NnABI4-Mediated ABA Regulation of Starch Biosynthesis in Lotus (Nelumbo nucifera Gaertn)

Starch is an important component in lotus. ABA is an important plant hormone, which plays a very crucial role in regulating plant starch synthesis. Using ‘MRH’ as experimental materials, the leaves were sprayed with exogenous ABA before the rhizome expansion. The results showed that stomatal conductance and transpiration rate decreased while net photosynthetic rate increased. The total starch content of the underground rhizome of lotus increased significantly. Meanwhile, qPCR results showed that the relative expression levels of NnSS1, NnSBE1 and NnABI4 were all upregulated after ABA treatment. Then, yeast one-hybrid and dual luciferase assay suggested that NnABI4 protein can promote the expression of NnSS1 by directly binding to its promoter. In addition, subcellular localization results showed that NnABI4 encodes a nuclear protein, and NnSS1 protein was located in the chloroplast. Finally, these results indicate that ABA induced the upregulated expression of NnABI4, and NnABI4 promoted the expression of NnSS1 and thus enhanced starch accumulation in lotus rhizomes. This will provide a theoretical basis for studying the molecular mechanism of ABA regulating starch synthesis in plant.     

Mathematical modeling and influence of ultrasonic pretreatment on microwave vacuum drying kinetics of lotus (Nelumbo nucifera Gaertn.) seeds

The people of Southeast Asia often use lotus as a highly sought-after food source. Here, the effects of ultrasonic pretreatment on the drying kinetics of lotus (Nelumbo nucifera Gaertn.) seeds under microwave vacuum drying were investigated. The best fit model to predict the drying kinetics was also proposed. Lotus seeds were subjected to ultrasonic pretreatment at frequencies of 20, 35, and 80?kHz and power intensity of 0.75 and 1.50?W/g for 10?min using an ultrasonic bath and then to microwave vacuum drying. Five different mathematical models were fitted to the experimental data and a newly proposed model was selected based on model with highest regression coefficient (R²), lowest root mean square error (RMSE), sum square error (SSE), and chi-square (χ²), respectively. Time-domain nuclear magnetic resonance and field scanning electron microscope were used to describe the water state of ultrasonic samples and examine microstructure, respectively. The results showed that ultrasonic pretreatment performed at a relatively low frequency and relatively high power intensity had a positive effect on reducing the drying time (6.25–31.25%) during microwave vacuum drying because of the redistribution of water and the formation of microchannels. In parallel studies, the new model showed the best fit to the drying curve.     

乳状液膜分离提取荷叶中3种生物碱

建立了用W/O型乳状液膜分离提取荷叶中3种生物碱——N-去甲基荷叶碱、O-去甲基荷叶碱和荷叶碱的方法。通过对迁移时间、表面活性剂Span 80用量、载体D2EHPA浓度、油内比、乳水比和内水相盐酸浓度的优化,获得了高效的液膜体系,为:迁移时间2.5 min,表面活性剂Span 80的质量分数为3.0%,载体D2EHPA的浓度为0.01 mol/L,油内比为10∶6,乳水比为10∶60,内水相盐酸浓度为0.2 mol/L。在优化的实验条件下,对荷叶中3种生物碱N-去甲基荷叶碱、O-去甲基荷叶碱和荷叶碱的萃取率分别达到了95.6%、100%和97.9%,相应的富集因子依次为8.73、8.50和8.04。说明该乳状液膜体系能够很好地分离提取荷叶中的N-去甲基荷叶碱、O-去甲基荷叶碱和荷叶碱。     

Structural Characterization of a Water-Soluble Polysaccharide from the Fruiting Bodies of Agaricus bisporus

An edible fungal polysaccharide termed as ABP was obtained by extraction with hot water, and followed successive chromatographic purification using DEAE-Sepharose Fast Flow column and Sephacryl S-300 High-Resolution column. A symmetrical peak was obtained on high-performance size-exclusion chromatography with an average molecular weight of 5.17 × 10⁴ Da, which was named ABP, and its main components were d-glucose and d-mannose. Based on the study of methylation analysis, along with FT-IR, GC, GC-MS, 1D ¹H and ¹³C NMR and 2D NMR (H-HCOSY, TOCSY, HMQC, and NOESY), its chemical structure was featured with a repeating unit (1→6) linking β-d-Glcp as the main backbone with (1→4)-linked α-d-Manp units. The structure of the mainly repeating units of ABP was established as:  → 6) - β - D - Glucp - (1 → 4) - α - D - Manp(1 → 6) - β - D - Glucp - (1 → 6) - β - D - Glucp - (1 →      

玉米须中植物多酚的提取及其抗氧化性研究

研究了玉米须中植物多酚的提取工艺及抗氧化性。以玉米须为原料,采用有机溶剂法提取玉米须中植物多酚,单因素试验优化植物多酚提取工艺条件。结果表明:有机溶剂提取法的最佳条件为:在50℃下,60%甲醇溶液作为提取剂,料液比为1∶60,提取时间4 h;玉米须中植物多酚的浓度达到60 mg/m L对羟基自由基清除率为62.16%,超氧自由基清除率为65.67%。     

油茶叶多糖的闪式提取工艺优化及其抗氧化活性

在单因素试验基础上用响应面法对油茶叶多糖的闪式提取工艺进行优化,并对较优条件下提取的多糖的抗氧化活性进行测试.研究结果表明:油茶叶多糖闪式提取的较佳工艺条件为料液比1:30 (g:mL),提取温度81℃,提取时间75 s,此条件下,油茶叶多糖得率为8.43％.油茶叶多糖对DPPH·、·ABTS+、OH·都有很强的清除能...     

Extraction,Preliminary Characterization and Evaluation of in Vitro Antitumor and Antioxidant Activities of Polysaccharides from Mentha piperita

This study describes the extraction, preliminary characterization and evaluation of the in vitro antitumor and antioxidant activities of polysaccharides extracted from Mentha piperita (MPP). The optimal parameters for the extraction of MPP were obtained by Box-Behnken experimental design and response surface methodology (RSM) at the ratio of water to raw material of 20, extraction time of 1.5 h and extraction temperature at 80 °C. Chemical composition analysis showed that MPP was mainly composed of glucuronic acid, galacturonic acid, glucose, galactose and arabinose, and the molecular weight of its two major fractions were estimated to be about 2.843 and 1.139 kDa, respectively. In vitro bioactivity experiments showed that MPP not only inhibited the growth of A549 cells but possessed potent inhibitory action against DNA topoisomerase I (topo I), and an appreciative antioxidant action as well. These results indicate that MPP may be useful for developing safe natural health products.     

皂苷提取纯化及其抗氧化活性的研究进展

皂苷是一种重要的天然产物,与水混合振摇时可生成持久性的似肥皂泡沫状物,具有很强的抗氧化性,即任何以低浓度存在就能有效抑制自由基的氧化反应。高纯度的皂苷有利于皂苷的抗氧化性的研究。本文对皂苷提取纯化和其抗氧化性方面的研究报道进行了综述,总结了9种提取方法和5种纯化方法,并说明优缺点。对抗氧性的测定方法和影响因素进行总结。     

杨梅色素苷的提取及抗氧化性研究

比较了浸提法、热煮法、粉碎法等3种方法提取杨梅色素苷的提取量,并对其抗氧化性能进行了研究。结果表明:浸提法提取效果最好,在510nm处的吸光度为0.198,而粉碎法为0.054;杨梅色素苷浓度与其抗氧化能力、超氧阴离子自由基及羟基自由基的清除能力之间存在明显正相关,当杨梅色素苷浓度为34mg·mL-1时,其对超氧阴离子自由基的清除率达到80%;相同浓度下杨梅色素苷的还原力高于抗坏血酸。     

雪莲果中绿原酸的提取及其抗氧化性测定

以雪莲果为原料,采用醇提法提取绿原酸,通过对不同乙醇质量分数、提取时间、提取温度、料液的提取效果进行比较分析,确定了最佳提取条件为：乙醇质量分数40%,提取时间2.5 h,提取温度80℃,料液比1∶20（g∶mL）,绿原酸提取量为1.63mg/g。邻二氮菲-Fe2＋法测定雪莲果提取物清除.OH（羟自由基）的能力,结果表明雪莲果中的绿原酸具有一定的抗氧化性。     

In vitro Antioxidant of a Water-Soluble Polysaccharide from Dendrobium fimhriatum Hook.var.oculatum Hook

A water-soluble crude polysaccharide (DFHP) obtained from the aqueous extracts of the stem of Dendrobium fimhriatum Hook.var.oculatum Hook through hot water extraction followed by ethanol precipitation, was found to have an average molecular weight (Mw) of about 209.3 kDa. Monosaccharide analysis revealed that DFHP was composed of mannose, glucose and galactose in a content ratio of 37.52%; 43.16%; 19.32%. The investigation of antioxidant activity in vitro showed that DFHP is a potential antioxidant.     

Antioxidant and Immunoregulatory Activity of Polysaccharides from Quinoa (Chenopodium quinoa Willd.)

The water-extractable (QWP) and the alkali-extractable (QAP) polysaccharides from quinoa (named QWP and QAP, respectively) and their four polysaccharide sub-fractions (QWP-1, QWP-2, QAP-1 and QAP-2), were isolated and purified by anion-exchange and gel filtration chromatography. QWP-1 and QWP-2 were composed of Rha, Ara, Gal and GalA. QAP-1 and QAP-2 were composed of Rha, Ara, Man, Gal and GalA. Antioxidant and immunoregulatory activities of the polysaccharides were evaluated. The results showed that QWP-1, QWP-2, QAP-1 and QAP-2 had significant antioxidant and immunoregulatory activities. The results suggest that QWP-1, QWP-2, QAP-1 and QAP-2 could be used as potential antioxidants and immunomodulators.     

Lignin Synthesis,Affected by Sucrose in Lotus (Nelumbo nucifera) Seedlings,Was Involved in Regulation of Root Formation in the Arabidopsis thanliana

Adventitious roots (ARs) have an unmatched status in plant growth and metabolism due to the degeneration of primary roots in lotuses. In the present study, we sought to assess the effect of sucrose on ARs formation and observed that lignin synthesis was involved in ARs development. We found that the lignification degree of the ARs primordium was weaker in plants treated with 20 g/L sucrose than in 50 g/L sucrose treatment and control plants. The contents of lignin were lower in plants treated with 20 g/L sucrose and higher in plants treated with 50 g/L sucrose. The precursors of monomer lignin, including p-coumaric acid, caffeate, sinapinal aldehyde, and ferulic acid, were lower in the GL50 library than in the GL20 library. Further analysis revealed that the gene expression of these four metabolites had no novel difference in the GL50/GL20 libraries. However, a laccase17 gene (NnLAC17), involved in polymer lignin synthesis, had a higher expression in the GL50 library than in the GL20 library. Therefore, NnLAC17 was cloned and the overexpression of NnLAC17 was found to directly result in a decrease in the root number in transgenic Arabidopsis plants. These findings suggest that lignin synthesis is probably involved in ARs formation in lotus seedlings.     

响应曲面法优化刺山柑水溶性多糖提取工艺及其抗氧化性能研究

以刺山柑果实为原料,在单因素实验的基础上,选择提取温度、提取时间和液料比为影响因子,以刺山柑水溶性多糖提取率为响应值,应用Box-Behnken中心组合方法建立数学模型,利用响应曲面法确定超声辅助提取刺山柑水溶性多糖的优化工艺条件为：提取温度85℃、提取时间89 min、液料比30∶ 1（mL∶g）,在此条件下刺山柑水溶性多糖平均提取率为8.89％.提取得到的刺山柑水溶性多糖对羟基自由基（·OH）和超氧阴离子自由基（·O2-）均有一定的清除作用,具有一定的抗氧化活性.     

猕猴桃根总黄酮的超声提取及抗氧化活性研究

以湘西“米良猕猴桃”根为原料,采用超声波辅助乙醇提取总黄酮, 通过单因素及正交实验优化提取工艺条件,考察总黄酮对羟基自由基清除效果及对油脂氧化的抑制作用,并与常用抗氧化剂作比较。结果表明,以60%乙醇按照料液比1∶30 (g∶mL) 在60 ℃水浴中超声提取40 min后,猕猴桃根中总黄酮得率为1.5%。该提取物对羟基自由基清除效果随浓度的增大而升高,对食用油脂的氧化有很好的抑制作用。     

石榴籽多酚类物质的功能及提取工艺

概述了石榴籽多酚类物质的功能及其提取工艺。以期为石榴压榨过程中产生的石榴籽的研究利用提供参考。     

超声辅助提取雪梨多糖及其在卷烟中的应用

以新鲜雪梨为原料,用超声辅助法提取雪梨多糖,考察超声功率、温度、料液比、时间对多糖收率的影响。在单因素实验基础上,采用正交实验对多糖提取工艺进行优化,并将雪梨多糖应用在卷烟中。正交实验结果表明,最优提取工艺条件为料液比1∶4(g/m L),温度50℃,时间50 min,超声功率160 W,在该条件下,多糖收率为3.18%。多糖加料评吸结果表明,雪梨多糖具有掩盖杂气、柔和细腻烟气、降低刺激性、提升烟香、生津感好等效果。     

栝楼籽多糖提取纯化、结构表征及降血糖活性

目的:探究栝楼籽多糖提取工艺、初级结构及降血糖活性。方法:采用热水浸提法对栝楼籽多糖的提取工艺进行优化。利用葡聚糖凝胶G-150进行纯化得均质多糖(WHP-I),并对多糖结构进行初步表征。通过体外和体内降血糖实验联合探究栝楼籽多糖降血糖活性。结果:栝楼籽多糖的最优提取条件为温度80℃、时间100 min、料液比1:25 (g/mL)、浸提次数2次。验证试验结果显示:多糖提取率17.54%,优化方案科学合理。WHP-I初级结构分析表明WHP-I重均分子量为47.65 kDa,并含有五种糖残基分别是→3)-Araf-(1→,→6)-Galp-(1→,→4)-Glcp-(1→, D-Glcp-(1→,和→4,6)-D-Glcp-(1→。WHP-I表面较为平整,表面有孔状结构,且附着有细小的颗粒。体外降血糖实验结果显示WHP-I抑制α-葡萄糖苷酶的IC50值为15.837 mg/mL。体内实验结果表明,WHP-I具有减缓T2DM引起脏器损伤的潜力,给药四周后,M-WHP-I组和H-WHP-I组小鼠的血糖值分别降低了32.13%和42.27%,且WHP-I对糖尿病小鼠的肾脏和肝脏具有修复作用。结论:优化的栝楼籽多糖工艺合理可行,多糖结构清晰,且具有明显的降血糖活性。     

托盘根中总多酚提取工艺及抗氧化活性研究

以悬钩子属植物托盘根为研究对象,采用超声辅助乙醇提取托盘根中总多酚.通过对乙醇浓度、料液比、超声时间、超声温度4种影响因素进行考察,在单因素实验结果基础上,采用正交试验优化其最佳提取工艺,并对托盘根总多酚的抗氧化能力进行评价.结果表明,托盘根活性成分的最佳提取工艺为乙醇浓度60％、超声温度80℃、超声时间50 min、...