采用白金板法对Surfactin的表面活性进行研究,并用浊度法和离心法对其乳化性进行研究。结果表明：Surfactin的临界胶束浓度为9.03×10-5 mol/L,可将水的表面张力由73.98 m N/m降至最低27.48 m N/m。在浓度为1×10-3~1.2×10...采用白金板法对Surfactin的表面活性进行研究,并用浊度法和离心法对其乳化性进行研究。结果表明：Surfactin的临界胶束浓度为9.03×10-5 mol/L,可将水的表面张力由73.98 m N/m降至最低27.48 m N/m。在浓度为1×10-3~1.2×10-2 mol/L的NaCl溶液中,Surfactin溶液的表面张力随盐浓度升高逐渐降低并最终稳定在34 m N/m;Surfactin在121℃处理20 min后,其表面张力仍能保持在37.10 m N/m;在pH值为2~12范围内,其表面活性稳定并良好;表明Surfactin具有较强的NaCl浓度、温度、pH值的耐受性。浊度法测得Surfactin亲水亲油平衡（hydrophile lipophilic balance,HLB）值为14,对所需HLB值为12~16的油相乳化性能良好。展开更多
地衣芽孢杆菌(B acillus lichen if orm is)NK-X3产生的脂肽类表面活性剂具有高表面活性,其临界胶束浓度(CM C)值为30 m g/L.采用接触角测量和烃粘附率实验研究低于CM C值的脂肽浓度对细胞表面亲疏水性和粘附性的影响.结果表明,脂肽具...地衣芽孢杆菌(B acillus lichen if orm is)NK-X3产生的脂肽类表面活性剂具有高表面活性,其临界胶束浓度(CM C)值为30 m g/L.采用接触角测量和烃粘附率实验研究低于CM C值的脂肽浓度对细胞表面亲疏水性和粘附性的影响.结果表明,脂肽具有改变细菌表面的疏水特性,使亲水性的NK-X3菌疏水性增强,疏水性的K 80-B菌疏水性减弱.脂肽改变细菌细胞表面的亲疏水性,从而改变细菌的粘附性.展开更多
目的研究小牛血清去蛋白提取物(deproteinated extract of calf blood,DECB)中生物活性物质的物理化学性质。方法分别将小牛血清去蛋白提取物进行加热、加酸、加碱、烘烤、有机溶剂萃取、接种微生物发酵等方法处理,然后分别用微量呼吸...目的研究小牛血清去蛋白提取物(deproteinated extract of calf blood,DECB)中生物活性物质的物理化学性质。方法分别将小牛血清去蛋白提取物进行加热、加酸、加碱、烘烤、有机溶剂萃取、接种微生物发酵等方法处理,然后分别用微量呼吸检压法检测呼吸活性。结果采用加热、加碱、加酸,接种微生物发酵的方法进行处理,DECB刺激呼吸活性的能力没有明显改变,而采用烘烤的方法处理,DECB的活性完全消失;用有机溶剂萃取DECB,可明显降低DECB刺激呼吸活性的能力,而有机相中含有了刺激呼吸活性物质。结论小牛血清去蛋白提取物(DECB)中刺激呼吸的活性物质耐高温、耐酸、耐碱,并且不易被普通微生物降解,但不耐烘烤,较易被有机溶剂萃取,由理化性质推测DECB中的活性物质可能是一种活性脂类。展开更多
To study the antioxidant constituents from the stems of Dendrobium nobile, and to discuss theft structure-activity relationship. Compounds were isolated from a 60% ethanolic extract by various chromatographic techniqu...To study the antioxidant constituents from the stems of Dendrobium nobile, and to discuss theft structure-activity relationship. Compounds were isolated from a 60% ethanolic extract by various chromatographic techniques and were identified by spectral analysis. The antioxidant activities of compounds were evaluated by DPPH free radical scavenging assay. Five phenanthrenes and four lignans were obtained from the active fractions ofD. nobile. Their structures were identified as fimbriatone （1）, confusarin （2）, flavanthrinin （3）, 2,5-dihydroxy-4,9-dimethoxyphenanthrene （4）, 3,7-dihydroxy-2,4-dimethoxyphenanthrene （5）, syringaresinol （6）, pinoresinol （7）, medioresinol （8） and lirioresinol-A （9）, respectively. Compounds 2 and 6 exhibited more potent DPPH scavenging activities than vitamin C. All the above compounds were reported from this plant for the first time, and compounds 3, 4 and 9 were reported for the first time from the genus of Dendrobiurn. For all phenanthrenes and lignans, an electron-donating methoxyl group in the ortho position to the phenolic hydroxyl group exhibits enhanced antioxidant activities.展开更多
AIM： To investigate the protective effects of magnolol on sepsis-induced inflammation and intestinal dysmotility. METHODS： Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide （LPS）. Male...AIM： To investigate the protective effects of magnolol on sepsis-induced inflammation and intestinal dysmotility. METHODS： Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide （LPS）. Male Wistar rats were randomly assigned to one of three treatment groups： magnolol prior to LPS injection （LPS/Mag group）; vehicle prior to LPS injection （LPS/Veh group）; vehicle prior to injection of saline （Control/Veh）. Intestinal transit and circular muscle mechanical activity were assessed 12 h after LPS injection. Tumor necrosis factor-α （TNF-α）, interleukin-10 （IL-10）, monocyte chemoattractant protein-1 （MCP-1） and inducible nitric oxide synthase （iNOS） mRNA in rat ileum were studied by RT-PCR 2 h after LPS injection. Nuclear factor-κB （NF-κB） activity in the intestine was also investigated at this time using electrophoretic mobility shift assay. In addition, antioxidant activity was determined by measuring malondialdehyde （MDA） concentration and superoxide dismutase （SOD） activity in the intestine 2 h after LPS iniection.RESULTS： Magnolol significantly increased intestinal transit and circular muscle mechanical activity in LPS- treated animals. TNF-α, MCP-1 and iNOS mRNA expression in the small intestine were significantly reduced after magnolol treatment in LPS-induced septic animals, compared with untreated septic animals. Additionally,magnolol significantly increased IL-10 mRNA expression in septic rat ileum. Magnolol also significantly suppressed NF-κB activity in septic rat intestine. In addition, magnolol significantly decreased MDA concentration and increased SOD activity in rat ileum. CONCLUSION： Magnolol prevents sepsis-induced suppression of intestinal motility in rats. The potential mechanism of this benefit of magnolol appears to be modulation of self-amplified inflammatory events and block of oxidative stress in the intestine.展开更多
In this report, we reviewed recent literature on physiologically active substances from sea cucumbers (SCs) andtheir activities together with results obtained from our study. Preventive properties against lipid metabo...In this report, we reviewed recent literature on physiologically active substances from sea cucumbers (SCs) andtheir activities together with results obtained from our study. Preventive properties against lipid metabolism were reported inrats using a whole SC preparation with no particular constituent specified. Administration of the preparation lowered serumand hepatic cholesterol levels and improved the HDL/LDL ratio. These functions may be attributed to the stimulatory effectof the extract on the secretion of cholesterol in feces. Novel fucosylated chondroitin sulfates (FCSs) from Ludwigothureagrisea significantly induced fibroblast growth factor 2-dependent angiogenesis in human umbilical vein endothelial cells (HU-VECs). The proangiogenetic activity seemed attributable to the action of the sulfated fucose branches on the polysaccharide.SCs contain mycosporine-like amino acids (MAAs) that are capable of absorbing UV. A biogenetic precursor of MAAs wasfirst reported in SCs. The anti-proliferative effects of a branched chain fatty acid from a sea cucumber on prostate cancercells was reported with the activity of 5-lipoxygenase. Glycosphingolipid constituents in SCs have been systematically ana-lyzed over the past ten years. The results showed that the gangliosides in several SCs differed from those of mammals in thata sialic acid of SC gangliosides directly binded to glucose of cerebroside. Neuritogenic activity of the glycosphingolipids wasdemonstrated in vitro experiments and may lead to the development of therapeutic products for neurological disorders. Ourstudy also showed that sphingoid bases, the hydrolyzed products of glycosphingolipids from SCs, induced significant apoptosisin several tumor cell lines.展开更多
文摘采用白金板法对Surfactin的表面活性进行研究,并用浊度法和离心法对其乳化性进行研究。结果表明：Surfactin的临界胶束浓度为9.03×10-5 mol/L,可将水的表面张力由73.98 m N/m降至最低27.48 m N/m。在浓度为1×10-3~1.2×10-2 mol/L的NaCl溶液中,Surfactin溶液的表面张力随盐浓度升高逐渐降低并最终稳定在34 m N/m;Surfactin在121℃处理20 min后,其表面张力仍能保持在37.10 m N/m;在pH值为2~12范围内,其表面活性稳定并良好;表明Surfactin具有较强的NaCl浓度、温度、pH值的耐受性。浊度法测得Surfactin亲水亲油平衡（hydrophile lipophilic balance,HLB）值为14,对所需HLB值为12~16的油相乳化性能良好。
文摘目的研究小牛血清去蛋白提取物(deproteinated extract of calf blood,DECB)中生物活性物质的物理化学性质。方法分别将小牛血清去蛋白提取物进行加热、加酸、加碱、烘烤、有机溶剂萃取、接种微生物发酵等方法处理,然后分别用微量呼吸检压法检测呼吸活性。结果采用加热、加碱、加酸,接种微生物发酵的方法进行处理,DECB刺激呼吸活性的能力没有明显改变,而采用烘烤的方法处理,DECB的活性完全消失;用有机溶剂萃取DECB,可明显降低DECB刺激呼吸活性的能力,而有机相中含有了刺激呼吸活性物质。结论小牛血清去蛋白提取物(DECB)中刺激呼吸的活性物质耐高温、耐酸、耐碱,并且不易被普通微生物降解,但不耐烘烤,较易被有机溶剂萃取,由理化性质推测DECB中的活性物质可能是一种活性脂类。
文摘To study the antioxidant constituents from the stems of Dendrobium nobile, and to discuss theft structure-activity relationship. Compounds were isolated from a 60% ethanolic extract by various chromatographic techniques and were identified by spectral analysis. The antioxidant activities of compounds were evaluated by DPPH free radical scavenging assay. Five phenanthrenes and four lignans were obtained from the active fractions ofD. nobile. Their structures were identified as fimbriatone （1）, confusarin （2）, flavanthrinin （3）, 2,5-dihydroxy-4,9-dimethoxyphenanthrene （4）, 3,7-dihydroxy-2,4-dimethoxyphenanthrene （5）, syringaresinol （6）, pinoresinol （7）, medioresinol （8） and lirioresinol-A （9）, respectively. Compounds 2 and 6 exhibited more potent DPPH scavenging activities than vitamin C. All the above compounds were reported from this plant for the first time, and compounds 3, 4 and 9 were reported for the first time from the genus of Dendrobiurn. For all phenanthrenes and lignans, an electron-donating methoxyl group in the ortho position to the phenolic hydroxyl group exhibits enhanced antioxidant activities.
基金Supported by Beijing Municipal Science & Technology Commission Major Sci-tech Program, No. H020920050130
文摘AIM： To investigate the protective effects of magnolol on sepsis-induced inflammation and intestinal dysmotility. METHODS： Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide （LPS）. Male Wistar rats were randomly assigned to one of three treatment groups： magnolol prior to LPS injection （LPS/Mag group）; vehicle prior to LPS injection （LPS/Veh group）; vehicle prior to injection of saline （Control/Veh）. Intestinal transit and circular muscle mechanical activity were assessed 12 h after LPS injection. Tumor necrosis factor-α （TNF-α）, interleukin-10 （IL-10）, monocyte chemoattractant protein-1 （MCP-1） and inducible nitric oxide synthase （iNOS） mRNA in rat ileum were studied by RT-PCR 2 h after LPS injection. Nuclear factor-κB （NF-κB） activity in the intestine was also investigated at this time using electrophoretic mobility shift assay. In addition, antioxidant activity was determined by measuring malondialdehyde （MDA） concentration and superoxide dismutase （SOD） activity in the intestine 2 h after LPS iniection.RESULTS： Magnolol significantly increased intestinal transit and circular muscle mechanical activity in LPS- treated animals. TNF-α, MCP-1 and iNOS mRNA expression in the small intestine were significantly reduced after magnolol treatment in LPS-induced septic animals, compared with untreated septic animals. Additionally,magnolol significantly increased IL-10 mRNA expression in septic rat ileum. Magnolol also significantly suppressed NF-κB activity in septic rat intestine. In addition, magnolol significantly decreased MDA concentration and increased SOD activity in rat ileum. CONCLUSION： Magnolol prevents sepsis-induced suppression of intestinal motility in rats. The potential mechanism of this benefit of magnolol appears to be modulation of self-amplified inflammatory events and block of oxidative stress in the intestine.
文摘In this report, we reviewed recent literature on physiologically active substances from sea cucumbers (SCs) andtheir activities together with results obtained from our study. Preventive properties against lipid metabolism were reported inrats using a whole SC preparation with no particular constituent specified. Administration of the preparation lowered serumand hepatic cholesterol levels and improved the HDL/LDL ratio. These functions may be attributed to the stimulatory effectof the extract on the secretion of cholesterol in feces. Novel fucosylated chondroitin sulfates (FCSs) from Ludwigothureagrisea significantly induced fibroblast growth factor 2-dependent angiogenesis in human umbilical vein endothelial cells (HU-VECs). The proangiogenetic activity seemed attributable to the action of the sulfated fucose branches on the polysaccharide.SCs contain mycosporine-like amino acids (MAAs) that are capable of absorbing UV. A biogenetic precursor of MAAs wasfirst reported in SCs. The anti-proliferative effects of a branched chain fatty acid from a sea cucumber on prostate cancercells was reported with the activity of 5-lipoxygenase. Glycosphingolipid constituents in SCs have been systematically ana-lyzed over the past ten years. The results showed that the gangliosides in several SCs differed from those of mammals in thata sialic acid of SC gangliosides directly binded to glucose of cerebroside. Neuritogenic activity of the glycosphingolipids wasdemonstrated in vitro experiments and may lead to the development of therapeutic products for neurological disorders. Ourstudy also showed that sphingoid bases, the hydrolyzed products of glycosphingolipids from SCs, induced significant apoptosisin several tumor cell lines.
