Preparation and characterization of microcapsules containing capsaicin

With urea‐formaldehyde (UF) resin as walls and capsaicin as core substances, microcapsules were prepared based on in situ polymerization process. The morphology and size distribution of the microcapsules were analyzed by Fourier transform infrared spectroscopy, laser particle size analyzer, and scanning electron microscopy. The microcapsulated capsaicin (MC) agents had a mean diameter of about 30–50 μm. Moreover, the thermal properties of the MC agents were measured by differential scanning calorimetry and thermogravimetric analysis. It was demonstrated that the melting point and thermal stability of the MC agents were greatly improved compared with that of the uncovered capsaicin, which were caused by the encapsulating crosslinked UF resin over the surface. The shell formation mechanism and the effects of the process conditions such as U/F ratio, shearing force, and acidification time on the particle size of the MC agents were discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

家蝇抗菌肽抑菌活性及其稳定性研究

通过体外抑菌实验,采用纸片扩散法对家蝇抗菌肽的抑菌性进行定性研究。试验用菌有金黄色葡萄球菌、大肠杆菌、绿脓杆菌、白色念珠菌和黑曲霉菌。在对家蝇抗菌肽抗菌谱研究的基础上,进一步用肉汤稀释法（试管法）定量测定其最低抑菌浓度（MIC）,并对其稳定性进行研究。结果表明,家蝇抗菌肽对金黄色葡萄球菌、绿脓杆菌和大肠杆菌3种细菌有较好的抑制作用,而对白色念珠菌和黑曲霉没有明显的抑制作用,对金黄色葡萄球菌、绿脓杆菌和大肠杆菌最低抑菌浓度（MIC）分别为0.156 mg/mL、0.312 5 mg/mL和6.25 mg/mL。另外,对其稳定性进行讨论,结果表明,家蝇抗菌肽的稳定性良好。     

辣椒碱微胶囊的释放动力学研究

测定合成辣椒碱微胶囊在盐水、碱性及酸性三种释放环境下的释放曲线.在三种释放环境下,合成辣椒碱的释放率(ARP)具有显著的差异,盐水环境下的释放率最小.通过零级动力学方程、一级动力学方程、Higuchi模型方程对所得数据进行拟合,结果表明,三种释放环境中合成辣椒碱的释放动力学均适用于一级动力学方程.     

辣椒碱的应用研究进展

介绍了国内外有关辣椒碱在医药、生物农药、涂料、食品添加剂及军事领域的应用研究进展,并预期辣椒碱的新用途会随着科学技术的进步得到不断开发,其应用前景相当广阔。     

獐牙菜苦苷的生物转化研究

利用黑曲霉、米曲霉、康氏木霉、短乳杆菌和大肠杆菌体外转化獐牙菜苦苷.色谱分析结果表明,黑曲霉、米曲霉、康氏木霉能有效地转化獐牙菜苦苷,其中以黑曲霉的转化能力最强,转化率达到36%;短乳杆菌和大肠杆菌没有可见的转化反应.从黑曲霉转化液中分离得到了两个转化产物,分别为红百金花内酯和(Z)-5-Ethylidene-8-hy...     

黑曲霉WB-1固态发酵产单宁酶的研究

对黑曲霉WB-1固态发酵产单宁酶进行了研究。考察了发酵温度、发酵时间、外加碳源对黑曲霉WB-1产单宁酶的影响,同时考察了单宁酶的储存稳定性以及最适反应温度、pH值。结果表明,黑曲霉WB-1产单宁酶的最佳发酵温度和发酵时间分别为28℃和96h,外加碳源有利于单宁酶的产生,且以甘油为外加碳源时效果最好。所产单宁酶的最适反应温度和pH值分别为30℃和6,且具有一定的低温(4℃)储存稳定性。     

苯乙醇微胶囊的稳定性及热释放行为研究

以苯乙醇为囊芯材料,以明胶和羧甲基纤维素(CMC)为壁材,采用复凝聚法制备了苯乙醇微胶囊,其包埋率达到92%。考察了温度和时间对苯乙醇微胶囊热释放行为的影响,以及其在卷烟纸上的贮存稳定性。结果表明,苯乙醇微胶囊可粘附在纸张纤维上,120℃加热10 min时微胶囊基本无变化,能够满足卷烟纸生产工艺要求。180℃加热40 min时微胶囊内部芯材基本挥发完全。在常温下密封保存60 d时苯乙醇保留率仍达到65%,稳定性较好。     

黑曲霉β-葡萄糖苷酶的研究进展

系统介绍了近年来黑曲霉β-葡萄糖苷酶(EC3.2.1.2)的酶解特征、酶学性质、催化机制、活性中心、生物学功能及应用技术等方面的研究进展,并展望了其应用前景。     

13种生物源杀菌剂对华重楼灰霉病的防治

[目的]通过比较13种生物源杀菌剂对华重楼灰霉病的防治效果.为华重楼灰霉病的科学防治提供参考。[方法]在室内条件下基于菌丝生长抑制法测定了重楼灰霉病菌Botrytis cinerea ES1对13种生物源杀菌剂的敏感性,在田间条件下,评价了4种生物源杀菌剂对华重楼灰霉病防治效果[结果]0.3%丁子香酚可溶性液剂、1%蛇床子素水乳剂、3%中生菌素可湿性粉剂和0.5%苦参碱水剂对Botrytis cinerea ES1的菌丝生长有较好的抑制效果,其EC₅₀值均小于100 mg/L,在离体华重楼叶片上,4种药剂对华重楼灰霉病的保护作用在70%左右,田间防效在60%左右[结论]丁子香酚、蛇床子素、中生菌素和苦参碱对华重楼灰霉病菌B.cinerea ES1菌丝生长很好的抑制效果并且在田间对华重楼灰霉病的防治也表现良好,可用于华重楼灰霉病的预防,配合发病后的化学药剂一起使用。     

番茄灰霉病菌(Botrytis cinerea)对3种杀菌剂的抗性监测及交互抗药性研究

采用菌丝生长速率法,测定了采自江苏和河南的158株番茄灰霉病菌对嘧菌酯、啶酰菌胺、啶菌(噁)唑等3种药剂的敏感性,并研究了部分抗性菌株的交互抗性情况.结果显示,供试菌株对嘧菌酯、啶酰菌胺、啶菌(噁)唑的EC50值分别在0.004 5～90.5、0.057 6～36.8、0.016 9～2.64μg/mL,并分别出现了 ...     

番茄灰霉病拮抗链霉菌S89发酵条件的研究

用7号培养基发酵番茄灰霉病拮抗链霉菌S89后的发酵液对番茄灰霉病菌的抑制作用最强,在初始pH值为6、培养温度为28～32℃的培养条件下,培养5 d产生的抗菌物质抑菌活性最强.对7号培养基进一步研究发现,碳源对抗菌物质的产生影响不大,氮源有显著影响,当牛肉膏与蛋白胨为1∶1作为氮源时抑菌作用最强;Mg2 、Mn2 和K 能促进抗菌物质的产生,Fe2 和Na 抑制抗菌物质的产生,Zn2 对抗菌物质的产生没有作用.     

Preparation of thermosensitive microcapsules and application on the controllable drug delivery of ibuprofen

To reduce the side effects of ibuprofen caused by prolonged or overdosed treatment on the human body, a series of thermosensitive poly(N,N′-methylene bisacrylamide-co-N-isopropylacrylamide) microcapsules were synthesized to control the release of ibuprofen by their thermosensitive properties. The release curves exhibited excellent controllable behavior, which turned from burst release to perfect sustained release by changing the ambient temperature from 25°C (<LCST, lower critical solution temperatures) to 37°C (>LCST). In addition, the NIPAm content and the shell thickness can be conveniently controlled during the polymerization processes, which will affect the drug release rate according to the temperature stimuli.     

Functionalization of microcapsules for the removal of heavy metal ions

BACKGROUND: Solvent extraction and ion exchange technologies have been widely used for the recovery or removal of heavy metals from aqueous phases. However, different problems have been encountered on applying these techniques. Although the extractants are highly selective, this technique requires a high level of mechanical agitation to improve the kinetics of the process, a requirement that promotes leakage of the extractant from the aqueous/organic interface to the aqueous phase during separation of the two phases. On the other hand, ion exchangers can easily be regenerated but gel form resins have low selectivity and those with high selectivity (chelating resins) have low diffusion coefficients, a characteristic that leads to low mass transfer rates. An interesting alternative to overcome these limitations is the microencapsulation of extractants within a functionalized polymeric shell. This new type of material would be expected to combine the advantages of the aforementioned methods and improve selective removal of heavy metals from an aqueous phase. RESULTS: Sulfonation of microcapsules indicated that the use of an ethylene glycol dimethacrylate (EGDMA) copolymer enhances the chemical and mechanical properties of the microcapsules. It was found that the recipe used to produce microencapsulated phase change materials (PCM) was also useful to prepare microcapsules with di(2‐ethylhexyl)phosphoric acid (DEHPA) as a core material. The synthesized material had a spherical and smooth shape and a DEHPA content of 28.15 wt%. Finally, the ion exchange capacity of the sulfonated material containing DEHPA (3.02 meq g^?1) was higher than that obtained without this additive (2.54 meq g^?1). High selectivity for copper uptake was also achieved. CONCLUSIONS: Microcapsules containing extractants can be manufactured by the same approach used to produce microcapsules containing PCMs. In addition, particles with improved chemical and mechanical resistance to sulfonation can be synthesized using EGDMA as a crosslinker. Ion exchange studies showed that the presence of DEHPA enhances the ion exchange capacity and selectivity of the microcapsules. Thus this material is a promising alternative for the separation of heavy metal ions. Copyright © 2010 Society of Chemical Industry     

丹皮酚及其席夫碱衍生物的抑菌性研究

以丹皮酚为先导,合成了丹皮酚缩1,3-丙二胺、丹皮酚缩2-羟基-1,3-丙二胺和丹皮酚缩糠胺3种丹皮酚席夫碱衍生物。琼脂扩散抑菌试验表明,丹皮酚及其衍生物对受试4种革兰氏阴性菌、阳性菌皆有明显的抑制作用。     

10%腐霉利烟剂防治番茄灰霉病药效试验

试验了烟剂农药新品种10%腐霉利烟剂对保护地番茄灰霉病的防治效果,结果表明其防效达80.11%~86.73%,使用的适宜剂量为300~450 a.i. g/hm2,持效期为7 d。     

超声辅助皂化提取黑曲霉中辅酶Q_(10)的研究

通过高效液相色谱鉴定证实黑曲霉菌体中含有辅酶Q10。采用正交实验设计法,研究了超声辅助皂化提取黑曲霉中辅酶Q10的最佳工艺条件。实验表明,焦性没食子酸添加量、皂化温度、超声时间为影响皂化提取效果的显著因子。在75%乙醇溶剂下,最佳提取工艺条件为:焦性没食子酸加入量为培养物的8%,皂化温度40℃,皂化时间45 min,醇碱浓度7.5 g NaOH/75 mL乙醇,超声功率280 W。最优条件下辅酶Q10提取率为0.421 mg/g干培养基,明显优于常规皂化提取。     

黑毛茶中产单宁酶真菌的筛选及产酶条件研究

采用富含单宁酸的平板培养基对黑毛茶中产单宁酶的真菌进行筛选,经纯化后初步鉴定该菌为黑曲霉,并对其中一株黑曲霉WC-2产单宁酶的发酵条件以及发酵培养基的组成进行了优化。优化后的条件为:五倍子渣含量80%,外加碳源为α-乳糖、添加量1%,外加氮源为硝酸铵、添加量0.5%,发酵温度37℃,发酵时间72h。在此条件下,单宁酶活力最高达到27.06U·g-1。     

Antioxidant, antimicrobial and antiproliferative activities of five lichen species

The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells.     

Composition and antioxidant and antimicrobial activities of white apricot almond (Amygdalus communis L.) oil

In order to improve the level of comprehensive utilization and to promote the development of functional products, the chemical composition of white apricot almond oil was analyzed by capillary GC‐MS and interpreted based on the standard mass spectral data, and biological activities were evaluated. Seven components of white apricot almond oil were identified. The scavenging capacity of white apricot almond oil in the superoxide anion radical system and hydroxyl radical system had a good performance. The IC₅₀ of white apricot almond oil to superoxide anion radical system and hydroxyl radical were 5.8 µg/mL and 0.17 mg/mL, respectively, and were stronger than that of ascorbic acid. In DPPH system, the IC₅₀ value of white apricot almond oil was 0.2 mg/mL and the IC₅₀ value of ascorbic acid was 0.07 mg/mL, but within the selected dosage, the highest scavenging capacity of white apricot almond oil was higher than that of ascorbic acid. White apricot almond oil was found to be a more effective antimicrobial agent than grape seed oil, fuji apple seed oil and mulberry seed oil. The minimum inhibitory concentration (MIC) of white apricot almond oil ranged from 0.2 to 0.4 mg/mL. The observed biological activities showed that the oil has a good potential for use in the food industry and pharmacy.     

蜜环菌菌索抗氧化作用初步研究

以芦丁为对照,从活性氧自由基清除效果及对DPPH自由基清除能力等方面对云南昭通蜜环菌乙醇提取物的抗氧化活性进行实验研究。结果表明:云南昭通蜜环菌乙醇提取物对光照核黄素自氧化产生的超氧阴离子、Fenton反应产生的羟自由基和DPPH自由基均有一定的清除作用,对DPPH·的清除率最高,而对超氧阴离子的清除能力较低。