Inhibitory effects of chlorogenic acids from green coffee beans and cinnamate derivatives on the activity of porcine pancreas α-amylase isozyme I

Nine kinds of chlorogenic acids (CGAs) account for 80% of the total CGA content in green coffee beans. They consist of three subgroups of caffeoylquinic acids (CQAs), feruloylquinic acids (FQAs), and dicaffeoylquinic acids (diCQAs). We previously reported the inhibitory effects of 5-CQA on porcine pancreas α-amylase (PPA) isozymes, PPA-I and PPA-II. In this paper, we investigated the PPA-I inhibition by eight kinds of CGAs. The IC₅₀ values of CQAs, FQAs, and diCQAs against the PPA-I-catalysed hydrolysis of p-nitrophenyl-α-D-maltoside were 0.08–0.23 mM, 1.09–2.55 mM, and 0.02–0.03 mM, respectively. All CQAs and FQAs and 3,5-diCQA showed mixed-type inhibition with binding to the enzyme–substrate complex (ES) being stronger than to the enzyme (E). 3,4-DiCQA and 4,5-diCQA showed mixed-type inhibition, but, conversely are suggested to bind to E stronger than ES.     

朱黄青霉α-1,6-葡聚糖酶在毕赤酵母中的分泌表达

α-1,6-葡聚糖酶是专一作用于α-1,6糖苷键产生小分子葡聚糖的一类水解酶,广泛的运用于制糖工业和啤酒工业中。采用PCR法扩增朱黄青霉（Penicillium minioluteum）C12114的α-1,6-葡聚糖酶基因,将其插入毕赤酵母表达载体pPIC9K。经SacI酶线性化电击转入毕赤酵母基因组,构建重组酵母GS115/pPIC9K-dex。对构建成功的转化子进行1.5%的甲醇诱导表达,在30℃条件下培养7d时酶活达到最大值,为88.35U/mL。     

α-亚麻酸的分离与纯化技术研究进展

α-亚麻酸作为一种对人体健康起着重要作用的多不饱和脂肪酸,具有其特殊的理化性质和独特的生理功能,分离纯化技术是α-亚麻酸工业化生产的关键技术之一.本文对目前采用的α-亚麻酸的主要分离与纯化技术进行了综述,分析了各自的优缺点,并对其未来的发展趋势进行了展望.     

Formulation and characterization of α-tocopherol loaded poly ?-caprolactone (PCL) nanoparticles

α-tocopherol-loaded poly ?-caprolactone (PCL) nanoparticles were prepared by emulsion solvent evaporation with ultrasonification technique. The influences of PCL concentration (3 and 5 g/100 mL), solvent in the oil phase (methylene chloride (DCM) and methylene chloride: acetonitrile = 50:50 (DCM:ACN)), and ultrasonification time (1, 2, and 3 min) were investigated. Encapsulation efficiency (%) was calculated by Duncan’s multiple rage tests and it decreased from 87.73 to 57.45 when ultrasonification time was increased from 1 to 3 min. DCM as a solvent in the oil phase and 5 g/100 mL PCL showed better encapsulation efficiency than DCM:ACN and 3 g/100 mL PCL. Particle mean size was decreased when ultrasonification time was increased from 1 to 3 min. Nanoparticles with DCM as a solvent in the oil phase had larger particle mean size than the particle with DCM:ACN. There were no significant differences in particle mean size between two PCL concentrations. PCL with 3 g/100 mL concentration had higher α-tocopherol loading (%) than 5 g/100 mL PCL. Overall, 5 g/100 mL PCL in DCM as solvent in the oil phase with 3 min ultrasonification time showed the best encapsulation formulation.     

Anti-inflammatory effects and chemical study of a flavonoid-enriched fraction from adlay bran

Anti-inflammation-guided fractionation and purification were used to evaluate the bioactivity and components of adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) bran. Results showed that the fraction with high phenolic and flavonoid contents from the ethanol extracts of adlay bran suppressed LPS-stimulated IL-6 and TNF-α secretions in a concentration-dependent manner in RAW 264.7 cells and murine peritoneal macrophages. Fifteen compounds, including a novel aurone derivative, two chromones, one dihydrochalcone, one chalcone, four flavanones, five flavones and one isoflavone, were isolated from the active fraction. The structure of the new compound was elucidated by spectroscopic methods, including 1D and 2D NMR and MS. All of the isolates are reported for the first time from adlay except naringenin. LC/MS was also provided as an analytical platform. Our results suggest that flavonoids in adlay bran, partially at least, contribute to its anti-inflammatory effect. Thus, adlay bran may be beneficial to the health of consumers.     

Evaluation of bioactive compounds and bioactivities of soybean dried by different methods and conditions

Soybean has attracted significant research and commercial interests due to its many health-promoting bioactive compounds, especially isoflavones (β-glucosides, malonyl-β-glucosides, acetyl-β-glucosides and aglycones). Isoflavones possess antioxidant activity and α-glucosidase inhibitory activity, which has proved effective in the treatment of type 2 diabetes mellitus. Prior to its use, however, soybean needs to be dried to extend its storage life and to prepare the material for subsequent food or pharmaceutical processing. The present study investigated the effects of drying methods and conditions on the drying characteristics, isoflavones, antioxidant activity and α -glucosidase inhibitory activity of dried soybean. Hot-air fluidized bed drying (HAFBD), superheated-steam fluidized bed drying (SSFBD) and gas-fired infrared combined with hot air vibrating drying (GFIR-HAVD) were carried out at various drying temperatures (50, 70, 130 and150 °C). The results showed that higher drying temperatures led to higher drying rates and higher levels of β-glucosides and antioxidant activity, but to lower levels of malonyl-β-glucosides, acetyl-β-glucosides and total isoflavones. At the same drying temperature GFIR-HAVD resulted in the highest drying rates and the highest levels of β-glucosides, aglycones and total isoflavones, antioxidant activity as well as α-glucosidase inhibitory activity of dried soybean. A drying temperature of 130 °C gave the highest levels of aglycones and α-glucosidase inhibitory activity in all cases. The relationships between all the studied parameters were monitored and simple correlations between them were determined.     

蓝色发光材料9,10-二(α-萘基)蒽的合成

以二-二苯基膦二茂铁二氯化钯(PdCl2(dppf))为催化剂,9,10-二溴蒽和α-萘硼酸为原料,采用Suzuki偶联法合成蓝色发光材料9,10-二(α-萘基)蒽。考察了反应条件,如催化剂用量、溶剂、碱、反应温度、α-萘硼酸与9,10-二溴蒽比率等对反应收率的影响,得出最佳的反应条件是:甲苯/乙醇/水体系(体积比6/1/2);α-萘硼酸与9,10-二溴蒽的物质的量比为3;催化剂量占卤代芳烃的0.5mol%;以碳酸钾为碱,反应7h,收率达到98%,结果远远好于常用的四-三苯基膦钯(Pd(PPh3)4)催化剂。产品经重结晶纯化后,纯度达99%以上,可直接用于OLED器件。     

3-和4-氧代-紫罗兰醇糖苷的合成研究进展

3-和4-氧代紫罗兰醇糖苷是一种糖苷类香料前体,用经典的Koenigs-Knorr法,溴代乙酰糖分别与3-氧代-α-紫罗兰醇和4-氧代-β-紫罗兰醇反应可得到3-氧代-α-紫罗兰醇糖苷和4-氧代-β-紫罗兰醇糖苷。详细地说明了3-氧代-α-紫罗兰醇和4-氧代-β-紫罗兰醇的各种合成方法,综述了香料前体3-氧代-α-紫罗兰醇糖苷和4-氧代-β-紫罗兰醇糖苷的合成研究进展。     

帕金森病相关蛋白α-Synuclein翻译后修饰的研究

帕金森病是中老年常见的神经退行性疾病,以黑质多巴胺能神经元变性缺失和路易小体形成为特征。α-Synuclein是路易小体的主要组成成分,由于它在介导帕金森病的神经毒性方面发挥很大的作用,而越来越引起人们的关注。帕金森病相关蛋白α-Synuclein存在多种翻译后修饰,可能促使路易小体形成,从而参与帕金森病的发生和发展。本文在研究α-Synuclein蛋白的磷酸化、硝基化和泛素化与帕金森病的关系的基础上进行了总结。     

面向敏感值的个性化隐私保护

 现有隐私保护匿名模型不能实现敏感值的个性化保护,为此,论文提出完全(α,k)匿名模型,该模型通过设置等价类中敏感值的出现频率来实现敏感值的个性化保护. 论文还提出(α,k)聚类算法来实现各种(α,k)匿名模型. 实验表明：完全(α,k)匿名模型能够以与其它(α,k)匿名模型近似的信息损失量和时间代价,获得更好的隐私保护.