微乳液介质苯基荧光酮光度法测定微量钴

研究了微乳液介质中,在pH=10.0硼砂 氢氧化钠缓冲溶液时,钴与苯基荧光酮(PF)显色生成稳定的1∶2配合物,在637nm处摩尔吸光系数为1.21×105L/(mol·cm),钴含量在0～1.0μg/mL范围内符合比耳定律,用所拟方法以巯基葡聚糖凝胶分离富集,可测定维生素B12中的微量钴,结果令人满意.     

谷氨酸脱羧酶在新型羧甲基化交联烯丙基葡聚糖凝胶树脂上的固定化

本文首次用合成的羧甲基化的以N，N’-甲叉双丙烯酰胺交联的烯丙基葡聚糖（简称CM—CADB）凝胶生化树脂为新型载体，研究了谷氨酸脱羧酸在CM—CADB树脂上的固定化与环境的依赖关系。确定了酶固定化最佳条件：缓冲体系为pH4．4，0．10mol／L磷酸氢二钠-0．05mol／L柠檬酸，载体为交联度35％，交换容量3．0meq／g的CM－CADB凝胶树脂，吸附平衡时间4h以上，酶用量为30．0mg／gdryresin，固定化环境温度控制在40℃。从理论上分析了上述结果。     

葡聚糖免疫磁性毫微粒的制备及作为复合靶向载体研究

用共沉淀法制备出具有超顺磁性的葡聚糖磁性毫微粒.研究了制备过程中葡聚糖浓度、铁盐用量、搅拌速度、氨水浓度和Fe～(3+)/Fe～(2+)摩尔比对葡聚糖磁性毫微粒有效粒径的影响.抗人乳腺癌单抗与高碘酸钠氧化的葡聚糖磁性毫微粒反应形成葡聚糖免疫磁性毫微粒,并对它的磁化率、形态和抗体保留活性等性质进行了研究.通过放射免疫实验考察葡聚糖免疫磁性毫微粒体外结合肿瘤抗原的能力,同时研究了放射性标记的葡聚糖免疫磁性毫微粒在动物体内的磁性和抗体导向能力.     

无外相的葡聚糖凝胶的合成

本文研究了无外相的葡聚糖凝胶的合成方法以及有关的催化剂用量,糖液浓度,反应时间,反应温度,交联剂用量和不同分子量的葡聚糖与合成凝胶的性能关系,并确定了最佳反应条件,从而制得了性能类似国外同类产品Sephadex的凝胶。     

核盘菌多糖的构象及其构象变化的研究

研究了一种由Ｓｃｌｅｒｏｔｉｎｉａｓｃｌｅｒｏｔｉｏｒｕｍｓｓ－００１产生的具有潜在抗肿瘤活性的微生物胞外多糖──核盘菌多糖的溶液行为及构象变化．通过对其在不同离子强度和不同ｐＨ值下［η］值的考察，发现其在不同离子强度下和一定的ｐＨ范围内溶液行为稳定．但当ｐＨ＞１２．３６时其［η］值急剧变小．利用透射电镜对样品在不同条件下分子形貌的研究表明，这种溶液行为的变化是由分子构象的变化产生的     

巯基葡聚糖凝胶分离富集催化光度法测定痕量铁（Ⅲ）

研究了在硫酸介质中Ｆｅ（Ⅲ）催经抗坏血酸、溴酸钾和对氯偶氮氯膦之间的褪色反应及动力学条件，建立了学光度法测定痕量Ｆｅ（Ⅲ）的新方法，其灵敏度为１．６×１０＾－９ｇ／Ｌ；建立范围为Ｆｅ（Ⅲ）０－０．１２ｍｇ／Ｌ，采用巯基葡聚糖凝胶分离干扰离子，使方法的选择性有很大的提高，已用于食品和人发中Ｆｅ（Ⅲ）的测定，结果令人满意。     

氨基葡聚糖对水溶液中铜离子的吸附与脱附

自虾、蟹壳等水产加工废料中提取的甲壳质,经脱乙酰基反应,可得氨基葡聚糖,单体结构可表示为左图。该碱性多糖无毒,不溶于水及碱性溶液,在pH～4.5的稀酸中会溶涨,酸性更强时可溶解并成盐。若要求该聚合物以稳定的固态存在于水中,介质的酸性只允许在很小的范围内变化。聚糖中的氨基与过渡金属离子有良好的螯合作用,可作为固体吸附剂吸附水中微量的有害重金属离子。据文献报导,这类吸附大多呈Langmuir型,但Pb(Ⅱ)与Cr(Ⅲ)是例外,它们的吸附等温线表现出单层吸附饱和后,又呈现多层吸附的特征。扫描电镜的照片表明聚糖吸附Pb(Ⅱ)、Cr(Ⅲ)后,表面有瘤状小结节生成。溶液pH升高有利于重     

STRUCTURE, MOLECULAR WEIGHT AND BIOACTIVITIES OF （1→3）-β-D-GLUCANS AND ITS SULFATED DERIVATIVES FROM FOUR KINDS OF LENTINUS EDODES

Abstract Lentinan samples, (1→3)-β-D-glucans containing 4.6-15.2 wt% proteins, coded as L-I1. L-I2. L-I3 and L-I4 (L-I)were isolated from four kinds of Lentinus edodes. These glucans were treated with acetone to remove the protein in order to obtain free protein glucans coded as LNP-I1. LNP-I2, LNP-I3 and LNP-I4 (LNP-I). The free-protein polysaccharides were sulfated to give derivatives (S-LNP-I) with degree of substitution (DS) from 0.4-0.8. The structural features and weight- average molecular weight (Mw) of the samples were investigated by using infrared spectroscopy, elemental analysis,^13C-NMR, size exclusion chromatography combined with laser light scattering (SEC-LLS) and viscometry. The effects of structure and conformation of the polysaccharides on antitumor activities were assayed in vivo (Sarcoma 180 solid tumors)and in vitro (Sarcoma 180, HL-60, MCF-7 and Vero tumors). The results indicated that the predominant species of the samples L-I and LNP-I in 0.2 mol/L NaCl aqueous solution existed as triple-helical chains with high rigidity and in dimethyl sulfoxide (DMSO) as single-flexible chains. Interestingly, the antitumor activities of LNP-I are lower than those of the native glucans (L-I), whereas their sulfated derivatives have higher inhibition ratio against Sarcoma 180 than LNP-I. The results reveal that the binding of protein, sulfated modification and the triple helix conformation are important factors in the enhancement of the antitumor activities of polysaccharides on the whole.     

羧甲基-β-1,3-葡聚糖对人肝癌HepG2细胞的放射增敏作用

本研究旨在探讨羧甲基-β-1,3葡聚糖（CMG）对人肝癌HepG2细胞X射线或12C6+离子束辐射敏感性的影响。首先用CCK-8法检测CMG对HepG2细胞的生长抑制情况,得到半数抑制浓度（IC50）为120.6μg/mL。用浓度为0.1×IC50的CMG预处理HepG2细胞24 h,再给予2 Gy X射线或12C6+离子束辐照（CMG+辐照组）;CMG未处理组直接接受2 Gy X射线或12C6+离子束辐照（辐照组）。对比分析辐照组和CMG+辐照组细胞的克隆存活、DNA损伤、凋亡与周期分布、细胞内活性氧（ROS）水平。发现:与X射线辐照组相比,相同剂量的12C6+离子辐照组克隆存活率更小,DNA损伤和周期阻滞更加严重,细胞凋亡率和细胞内ROS水平也更高。与单独X射线或12C6+离子束辐照组相比,CMG+辐照组克隆存活率明显降低,细胞凋亡率随辐照后CMG作用时间的延长而明显增加,CMG使辐照后细胞内ROS维持在一个较高的水平,同时CMG明显加重了单独辐照诱导的DNA损伤和周期阻滞。结果表明,与X射线相比,HepG2细胞对相同剂量的12C6+离子辐射更敏感;CMG可增加HepG2细胞对X射线或12C6+离子辐射的敏感性;CMG可能通过增加受照HepG2细胞内的ROS水平,加剧辐照诱导的DNA损伤,促进辐射诱导细胞凋亡而起到辐射增敏作用。This study aims to investigate the effect of carboxymethy-β-1, 3-glucan (CMG) on the sensitivity of human hepatoma HepG2 cells to X-rays or 12C6+ ions irradiation. First, the inhibitory effect of CMG on the growth of HepG2 cells was detected by CCK-8 assay, and the half maximal inhibitory concentration (IC50) was 120.6 μg/mL. HepG2 cells were pretreated with CMG at a concentration of 0.1×IC50 for 24 h and then irradiated with 2 Gy X-ray or 12C6+ ion beams (CMG + irradiation group). CMG untreated group was directly irradiated by 2 Gy X-rays or 12C6+ ions beam (irradiation group). The clone survival, DNA damage, cell apoptosis, cell cycle distribution, and intracellular reactive oxygen species (ROS) levels in irradiation group and CMG + irradiation group were comparatively analyzed. The results showed that the clone survival rate was lower, DNA damage and cycle arrest were more serious, and the rate of apoptosis and intracellular ROS levels were higher in 12C6+ ions irradiation group than those in the same dose of X-rays irradiation group. Compared with X-rays or 12C6+ ions irradiation group, the clone survival rate of CMG + irradiation group was significantly decreased, and the apoptosis rate significantly increased with the prolongation of CMG treatment post-irradiation; CMG maintained intracellular ROS at a higher level after irradiation, CMG also significantly aggravated radiation-induced DNA damage and cycle arrest. These results indicated that HepG2 cells were more sensitive to 12C6+ ions radiation than those at the same dose of X-rays. CMG increased the sensitivity of HepG2 cells to X-rays or 12C6+ ions irradiation by increasing intracellular ROS level, exacerbating radiation-induced DNA damage and promoting radiation-induced apoptosis in irradiated HepG2 cells.     

重组大肠杆菌固定床间歇生产β-葡聚糖酶

以多孔陶瓷为载体,吸附法固定化重组大肠杆菌并进行固定床间歇培养.在循环流速44.19mL/min,曝气量为0.6mL/min时,培养48h后发酵液的酶活力达100.3U/mL.固定化细胞具有良好的重复使用能力,在连续5批次实验中,培养48h后的酶活力均在100U/mL左右.