不同提取工艺下白首乌C21甾苷含量研究

对白首乌中C21甾苷的提取方法进行了研究,在比较了3种不同提取方法的基础上,确定采用热回流的方法,选用乙醇为提取溶剂,通过单因素和中心组合试验,对影响白首乌中C21甾苷提取的因素进行了研究。结果表明,乙醇体积分数为61.25%的乙醇为溶剂,料液比为1:10(g:ml),水浴温度为75.23℃,提取3h为最佳提取工艺。     

磺基醋酸汞试剂法用于C21甾苷定量检测的可行性研究

经实验确定了甾苷定量测定的官能团反应方法。用定量测定3－羟基族化合物的最特效的方法磺基醋酸汞试剂法直接测定C21甾苷元的C3－OH，从而间接测定C21甾苷，实验证明该方法是可行的。     

白首乌中多糖等活性成分对酪氨酸酶活力的影响

为了探讨白首乌对黑素合成的影响,从白首乌中提取分离了多糖、C21甾苷及磷脂,用蘑菇酪氨酸酶多巴速率氧化法测定了白首乌含有的多糖、C21甾苷及磷脂对蘑菇酪氨酸酶活力的影响。结果表明白首乌含有的多糖对酪氨酸酶二酚酶活力有显著的抑制作用,IC50为31.8μg/mL,多糖是酪氨酸酶的可逆性抑制剂,抑制类型为竞争性抑制,磷脂对酪氨酸酶的抑制作用较弱,而C21甾苷对酪氨酸酶有激活作用。提示白首乌含有的多糖有可能被用作皮肤增白剂或作为色素沉着抑制剂,也有可能成为安全有效的食品褐变抑制剂。     

超临界CO2萃取白首乌中的C21甾苷

目的：对白首乌中C21 甾苷超临界CO2 流体萃取工艺参数进行优化。方法：采用L16(45)正交试验,以萃取压力(A)、萃取温度(B)、萃取时间(C)、原料粒度(D)、夹带剂量(E)作为考察因素,每个因素选四个水平,采用2- 去氧糖反应法测定各萃取条件下C21 甾苷的相对含量,以波长590nm 处吸光度为判定依据,确定最优萃取条件。结果：B、D、E 因素对C21 甾苷提取能力的影响最大,C 因素影响最小。结论：最优萃取条件为萃取压力30MPa、萃取时间90min、萃取温度55℃、原料粉碎粒度40 目、夹带剂量2.0ml/g。     

白首乌C_(21)甾苷对大鼠心肌缺血再灌注损伤的保护作用

目的:探讨白首乌C21甾苷对大鼠心肌缺血再灌注损伤的保护作用。方法:健康清洁级Wistar系雄性大鼠40只随机分为4组:假手术组:打开胸腔,冠状动脉左前降支(LAD)下穿线但不结扎;缺血再灌注组:结扎LAD;去势组:去势后恢复4w,然后再结扎LAD;白首乌C21甾苷治疗组:结扎LAD手术前1w胃给予白首乌C21甾苷1.0 g/kg,连续7d,然后结扎LAD。采用ELISA法检测血浆肌钙蛋白(c Tn T)和心肌组织肿瘤坏死因子α(TNF-α),白细胞介素6(IL-6)含量,并对心肌组织进行病理学分析。结果:与缺血再灌注组比较,白首乌C21甾苷治疗组TNF-α、IL-6和c Tn T含量明显降低,心肌病理损伤减轻。结论:白首乌C21甾苷可显著抑制心肌炎症因子,缩小梗死面积,减轻心肌组织形态损伤,改善受损的心肌功能,从而起到保护心肌的作用。     

C21甾甙在白首乌保健功能中的地位

通过动物实验比较了白首乌总甙，醇提物和全粉的功效性的毒性。结果表明三种样品中醇提物的功效性最好，可能是因为其提取白首乌中包括C21甾甙在内的多数活性物质而又易于吸收利用所致；醇提物和全粉未表现出急性毒性反应，总甙具有一定的急性毒性。这说明虽然C21甾甙是白首乌的主要有效成分，但以醇提物的方式开发白首乌保健食品更具有实际意义。     

龙葵中甾体类生物总碱的含量测定

目的:建立龙葵甾体类生物总碱的提取和检测方法。方法:采用醇提-酸醇水解法提取龙葵内的澳洲茄胺,定性定量分析澳洲茄胺;以澳洲茄胺为参照品,表征龙葵中甾体类生物总碱的含量。结果:建立了龙葵甾体类生物总碱的提取和检测方法。结论:新建立的甾体类生物总碱提取和检测方法可快速、准确地测定龙葵中甾体类生物总碱的含量;以澳洲茄胺为苷元的甾体类生物总碱主要富集在龙葵未成熟果实中,龙葵茎叶内含量小。     

萝摩科植物C21甾甙含量的测定方法

在确定了C2 1甾甙提取方法定量测定官能团反应方法的基础上 ,建立了C2 1甾甙含量的测定方法 ,主要包括标准物的选择、方法的建立及对方法的检验和评价 .结果表明 ,该方法符合分析要求 ,可用于萝摩科植物C2 1甾甙含量的定量测定 .     

白首乌中C21甾甙元的分离与结构鉴定

进行了白首乌中C2 1甾甙元的分离和结构鉴定 .首先从白首乌中提取了C2 1甾甙元 ,通过酸解和进一步提取得到C2 1总甙元 .总甙元再经色谱分离和制备 ,得两种甾甙元 ,通过红外、质谱、核磁图谱分析 ,确定两种甙元分别为告达庭甙元和开德甙元     

苦瓜中胡萝卜甾苷的高效薄层色谱分析方法研究

以硅胶G60为固定相、氯仿-乙醚-丙酮-冰醋酸-水-吡啶为流动相,建立了苦瓜胡萝卜甾苷的高效薄层色谱分析方法。苦瓜胡萝卜甾苷标样和醇提液上展开5cm,其Rf值为0.70。苦瓜胡萝卜甾苷的检测量在200～1000ng范围,其斑点的面积与苦瓜甾苷的检测量具有良好的线性关系,相关系数为0.9953。胡萝卜甾苷的平均回收率达100.64%,方法的精密度良好(RSD<1.5%),该方法快速、准确,可用于苦瓜甾苷的定性定量分析。     

纤维素酶法提取胡芦巴甾体总皂苷工艺条件的优化

以甾体皂苷元的提取率为指标,应用L9(34)正交试验设计优化了胡芦巴种子中甾体皂苷的酶法提取工艺,实验结果表明,影响酶法提取甾体皂苷的主次因素为:酶用量>提取温度>固液比>水解时间。纤维素酶处理能显著提高甾体皂苷的提取率,加酶后甾体皂苷元提取率的平均值为83.6%,而未加酶的结果则为58.4%。酶法提取新工艺能显著提高胡芦巴甾体皂苷的提取率。     

Method validation of analytical method for 12 flavonol glycosides in foods using ultra high-performance liquid chromatography coupled with photodiode array detection

An analytical method for the simultaneous determination of 12 flavonol glycosides in buckwheat, black tea, and wild parsley using ultra high-performance liquid chromatography (UHPLC) coupled with a simple liquid extraction method using dimethyl sulfoxide (DMSO) was validated in precision, accuracy, and linearity. The UHPLC separation of target compounds was performed on a C18 column using a photodiode array (PDA) detector and the wavelength was fixed at 350 nm. The recovery values for flavonol glycosides ranged from 85.44 to 108.79%. The limits of detection and limits of quantification were less than 0.32 mg/kg and less than 0.97 mg/kg, respectively. The intraday and interday precisions were less than 13.69% for all the test samples. This method coupled with UHPLCPDA detection could be expected to provide more convenient sample preparation than conventional methods in the tested foods.     

Comparison of methods for the hydrolysis of flavonoids and phenolic acids from onion and spinach for HPLC analysis

For the quantitative determination of individual flavonoid glycosides in plant materials, the glycosides are normally hydrolysed and the resulting aglycones are identified and quantified. However, the hydrolysis conditions which result in optimal breakdown of glycosides are too harsh for some of the other phenolic compounds present in the same plant material. Therefore, the effects of different hydrolysis conditions and different antioxidants on pure flavonoid glycones and aglycones were studied. On the basis of the results obtained with standards, suitable hydrolysis methods for red spring onion and spinach were developed. The best results from these vegetables were obtained by refluxing at 80 °C for 2 h with 1.2 M HCl in 50% aqueous methanol with addition of 2 mg ascorbic acid as an antioxidant. The method developed in this study is suited to the screening of flavonoids in vegetables and leafy vegetables.     

Determination by high performance chromatography, steroid saponins in a biologically active food supplements containing the extract of Tribulus terrestris

Steroidal saponins are bioactive substances of Tribulus terrestris and can be used to assess the quality of raw materials and processed products from them. For this purpose has been developed the method of qualitative and quantitative determination of steroidal saponins by high performance liquid chromatography with spectrophotometric and mass-selective detection and optimal conditions of sample preparation (70% methanol extraction with sonication and heating); also has been studied steroidal saponins composition of Tribulus terrestris (protodioscin, tribulosaponin B, metilprotodiostsin, terrestrozin H, prototribestin, gracillin and others were found).