硫酸酯化洋葱多糖的制备及其抗氧化活性的研究

以洋葱为原料,采用水提醇沉法制备洋葱多糖。用浓硫酸法对洋葱多糖进行硫酸酯法修饰,采用硫酸酯取代度为指标,对硫酸酯化反应的浓硫酸与正丁醇的体积比和反应时间进行优化,并对不同浓度的硫酸酯化洋葱多糖进行体外抗氧化实验。结果表明,制备硫酸酯化洋葱多糖的较佳工艺为浓硫酸和正丁醇体积比3∶1,反应时间20min和反应温度0℃,在此条件下多糖硫酸根取代度为0.51。同时,洋葱多糖硫酸酯化改性后可显著提高抗氧化性。     

Molecular characterization and biological activities of watersoluble sulfated polysaccharides from Enteromorpha prolifera

Sulfated polysaccharides isolated from Enteromorpha prolifera and fractionated using ion exchange and gel permeation chromatography were investigated to determine their molecular characteristics and biological activities. The crude and fractionated polysaccharides (F₁, F₂, and F₃) consisted mostly of carbohydrates (50.8–62.5%), sulfates (14.5–18.8%), and uronic acid (13.8–16.6%) with different levels of monosaccharides, including rhamnose (57.1–87.6%), glucose (3.6-39.1%), and xylose (2.4–8.8%). The protein content ranged from 1.0 to 13.9%, and after the fractionation, most proteins were included in the F₂ fraction (11.3%). The crude, F₁, F₂, and F₃ exhibited the molecular weights (Mw) of 37–1,281×10³ g/mol. The polysaccharides had no significant direct cytotoxicity to cancer cells AGS or DLD- 1. On the other hand, the F₁ and F₂ stimulated Raw 264.7 cells to produce a considerable amount of nitric oxide (NO). The investigation of F₂ subfractions failed to reveal a specific subfraction more significantly affecting the NO production, thus requiring further systematic elucidation of their structural characteristics.     

米糠多糖及硫酸酯化米糠多糖的体外免疫应答和抗肿瘤活性研究

以小鼠黑色素瘤细胞(B16)为抗肿瘤模型,通过MTT比色法评价米糠多糖及硫酸酯化米糠多糖对B16增殖抑制能力。以小鼠巨噬细胞Raw264.7细胞系为免疫模型,通过MTT比色法评价Raw264.7增殖能力,中性红吞噬试验评价巨噬细胞活性,Griess方法检测一氧化氮(NO)释放量,以及酶联免疫(ELISA)检测肿瘤坏死因子(TNF-α)分泌量,考察米糠多糖及硫酸酯化米糠多糖的免疫活性。研究发现:米糠粗多糖(RBP)和米糠多糖纯化组分(RBP2a)主要通过增强机体的免疫功能而间接抑制肿瘤细胞。质量浓度为250μg/m L时,RBP和RBP2a样品组的NO释放量分别为对照组的4.67、6.36倍,TNF-α分泌量为对照组的441.1、465.5倍;RBP直接组和间接组的B16抑制率分别为8.16%、45.55%,间接组的B16抑制率比直接组增长458%。硫酸酯化米糠多糖(SRBP-B,SRBP-D,SRBP2a-B)一方面可以直接抑制B16增殖,质量浓度为1 000μg/m L时,对B16抑制率达73.65%、65.53%、78.43%,另一方面也可通过免疫途径提高NO和TNF-α等细胞因子释放,进一步提高抗肿瘤活性。但高浓度SRBP-B,SRBP-D,SRBP2a-B能抑制Raw264.7增殖,在500μg/m L时,Raw264.7存活率仅为83.26%、81.8%、79.78%。     

Antioxidative activities and chemical characterization of polysaccharides extracted from the basidiomycete Schizophyllum commune

Antioxidant properties of hot water extract (HWE), hot water extracted polysaccharides (HWP) and hot alkali extracted polysaccharides (HWAE) were obtained from fruiting bodies of the wild basidiomycete Schizophyllum commune. All extracts contained both α- and β-glucans as determined by Megazyme β-glucan assay kit. Glucose was found by TLC and NMR to be the prevalent monosaccharide in all extracts. Total phenol contents were in descending order of HWP ≈ HWE > HWAE. Median effective concentrations (EC₅₀ values) of antioxidant activities were 8.3 ± 0.1, 6.9 ± 0.0 and 8.9 ± 0.1 mg/mL, and of the DPPH scavenging activity 0.8 ± 0.0, 0.6 ± 0.0 and 1.8 ± 0.0 mg/mL, for HWE, HWP and HWAE, respectively. EC₅₀ values of reducing power were 7.6 ± 0.1, 7.9 ± 0.0 and 12.5 ± 0.1 mg/mL, whereas those of the chelating abilities on ferrous ions were 3.1 ± 0.0, 4.6 ± 0.1 and 4.9 ± 0.1 mg/mL. The EC₅₀ values of the antioxidant activity, of the DPPH scavenging, and of the reducing power were correlated with total polysaccharide as well as with total phenol content. The antioxidant activities of all the extracts may be caused by both polysaccharides and polyphenols or by a complex of both.     

Antioxidative and anti-inflammatory activities of an ethanol extract from fig (Ficus carica) branches

The edible fruit of common fig (Ficus carica) or just the fig has been traditionally used for treating hemorrhoids, insect stings, gout, ulcers, and skin infections such as warts and viruses. An ethanol extract of fig branches and its ethyl acetate, hexane, butanol, and water fractions were prepared and examined for their abilities to scavenge free radicals and inhibit inflammatory reactions. Our data showed that the ethyl acetate fraction contained the largest amount of phenolic compounds and showed the highest free radical scavenging activity. Every fraction of fig, particularly the ethanol extract and the ethyl acetate and hexane fractions, inhibited nitric oxide production in RAW264.7 cells. Tumor necrosis factor-α level also decreased significantly in all groups tested. Our results demonstrate that fig branches possessed pharmacological activity and might be useful for developing antioxidant or antiinflammatory agents.     

草苁蓉多糖抗氧化活性研究

研究草苁蓉多糖(BRPS)的抗脂质过氧化活性。以铁还原法检测BRPS的总抗氧化能力,以硫代巴比妥酸(TBA)法测定H2O2、Fe2+以及.OH所致肝匀浆丙二醛(MDA)生成量。结果表明,BRPS具有较强的总抗氧化能力,其总抗氧化能力随浓度增高而升高,回归方程为y=21.988x+1.1247,R2=0.9996;呈量效关系。同时,BRPS可浓度依赖性地抑制H2O2、Fe2+以及.OH诱导的肝匀浆和肝线粒体体系的脂质过氧化作用。提示,BRPS具有体外抗脂质过氧化活性。     

桑叶多酚、多糖及其复配物的体外模拟消化特性、降糖降脂和促益生菌增殖活性研究

目的 考察桑叶多酚(mulberry leaf polyphenol, MLPP)、桑叶多糖(mulberry leaf polysaccharide, MLPS)相互作用对其体外消化特性、降糖降脂和促益生菌增殖活性的影响。方法 以MLPP、MLPS和桑叶多酚多糖复配物(mulberry leaf polyphenol-polysaccharide complex,PPPS)为研究对象,通过高效液相色谱法和傅里叶变换红外光谱法分析MLPP、MLPS和PPPS在模拟消化口腔、胃和肠阶段的变化,采用微孔法分析三者的糖消化酶和脂肪消化酶抑制活性,采用稀释平板法考察三者促益生菌增殖作用。结果 MLPP在口腔、胃、肠阶段的消化率分别为5.26%、20.91%、59.49%; PPPS在口腔、胃、肠阶段的消化率增长至20.75%、39.01%、79.95%,表明桑叶多酚多糖复配后可提高多酚的消化率。MLPS、PPPS在口腔、胃、肠阶段消化中均未检出游离单糖,表明多酚的加入对多糖的消化无影响。PPPS对淀粉的消化和α-淀粉酶均有良好的抑制作用,且效果显著优于MLPP、MLPS (P<0.05)...     

羊栖菜硫酸多糖的提取工艺与最佳提取条件

采用三因素四水平L16(43)正交实验方案,研究提取温度、时间和pH对羊栖菜硫酸多糖得率和基本组分的影响。结果表明,影响羊栖菜硫酸多糖(粗品)得率的因素主次顺序为:温度>时间>pH;最佳提取条件为:温度90℃,时间3h,pH4。在该条件下,硫酸多糖粗品的产率最高,达到3.78%,而且其总糖、硫酸根和岩藻糖含量三项指标也达到或接近最高,分别达到33.92%、15.86%和5.69%。      

腾冲红花油茶多糖体外抗氧化活性研究

以水为溶剂对腾冲红花油茶多糖进行提取,并对腾冲红花油茶多糖进行了体外抗氧化活性研究。结果表明:腾冲红花油茶多糖对DPPH自由基、超氧阴离子自由基、羟基自由基有良好的清除作用,其半抑制率浓度(IC50)分别为9.35、0.95、2.85 mg/mL。     

几种中药浸提物的抗氧化活性研究

研究了山楂、白蒺藜及枸杞乙醇和水浸提物在卵黄脂蛋白不饱和脂肪酸(PUFA)过氧体系中的抗氧化活性,并比较了几种浸提物对OH·自由基和O·-自由基的清除能力,结果表明:3种中药在PUFA体系具有不同的抗氧化能力;山楂和白蒺藜具有一定的清除OH·的能力;3种中药均具有较强的清除O·-的能力。     

Texture and Quality Properties of Chinese Fresh Egg Noodles Formulated with Green Seaweed (Monostroma nitidum) Powder

ABSTRACT: The objective of this study was to compare fresh Chinese noodles made with different levels of green seaweed. Green seaweed powder was incorporated in proportions of 4%, 6%, and 8% in noodles, which were made with or without additional eggs. Proximate compositions, cooking properties, textural intensities, and sensory qualities of noodles were assessed. The addition of seaweed powder increased the crude fiber contents of raw fresh noodles; the fiber contents were 0.100%± 0.015 to 0.449%± 0.013 for noodles made with eggs from 0% to 8% additional seaweed and 0.247%± 0.018 to 0.344%± 0.021 for those without eggs. Higher cooking yields were found in the noodles, due to water absorption during cooking by the fibers and polysaccharides in the seaweed. Significantly higher cooking yields (P < 0.05) were found in the noodles with 8% additional seaweed powder; water uptake readings measured 2.39 ± 0.38 and 2.43 ± 0.25 g H₂O/g noodle for samples made without and with eggs, respectively. Higher water absorption by the seaweed led to softer and spongier textural intensities in the noodles. Breaking energy of cooked fresh egg noodles were 28.94 ± 3.42 to 6.43 ± 1.01 N × mm for 8% to 0% additional seaweed, and the intensities decreased as the amount of seaweed increased; the same pattern was observed in noodles without eggs, where readings were 8.66 ± 1.02 to 3.49 ± 0.25 N × mm. Capacities of extensibility measured 61.81 ± 2.04 to 30.74 ± 0.90 mm for fresh egg noodles with additional seaweed powder from 0% to 8%, and 47.46 ± 2.41 to 28.36 ± 2.25 mm for cooked fresh noodles without eggs. The results from Pearson's correlation analysis indicated that textural parameters were influenced not only by additional eggs and seaweed powder, but also by cooking properties.     

超声酸提江蓠硫酸酯多糖工艺及其性质研究

采用超声波酸法从江蓠菜提取硫酸酯多糖,通过单因素实验和正交实验,确定制备最佳工艺条件为酸度(HO)0.20 mol/L、时间为25 min、物料比1:40及温度65℃.按最佳提取条件,采用乙醇分级沉淀法制得多糖样品,多糖含量平均为21.71%,硫酸基含量平均为10.23%,蛋白含量平均为0.76%,并对其理化性质进行研究.     

银杏果精多糖的降血脂作用

采用水提醇沉法提取,Sevag法除蛋白,大孔树脂法脱色精制多糖,并对高脂模型小鼠进行实验,研究银杏果精多糖对高脂模型小鼠体重、脏器指数、血清的总胆固醇(TC)、甘油三脂(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)和动脉粥样硬化指数(AI)的影响。结果表明:银杏果精多糖高剂量组能显著降低小鼠体重和肝脏指数,提高小鼠肾脏指数,也能使小鼠血清中TC、TG和LDL-C的含量显著降低、HDL-C的含量显著升高、AI指数显著下降;银杏果精多糖中剂量组能使小鼠血清中TG和LDL-C的含量显著降低、AI指数显著下降;银杏果精多糖低剂量组可使小鼠血清中TG的含量显著降低、AI指数显著下降。说明银杏果精多糖具有降血脂作用,对冠心病和动脉粥样硬化有一定的预防作用。     

胶红酵母Rhodotorula mucilaginosa CICC 33013胞外多糖的分离纯化及抗氧化活性研究

研究胶红酵母Rhodotorula mucilaginosa CICC 33013菌株胞外多糖的初级结构与抗氧化活性。分离纯化得到胞外多糖的单一组分REPS2-A,分析其分子质量分布及自由基清除活性。结果表明,多糖组分REPS2-A的分子质量为7. 125×106Da,质量浓度为8 mg/m L时,DPPH自由基清除率为49. 1%,ABTS自由基清除率为51. 2%,还原力为0. 352。该文为了解胶红酵母菌的胞外多糖结构与功能提供了新的数据依据,为后续胶红酵母菌胞外多糖的构-效关系研究提供了实验基础。     

不同取代度的硫酸化肠浒苔多糖抗氧化活性研究

采用氨基磺酸-N,N-二甲基甲酰胺法进行多糖的硫酸化修饰,获得不同取代度的硫酸化肠浒苔多糖,通过测定硫酸化肠浒苔多糖对DPPH自由基,羟基自由基,超氧阴离子的清除能力和还原能力,考察了肠浒苔多糖取代度与抗氧化活性的关系。结果表明,取代度的大小受到硫酸化温度、硫酸化时间、DMF用量、氨基磺酸用量等的影响,其中氨基磺酸用量的影响最显著。随着取代度增大,肠浒苔多糖的抗氧化性先增强后减小,取代度在0.8¹.2范围内,肠浒苔多糖的抗氧化性较强,表明适度进行硫酸化修饰是提高肠浒苔多糖抗氧化活性的有效方式。      

Chemical structure of sulfated polysaccharides from brown seaweed (Turbinaria turbinata)

The chemical structure of three sulfated polysaccharides fractions (TtF1, TtF2, and TtF3) obtained from anion-exchange separation of aqueous extracts of brown seaweed (Turbinaria turbinate) were studied. The infrared spectra patterns showed that the fractions possess functional groups similar to that of sulfated polysaccharides. The sulfated polysaccharides fractions exhibited molecular weights of 223.5, 495.5, and 326.05 kDa, respectively, for TtF1, TtF2, and TtF3. ¹H NMR spectra of TtF2 and TtF3 contain α-anomeric protons (5–5.6 ppm), ring protons (3.4–4.4), and methyl protons (1–1.3 ppm) while that of TtF1 only exhibited ring protons and methyl protons. Rheological data were fitted to power law which revealed that the fractions were Newtonian and/or presented weak pseudoplastic behavior. Consistency values increased with concentration in all fractions. Consistency values of TtF2 were the highest, followed by TtF1 and then TtF3. Thermal degradation patterns of TtF1 and TtF2 were similar but different from that of TtF3. This study confirmed that chemical and physical characteristics of sulfated polysaccharides fractions are interrelated and provided in-depth understanding of sulfated polysaccharides of brown algae.