苦瓜藤中苦瓜素Ⅰ的分离鉴定和抑菌作用

本文研究苦瓜藤的三萜类化学成分及其抑菌作用。采用75%(v/v)乙醇提取及D101大孔树脂、硅胶、MCI树脂和ODS硅胶等多种吸附分离方法从苦瓜藤中分离三萜类化合物,经超高效液相、电喷雾质谱、核磁共振测定、分析所得三萜类化合物的纯度、分子量及结构,采用肉汤稀释法测定所得三萜类化合物的抑菌活性。结果表明:苦瓜藤中分离的三萜类化合物经鉴定为19-Norlanosta-5,24-diene-9-carboxaldehyde,3,7,23-trihydroxy-,(3β,7β,9β,10α,23α)-,俗名苦瓜素Ⅰ;苦瓜素Ⅰ对大肠杆菌(Escherichia coli AB1157)无显著抑菌活性,MIC值大于100μg/m L。其对金黄色葡萄球菌(Staphylococcus aureus Newman)的生长具有抑制作用,MIC值达到12.5~25μg/m L。     

高效液相色谱-电喷雾负离子串联质谱分析大豆皂甙

采用大孔树脂柱层析分离得到大豆皂甙SS-Ⅰ、SS-Ⅱ、SS-Ⅲ三个级分,利用高效液相色谱-电喷雾负离子串联质谱对SS-Ⅲ进行了详细研究。结果表明:在线的高效液相色谱-电喷雾负离子一级质谱提供了准分子离子峰,二级质谱出现大量的糖链碎片信息,通过分析确定SS-Ⅲ中含有四种B组大豆皂甙,一种E组大豆皂甙,并发现一种未见报道的E组皂甙。     

苦瓜皂甙的研究进展

综述了苦瓜皂甙的分子结构、理化性质、生理功能等的研究进展情况，并提出了对苦瓜皂甙的研究和开发中应注意的问题。化学研究表明，苦瓜皂甙主要属于四环三萜类葫芦素烷型皂甙，由皂甙元和低聚糖构成，已经提取分离出的有苦瓜皂甙A、B、F、G、I等成分。现代医学研究发现，苦瓜皂甙具有降血糖、抗氧化、提高免疫能力、降低胆固醇、抗肿瘤和抗艾滋病毒等生理功能。苦瓜皂甙具有多种生物学和药学性质，将广泛应用于食品、医药、化妆品和饲料等行业中，开发苦瓜皂甙具有广阔的前景。     

一种苦瓜皂甙的分离纯化及结构推断

通过正相硅胶色谱和反相硅胶柱色谱从苦瓜中分离得到一种物质,定性检验该物质为苦瓜皂甙,薄层色谱检验为单一化合物,反相高效液相色谱鉴定其纯度为98.45%.进一步用质谱对其分子结构进行初步推断,这种皂甙是一个连有2个糖基的母核荷质比为491、相对分子质量为815的皂甙.     

大豆皂甙A1、A4的电喷雾串联质谱裂解规律研究

采用大孔树脂柱层析分离得到大豆皂甙SS-Ⅰ、SS-Ⅱ、SS-Ⅲ三个级分,利用高效液相色谱-电喷雾串联质谱联用技术对这三个组分进行了系统分析与鉴定。与SS-Ⅱ和SS-Ⅲ相比,SS-Ⅰ中富含A1和A4两种皂甙,本文探讨了这两种皂甙的电喷雾串联质谱的裂解规律。     

HPLC-TOF/MS测定茶籽粕中的茶皂素

本文利用高效液相色谱-电喷雾-飞行时间质谱（HPLC-ESI-TOF/MS）在负离子模式下成功检测了茶籽粕中提取的茶皂素。高效液相色谱分析茶皂素超纯品得到5个主要皂甙峰,出峰时间分别为4.01、19.52 、27.74、29.23 和34.01 min,各吸收峰峰形对称,茶皂素组分能够较好分离。不同浓度茶皂素的定量曲线表明5个峰的峰面积与茶皂素含量的线性回归方程相关系数r值均在0.99以上。ESI-TOF/MS质谱分析结果表明5个组分分别含有2-5种五环三萜类皂甙, 合计18种。该法有较高的精确性,可用于茶皂素的定性、定量分析。     

苦瓜皂甙降糖机理研究

本研究从苦瓜皂甙对α-葡萄糖苷酶的活性影响,口服耐糖量试验,苦瓜皂甙对小鼠肝糖原和胰岛素水平影响这几个方面研究了苦瓜皂甙的净血糖机理.结果表明,苦瓜皂甙对α-葡萄糖苷酶没有抑制作用,葡萄糖耐量试验表明苦瓜皂甙能够使葡萄糖表现为正常耐受量,苦瓜皂甙还能使小鼠的肝糖原升高,但对小鼠的胰岛素水平没影响,这些结果表明:苦瓜皂甙不是通过抑制α-葡萄糖苷酶的活性来降低血糖,苦瓜皂甙能够使受损的胰岛β细胞恢复正常的分泌功能.苦瓜皂甙可能是通过刺激肝糖原合成来降低血糖作用.     

赤灵芝中三萜类活性成分的提取筛选和质谱分析

研究赤灵芝总三萜最佳提取工艺条件,评价三萜类化合物对脂肪氧化酶的抑制效果。采取单因素实验和响应面法分析提取时间、提取次数、液料比和乙醇浓度对赤灵芝三萜得率的影响,筛选最佳工艺参数;利用高效液相色谱-电喷雾质谱联用技术（HPLC-ESI-MS）对赤灵芝中三萜类提取物化学成分进行分析鉴定,以脂肪氧化酶为生物靶分子,采用超滤质谱技术筛选酶抑制剂,探究三萜类化合物对脂肪氧化酶的抑制效果。结果显示：最佳工艺条件为料液比1:30、乙醇浓度75%、提取次数3次和提取时间1.5 h;在这些条件下,总三萜得率为1.04%;从赤灵芝中筛选出5种脂肪氧化酶抑制剂,5种化合物对1.0 U/mL脂肪氧化酶活性有较强抑制作用,抑制效果的强弱顺序为灵芝酸B（52.64%）>灵芝酸C2（40.21%）>灵芝酸D2（31.25%）>灵芝酸F（12.69%）>灵芝酸A（10.82%）。实验结果表明,响应面法筛选赤灵芝三萜的提取工艺参数准确可靠,可用以赤灵芝三萜的生产制备;赤灵芝中三萜类活性成分可抑制脂肪氧化酶,表明有缓解炎症的功效,研究结果可为赤灵芝中抗炎成分的进一步研究提供一定理论基础。     

人参中人参皂甙成分的高分辨多级质谱分析

人参皂甙是人参的主要成分,具有抗衰老、抗疲劳、增强记忆力等多种药理作用,而某些人参皂甙如Rh2和Rg3四环三萜类原人参二醇型低糖链皂甙单体,更具有抗癌作用的特殊药理活性。人参皂甙种类繁多,还有各种异构体,从人参中已经分离出39种人参皂甙单体。而质谱技术的发展,尤其是高分辨质谱和多级质谱的组合使用能够更快、更容易地发现其它或者新的人参皂甙类成分,而不需要将各个成分逐步分离后再鉴定,从而提供了一种天然产物化学成分研究的新方法。     

5种丁香酚类化合物的电喷雾质谱裂解规律研究

目的研究5种渔用麻醉剂的电喷雾质谱裂解规律。方法采用电喷雾离子源(ESI源),对丁香酚、甲基丁香酚、甲基异丁香酚、乙酰基异丁香酚和MS-222进行质谱分析。根据结构分为正、负2种离子检测方式(ESI~(+/-)),含有酚羟基团的丁香酚采用负离子检测方式,其余4种化合物采用正离子检测方式。结果在正、负离子检测模式下,5种渔用麻醉剂准分子离子分别为[M+H]~+和[M-H]~-。对准分子离子进行碰撞诱导解离(collision induced dissociation,CID),得到特征离子碎片。分析了5种化合物在相应离子模式下的电喷雾质谱裂解途径。结论本研究所提出的电喷雾质谱裂解规律,可为同类型分子结构的渔用麻醉剂的结构分析和鉴定研究提供了参考依据。     

芦笋下脚料皂苷超声提取工艺

采用超声强化技术对芦笋下脚料中的皂苷成分进行提取,通过两轮均匀试验对提取工艺进行优化。结果得到的最优提取工艺为液料比1:1、温度30℃、占空比0.4:1.6、功率200W、提取时间30min、pH5.05、酒精体积分数70%,该工艺条件下单次提取得率为7.5%(干基);两次提取累积回收率达到93.37%,3次提取累积回收率达到98.40%。在2L循环超声提取装置中的放大实验表明,两次提取累积回收率达到97.49%,3次可提取完全。表明超声强化方法适用于芦笋下脚料中皂苷的提取。     

Optimization of Ultrasonic-Assisted Extraction of Total Saponins from Eclipta prostrasta L. Using Response Surface Methodology

Eclipta prostrasta L. is a traditional Chinese medicine herb, which is rich in saponins and has strong antiviral and antitumor activities. An ultrasonic-assisted extraction (UAE) technique was developed for the fast extraction of saponins from E. prostrasta. The content of total saponins in E. prostrasta was determined using UV/vis spectrophotometric methods. Several influential parameters like ethanol concentration, extraction time, temperature, and liquid/solid ratio were investigated for the optimization of the extraction using single factor and Box-Behnken experimental designs. Extraction conditions were optimized for maximum yield of total saponins in E. prostrasta using response surface methodology (RSM) with 4 independent variables at 3 levels of each variable. Results showed that the optimization conditions for saponins extraction were: ethanol concentration 70%, extraction time 3 h, temperature 70 °C, and liquid/solid ratio 14:1. Corresponding saponins content was 2.096%. The mathematical model developed was found to fit well with the experimental data. Practical Application: Although there are wider applications of Eclipta prostrasta L. as a functional food or traditional medicine due to its various bioactivities, these properties are limited by its crude extracts. Total saponins are the main active ingredient of E. prostrasta. This research has optimized the extraction conditions of total saponins from E. prostrasta, which will provide useful reference information for further studies, and offer related industries with helpful guidance in practice.     

苦瓜皂甙预防去卵巢大鼠骨质疏松的实验研究

以去卵巢骨质疏松症模型大鼠为研究对象,以血清参数、骨密度(BMD)、股骨和子宫组织形态为指标,研究连续给与苦瓜皂甙65、130、260mg/(kg bw·d) 12 周后对去卵巢大鼠骨质疏松的预防作用。结果表明：苦瓜皂甙用药组大鼠与模型组相比较血清雌二醇、Ca2+ 水平提高,股骨骨密度提高,股骨近端干骺端骨组织形态得到改善,而体质量、子宫质量以及子宫组织形态与模型组大鼠无显著差异。因此,苦瓜皂甙可预防去卵巢大鼠骨质疏松的形成。     

Occurrence of saponins and sapogenols in Andean crops

Samples of bitter seeds of local ecotypes and cultivars of lupin (Lupin mutabilis), white and yellow ecotypes of quinoa (Chenopodium quinoa Wild) and a local ecotype of amaranth (Amaranthus caudatus) grown in the Peruvian highlands were analysed for total saponin content and sapogenol composition. Sweet cultivars of L albus and L luteus cultivated in mild-rainy lowlands of Chile were also analysed for comparison. Fast atom bombardment-mass spectrometry (FAB-MS) of the saponin extracts and gas chromatography (GC) analysis of the sapogenols after acid hydrolysis of the crude extract-were used for the identification and quantification of saponins. It was found that L albus and amaranth had undetectable levels of saponins making them attractive for human consumption. The cultivars and ecotypes of L mutabilis contained saponin levels in the range of 229.8–390.5 mg k^?1. FAB-MS showed the presence of soya saponins I and II, whereas GC allowed the identification of soya sapogenols A and B. The same saponin composition was determined in L luteus whose total content was 55.3 mg kg^?1. Saponin composition in quinoa seeds comprised oleanolic acid and three other sapogenols identified as hederagenin, phytolaccagenic acid and deoxyphytolaccagenic acid. Oleanolic acid saponins were found to be the main class of saponin in quinoa seeds sampled for this study. The yellow ecotype of quinoa presented a significantly higher content of saponins and of oleanolic acid as compared to white ecotypes. Since only one ecotype of amaranth was analysed, the nutritional significance of no detectable saponin needs further study. It was concluded that the environmental conditions in the Peruvian highlands are determinants of the amount and composition of saponins present in bitter lupine and quinoa.     

Variation in saponin content during the growing season of spotted medic [Medicago arabica (L.) Huds.]

BACKGROUND: Spotted medic [Medicago arabica (L.) Huds.] is a minor forage species containing saponins which are reported to be biologically active. This study assessed the concentration and composition pattern of spotted medic saponins during the growing season and at senescence. The pattern of saponins was based on identification and quantification of their constituent sapogenins. At senescence, individual saponin concentrations of aerial and subterranean plant organs were also determined. RESULTS: Leaf total saponin content did not vary during the growing season and decreased remarkably at senescence. Seven sapogenins were identified and quantified during the season, bayogenin and hederagenin being the most abundant ones throughout. Total saponin content varied among plant organs at senescence, with the highest concentration in roots. A variable number of saponins from one (in seeds) to 19 (in leaves) were quantified. A clear relationship between leaf concentrations of sapogenins and those of their derivative saponins was revealed by correlation analysis. CONCLUSION: The species displayed a sapogenins/saponins pattern markedly different from those of other perennial or annual Medicago species. Saponins of queretaroic acid and 2β‐hydroxy queretaroic acid had no precedent in the Leguminosae. The high concentration of biologically active hederagenin suggested further assessment of possible effects on feeding animals. Copyright © 2010 Society of Chemical Industry     

Molecular Characterization and Quantification of Saponins from Sugar Beet (Beta vulgaris ssp. vulgaris var. altissima)

Consumer demand for sustainably and ecologically produced food has grown in recent years. However, for numerous reasons, this demand has not always been met. New solutions are still being sought, particularly in the area of emulsifiers, an integral ingredient of many food products. The biggest challenge is the limited scope of application offered by current alternatives. While some progress has been made using foam active quillaja saponins, they are neither pleasant-tasting nor sustainably produced. Only very little is known about other alternatives, and especially the behavior of saponins, particularly on a molecular level, is not very well understood. Moreover, it is often not known which parts of a plant contain the highest levels of saponins and are therefore most suitable for extraction. To expand the current level of knowledge about emulsifying and foam active extracts, saponin extracts were made from oat bran, beetroot as well as sugar beet and characterized in close cooperation with the Department of Food Physics and Meat Science at the University of Hohenheim. Measurements conducted on these extracts showed that foam activity is a good indicator of their emulsifying ability. The most promising one - sugar beet extract - was examined in more detail using taste dilution analysis, which revealed saponin fractions with a slight off-taste and high foam activity. A series of eight saponins was obtained from these fractions and further characterized, together with three commercially available ones that were identified using non-targeted screening. The unequivocal identification and structure elucidation was performed using a combination of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and both one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy. For most substances, this was the first time that a complete assignment of ¹H and ¹³C NMR signals had been made. All of these saponins possess taste recognition values above 1000 μmol/L, which is higher than most values for the taste- active saponins reported in the literature. The foam activity of these substances was measured using a self-developed small-scale foam activity assay. It was measured for different concentrations of saponins in a buffer solution. The foam activity of numerous other saponins was also determined, resulting in the most comprehensive overview of the foam activities of individual saponins. In addition to these isolation and characterization activities, an LC-MS/MS method of performing simultaneous quantitative analyses of all the obtained sugar beet saponins was developed and validated. These were quantified in several sugar beet varieties (root and leaves), different sugar beet compartments, and side streams originating during the sugar beet converting process. Great variations in mass fractions were found in these materials, ranging from 862 mg/kg to 2,452 mg/kg for the various sugar beet root varieties and from 907 mg/kg to 5,398 mg/kg for the sugar beet leave varieties. Sugar beet fiber was identified as the best saponin source, with a total saponin quantity of 12.7 g/kg, followed by dried sugar beet pulp, with a total quantity of 10.3 g/kg. As a by-product stream, dried sugar beet pulp is highly suitable for the sustainable manufacture of saponins. The results obtained are of key significance to the utilization of sugar beet saponins as well as saponins extracted from other plant materials or by-product streams for use as food additives.     

Listeria monocytogenes contamination pattern in pig slaughterhouses

Ten low-capacity slaughterhouses were examined for Listeria by collecting a total of 373 samples, of which 50, 250, and 73 were taken from carcasses, pluck sets, and the slaughterhouse environment, respectively. Six slaughterhouses and 9% of all samples were positive for Listeria monocytogenes. Of the samples taken from pluck sets, 9% were positive for L. monocytogenes, the highest prevalence occurring in tongue and tonsil samples, at 14% and 12%, respectively. Six of 50 (12%) carcasses were contaminated with L. monocytogenes. In the slaughterhouse environment, L. monocytogenes was detected in two, one, one, and one sample originating from the saws, drain, door, and table, respectively. Carcasses were contaminated with L. monocytogenes in those two slaughterhouses, where the mechanical saws, used for both brisket and back splitting, were also positive for L. monocytogenes. A total of 58 L. monocytogenes isolates were characterized by pulsed-field gel electrophoresis typing. The isolates were divided into 18 pulsotypes, 15 of which were detected in pluck sets. In two slaughterhouses, where the carcasses were contaminated with L. monocytogenes, the same pulsotypes were also recovered from splitting saws. In addition, identical pulsotypes were recovered from pluck sets. Our findings indicate that L. monocytogenes of tongue and tonsil origin may contaminate the slaughtering equipment that may in turn spread the pathogen to carcasses. Thus, it is of the utmost importance to follow good manufacturing practices and to have efficient cleaning and disinfection procedures to prevent equipment being contaminated with L. monocytogenes.     

超声波提取苜蓿总皂苷优化工艺的研究

用超声波法提取苜蓿皂苷,通过L9(34)正交试验,探讨了提取条件对苜蓿总皂苷提取量的影响。结果显示:各试验因素对苜蓿总皂苷类物质提取量的影响依次为超声时间、物料比、超声功率、超声温度;最佳工艺条件为A2B3C2D1,即物料比1:20、超声时间30min、超声功率80W、超声温度20℃。在上述最佳条件下,总皂苷的提取率可达1.975%。     

苦瓜皂苷对成骨细胞增殖和ALP 的影响

研究苦瓜皂苷对体外培养的新生SD 乳鼠成骨细胞增殖和ALP 的影响。以1 × 10-8～1 × 10-4mol/L 浓度梯度的苦瓜皂苷的MEM 含药培养液对新生 SD 乳鼠24h 内颅盖骨进行体外细胞培养,分别用 MTT 法和 PNPP 法检测成骨细胞的增殖和碱性磷酸酶(alkaline phosphatase,ALP)活性。结果表明：苦瓜皂苷具有时间和剂量依赖性地促进成骨细胞增殖和提高成骨细胞 ALP 活性。     

茶皂素β-D-葡萄糖醛酸酶水解物的结构分析

茶皂素有较强的溶血性,但经β-D-葡萄糖醛酸苷酶水解后溶血性降低。 该研究利用正丁醇和乙酸乙酯分别对茶皂素及其 β-D-葡萄糖醛酸苷酶酶解产物进行萃取纯化,采用超高效液相-质谱鉴定酶解前后茶皂素各组分含量的变化,从而分析其结构变化。结果表明,酶解后乙酸乙酯提取物中糖苷型茶皂素从75.06%降为5.24%,苷元型组分从6.76%增至67.05%。正丁醇提取物中糖苷型茶皂素从51.61%降为34.98%,从而推断可能是β-D-葡萄糖醛酸苷酶酶解后,茶皂素亲水性的糖基与疏水性的配基分离,两亲性下降,从而使其溶血性降低。