃,采用峰面积外标法计算含量.通过比较水解前、后黄酮苷元的检测量,发现水解后检测到黄酮量高.此法测得车前草中槲皮素的含量为1.36mg/g,木犀草素的含量为0.35mg/g,黄芩素的含量为0.89mg/g,3种苷元的含量之和为2.60mg/g.首次以水解后的车前草总黄酮苷元作为车前草黄酮含量的评价指标,首次建立了水解-HPLC法检测车前草黄酮含量,为测定车前草及其提取物中黄酮类化合物的含量提供了灵敏、准确和快速的测定方法,为不同品种和产地的车前草及其提取物质量监控提供依据.     

山楂总黄酮提取及其抗氧化作用

用微波提取法提取山楂总黄酮,探讨最佳提取条件及其抗氧化活性.研究表明最佳提取工艺条件为乙醇浓度50％、提取时间20min、微波功率300W、料液比1∶30（g/mL）,总黄酮提取率可达13.4％;并以过氧化值（POV）为指标,研究了山楂总黄酮对猪油的抗氧化性能,其抗氧化效果明显.     

FAAS法测定二色补血草中不同部位的金属元素

采用浓硝酸-高氯酸(4+1)溶解消化方法进行样品处理,用火焰原子吸收光谱法对二色补血草花、茎、叶、根中K,Mg,Ca,Na,Fe,Zn,Cu和Co八种微量金属元素进行了分析测定,获得了测定仪器的最佳工作条件、方法的准确性和精密度。结果表明,各元素平均回收率(n=7)在99.3%～105.3%之间,平均RSD值(n=7)为0.34%～1.04%。二色补血草不同部位各金属元素含量有一定差异,花中Na＞K＞Mg＞Ca＞Fe＞Zn＞Co＞Cu,茎中K＞Mg＞Ca＞Na＞Fe＞Zn＞Cu＞Co,叶中K＞Mg＞Ca＞Na＞Fe＞Zn＞Co＞Cu,根中K＞Mg＞Na＞Fe＞Ca＞Zn＞Cu＞Co。各部位均含有丰富的Ca,Mg,K,Na和Fe元素。测定方法快速、简单,准确度和精密度均较好,能达到分析要求。     

Intensification of bio-actives extraction from pomegranate peel using pulsed ultrasound: Effect of factors,correlation, optimization and antioxidant bioactivities

Pomegranate peel (PP) is one of the interesting agri-food by-products because of its abundant bioactive phytochemicals. However, the bioactivity of valuable compounds is affected due to the extraction method used. A pulsed ultrasound-assisted extraction (PUAE) was carried out to intensify the extraction efficacy with reduced power and time. Influence of several process variables viz. peel solids/ solvent ratio, sonication power, duty cycle, and extraction time was studied using empirical quadratic models followed by multicriterial numerical optimization with respect to face-centered composite design. Power-duty cycle combination was found to be most significant (p < 0.05) for process intensification. The optimal process conditions of 2.17 g/100 mL S/S ratio at 116 W power with 80% duty cycle for 6 min resulted into 0.48 g/g yield, 177.54 mg GAE/g total phenolics content, 35.71 mg QE/g total flavonoids, 160.54 mg GAE/g antioxidant capacity, 21.65 mg cyn-3-glc/100 g anthocyanin content with 54.92 browning index in dry pomegranate peel. Significant Pearson correlation analysis was established in all responses with potent phenols and flavonoid relation with highest coefficient (r) 0.931. All response models were significantly validated with regression coefficient (R²) above 0.965. Remarkable antioxidant bioactivities were recorded for the resultant peel extract. Hence, it is strongly recommended that PUAE could be successfully applied for the intensification of the extraction process of bioactive from any peel and or plant systems with minimal process time and power consumption with a green label.     

Ultrasound-assisted extraction,optimization, isolation,and antioxidant activity analysis of flavonoids from Astragalus membranaceus stems and leaves

Astragalus membranaceus is a medicinal and edible species in China, with a variety of biological activities. This study evaluated the reuse potential of A. membranaceus waste as a source of food antioxidants. Antioxidant and antifungal activities of flavonoids, polysaccharides, and saponins from A. membranaceus stems and leaves were evaluated. Results showed that inhibition rate of flavonoids on six tested fungi reaches 100 % at a concentration of 5 mg/mL, and the antioxidant test demonstrated satisfactory antioxidant activity. On this basis, an extremely economical ultrasonic-assisted extraction of flavonoids from A. membranaceus stems and leaves was developed and optimized via response surface methodology (RSM). Optimized conditions included an extraction time of 35 min, ethanol concentration of 75 %, liquid–solid ratio of 40 mL/g, and extraction temperature of 58 °C, in which the extraction yield of flavonoids was 22.0270 ± 2.5739 mg/g. The total flavonoids were separated and purified using activity-guided isolation technology, and frac. ccd with strong antioxidant activity were analyzed via HPLC-MS/MS. Results showed that main components are isoquercitrin and astragalin. This study can provide a potential innovative application for the development of natural food antioxidants from A. membranaceus waste.     

Antioxidant and anti-inflammatory polyphenols in ultrasound-assisted extracts from salvilla (Buddleja scordioides Kunth)

Salvilla is a widely distributed plant used in treatments against gastrointestinal disorders due to its phenolic antioxidant and anti-inflammatory potential. Major yield and quality of bioactive polyphenols must be obtained with no degradation during suitable processes such as Ultrasound-Assisted Extraction (UAE), which allows an efficient extraction of metabolites at appropriate parameter conditions. Salvilla extractions were made using UAE and aqueous ethanolic solutions. Variables used in UAE were sonication time, wave amplitude and percentage of ethanol in solvent. Extracts were tested for total flavonoids, antioxidant activity (ABTS, FRAP and ORAC) and an identification and quantification of phenolic compounds was carried out by UPLC-PDA-ESI-MS/MS. Once elected the better extraction conditions, an anti-inflammatory test was performed for this treatment. As a result, total flavonoids content in extracts was 147 to 288 µg catechin equivalents/mg of dry salvilla extract. All extracts have shown good antioxidant activity (86 to 280 mM Trolox eq/mg dry salvilla extract). Flavonoids contents by chromatography were higher than hydroxybenzoic and hydroxycinnamic acids specially the flavone, flavanol and flavanone groups. Treatment T6 (75% ethanol, 30% amplitude and 10 min extraction time) was the best extract in terms of significant flavonols, antioxidant activity, and higher anti-inflammatory potential.     

臭牡丹黄酮类化合物提取及其抗氧化作用

研究臭牡丹中黄酮类化合物的最佳提取工艺条件及其抗氧化活性.以提取时间、料液比、提取温度、乙醇体积分数为主要影响因素,以黄酮类化合物提取率为考察指标,确定最佳提取工艺条件,并通过对亚硝酸盐、超氧阴离子自由基、羟自由基的清除效果及对猪油的抗氧化研究其抗氧化活性.结果表明,臭牡丹中黄酮类化合物的最佳提取工艺条件为提取时间2.0h、料液比1∶40（g/mL）、提取温度70℃、乙醇体积分数70％的条件下提取效果最好,臭牡丹中黄酮类化合物在各抗氧化体系中均表现出较强的抗氧化活性,且其作用具有剂量效应关系,其抗氧化活性均强于维生素C.     

灰毛大青黄酮苷的分析方法和提取工艺

采用紫外分光光度法、硝酸铝-亚硝酸钠法和高效液相色谱法分别测定了灰毛大青黄酮苷含量,通过正交试验研究了灰毛大青黄酮苷提取工艺.试验结果表明3种分析方法结果相差较大,通过测定机理分析,确立了硝酸铝-亚硝酸钠法为灰毛大青黄酮苷含量测定的适宜方法,3种方法都具有较好的线性关系,精密度、稳定性、重现性和回收率均符合要求;正交试验的适宜工艺条件为料液比1∶6 （g/V）、提取温度70℃、提取时间60min和提取次数3次,在此条件下黄酮苷得率为9.9330mg/g.     

蒙药材冷蒿中黄酮类化合物的测定及体外抗氧化性研究

采用分光光度法测定了冷蒿中黄酮类化合物的含量,通过Fenton反应测定了冷蒿黄酮类化合物提取液清除羟基自由基的能力。结果表明,冷蒿中黄酮类化合物含量为42.3mg/g,样品回收率为92.0%—99.6%。黄酮类化合物提取液对羟基自由基清除作用随黄酮类化合物含量的增高而增加。