锡兰肉桂的杀螨活性及有效成分

室内测定锡兰肉桂提取物对几种害螨的杀螨活性及其作用方式,并在活性跟踪的基础上,通过萃取、柱层析、核磁共振和质谱等方法对其有效成分进行分离及鉴定。结果表明,锡兰肉桂不同部位乙醇提取物均有一定的杀螨活性,其中叶和树皮的提取物活性最高。叶乙醇提取物对朱砂叶螨、皮氏叶螨、比哈小爪螨均有毒杀作用,其24h的LC50值分别为0.885、0.641、1.308g/L;对皮氏叶螨和朱砂叶螨还具有一定的杀卵作用,LC50分别为0.604、1.167g/L。从叶提取物中分离鉴定出活性成分丁香酚和松油烯-4-醇。丁香酚对皮氏叶螨表现出较高的毒杀活性,24h的LC50值为0.243g/L。而松油烯-4-醇则对皮氏叶螨的毒杀作用低于丁香酚,24h的LC50值为0.639g/L。分析认为,丁香酚可能为锡兰肉桂叶中主要的杀螨活性成分之一。     

圆滑番荔枝叶乙醇提取物不同萃取组分对胡椒瘟病菌的抑菌活性测定

采用液-液分配法对圆滑番荔枝叶乙醇提取物进行萃取分离,得到石油醚、三氯甲烷、乙酸乙酯等不同萃取组分。采用生长速率法测定不同萃取组分对胡椒瘟病菌的抑制作用。结果表明：乙酸乙酯萃取组分对胡椒瘟病菌的抑制作用最强,其中20 mg/mL乙酸乙酯萃取组分对胡椒瘟病菌菌丝生长的抑制率达到74.43%,具有较好的抑菌效果。     

茜草不同极性提取物的体外抑菌活性研究

本文采用k-b纸片法研究了茜草不同极性溶剂提取物的抑菌作用,结果表明,石油醚提取物浓度为50mg／ml时,抑菌率为25．03％;乙酸乙酯层提取物浓度为50mg／mL时抑制率最高,为48．64％;丙酮层提取物浓度为50mg／mL时抑制率最高,为61．59％;甲醇层提取物浓度为50mg／mL时抑制率最高,为46．09％。     

12种热带植物粗提物对胡椒瘟病的抑菌活性测定

用生长速率法测试了12种热带植物乙醇粗提物对胡椒瘟病菌的离体抑菌活性。结果表明，当供试质量浓度为干样10 mg/mL时，鹰爪和马缨丹粗提物对胡椒瘟病菌菌丝生长的抑菌率均达到90%以上，分别为91.95%和94.32%。可见这两种植物粗提物对供试病原菌菌丝生长具有明显的抑制作用，值得进一步研究开发。     

仙人掌不同提取物的抑菌效果

用抑菌圈方法,研究了仙人掌(Opuntia dillenii Haw)的各种提取物对革兰氏阴性菌、阳性菌和真菌的抑制作用.结果表明,仙人掌的乙醇和水提取物对不同种类的病原菌具有不同的抑菌活性,以对枯草芽孢杆菌、乙型溶血性链球菌、甲型溶血性链球菌、肺炎链球菌、金色葡萄球菌等革兰氏阳性菌的抑制作用最显著,对大肠杆菌等革兰氏阴性菌的效果相对稍差,而对黑根霉、黑曲霉等真菌的效果则很小.另外,不同处理方式、不同部位所得到的仙人掌提取物,其抑菌效果也不同,以从花的干粉中得到的水提取物的效果最好,其抑菌谱广,抑菌效果也最明显.     

黄麻韧皮纤维石油醚提取物的化学成分及抑菌分析

为充分利用黄麻资源,试验以黄麻韧皮纤维为原料,采用石油醚加热回流法提取,对提取物分别采用GC-MS法、纸片扩散法进行化学成分及抑菌分析。通过气相色谱—质谱法(GC-MS)分析鉴定出56种化合物,包括开链烃类22种、闭链烃类4种、卤代烃类5种、醇类7种、醛类1种、酚类2种、醚类2种、酮类1种、酸类3种、杂环类3种、酯类6种,其总相对含量分别为60.98%、2.65%、2.62%、22.33%、0.42%、1.35%、1.17%、0.35%、0.59%、2.70%、4.09%。采用纸片扩散法测定出提取物对金黄色葡萄球菌、大肠杆菌均能产生明显的抑制作用,对白色念珠菌抑制作用不明显。结果表明,石油醚可提取黄麻韧皮纤维中的γ-谷甾醇、白藜芦醇、羽扇豆醇、豆甾醇、25-羟基胆固醇、丙丁酚等多种有效药理活性物质,拓展了功能纤维利用价值。     

鹅掌柴提取物的抗氧化活性

从清除超氧阴离子自由基(O-2)、还原力、清除DPPH自由基、清除羟基自由基(·OH)等方面,研究鹅掌柴提取物的抗氧化活性.结果表明:鹅掌柴提取物对DPPH自由基和羟基自由基的清除能力较强,清除率分别为78.57%和74.99%,对脂质体过氧化的的抑制率为21.41%;与VE、VC、BHT相比,鹅掌柴提取物的还原能力和对Fe2+的络合能力也较强;但对超氧阴离子自由基的清除能力较弱.因此.鹅掌柴提取物是一种抗氧化功效较强的活性物质,具有很好的保健功能.     

28种杀菌剂对大麦条纹病菌活性的室内测定

为了筛选防治大麦条纹病的新药剂,采用平皿法在室内测定了28种杀菌剂对大麦条纹病菌禾内齐蠕孢(Drechslera graminea)菌丝生长的抑制活性。结果表明,供试药剂对大麦条纹病菌的菌丝生长均有不同程度的抑制活性,其中95.3%戊唑醇TC、97.37%咪鲜胺TC、95%吡唑醚菌酯TC、98%二硫氰基甲烷TC、93%氟硅唑TC、99.4%咯菌腈TC、96.8%嘧霉胺TC、98%丙硫唑TC和84.39%啶酰菌胺TC显示有较高的抑菌活性,其抑制菌丝生长的EC50值分别为0.0019、0.0016、0.0254、0.0390、0.0057、0.0012、0.0788、0.1211、0.0773 mg/L。     

不同年份茯砖茶水提取物的抑菌效果研究

选用1996、2002及2009年生产的茯砖茶水提取物分别测定其对大肠杆菌（Escherichiacoli）、沙门氏杆菌（Salmonella）、溶血性链球菌（Streptoeoccthehemolytcus）、金黄色葡萄球菌（Staphylococcusaureus）、枯草芽孢杆菌（BacillusSllbtilis）、志贺氏杆菌（Shigella）不同供试细菌的抑制效果,结果显示均有一定的抑制作用。2009及2002年生产的茯砖茶水提取物对志贺氏杆菌的抑菌效果最好,抑菌圈直径分别达到20．40mm±0．87mm及18．10mm±0．91mm;1996年生产的茯砖茶水提取物仅对沙门氏菌和大肠杆菌有抑制作用,但效果不太明显。最低抑菌浓度的测定结果显示,2009年生产的茯砖茶的抑菌效果最好,1996年生产的茯砖茶的抑菌效果最差。茯砖茶的保存时间越长,其抑菌效果越差。     

海南薇甘菊调查监测及其风险评估

通过对海南省主要农田、森林、自然保护区等生境及重要港口、旅游区的调查监测,掌握了薇甘菊在海南省的最新分布、危害现状与发生规律,并对其入侵风险进行了评估。结果表明,薇甘菊在海南省海口、文昌、临高、澄迈、五指山、琼海、定安、昌江、东方和屯昌10个市县、约40个乡镇均有发生,面积约1 105.3 hm2。薇甘菊的入侵风险评估值R达2.3,具有高度的入侵风险。薇甘菊已经入侵到海南的橡胶园、香蕉园、甘蔗园和生态林地中,对农业、林业、畜牧业等生产造成了不同程度的危害,对海南的生物多样性和生态环境产生了严重的潜在威胁,必须采取措施对其严格监测和防控。     

香蕉枯萎病菌esyn1基因的克隆与序列分析

采用RT-PCR方法扩增了香蕉枯萎病菌恩镰孢菌素合成酶基因esyn1的cDNA片段,测序结果表明,esyn1基因核苷酸序列阅读框架全长546 bp。核苷酸序列分析显示该基因片段编码181个氨基酸,推测分子量为19.9 ku,等电点为5.06。氨基酸序列比对结果表明,它与半裸镰刀菌、层出镰刀菌、拟枝孢镰刀菌esyn1基因的氨基酸序列的相似性分别为96%、94%、77%。     

孔雀草试管苗叶片AP1基因的克隆及其生物信息学分析

以孔雀草试管苗叶片为材料,成功克隆了孔雀草AP1基因的cDNA全长,并对其进行了生物信息学分析。AP1基因全长919 bp(GenBank登录号为JX310277),其中5′-UTR 92bp、3′-UTR 149bp、3′端poly(A)尾巴25 bp,开放阅读框为678 bp,编码225个氨基酸。AP1-1可能存在于细胞核中,为亲水蛋白,不含信号肽,共形成4个卷曲螺旋结构;二级结构主要有α螺旋和无规则卷曲构成,存在亮氨酸拉链结构和1个MADS-box区。此蛋白可能发生磷酸化位点的位置有7个。从系统进化树分析表明,该蛋白与甘菊具有较高的亲缘关系。     

New Hippolide Derivatives with Protein Tyrosine Phosphatase 1B Inhibitory Activity from the Marine Sponge Hippospongia lachne

Five new sesterterpenoids, compounds 1–5, have been isolated from the sponge Hippospongia lachne off Yongxing Island in the South China Sea. The structures of compounds 1–5 were elucidated through extensive spectroscopic analysis, including HRMS, 1D, and 2D NMR experiments. The stereochemistry, including absolute configurations of these compounds, was determined by spectroscopic, chemical, and computational methods. Compounds 1 and 5 showed moderate protein tyrosine phosphatase 1B (PTP1B) inhibitory activities with IC₅₀ values of 5.2 μM and 8.7 μM, respectively, more potent than previously reported hippolides.     

优化提取裸花紫珠总黄酮含量及对表皮伤口易感染菌抑菌性的研究

为了选出裸花紫珠总黄酮提取的最优方法,比较了ASE、超声、微波萃取和多功能浓缩4种提取方法在裸花紫珠总黄酮提取率上的差异,并利用微孔刃天青法测定总黄酮对表皮易感染菌的MIC值。结果发现ASE法总黄酮提取率最高,约为1.26%,其次为超声和微波萃取法,总黄酮提取率分别约为1.03%和0.98%,多功能浓缩法提取率最低,约为0.36%,且耗时最长。而且研究发现,ASE的MIC值最低。最终得出ASE提取效率最高,且提取物有较好的抑菌性,是裸花紫珠总黄酮提取的最优方法。     

PTP1B Inhibitory and Anti-Inflammatory Effects of Secondary Metabolites Isolated from the Marine-Derived Fungus Penicillium sp. JF-55

Protein tyrosine phosphatase 1B (PTP1B) plays a major role in the negative regulation of insulin signaling, and is thus considered as an attractive therapeutic target for the treatment of diabetes. Bioassay-guided investigation of the methylethylketone extract of marine-derived fungus Penicillium sp. JF-55 cultures afforded a new PTP1B inhibitory styrylpyrone-type metabolite named penstyrylpyrone (1), and two known metabolites, anhydrofulvic acid (2) and citromycetin (3). Compounds 1 and 2 inhibited PTP1B activity in a dose-dependent manner, and kinetic analyses of PTP1B inhibition suggested that these compounds inhibited PTP1B activity in a competitive manner. In an effort to gain more biological potential of the isolated compounds, the anti-inflammatory effects of compounds 1–3 were also evaluated. Among the tested compounds, only compound 1 inhibited the production of NO and PGE₂, due to the inhibition of the expression of iNOS and COX-2. Penstyrylpyrone (1) also reduced TNF-α and IL-1β production, and these anti-inflammatory effects were shown to be correlated with the suppression of the phosphorylation and degradation of IκB-α, NF-κB nuclear translocation, and NF-κB DNA binding activity. In addition, using inhibitor tin protoporphyrin (SnPP), an inhibitor of HO-1, it was verified that the inhibitory effects of penstyrylpyrone (1) on the pro-inflammatory mediators and NF-κB DNA binding activity were associated with the HO-1 expression. Therefore, these results suggest that penstyrylpyrone (1) suppresses PTP1B activity, as well as the production of pro-inflammatory mediators via NF-κB pathway, through expression of anti-inflammatory HO-1.     

Mechanisms Leading to Excess Alpha -Amylase Activity in Wheat (Triticum aestivum, L) Grain in the U.K.

The frequency and mechanisms of four modes of alpha -amylase enzyme accumulation in U.K. wheat, retained pericarp alpha -amylase activity (RPAA), pre-maturity alpha -amylase activity (PMAA), pre-maturity sprouting (PrMS) and post-maturity sprouting (PoMS), were investigated in field and laboratory experiments. Of 56 cultivar site year combinations (four model cultivars grown at up to four sites from 1994–1997), enzyme activity was detected in 32 cases, in 23 cases sufficient to reduce Hagberg falling number (the usual industry measure of alpha -amylase) below the commercial criterion (250 s). The frequency of occurrence of different modes of enzyme accumulation was in the order PoMS>PMAA>PrMS>RPAA. Both PMAA and PrMS were more common than expected and the most usual pattern was for alpha -amylase to accumulate by several modes. Although green grains are rejected as impurities, study of grain colour in relation to pericarp alpha -amylase activity showed that the enzyme could persist in non-green grains in levels sufficient to affect the Hagberg value. Two factors thought to promote PMAA, grain drying rate and transient changes in temperature in early development, were studied in the field and controlled environment cabinets. No significant difference was found in grain drying rate between samples where PMAA was or was not identified. However, out of 19 transfers from a cool (16/10 °C) to a warm (26/20 °C) temperature regime, six led to significant increases in PMAA. No transfers after 45% grain moisture increased PMAA. PrMS occurred as early as 67% grain moisture and susceptibility usually increased with stage of development, being greatest in the grain dough stage. PrMS susceptibility varied with cultivar (in the same order as PoMS sensitivity) and was affected by environmental factors.     

人工改造基因Cry1Abm的合成、原核表达及其抗虫鉴定

根据植物密码子的偏好性及使用频率,对苏云金芽孢杆菌Cry1Ab野生型基因的编码区序列进行优化和改造,改造后的Cry1Abm基因序列与原始序列同源性为66.2%,G+C含量由37.3%提高到62.7%。人工合成Cry1Abm基因,并将人工合成的改造后的Cry1Abm基因构建到原核表达载体pET28b中,构建原核表达载体pETAbm。将原核表达载体转入大肠杆菌BL21（DE3）中进行诱导表达,用诱导表达的蛋白进行饲虫（玉米螟）实验。结果表明,该蛋白对幼虫具有很强毒性,幼虫的死亡率高达86.63%,同时,存活幼虫的生长发育也受到明显抑制。该基因可以作为杀虫工程及培育转基因抗虫作物的候选基因。     

Effect of the 1BL.1RS translocation and of the Glu-B3 variation on fifteen quality tests in a doubled haploid population of wheat (Triticum aestivum L.)

To investigate the impact of 1BL.1RS translocation on protein content, starch quality, dough rheology, RMT volumes and other quality traits, a doubled haploid population was created and sown in a two-year field experiment. Translocated genotypes accumulated more proteins in the endosperm than non-translocated genotypes. Decrease in the gelatinization of starch was associated with the 1BL.1RS translocation. As for rheological parameters, adapted to bread types not requiring high mixing energy, the 1BL.1RS translocation significantly reduced the elasticity, tenacity and strength of the dough compared to allele c of Glu-B3. Tolerance to over-mixing was also significantly lower in translocated DH lines. In contrast to previously published work, the presence of allele Glu-D3 c resulted in significantly higher tenacity, and thus strength, compared with the allele Glu-D3 b in the present DH population. The final baking test performed on the DH lines of the population, combining favourable alleles for dough rheology and high protein content, demonstrated that in some cases lower tenacity induced by the 1BL.1RS translocation or by Glu-B3 b increases the volume of the loaves.