防霉剂对霉菌和食用菌菌丝生长的影响

试验证明，不同防霉剂对不同霉菌有不同的抑制作用，对食用菌菌丝生长的影响也不同，广谱抑菌的富马酸二甲酯(DMF)是一种较好的食用菌防霉剂。     

延胡索酸泰妙菌素对猪支原体肺炎的临床疗效实验

为了研究延胡索酸泰妙菌素对猪支原体肺炎的临床疗效,选用体重90 kg左右的2月龄健康杜洛克长白杂交猪,通过建立疾病模型和疗效评价指标判别延胡索酸泰妙菌素的治疗效果。结果表明,按1000 kg饲料添加100 g或200 g延胡索酸泰妙菌素,可以显著减轻感染猪的临床症状和病理变化,提高猪的增重,其效果优于磷酸泰乐菌素预混剂。     

DIPHOSPHONATE TREATMENT OF A PRIMARY OSTEOSARCOMA IN A DOG: A CASE REPORT

The following sequence of treatments was administered to a Saint Bernard dog with a primary distal right radius osteosarcoma: 54 days of daily disodium 1-hydroxyethylidenediphosphonate (HEDP) subcutaneous injections; 53 days of HEDP per os ; one ³²P-HEDP intravenous injection. During the pretreatment period, there was an extensive increase in calcific tumor growth and osteoblastic proliferation. After the subcutaneous HEDP treatment, almost complete tumor necrosis was seen. After the oral HEDP treatment, only the deepest tumor portion contained active osteoblasts, calcific growth of the tumor was completely blocked, and uptake of ^99mTc-Sn-HEDP was reduced to one fourth of the pretreatment uptake. After a single ³²P-HEDP dose, large areas of tumor necrosis were evident histopathologically. However, subsequent resumption of cellular activity occurred in the tumor, and the uptake of ^99mTc-Sn-HEDP increased to pretreatment values. These data suggest that systemically administered HEDP should be studied further for its possible therapeutic potential in the treatment of osteosarcoma and indicate a need for further study of ³²P-HEDP or possibly ³³P-HEDP.     

食品防霉剂富马酸二甲酯的合成

以四氯化锡为催化剂,马来酸酐和甲醇为原料,采用"一锅法"催化合成富马酸二甲酯。考察了反应时间、醇酸摩尔比、催化剂的用量对产率的影响,并进行了正交实验设计。结果表明:醇酸摩尔比对产率的影响高度显著,当甲醇与马来酸酐的摩尔比为15∶1,四氯化锡质量分数0.8g,回流反应时间2.5h,产率达88.72%。通过熔点测试和红外光谱分析,确定合成产物即是富马酸二甲酯。     

Cytotoxic, cytoprotective and antioxidant effects of isolated phenolic compounds from fresh ginger

Twenty-nine phenolic compounds were isolated from the root bark of fresh (Yunnan) ginger and their structures fully characterized. Selected compounds were divided into structural categories and twelve compounds subjected to in-vitro assays including DPPH radical scavenging, xanthine-oxidase inhibition, monoamine oxidase inhibition, rat-brain homogenate lipid peroxidation, and rat pheochromocytoma PC12 cell and primary liver cell viability to determine their antioxidant and cytoprotective properties. Isolated compounds were also tested against nine human tumor cell lines to characterize anticancer potency. Several diarylheptanoids and epoxidic diarylheptanoids were effective DPPH radical scavengers and moderately effective at inhibiting xanthine oxidase. An enone–dione analog of 6-shogaol (compound 2) was isolated and identified to be most effective at protecting PC12 cells from H₂O₂-induced damage. Almost all tested compounds inhibited lipid peroxidation. Three compounds, 6-shogaol, 10-gingerol and an enone-diarylheptanoid analog of curcumin (compound 6) were identified to be cytotoxic in cell lines tested, with KB and HL60 cells most susceptible to 6-shogaol and the curcumin analog with IC₅₀ < 10 μM. QSAR analysis revealed cytotoxicity was related to compound lipophilicity and chemical reactivity. In conclusion, we observed distinct compounds in fresh ginger to have biological activities relevant in diseases associated with reactive oxygen species.     

延胡索酸泰妙菌素成盐结晶工艺优化

水洗后的泰妙碱4-甲基-2-戊酮(MIBK)溶液通过降膜浓缩,使MIBK与水形成的二元共沸物在减压条件下蒸发,脱去水分,代替向泰妙碱溶液加入无水硫酸钠吸水的生产工艺。提高成盐结晶溶剂甲醇的加入比例,对结晶过程的搅拌速度分段控制,严格控制析晶过程各项参数。将延胡索酸泰妙菌素晶体干粉溶于甲醇,重结晶析出的纯净的针形晶体干燥后磨细作为晶种。这些措施优化了延胡索酸泰妙菌素成盐结晶工艺流程,降低了生产成本,提高了结晶收率和产品质量。     

基于不同方法测定土壤酸性磷酸酶活性的比较

土壤酸性磷酸酶与有机磷的矿化及植物的磷素营养关系最为密切。目前国内学者在测定酸性磷酸酶活性时主要参照关松荫《土壤酶及其研究法》中以磷酸苯二钠为基质的测定方法,而国外学者主要参照Dick《Methods of Soil Enzymology》中以对硝基苯磷酸二钠为基质的测定方法(PNPP)。但是,在以磷酸苯二钠为基质测定生成物的过程中,常出现显色程度不明显的问题;另外,采用不同基质测定酸性磷酸酶活性也造成了测定方法选择的困难。为合理选择土壤酸性磷酸酶活性的测定方法,本研究选用酸性、中性和碱性土壤各10个土样,分别采用以磷酸苯二钠为基质,且在显色阶段分别加入pH5.0醋酸盐缓冲液(DPP 1)和pH9.4硼酸盐缓冲液(DPP 2)的方法,以及PNPP方法测定土壤酸性磷酸酶活性。同时也研究了不同pH缓冲液和苯酚浓度对生成物显色反应的影响。结果表明:以磷酸苯二钠为基质、在显色反应阶段加入pH≤6的缓冲液时,苯酚和2,6-二溴苯醌氯亚胺不显色;当加入pH≥8的缓冲液时,两者之间显色且苯酚浓度和吸光值的Pearson相关系数极显著。这说明pH低是导致高苯酚浓度和2,6-二溴苯醌氯亚胺显色效果差的一个主要原因。此外,采用PNPP方法测定时,在酸性、中性和碱性土壤中,10个样本酸性磷酸酶活性的变异系数分别较DPP 2增加了70.04%、42.44%和21.17%;极差分别是DPP 2的27.18倍、26.85倍和39.43倍。总之,如果选用磷酸苯二钠为基质测定土壤酸性磷酸酶活性,应在显色阶段加入碱性硼酸盐缓冲液;选用对硝基苯磷酸二钠为基质,是更为简单和灵敏的方法。     

GC法检测三类食品中富马酸二甲酯的含量

选取饮料、饼干、腌菜三类保质期较短的食品为研究对象,试验了不同提取溶剂、提取方法、色谱条件的影响,建立了气相色谱法测定食品中富马酸二甲酯残留量的检测方法。试样经三氯甲烷提取后,超声15 min,DB\|FFAP柱分离,氢火焰离子化检测器(FID)检测。富马酸二甲酯浓度在10～600 μg·mL-1范围内,标准曲线的回归方程为y=24825x,相关系数r=0.9999,检出限0.072 mg·kg-1,分别对饮料、饼干、腌菜三类样品进行高低两水平添标回收试验,平均回收率在87.8%～105.2%,相对标准偏差2.4%～4.5%(n=6),本方法操作简单、快速、准确,灵敏度高,重现性好,适用于食品中富马酸二甲酯的检测。     

新型食品抗菌剂富马酸糠醇甲酯的抗菌活性及稳定性研究

 研究合成了一种具有α,β-不饱和羰基结构的化学抗菌剂——富马酸糠醇甲酯，并对其抗菌活性进行研究。结果表明，其抑菌谱较广，对细菌、酵母和霉菌均具有较强的抑制作用，同时可以有效延长混合微生物的生长适应期，显著降低其生长量，而且效果明显优于常用抗菌剂苯甲酸钠，另外，糠醇甲酯具有较好的热稳定性并且在不同pH均表现良好的抗菌活性，说明它可以用于更多食品的防腐，是一种具有广泛开发前景的抗菌剂。     

Bola型表面活性剂磺化脱氢松香酸二钠盐的表面化学性质

以脱氢松香酸为原料,经磺化、中和反应合成了一种非对称Bola型表面活性剂磺化脱氢松香酸二钠盐(DSDA),利用FT-IR、1H NMR及MS对目标产物结构进行确证,采用表面张力法确定了DSDA在303.0K、pH值为10.5时的临界胶束浓度(CMC),考察了其在不同NaCl浓度(0～0.50mol/L)下的表面活性.结果表明,DSDA溶液表面张力-浓度曲线出现了一个转折点;一定温度下,随着NaCl浓度的增大,DSDA溶液CMC从25mmol/L降至3.83mmol/L,表面极限吸附量(Г∞)下降,最低表面张力(γCMC)基本不受影响.