羊毛生物酶联合防毡缩整理

针对传统的氯化法羊毛防毡缩技术对环境污染严重,单一蛋白酶防毡缩整理技术效果不理想,一浴两步酶处理法工艺流程长、强力损伤大等问题,采用蛋白酶与生物酶活化剂联合组成的混合溶液协同对羊毛进行一浴一步浸轧处理,实现羊毛的生态快速无氯防毡缩整理。选用三羧基乙基膦分别与蛋白酶8.0T、蛋白酶2.5L、蛋白酶16L组成的混合溶液对羊毛纤维进行处理,测试处理后羊毛的断裂强力、断裂伸长、毡缩球密度,借助扫描电子显微镜观察分析处理后羊毛鳞片层的形貌。结果表明,三羧基乙基膦分别与3种蛋白酶联合处理羊毛的防毡缩效果均显著,且蛋白酶16L的防毡缩效果为最佳。通过正交试验优化得出最佳工艺条件:蛋白酶16L质量浓度为1.8 g/L,三羧基乙基膦质量浓度为1.0g/L,处理温度为50℃,处理时间为2 min。

Antioxidant enzyme activities in different genders and tissues of amphioxus Branchiostoma belcheri tsingtauense

Information regarding antioxidant enzymes in amphioxus remains lacking, and this study was carried out to examine the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in different genders and tissues of amphioxus Branchiostoma belcheri tsingtauense. Results show that (1) CuZn-SOD, CAT and GPX activities in the whole amphioxus B. belcheri tsing- tauense were basically at the same levels in male and female amphioxus, whereas both T-SOD and Mn-SOD activities in male amphioxus were significantly higher than that in the female (P<0.05); (2) The testis had significantly higher T-SOD and CuZn-SOD activities than the ovary (P<0.05); (3) CuZn-SOD activity was undetectable in the guts of male and female amphioxus; (4) For both male and female am- phioxus, the activities of CAT and GPX in the gonads including testis and ovary were the lowest (P<0.05) among the tissues examined; (5) The gut and gill had the same level GPX activities while the gut had a higher CAT activity; (6) There was no clear difference in CAT and GPX activities in the corresponding tissues between male and female amphioxus. The study on SOD, CAT and GPX activities in different genders and tissues of the protochordate provides data for future comparison of amphioxus antioxidant enzymes with those of invertebrates and vertebrates.

Biocatalytic desymmetrization of 3-substituted glutaronitriles by nitrilases. A convenient chemoenzymatic access to optically active (S)-Pregabalin and (R)-Baclofen

Desymmetrization of prochiral 3-substituted glutaronitriles offers a new approach to access （S）-Pregabalin and （R）-Baclofen. A number of nitrilases from diverse sources were screened with 3-isobutylglutaronitriles （1a） or 3-（4＇-chlorophenyl）glutaronitriles （1b） as the substrate. Some nitrilases were found to catalyze the desymmetric hydrolysis of la and lb to form optically active 3-（cyanomethyl）-5-methylhexanoic acid （2a） and 3-（4＇-chlorophenyl）-4-cyanobutanoic acid （2b） with high enantiomeric excesse （ee）, respectively. This cannot be achieved using traditional chemical hydrolysis. Among them, AtNIT3 generated （R）-2b whereas BjNIT6402 and HsN1T produced the opposite （S）-enantiomer with high conversions and ee values. Not only the nitrilases showed different activities and stereoselectivities toward these 3-substituted glutaronitriles, the 3-substitueut of the substrates also exerted great effect on the enzyme activity and stereoselectivity. （S）-2a and （S）-2b were prepared with high yields and ee values using BjNIT6402 and HsNIT as the biocatalysts, respectively. A straightforward Curtius rearrangement of （S）-2a and （S）-2b, followed by the acidic hydrolysis, afforded （S）-Pregabalin and （R）-Baclofen. This offers a new platform methodology for the synthesis of optically active β-substituted T-amino acids of pharmaceutical importance.

Hemin-histamine-montmorillonite clay conjugate as a model biocatalyst to mimic natural peroxidase

We successfully synthesized the first hemin-montmorillonite bio-conjugate with an amino acid residue to mimic natural peroxidase enzyme. Histamine was intercalated in montmorillonite by cation exchange, then a heroin molecule was loaded onto the histamine-montmorillonite with an adsorption capacity of 7.0 mg· g^-1. The hemin-histamine-montmorillonite conjugate shows high peroxidase activity as indicated by the oxidation of guaiacol, which is attributed to the activation of hemin by Fe-N complex formation between the imidazole group in histamine and the iron ion in the hemin molecule. Temperaturedependent peroxidase activity for this synthesized biomimetic material indicates that raising the reaction temperature could significantly enhance the activity of the conjugate. The biomimetic catalyst has good reusability; nearly 100% activity can be retained after three cycles. Because montmorillonite clay is widely distributed in the environment, this material offers great potential for in situ and ex situ remediation of many organic contaminants in surface/subsurface soils.

New antiglycation and enzyme inhibitors from Parmotrema cooperi

Lichens are unique individuals which have been widely used in traditional medicines. This study was focused on the bioassayguided phytochemical investigation, and bioactivity evaluation on a lichens species, Parmotrema cooperi. This first bioassaydirected chemical study on P. cooperi has led to the isolation of ethyl heamatomate （1）, atraric acid （2）, ethyl orsellinate （3）, orsellinic acid （4）, lecanoric acid （5）, gyrophoric acid （6）, and licanorin （7）. The structures of 1-7 were mainly elucidated from spectroscopic methods including 1D, and 2D NMR spectroscopy, and mass spectrometry. These compounds were evaluated for their antiglycation, urease, a-chymotrypsin, and β-glucoronidase inhibitory activities. Few of the phenolic compounds showed significant, while most of them showed good inhibition of protein glycation, and urease activities.