The Ethanol Extract of Syringa oblata Heartwood,a Mongolian Folk Medicine Containing Major Lignans,Exerts Analgesic and Sedative Effects on Mice

The heartwood of Syringa oblata Lindl. (SO) is one of Mongolian folk medicines to treat insomnia and pain, while its pharmacological evaluation and underlying mechanism remain unclear. In this study, the sedative effect of ethanol extract of SO (ESO) was evaluated with the locomotor activity test and the threshold dose of pentobarbital sodium-induced sleep test in mice, and the hot plate test, acetic acid-induced writhing test, and formalin test in mice were used to evaluate its analgesic effect. The underlying mechanism of ESO analgesia was explored by RT-PCR and western blot analysis, which is associated with the regulation of the NF-κB signaling pathway. Besides, the main constituents of ESO were characterized by LC/MS data analysis and comparison with isolated pure compounds. The current findings brought evidence for clinical application and further pharmacological and phytochemical studies on SO.     

TAI系列Ⅱ天兰冰草染色体上的酯酶同工酶基因定位

本文分析了小冰麦异附加系列Ⅱ,八倍体小冰麦,普通小麦和天兰冰草的叶片酯酶（ESTL）,胚乳酯酶（ESTE）,根酯酶（ESTR）和胚芽鞘酯酶（ESTG）的酶谱表型。把冰草同工酶基因Estl-Ag1,Este-Agi1,Estr-Agij,Estc-Agi1,Estl-Agi2和Este-Agi2定位到异附加系TAI－23,把基因Estr-Agi4和Estc-Agi4定位到TAI－24中的冰草染色体上,根据这些基因定位,结合某些植株形态学特征,推测TAI－23和TAI－24中的冰草染色体分别与小麦第3和6同祖群有一定的部分同源关系。     

Picroside III,an Active Ingredient of Picrorhiza scrophulariiflora,Ameliorates Experimental Colitis by Protecting Intestinal Barrier Integrity

This study aims to explore the protective effects of Picroside III, an active ingredient of Picrorhiza scrophulariiflora, on the intestinal epithelial barrier in tumor necrosis factor-α (TNF-α) induced Caco-2 cells and dextran sulfate sodium (DSS) induced colitis in mice. Results show that Picroside III significantly alleviated clinical signs of colitis including body weight loss, disease activity index increase, colon shortening, and colon tissue damage. It also increased claudin-3, ZO-1 and occludin expressions and decreased claudin-2 expression in the colon tissues of mice with colitis. In vitro, Picroside III also significantly promoted wound healing, decreased the permeability of cell monolayer, upregulated the expressions of claudin-3, ZO-1 and occludin and downregulated the expression of claudin-2 in TNF-α treated Caco-2 cells. Mechanism studies show that Picroside III significantly promoted AMP-activated protein kinase (AMPK) phosphorylation in vitro and in vivo, and blockade with AMPK could significantly attenuate the upregulation of Picroside III in ZO-1 and occludin expressions and the downregulation of claudin-2 expression in TNF-α treated Caco-2 cells. In conclusion, this study demonstrates that Picroside III attenuated DSS-induced colitis by promoting colonic mucosal wound healing and epithelial barrier function recovery via the activation of AMPK.     

中国东北地区三种蜜环菌的生物学特性及奥氏蜜环菌人工培养

蜜环菌属Armillaria真菌具有较高的食药用价值。由于蜜环菌的生长发育过程较复杂,还未完全实现商业化栽培,野生资源的供应受到季节性和地域性的影响。本研究以采自东北地区蜜环菌属的3个菌株为研究对象,通过培养物的形态特征及分子标记确定菌株JG19016为奥氏蜜环菌A. ostoyae,菌株JG19017为高卢蜜环菌A. gallica,菌株JG19018为中国蜜环菌生物种C。奥氏蜜环菌JG19016最适生长温度为25 ℃,高卢蜜环菌JG19017的最适生长温度为22 ℃,中国蜜环菌生物种C JG19018则在22-25 ℃时菌丝生长速度最快;3个菌株最适pH为5-6。奥氏蜜环菌JG19016对葡萄糖和蔗糖利用率较好,高卢蜜环菌JG19017对葡萄糖利用率较好,中国蜜环菌生物种C JG19018对葡萄糖和淀粉利用率较好;蛋白胨对3个菌株促进作用最强,为最适氮源。培养基中加入VB₁,对3个菌株的菌丝生长均有明显的促进作用。奥氏蜜环菌JG19016菌丝生长的最优培养基配方为：葡萄糖20 g,蛋白胨3 g,磷酸二氢钾2 g,硫酸镁1.5 g,VB₁ 10 mg,琼脂20 g,水1 L。在木屑基质中培养,其配方的最优碳氮比为38:1,最佳木屑粗细比为3:1以上。出菇条件探索结果显示,菌丝及菌索长满菌袋(17 mm×33 mm×5 mm丝聚乙烯袋)需要50-60 d,之后在18 ℃、60%湿度和12 h散射光的环境中,10 d左右可观察到原基产生。增加菇房湿度到90%-95%,2-3 d可观察到1-3 cm的幼子实体,7 d左右菌柄和菌盖完全分化,10 d左右观察到菌盖展开。     

A short-chain carbonyl reductase mutant is an efficient catalyst in the production of (R)-1,3-butanediol

R-1,3-butanediol (R-1,3-BDO) is an important chiral intermediate of penem and carbapenem synthesis. Among the different synthesis methods to obtain pure enantiomer R-1,3-BDO, oxidation–reduction cascades catalysed by enzymes are promising strategies for its production. Dehydrogenases have been used for the reduction step, but the enantio-selectivity is not high enough for further organic synthesis efforts. Here, a short-chain carbonyl reductase (LnRCR) was evaluated for the reduction step and developed via protein engineering. After docking result analysis with the substrate 4-hydroxy-2-butanone (4H2B), residues were selected for virtual mutagenesis, their substrate-binding energies were compared, and four sites were selected for saturation mutagenesis. High-throughput screening helped identify a Ser154Lys mutant which increased the catalytic efficiency by 115% compared to the parent enzyme. Computer-aided simulations indicated that after single residue replacement, movements in two flexible areas (VTDPAF and SVGFANK) facilitated the volumetric compression of the 4H2B-binding pocket. The number of hydrogen bonds between the stabilized 4H2B-binding pocket of the mutant enzyme and substrate was higher (from four to six) than the wild-type enzyme, while the substrate-binding energy was decreased (from −17.0 kJ/mol to −29.1 kJ/mol). Consequently, the catalytic efficiency increased by approximately 115% and enantio-selectivity increased from 95% to 99%. Our findings indicate that compact and stable substrate-binding pockets are critical for enzyme catalysis. Lastly, the utilization of a microbe expressing the Ser154Lys mutant enzyme was proven to be a robust process to conduct the oxidation–reduction cascade at larger scales.     

燕麦-绿豆间作效应及氮素转移特性

为探究燕麦(Avena sativa)-绿豆(Phaseolus radiatus)间作效应及氮素转移特性, 在不施氮肥的大田试验条件下, 设置3种种植模式(燕麦单作、绿豆单作和燕麦-绿豆间作), 采用传统挖根法和¹⁵N同位素标记法进行研究。结果表明, 间作系统中燕麦侵袭力强于绿豆, 绿豆生长受到抑制。整个生育期, 间作燕麦地上部干物质积累量比单作增加14.9%-33.1%, 2年成熟期间作燕麦的氮素积累量比单作分别提高53.1%和44.8%; 间作减少了开花结荚期绿豆氮素积累量和根瘤重量, 降低了绿豆的固氮效率, 绿豆的固氮效率2年平均降低23.7%, 生物固氮量平均减少11.66%。间作绿豆向燕麦的氮素转移率2年平均值达31.7%, 氮素转移量为212.16 kg∙hm^-2。燕麦-绿豆间作降低了开花结荚期绿豆的根瘤固氮酶活性和固氮效率, 但绿豆体内氮素转移增加了燕麦对氮素的吸收利用, 实现了地上部与地下部生长的相互调节和促进, 优化了农田生态系统的氮素管理。     

一例智力低下患者7q~ 标记染色体的来源鉴定

以人类染色体显微切割、PCR技术构建的现有人类染色体特异性和染色体区带特异性探针池作为绘画探针,采用正向染色体绘画技术,结合染色体筛查方法,查明了一例7q~ 标记染色体患者的染色体附加片段来源于3q26→3qter。确定该患者的核型为46,XX,-7, der(7)t(7;3)(7pter→7q32::3q26→3qter)。应用这个策略,能够快速有效地鉴定标记染色体的来源。