苜蓿皂苷研究概述

综合近年来国内外有关苜蓿皂苷的研究,从苜蓿皂苷特征、分离提取、生理功能、应用前景等方面对其进行了详细介绍,为今后苜蓿皂苷资源的深入研究和开发利用提供一定的参考和借鉴作用。     

新疆贝母属8种药用植物地上部位叶的组织化学研究

[目的]研究新疆贝母属药用贝母主要药用成分在叶片中的分布及含量差异.[方法]采用植物解剖学和组织化学方法对新疆贝母属8种药用贝母叶片中生物碱及皂苷成分的分布进行观察研究.[结果]生物碱主要存在于新疆贝母属8种药用贝母叶片的叶肉细胞上,其总生物碱含量从高到低的顺序为伊犁贝母＞新疆贝母≈裕民贝母≥托里贝母＞黄花贝母≈大白花贝母≈滩贝母＞小花贝母;皂苷主要存在于新疆贝母属8种药用贝母叶片的叶肉细胞上,其总皂苷含量从高到低的顺序为大白花贝母＞托里贝母≈黄花贝母≥新疆贝母＞滩贝母≥伊犁贝母＞裕民贝母≥小花贝母,且在种间随着总生物碱含量的增加而总皂苷含量相应减小.[结论]活性成分含量与叶肉细胞占叶片横切面的百分比有一定联系,在选择药用品种时要充分考虑这一因素,同时研究结果也可为合理采收及扩大新药源提供理论依据.     

Effects of Pressurized Low Polarity Water Extraction Parameters on Antioxidant Properties and Composition of Cow Cockle Seed Extracts

Antioxidant activity of pressurized low polarity water (PLPW) extracts of cow cockle seed and extraction residues were determined using DPPH, ABTS, and FRAP assays. The effect of extraction conditions (temperature (125, 150 and 175 °C) and time) on the antioxidant activity and the relationship amongst the antioxidant activity and extract composition (total phenolics and saponin content) were determined. The antioxidant activity of PLPW extracts increased with extraction temperature. Increasing activity with time was also observed at 175 °C. PLPW extraction residues had the highest activity suggesting antioxidant compounds were not completely extracted by PLPW. Antioxidant activity correlated well with total phenolics content of samples (R ² ≥ 0.94), however no correlation was observed with the saponin content. A strong correlation was observed between the antioxidant activity values obtained using different methods (R ² ≥ 0.94). These results point to the potential of PLPW extraction as a method to modify the activity of biological materials for the production of customized extracts.     

Nematicidal potential of materials from <Emphasis Type="Italic">Medicago</Emphasis> spp.

The nematicidal effect of soil amendments with dry top and root material from Medicago sativa and/or Medicago arborea was evaluated on the root-knot nematode Meloidogyne incognita and on the cyst nematode Globodera rostochiensis in potting mixes. All amendments suppressed root and soil population densities of both nematode species compared to non-treated and chemical controls. The suppressiveness of M. sativa differed between top and root material and among the amendment rates. In field conditions soil amendments with 20 or 40 t ha⁻¹ of a pelleted M. sativa meal increased tomato crop yield and reduced soil population densities and root galling by M. incognita. It is suggested that saponins were at least partly responsible for the nematicidal activity.     

黄芪中皂甙·黄酮和多糖综合利用的工艺研究

[目的]探索从黄芪中同时获取皂甙、黄酮和多糖的工艺条件。[方法]根据皂甙、黄酮和多糖3种有效成分溶解度的差异,先用乙醇回流法提取黄芪中的皂甙和黄酮,再用蒸馏水提取药渣中的黄芪多糖。对乙醇提液中的黄芪皂甙和黄酮,采用D280阴离子交换树脂进行分离纯化。[结果]黄芪皂甙的最佳提取条件为：浓度70％乙醇作为溶剂,液固比7：1,78℃提取3次,每次100min;黄芪黄酮的最佳提取条件为：浓度80％乙醇作为溶剂,液固比7：1,78℃提取4次,每次80min;黄芪多糖的最佳提取条件为：以蒸馏水为溶剂,液固比16：1,100℃提取3次,提取2h。D280阴离子交换树脂分离黄芪黄酮和皂甙的最佳条件：醇提液减压浓缩、调pH值至8．0后上柱,收集流出液和浓度0．1％NaOH淋洗液得到皂甙,用浓度80％乙醇和10％NaOH-80％乙醇洗脱得到黄酮。[结论]黄芪皂甙、黄酮和多糖在上述同一工艺流程中被提取分离,可综合利用黄芪中的有效成分。     

Protective effect of saponins from Argania spinosa against free radical-induced oxidative haemolysis

Saponins from Argania spinosa at a non-haemolytic concentration diminish by 53.2% erythrocyte haemolysis induced by free radicals. 2 mM aspirin and acetaminophen diminish by 75% and 68% , respectively, erythrocyte haemolysis induced by free radicals, while 0.3 muM vitamin E shows no significant antioxidant activity. Interestingly, a combination of 1 mg/l of A. spinosa saponins and vitamin E at 0.3 muM resulted in a 68% level of protection against free radical-induced erythrocyte haemolysis, which may suggest that A. spinosa saponins enhance the antioxidant effect of vitamin E. In contrast, no synergic effect was observed for acetaminophen (2 mM) when in combination with vitamin E (0.3 muM). These results demonstrate the antioxidant properties of saponins from A. spinosa and their ability to potentate the antioxidant effect of vitamin E.     

Antifungal properties of quinoa (Chenopodium quinoa Willd) alkali treated saponins against Botrytis cinerea

Quinoa (Chenopodium quinoa Willd) is a Latin American food staple readily available in large quantities in Peru, Bolivia and Ecuador. The outer husk of the grain is removed prior to consumption to reduce its bitter taste. At present, quinoa husks are considered as a by-product with no commercial value, despite its high content of triterpenoid saponins (20–30%). Due to this, the present work was undertaken to test if quinoa saponins have antifungal properties against Botrytis cinerea and if this activity is enhanced after alkaline treatment, since recent reports indicate that alkaline treatment of quinoa saponins increase their biological activity. Six products were tested against B. cinerea: (1) non-purified quinoa extract, (2) purified quinoa extract, (3) alkali treated non-purified quinoa extract, (4) alkali treated purified quinoa extract, (5) non-purified quinoa extract treated with alkali but without thermal incubation and (6) purified quinoa extract treated with alkali but without thermal incubation.

Untreated quinoa extracts showed minimum activity against mycelial growth of B. cinerea. Also, no effects were observed against conidial germination, even at 7 mg saponins/ml. However, when the saponin extracts were treated with alkali, mycelial growth and conidial germination were significantly inhibited. At doses of 5 mg saponins/ml, 100% of conidial germination inhibition was observed, even after 96 h of incubation. Fungal membrane integrity experiments based on the uptake of the fluorogenic dye SYTOX green showed that alkali treated saponins generate membrane disruption, while non-treated saponins had no effects.

The higher antifungal activity of alkaline treated saponins is probably due to the formation of more hydrophobic saponin derivatives that may have a higher affinity with the sterols present in cell membranes.     

Study of bitterness perception of quinoa (Chenopodium quinoa wild.) saponin extracts

The thresholds and behavior of bitterness perception over time were studied for quinoa saponins. The detection threshold was calculated in two ways using R-index values: linear equation (as previously used) and regression analysis (proposed hereby). Panelists were grouped depending on their bitterness sensitivity, and differences were found among dynamic panelist perceptions. At the threshold level, the sensation dynamic was lower than the caffeine threshold. By HPLC analysis, we identified three main types of saponins (A, B, and C), which positively correlated with the stimulus concentration. The saponin fractions were more related to the time-intensity parameters than the total saponins. Pearson's correlations showed that maximum intensity, total duration, area under the curve, and rising slope were best correlated with A, B, and C saponins. Interestingly, bitterness was perceived before chemical differentiation. It is important to study the saponin bitterness thresholds and perception, as they directly influence consumer choices and must be addressed before being used in quinoa products in the food industry.     

植物皂甙降低机体胆固醇的作用及其机理研究进展

综述了具有降低胆固醇作用的植物及其活性成分、皂甙的生物学功能及其降低胆固醇的作用机理等方面研究进展,对今后的研究提出了展望。     

刺五加糖基转移酶基因的表达及其对皂苷含量的影响

为了探明刺五加糖基转移酶基因（glycosyltransferase,GT）的表达特点及其对刺五加总皂苷含量的影响。以GAPDH基因为内参照基因,采用实时定量PCR技术分析了不同产地、不同生长发育时期、不同器官刺五加中GT基因的表达规律及茉莉酸甲酯（MeJA）对其表达的影响。并采用浓硫酸-香草醛比色法测定刺五加总皂苷的含量,利用SPPS17.0软件进行相关性分析。结果表明,GT基因在根、幼茎、叶片和叶柄中均有表达,但表达量差异不显著。刺五加的GT基因在叶片完全展开期的表达量最高,盛花期和果实基本成熟期的表达量最低,仅为叶片完全展开期表达量的66.9%。MeJA处理可显著提高GT基因的表达量（p〈0.05）。不同产地刺五加的GT基因表达量和总皂苷含量差异显著,但GT基因的表达量与总皂苷含量同升同降,存在极显著的正相关关系（p〈0.01）。初步判定,GT基因的表达量决定了刺五加中总皂苷的含量,GT是决定刺五加中总皂苷含量的关键酶。