Deproteinization and structural characterization of bioactive exopolysaccharides from Ganoderma sinense mycelium

Deproteinization was comparatively employed for the purification of crude exopolysaccharide (CEP) of Ganoderma sinense mycelium. Results showed that ammonium sulfate (70% saturation) salting out could remove 95% proteins of CEP, whereas 20% trichloroacetic acid precipitation was best with a polysaccharide loss less than 20%. Protein-bound polysaccharides could be removed by both methods, and polysaccharides with high molecular weight dominated in the lost polysaccharides. Through anion-exchange chromatography, a highly branched α-(1→6)-D-mannan and a protein-bound heteropolysaccharide were prepared from CEP. Both fractions could inhibit the in vitro proliferation of tumor cells BEL-7402, and induce TNF-α secretion of murine splenocytes.     

海南甘蔗育种场甘蔗种质种性研究（Ⅲ）

本文报告了１９９７年及１９９８年海南甘蔗育种场甘蔗基础种质性研究及其近年研究的综合评价，通过大量性状、糖分及抗病（黑穗病、嵌纹病）性诸方面的综评推荐一批优良原种种质作为基础杂交亲本，通过基础杂交、培育与选择，期望快速、有效获得用于经济杂交的新型种质与亲本，从而扩大甘蔗遗传育种基础，提高品种水平．     

攀枝花和会东地区中华块菌营养成分检测及含量差异化分析

中华块菌是我国重要的商业块菌之一,攀枝花和会东地区是中华块菌的主要产地,为探究攀枝花与会东地区中华块菌的组成成分及差异性,利用气相色谱质谱联用仪(GC-MS)技术对这2个地区新鲜中华块菌成分进行检测和分析。主成分分析表明两地中华块菌组成成分差异较小,两地中华块菌均鉴定出83种有效化合物,包括：15种氨基酸(其中8种为必需氨基酸)、10种糖类、22种有机酸等。偏最小二乘法分析表明两地中华块菌在肌醇半乳糖苷、尿苷、亚油酸、9-(E)-十八烯酸、花生四烯酸等物质含量上有显著性差异。该研究通过分析不同地区中华块菌的组成成分及含量差异,探究中华块菌成分组成的同时还能辅助区分中华块菌的产地,弥补了传统的真菌内转录间隔区鉴定法不能对中华块菌进行产地区分的缺点。     

黑松露多糖提取工艺优化及体外抗氧化活性分析

选取云南黑松露为研究对象,对黑松露多糖优化提取工艺,纯化后单糖组成和体外抗氧化活性进行研究。应用响应曲面法优化后最佳提取工艺条件为：提取温度75.36 ℃,提取时间1.02 h与料液比1:31.32 g/mL,在此条件下,多糖的实验得率为11.79%,预测得率为11.86%。采用DEAE-Sepharose快速流动柱从黑松露粗多糖中分离纯化出4个新的多糖组分（TSP-1、TSP-2、TSP-3、TSP-4）。应用离子色谱法分析多糖成分,得出TSP-1的单糖组成为盐酸氨基半乳糖、葡萄糖和甘露糖,比例为2.8:77.1:20;TSP-2为鼠李糖、盐酸氨基葡萄糖、半乳糖、葡萄糖和甘露糖,比例为18.7:1.5:2:40.6:37.3;TSP-3为鼠李糖、盐酸氨基葡萄糖、葡萄糖、甘露糖、葡萄糖醛酸和半乳糖的比例为13:3.5:58.4:21.1:2.7:1.2。粗多糖（crud TSP）和TSP-1、TSP-2、TSP-3三个纯化组分多糖浓度在0.25~4 mg/mL范围内,对DPPH自由基的最大清除率分别为73.93%、36.67%、73.60%和54.10%;对ABTS自由基的最大清除率分别为60.47%、36.20%、41.87%和52.73%;金属螯合力分别为61.63%、27.00%、52.50%和43.17%;还原力吸光度值分别为0.39、0.34、0.28和0.56。该研究旨在为研究黑松露多糖具生物活性的物质基础及开发利用提供理论依据,并对其保健食品研发具有重要意义。     

中国弯颈霉提取物抗氧化和抗肿瘤体外活性研究

中国弯颈霉(Tolypocladium sinense)分离自冬虫夏草,其生长最适温度25～28℃,最适pH6～7。在液体培养基(葡萄糖 4%、蛋白胨 0.5%、酵母膏1%、KH2PO4 0.1%、MgSO4 0.05%)中,经过28℃下摇床(150r/min)培养4～10d 后,菌丝体生物量达8.49～9.73g/L。其菌丝体石油醚、乙酸乙酯、无水乙醇和蒸馏水提取率分别为3.51%、1.62%、4.84%、23.33%,菌丝体多糖提取率为5.31%。各提取物对DPPH 自由基均具有清除作用,2mg/ml 多糖具有较强的清除作用,清除率为49.13%;菌丝体多糖(0.08mg/ml)能显著地清除羟自由基,清除率为82.5%。MTT 法检测发现乙酸乙酯提取物具有较强的抑制白血病细胞增殖作用;作用于K562 和SHI-1 细胞2d 后,乙酸乙酯提取物IC50 分别为26.55、17.75μg/ml;该提取物对正常细胞(人PBMC 和小鼠骨髓细胞)的抑制作用较弱;AO/EB 双染和TUNEL 法检测提示菌丝体的乙酸乙酯提取物可以诱导K562 细胞凋亡。上述实验结果表明,中国弯颈霉具有抗氧化和抗肿瘤方面的应用开发前景。     

AB-8大孔树脂对中华补血草根多酚的吸附洗脱特性

从S-8、NKA-9、AB-8、NKA和D4020大孔树脂中筛选出AB-8树脂,研究了AB-8树脂对中华补血草根多酚的吸附洗脱特性。结果表明:AB-8树脂对中华补血草根多酚的饱和吸附时间为5h,吸附等温线符合Lang-muir模型,饱和吸附量为55.30mg/g,提取液pH值对吸附过程影响不显著;以质量浓度1.99mg/mL的提取液上柱,流速为1mL/min时,吸附泄漏点为10BV(柱床体积,1BV=30mL),饱和点为32BV,因此,采用串柱法有利于AB-8树脂吸附能力的发挥;用体积分数70%乙醇作为洗脱剂,以流速1mL/min洗脱,获得的多酚纯度为58.29%。     

小蜡色素稳定性研究

对小蜡色素的理化性质和稳定性进行研究。结果表明：小蜡色素易溶于水,属于花色苷类色素;在酸性条件下,对热有一定的耐受性。耐可见光和紫外光的性能也较好,抗坏血酸和防腐剂对色素稳定性无影响,而氧化剂H202对色素的稳定性有不良影响,还原剂Na2S03对色素的影响比较大,金属离子中Fe3＋、Cu2＋和Sn2＋离子对色素的稳定性有不良影响,而Na＋、K＋、Mg2＋、Fe2＋、Al3＋、Pb2＋对色素的稳定性无影响。     

环孢菌素A生产菌原生质体转化系统的建立

以腐草霉素抗性为选择标记,建立了环孢菌素A生产菌株的基因转化体系,成功将外源基因转入环孢菌素A生产菌,并整合到染色体上。传代实验表明,外源基因可以稳定表达。该体系的建立为环孢菌素A生产菌的基因工程育种奠定了基础。     

甘蔗皮红色素提取工艺的研究

利用正交试验设计和Duncan法检验,确立了甘蔗皮红色素的最佳提取条件及其提取率.结果表明,用95%乙醇水溶液作为提取剂,料液比为1∶10,60℃恒温浸提15 min,提取率为86.1%.     

Identification and directed biosynthesis of efrapeptins in the fungusTolypocladium geodes gams (Deuteromycotina: Hyphomycetes)

HPLC analysis of crude dichloromethane extracts of shaken liquid cultures of the hyphomycetous fungusTolypocladium geodes Gams revealed the presence of efrapeptins. These peptides, which have mitochondrial ATPase inhibitory activity as well as antifungal and insecticidal properties, are previously known only from the congeneric species,T. niveum Rostrup. The identity of efrapeptins was confirmed by fast atom bombardment mass spectrometry and by amino acid analysis. HPLC analyses of efrapeptins extracted from single isolates of bothT. geodes andT. niveum indicated that both species produced the same efrapeptins but the profile of relative abundance of the compounds produced was diagnostic for the isolates examined. Efrapeptin F was the major component of the mixture fromT. geodes with the order of abundance of the six efrapeptins detected being F >G>DE>H>C. Efrapeptin D was the major component fromT. niveum with the order of abundance of the six efrapeptins detected being D >E>F>CG>H. Efrapeptin F diifers from efrapeptin D by a single amino acid residue, efrapeptin F having an alanine where efrapeptin D has a glycine. Addition of alanine to the culture medium increased the relative abundance of efrapeptin F in the profile of both species. Conversely, addition of glycine increased the relative abundance of efrapeptin D in the profile of both species.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.