黄花蒿提取物的杀虫活性

黄花蒿精油对米象、玉米象、绿豆象和蚕豆象等４种仓库害虫具有很强的熏杀活性,其甲醇和乙醇提取物对小菜蛾、菜青虫、大菜粉蝶、银纹夜蛾和斜纹夜娥幼虫也具有一定的杀虫活性。     

樟树和黄花蒿浸提物对菜粉蝶幼虫的生物活性

研究了樟树和黄花蒿的乙醇、氯仿、石油醚浸提物对菜粉蝶幼虫的拒食作用、触杀作用。结果表明黄花蒿乙醇浸提物和樟树石油醚浸提物的活性较好,48 h拒食率分别为72.11%、57.86%;干物质触杀作用的LC50分别为1.232 g/L、1.275 g/L。     

藜芦乙醇提取物对植物病原真菌的抑菌活性研究

通过测定藜芦的乙醇提取物以及各萃取部分对植物病原真菌的抑菌活性,寻找藜芦中的农用活性物质,为其综合开发利用提供科学依据。采用菌丝生长速率法测定了藜芦球茎和根乙醇提取物对6种植物病原菌的抑制作用。试验结果表明,当供试浓度为5.0 mg/mL时,对苹果腐烂病菌(Valsa mali)、棉花枯萎病菌(Fusarium oxysporum f.sp.vasinfectum)和苹果轮纹病菌(Physalospora piricola nose)的抑菌率比较高,分别为96.4%、78.1%和74.3%。藜芦乙醇提取物的不同极性溶剂萃取物的抑菌活性较高,乙酸乙酯萃取物对苹果腐烂病菌和苹果轮纹病菌的EC50分别为0.161 mg/mL和0.551 mg/mL;正丁醇萃取物对苹果腐烂病菌和苹果轮纹病菌的EC50分别为0.190 mg/mL和0.451 mg/mL。乙酸乙酯萃取物是进一步研究的重点。     

20种植物提取物对植物病原细菌的抑制活性

[方法]以水稻白叶枯病菌(Xanthomonas oryzae pv.oryzae)、桃树细菌性穿孔病菌[Xanthomonus campestrispv.pruni(Smith) Dye.]为供试菌,对20种植物提取液进行抑菌活性筛选;采用液-液萃取法初步分离石榴皮、五倍子的抑菌活性成分.[结果]石榴皮、五倍子对2种病原细菌抑制效果最好;石榴皮的抑菌活性成分主要存在于正丁醇萃取层,五倍子乙酸乙酯萃取物的抑菌活性成分较好.[结论]石榴皮对2种病原细菌的抑制活性最好,其正丁醇萃取物是下一步研究的重点.     

八宝景天叶乙醇提取物的抑真菌活性

[方法]采用菌丝生长速率法研究了八宝景天叶乙醇提取物对9种植物病原真菌的抑制作用,同时采用菌丝生长速率和孢子萌发2种方法测定其对玉米弯孢病菌的抑菌活性。[结果]在质量浓度为200 g/L时,对9种植物病原真菌均有一定的抑制作用,且抑制率均达75%以上,其中对玉米弯孢病菌的抑制作用最强,抑制率为82.27%,对其孢子萌发的抑菌活性高于对其菌丝生长的抑菌活性,EC50值分别为74.18、66.53 g/L。[结论]八宝景天叶有着良好的抑菌效果,具有很好的开发价值。     

9种植物提取物对植物病原真菌的生物活性筛选

以苹果腐烂病菌、小麦赤霉病菌、苹果轮纹病菌、棉花枯萎病菌、柑橘炭疽病菌和黄瓜枯萎病菌为供试菌种。采用菌丝生长速率法测定了9种植物乙醇提取物对6种植物病原真菌的抑制作用,结果表明,浓度为5mg/mL时,荆条花乙醇提取物对6种植物病原真菌均有一定程度的抑制作用,其中对苹果腐烂病菌、棉花枯萎病菌、苹果轮纹病菌和黄瓜枯萎病菌的抑菌率分别为91.07%、72.97%、64.54%和63.20%。采用抑制孢子萌发法测定了9种植物乙醇提取物对2种植物病原真菌的抑制作用,结果表明,浓度为20mg/mL时,雪松叶和仙鹤草叶乙醇提取物对黄瓜枯萎病菌和柑橘炭疽病菌的孢子抑制率为100%。     

箬竹叶提取物对烟草病原真菌的抑制作用

采用菌丝生长速率法和孢子萌发法,对选用无水乙醇、冰乙酸和蒸馏水混合溶剂浸提所得的箬竹叶粗提物以及依次采用石油醚、乙酸乙酯和正丁醇进行液-液萃取所得的萃取物进行了抑菌活性测试。结果表明:箬竹叶粗提物对烟草链格孢菌和烟草疫霉菌菌丝生长均具有抑制活性,其对两种真菌抑制的EC50值分别为3.98mg·mL-1和0.88mg·mL-1、EC90值分别为7.33mg·mL-1和1.73mg·mL-1;对烟草链格孢菌孢子萌发抑制的EC50值和EC90值分别为4.68mg·mL-1和9.09mg·mL-1。2mg·mL-1的石油醚、乙酸乙酯、正丁醇萃取物和萃余水相对烟草链格孢菌菌丝生长的抑制率分别为31.27%、36.18%、6.06%和-7.05%;对烟草疫霉菌菌丝生长的抑制率分别为56.82%、81.53%、12.32%和-18.10%。乙酸乙酯萃取物对烟草链格孢菌和烟草疫霉菌菌丝生长的抑制活性明显高于箬竹叶粗提物,其对两种真菌抑制的EC50值分别为2.99mg·mL-1和0.80mg·mL-1、EC90值分别为5.41mg·mL-1和2.83mg·mL-1。乙酸乙酯萃取物对烟草链格孢菌孢子萌发抑制的EC50值和EC90值分别为1.03mg·mL-1和3.54mg·mL-1。     

大蓟提取物对植物病原真菌的抑菌活性成分研究

[目的]大蓟有广泛的生物活性,具有生物农药的开发潜力。确定其中抗植物病原菌的主要活性成分,以期为其在农药领域的开发利用提供依据。[方法]通过溶剂提取法提取,用生长速率法测定提取物对5种植物病原真菌的抑菌活性,并用柱层析法分离活性物质。[结果]在质量浓度50 g/L时石油醚提取物对石榴枯萎病菌的抑菌活性最高,抑制率达100%,EC50值为5.1 g/L;从中分离出一个三萜类单体化合物,经鉴定为3β,21β-dihydroxyl-20(30)-en-taraxastane。[结论]大蓟对植物病原真菌有良好的抑菌活性,所分离到的单体化合物为大蓟中的主要抑菌活性成分。     

荆条乙醇提取物对植物病原真菌的抑菌活性初步研究

探索荆条的抑菌活性,为综合开发利用提供科学依据。采用生长速率法测定了荆条花和叶的乙醇提取物以及各萃取物对植物病原真菌的抑制作用。结果表明:荆条花乙醇提取物的抑菌活性好于叶。当供试质量浓度为5.0 g/L时,花的乙醇提取物对苹果腐烂病菌、白菜黑斑病菌、番茄早疫病菌和棉花枯萎病菌的抑菌率分别为87.72%、77.32%、72.69%和71.37%。荆条花乙醇提取物不同溶剂萃取物中,石油醚和乙酸乙酯的抑菌活性较高。石油醚萃取物和乙酸乙酯萃取物对苹果腐烂病菌的EC50值分别为0.32 g/L和0.23 g/L;石油醚萃取物和乙酸乙酯萃取物对白菜黑斑病菌的EC50值分别为0.45 g/L和0.20 g/L。石油醚萃取物是进一步研究的重点。     

穗花马先蒿对小菜蛾的生物活性

研究了穗花马先蒿乙醇提取物对小菜蛾的触杀、拒食和抑制生长的作用.结果表明,穗花马先蒿乙醇提取物对小菜蛾3龄幼虫具有较高的的触杀和拒食活性,浸渍法处理对小菜蛾3龄幼虫72h的致死中浓度(LC50)为4.663 g/L,24、48h的拒食中浓度(AFC50)分别为8.238、9.185g/L;乙醇提取物对小菜蛾的生长发育抑制作用也明显,随施药剂量的增加,生长抑制率增大,化蛹率和羽化率降低,处理剂量为50.00g/L时,生长抑制率大于100%,化蛹率为41.11%,羽化率仅为12.22%.     

黄花蒿人工栽培及精油提取技术研究

系统地对野生黄花蒿的人工繁育、栽培及精油提取进行了探讨,提出了人工繁育、高产栽培及精油提取的具体技术条件,阐述了黄花蒿精油的香型及应用价值。     

碘量法测定黄花蒿中青蒿素含量

为了快速简便准确测定黄花蒿中青蒿素含量,利用碘量法建立一种青蒿素的测定方法。使用间接碘量法,以淀粉为指示剂,硫代硫酸钠为滴定剂,测定黄花蒿的石油醚提取液中青蒿素含量。通过稳定性、重现性、线性关系考察和加样回收率等指标考察方法的可行性。碘量法测定黄花蒿中青蒿素含量具有良好的线性关系,重现性、稳定性和加样回收率满足分析要求。     

超临界CO2从黄花蒿中提取青蒿素的研究

研究了用超临界二氧化碳从黄花蒿中萃取青蒿素的影响因素.在15.2～29.7MPa和40～60℃范围内,萃取压力和萃取温度升高,萃取率增大,萃取选择性下降.以萃取率和萃取选择性为目标,优化了超临界萃取工艺条件,得到较佳的操作条件萃取压力20MPa,萃取温度50℃,CO2流量1kg/(h·kg原料),原料粒径60～80目.在优化条件下萃取4h,萃取率达到95%以上,萃取物纯度10%以上.     

Optimization of Ultrasound-Assisted Extraction of Artemisinin from Artemisia annua L. by Response Surface Methodology

Artemisinin is a compound extracted from Artemisia annua L. with a remarkable curative effect against malaria. It can be extracted using ultrasound-assisted extraction (UAE) and then detected via HPLC. In this study, response surface methodology (RSM) was used to optimize UAE conditions for obtaining the maximum yield of artemisinin. Three independent variables (ratio of solvent to material, extraction temperature, and ultrasonic power) were evaluated using the Box-Behnken experimental design, with the yield of artemisinin as a response variable. Experimental data were highly fitted to a mathematical-regression model using multiple linear regression (MLR). Based on response surface plots, the three independent variables exhibited interactive effects on the yield of artemisinin. The optimal extraction conditions were as follows: 42.71 mL/g ratio of solvent to material, 41.86°C extraction temperature and 120 W ultrasonic power. The predicted yield of artemisinin by model was 0.7848%, whereas the actual yield in the extracts was 0.7826% ± 0.0790% in adjusted optimal conditions, with a relative error of 0.28%. The results undoubtedly demonstrated that RSM could be used to explore the optimum conditions of artemisinin extraction.     

青蒿中青蒿素的纯化工艺研究

建立了一种青蒿中青蒿素的纯化方法:采用中性氧化铝柱层析,考察不同洗脱溶剂的分离效果,并对重结晶溶剂进行选择.氧化铝柱层析纯化青蒿素的最佳操作条件为洗脱剂石油醚∶异丙醚(V/V)=70∶30,青蒿素含量提高到85%以上,回收率达90%;经过50%乙醇重结晶,青蒿素含量大于99.5%.该方法简便,产品纯度高,回收率高.     

青蒿毛状根悬浮培养动力学及其计量关系

分析了青蒿毛状根悬浮培养过程中生长、青蒿素合成、底物消耗及电导率变化的动力学,认为毛状根生长和青蒿素合成非偶联,毛状根生物量与电导率之间存在明显的线性关系.计算了生物量对碳、氮源的得率系数,并通过元素分析,建立了毛状根生长的基本计量关系式,从理论上计算出了得率系数及呼吸商.     

Antifungal activity of chitosan against Fusarium oxysporum f. sp. cubense

The in vitro antifungal activity of chitosan against Fusarium oxysporum f. sp. cubense Race 4 (FocR4) the causal agent of banana wilt was investigated. Chitosan at all concentrations tested reduced the hyphal growth of FocR4 on potato dextrose agar media and recording maximum inhibition of 76.36% at 8 mg/mL. The inhibitory effect was found to increase as chitosan concentration increases. The 50% effective concentration value was estimated by probit analysis, and it was 1.4 mg/mL. Chitosan was more effective in potato dextrose broth where it completely inhibited the mycelial growth of FocR4 at all concentrations tested. Chitosan inhibited the sporulation of FocR4 by a maximum of 96.53% at 8 mg/mL chitosan, and 100% inhibition for spore germination was recorded at all concentrations tested. Chitosan at concentrations of more than 1.6 mg/mL was also found to induce morphological changes in FocR4 characterized by agglomeration of hyphae, abnormal shapes, vesicles, or empty cells devoid of cytoplasm in the mycelia. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

p53 Enhances Artemisia annua L. Polyphenols-Induced Cell Death Through Upregulation of p53-Dependent Targets and Cleavage of PARP1 and Lamin A/C in HCT116 Colorectal Cancer Cells

Plant-derived natural polyphenols exhibit anticancer activity without showing any noticeable toxicities to normal cells. The aim of this study was to investigate the role of p53 on the anticancer effect of polyphenols isolated from Korean Artemisia annua L. (pKAL) in HCT116 human colorectal cancer cells. We confirmed that pKAL induced reactive oxygen species (ROS) production, propidium iodide (PI) uptake, nuclear structure change, and acidic vesicles in a p53-independent manner in p53-null HCT116 cells through fluorescence microscopy analysis of DCF/PI-, DAPI-, and AO-stained cells. The pKAL-induced anticancer effects were found to be significantly higher in p53-wild HCT116 cells than in p53-null by hematoxylin staining, CCK-8 assay, Western blot, and flow cytometric analysis of annexin V/PI-stained cells. In addition, expression of ectopic p53 in p53-null cells was upregulated by pKAL in both the nucleus and cytoplasm, increasing pKAL-induced cell death. Moreover, Western bot analysis revealed that pKAL-induced cell death was associated with upregulation of p53-dependent targets such as p21, Bax and DR5 and cleavage of PARP1 and lamin A/C in p53-wild HCT116 cells, but not in p53-null. Taken together, these results indicate that p53 plays an important role in enhancing the anticancer effects of pKAL by upregulating p53 downstream targets and inducing intracellular cell death processes.