α-硫辛酸脂质体的制备及质量评价

以大豆磷脂和胆固醇为膜材,采用薄膜-超声乳化分散法制备了α-硫辛酸脂质体。研究了配方中不同组分的比例对包封率的影响,并对脂质体的结构和形态、稳定性、表面电位、存贮条件进行了考察。结果表明,在大豆磷脂、胆固醇、α-硫辛酸的质量比为5∶1.5∶0.08时,制备的脂质体包封率为80.9%。该方法制备的α-硫辛酸脂质体为球形的单室结构,平均粒径为237 nm左右,表面电位为负,脂质体乳液的pH=6.5,适宜的贮存条件是3～5℃冰箱冷藏。     

α-氯代脂肪酸水热法中性水解合成α-羟基脂肪酸

开发了一条从天然脂肪酸合成α-羟基脂肪酸(α-HFA)的高产率、低污染且低成本的合成路线,即从天然脂肪酸制备α-氯代脂肪酸(α-CFA),再以α-CFA为原料通过水热法中性水解合成α-HFA。用GC-MS和IR鉴定了产物的结构,ESI-MS表征了产物的相对分子质量(以下简称分子量),纯化后α-HFA纯度达99%(GC)以上。探讨了水热中性水解反应中原料配比、反应加水量、反应温度、反应时间等因素对该水热工艺的影响,结果表明,当n(CaCO3)∶n(α-CFA)=1.05∶1,m(H2O)∶m(α-CFA)=2∶1,C12～C18的α-氯代天然脂肪酸在155℃水热条件下反应4 h后,α-HFA同系物的产率均高达98%～99%。     

AMS加氢制异丙苯反应动力学及机理

用α-甲基苯乙烯（AMS）在自制Pd/γ-Al₂O₃催化剂上加氢生成异丙苯，于间歇搅拌釜内研究了该反应的本征动力学，在排除内外扩散影响的前提下，分别在不同温度、氢压、原料浓度下测定了反应级数，分析了反应机理。结果表明，该反应对氢为一级，而对AMS为变级数反应。     

竞争性抑制剂对反胶团萃取过程中α胰凝乳蛋白酶活力的稳定作用

研究了竞争性抑制剂苯基硼酸对a胰凝乳蛋白酶反胶团萃取过程的影响及对酶活力的稳定作用. 研究发现,向AOT/isooctane 反胶团中添加一定量的苯基硼酸,萃取率会略有增加,反萃取率则无显著变化. 酶活力的回收率显著提高,酶活力对萃取和反萃时间的耐受性显著增强. 苯基硼酸和a胰凝乳蛋白酶之间的特异性亲和作用是产生这种影响的原因.     

Evaluation of vitamin E by HPLC in a variety of olive-based foodstuffs

A survey of vitamin E levels in a wide variety of olive-based foodstuffs was conducted. Vitamin E was determined by normal-phase HPLC. The only form of vitamin E found in all commercial presentations of table olives was α-tocopherol, with an average content of 3.1 mg/100 g edible portion. A very low content (<0.4 mg/100 g edible portion) of γ-tocopherol was found in most of the samples analyzed. The main sources of variation of vitamin E were olive cultivars and commercial presentations. Processing type (Spanish style green olives, directly brined olives, ripe olives) had a limited influence. Irrespective of the elaboration style, the Gordal cultivar was the poorest with respect to the vitamin E content. On the other hand, all commercial presentations based on the Hojiblanca cultivar had high contents of vitamin E. The results of this study may be used by the industry for requirements of nutritional labeling or by nutritionists to estimate vitamin E intakes in diets that include table olives.     

负载型铜在萘的α-硝基化反应中的催化性能

目前工业上合成 α-硝基萘仍然采用传统的混酸硝化法,然而该方法存在区域选择性不高、官能团耐受性差、产生过量酸性废液以及后处理费用高等诸多局限性,导致环境污染以及生产成本的提高,不符合绿色化学的理念。鉴于 α-硝基萘的应用前景,本文通过浸渍-焙烧-还原等步骤设计合成一系列负载型铜催化剂,实现了萘向 α-硝基萘的高效、经济、绿色的催化转化。其中,以ZSM-5等为载体合成的催化剂Cu/ZSM-5催化效果最好,以较高的分离产率（高达95%）和优异的区域选择性[(α-∶β-)>(98∶2)]得到了目标产物α-硝基萘,而且在重复使用4次后依然保持较高的催化活性和结构稳定性。     

十三碳二元酸发酵与肉毒碱乙酰基转移酶酶活动力学研究

在利用热带假丝酵母发酵生产十三碳二元酸(DCA13)的过程中,建立了用荧光法测定酵母体内肉毒碱乙酰基转移酶(CAT)酶活的方法,方法简单,重现性高,测量精确。研究了热带假丝酵母中CAT酶活动力学与产酸速率的关系,结果表明:代谢前期细胞以生长为主,CAT酶活较高可提供更多的生长动力,而代谢后期细胞进入产酸期,CAT酶活与产酸速率的变化趋势成反比,即产酸速率高时,CAT的酶活较低。     

Integrative Extraction of Ergosterol, （1→3）-α-D-Glucan and Chitosan from Penicillium chrysogenum Mycelia

Abstract Ergosterol,（1→3）-α-D-glucan and chitosan are important biomaterials. In this research, a process has been developed to integratively extract ergosterol, （1→3）-α-D-glucan, and chitosan from Penicillium chrysongenum mycelium. First the mycelia are pretreated with 0.1mol·L^-1 of NaOH. After recovery by centrifugation the solid portion is made to undergo saponification and deacetylation reactaons by addition of 2mol·L^-1 NaOH and et anol.After reaction, extraction is carried out by addition of petroleum ether, which separates the reaction mixture into two phases. The upper layer of petroleum ether contains extracted ergosterol, and the .bottom layer of NaOH solution contains （1→3）-α-DEglucan; the chitosan is on the mycelia residuum. After isolation, the recovery yield of ergosterol is 0.52% of dry mycelium. That of （1→3）-α-D-glucan is about 8.2%; and chitosan is 5.7% with 86% deacetylation. The compositions have been characterized by 1R, HPLC analyses.     

The electroreduction of alkyl iodides and polyiodides: The kinetic model of EC(C)E and ECE-EC(C)E mechanisms with included transfer coefficient variability

The cyclic voltammetry electroreduction of seven alkyl iodides was investigated in 0.3 M TBAP/DMF on glassy carbon electrode. The influence of carbon chain length and the number of iodine atoms in the molecule was examined. The two-electron reductive cleavage with iodine elimination was numerically resolved into one-electron consecutive steps. The mechanism of the process was discussed applying the mathematical EC(C)E and ECE-EC(C)E kinetic models with included transfer coefficient variability for one stage electroreduction of RI and two stage electroreduction of RI₂, respectively. For electroreduction of diiodomethane the discrimination of elementary alpha parameter between two reduction stages was determined.     

原位添加α晶成核剂对高熔体强度聚丙烯性能的影响

采用过氧化苯甲酰(BPO)为引发剂,通过一步反应挤出法将接枝单体苯乙烯(St)和端乙烯基硅油(VS)接枝到等规聚丙烯(i PP)上制备高熔体强度聚丙烯(HMSPP),同时在制备过程中原位添加α晶成核剂S20或NA11,考察了两种不同的α晶成核剂对HMSPP的制备及其结晶性能、力学性能和发泡性能的影响。熔体流动速率和分子量分布的测试结果表明,S20或NA11的原位添加没有影响i PP接枝反应的进行;差示扫描量热研究表明,成核剂的加入可以有效促进HMSPP的成核结晶,消除了HMSPP结晶过程中的双结晶峰现象,但成核剂的加入对HMSPP的力学性能并无显著影响。S20或NA11的加入可以有效调控发泡样品的泡孔尺寸,使得泡孔直径从38μm增大到50μm以上,发泡倍率也分别从25倍增大到36倍和37倍。