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1.
In the present work, the potential of acaricidal activity of chamomile flowers' extract was studied against engorged Rhipicephalus annulatus tick under laboratory condition. For this purpose, the engorged females ofRhipicephalus annulatus were exposed to two-fold serial dilutions of chamomile flowers' extract (0.5%, 1.0%, 2.0%, 4.0% and 8.0%) using "dipping method" in vitro. The engorged ticks were immersed in different plant dilutions (five ticks for each dilution) for l rain and they were immediately incubated in separate Petri dishes for each replicate at 26℃ and 80% relative humidity. Mortality rate for each treatment was recorded 5 d after incubation. The mortality rate caused by different dilutions of chamomile flowers' extract ranged from 6.67% to 26.7%, whereas no mortality was recorded for non-treated control group. The mass of produced eggs varied from 0.23 g (in 8.0% solution) to 0.58 g (in control), with no statistical differences between the treatments and control (/'〉0.05). Also the chamomile flowers' extract in highest concentration used (8.0%) caused 46.67% failure in egg laying in engorged females while no failure was observed for non-treated control group. Macroscopic observations indicated that in effective concentrations of plant (4.0% and 8.0%), patchy hemorrhagic swelling appeared on the skin of treated ticks. The results presented for the first time in this study imply that chamomile may be considered as a promising plant for biocontrol of cattle fever tick disease in the field condition.  相似文献   

2.
In the present work, the potential of acaricidal activity of chamomile flowers' extract was studied against engorged Rhipicephalus annulatus tick under laboratory condition. For this purpose, the engorged females of Rhipicephalus annulatus were exposed to two-fold serial dilutions of chamomile flowers' extract (0.5%, 1.0%, 2.0%, 4.0% and 8.0%) using "dipping method" in vitro. The engorged ticks were immersed in different plant dilutions (five ticks for each dilution) for 1 min and they were imme-diately incubated in separate Petri dishes for each replicate at 26 °C and 80% relative humidity. Mortality rate for each treatment was recorded 5 d after incubation. The mortality rate caused by different dilutions of chamomile flowers' extract ranged from 6.67% to 26.7%, whereas no mortality was recorded for non-treated control group. The mass of produced eggs varied from 0.23 g (in 8.0% solution) to 0.58 g (in control), with no statistical differences between the treatments and control (P>0.05). Also the chamomile flowers' extract in highest concentration used (8.0%) caused 46.67% failure in egg laying in engorged females while no failure was observed for non-treated control group. Macroscopic observations indicated that in effective concentrations of plant (4.0% and 8.0%), patchy hemorrhagic swelling appeared on the skin of treated ticks. The results presented for the first time in this study imply that chamomile may be considered as a promising plant for biocontrol of cattle fever tick disease in the field condition.  相似文献   

3.
Antibacterial potency of methanol extracts of three green lower plants, Pneumatopteris afra, Platycerium bifurcatum and Nephrolepsis bisserata was determined using agar dilution method on clinical strains of Escherichia coli, Staphylococcus aureus, Klebsiella spp. and Salmomelia typhi. Antibacterial activities were observed at concentrations of 12.5, 25.0, 50.0 and 100.0 μg/ml. Their minimum inhibitory concentrations ranged from 12.5~100 μg/ml. Extracts of P. afra and P. bifurcatum were most active. Antibacterial activities observed with N. bisserata were less pronounced with no detectable activity at extract con-centrations of 12.5 and 25.0 μg/ml. E. coli, together with S. aureus appeared to be the most susceptible of the test bacteria while Klebsiella spp. was least sensitive. The significance of our findings is discussed.  相似文献   

4.
The separation of ternary methanol/methyl butyl ether/1-butylchloride mixtures was investigated, which are the main components of the waste liquid. After preliminary studies on the ternary system, the integrated process of extraction and distillation was put forward to separate the ternary system. The results show that methanol carl be removed from the mixtures by extraction using water as the extracting agent. Through distillation of extract and dried raffinate respectively, methanol, methyl butyl ether and 1-butylchloride can be separated and recovered. In addition, the optimal volume for the extracting agent and effects of reflux ratio on the yield of product were also studied. The optimal volume ratio of the extracting agent to material is 1: 3.5, and the yield of the product increases with the increase of reflux ratio.  相似文献   

5.
The partition behaviors of β-1,3-1,4-glucanase, α-amylase and neutral proteases from clarified and whole fermentation broths of Bacillus subtilis ZJF-1A5 were investigated. An aqueous two-phase system (polyethylene glycol (PEG)/MgSO4)was examined with regard to the effects of PEG molecular weight (MW) and concentration, MgSO4 concentration, pH and NaCl concentration on enzyme partition and extraction. The MW and concentration of PEG were found to have significant effects on enzyme partition and extraction with low MW PEG showing the greatest benefit in the partition and extraction of β-glucanase with the PEG/MgSO4 system. MgSO4 concentration influenced the partition and extraction of β-glucanase significantly. pH had little effect on β-glucanase or proteases partition but affected α-amylase partition when pH was over 7.0. The addition of NaCl had little effect on the partition behavior of β-glucanase but had very significant effects on the partitioning of α-amylase and on the neutral proteases. The partition behaviors of β-glucanase, α-amylase and proteases in whole broth were also investigated and results were similar to those obtained with clarified fermentation broth. A two-step process for purifying β-glucanase was developed, which achieved β-glucanase recovery of 65.3% and specific activity of 14027 U/mg, 6.6 times improvement over the whole broth.  相似文献   

6.
The process of synthesis of dimethyl-2,6-naphthalene dicaboxylate from esterification of 2,6-naphthalene dicarboxylic acid (2,6-NDCA) by methanol using sodium tungstate as catalyst was investigated. The orthogonal tests method was used for optimizing the process factors. The effects of reaction temperature, mass percentage of catalyst, reaction time and mass ratio of methanol to 2,6-NDCA on the 2,6-NDCA conversion were investigated. It was found that all the four factors had significant effect on the conversion. The optimum reaction conditions were reaction temperature 215℃ ,mass percentage of catalyst 356, reaction time 3 h, mass ratio of methanol to 2,6-NDCA 6: 1. The 2,6-NDCA conversion at above condition was 92. 80%.  相似文献   

7.
Sequential methodology based on the application of three types of experimental designs was used to optimize the fermentation conditions for elastase production from mutant strain ZJUEL31410 of Bacillus licheniformis in shaking flask cul- tures. The optimal cultivation conditions stimulating the maximal elastase production consist of 220 r/min shaking speed, 25 h fermentation time, 5% (v/v) inoculums volume, 25 ml medium volume in 250 ml Erlenmeyer flask and 18 h seed age. Under the optimized conditions, the predicted maximal elastase activity was 495 U/ml. The application of response surface methodology resulted in a significant enhancement in elastase production. The effects of other factors such as elastin and the growth factor (corn steep flour) on elastase production and cell growth were also investigated in the current study. The elastin had no significant effect on enzyme-improved production. It is still not clear whether the elastin plays a role as a nitrogen source or not. Corn steep flour was verified to be the best and required factor for elastase production and cell growth by Bacillus licheniformis ZJUEL31410.  相似文献   

8.
Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with technetium-99m (^99mTc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with ^99mTC. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with ^99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with ^99mTc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with ^99mTc. The data showed significant (P〈0.05) alteration of ATI in BC from blood incubated with guava extract.  相似文献   

9.
Crude decoction, aqueous and ethanolic extracts of two medicinal plants (Psidiura guajava and Diospyros raespiliformis), widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.  相似文献   

10.
Enhancing the dispersion and dissolution of substrate particles in substrate water suspension is a feasible way to improve steroid bioconversion. The aim of the present study is to investigate the effects of applying surfactant to microbial conversion system on the dispersion, solubilization and in turn bioconversion of steroid substrate. The model system is hydroxylation of substrate 19α- 17α-epoxy- 4-pregnene- 3.2It-dine by microbial enzymes from Rhizopus nigricanl. The results show that the presence of substrate leads to an increase in critical micelle concentration ( CMC) of surfactant PSE compared with the normal CMC of PSE in aqueous solution. The grinding time during substrate suspension preparation affects the substrate aqueous solubility differently with the varied surfactant concentrations while barely making any difference in substrate solubility in the absence of surfactant. The properly prolonged grinding time can make up for the loss in substrate solubility arising from the reduction in surfactant concentration. The surfactant complexes composed of surfactants PSE and MGE at appropriate ratios are screened out with orthodoxy experiment method. the interaction between PSE and MGE exerts the most prominent effects on substrate bioconversion, and the surfactant complexes show more beneficial effects on steroid bioconversion than the surfactant PSE used alone.  相似文献   

11.
Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Collosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects; none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%∼100% whereas in S. zeamais, the mortality ranged from 87.5%∼100% and 70%∼100% in concentrations of 1 g extract+3 ml methanol and 1 g extract+5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract+15 ml methanol had no significant lethal effect on Sitophilus zeamais.   相似文献   

12.

Objective

This study examined the anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidia and var. angustifolia, a natural slimming aid, on 3T3-L1 adipocytes.

Methods

Methanol and water extracts of leaves of the F. deltoidea varieties were analyzed to determine their total flavonoid content (TFC) and total phenolic content (TPC), respectively. The study was initiated by determining the maximum non-toxic dose (MNTD) of the methanol and water extracts for 3T3-L1 preadipocytes. Possible anti-adipogenic effects were then examined by treating 2-d post confluent 3T3-L1 preadipocytes with either methanol extract or water extract at MNTD and half MNTD (1/2MNTD), after which the preadipocytces were induced to form mature adipocytes. Visualisation and quantification of lipid content in mature adipocytes were carried out through oil red O staining and measurement of optical density (OD) at 520 nm, respectively.

Results

The TFCs of the methanol extracts were 1.36 and 1.97 g quercetin equivalents (QE)/100 g dry weight (DW), while the TPCs of the water extracts were 5.61 and 2.73 g gallic acid equivalents (GAE)/100 g DW for var. deltoidea and var. angustilofia, respectively. The MNTDs determined for methanol and water extracts were (300.0±28.3) and (225.0±21.2) μg/ml, respectively, for var. deltoidea, while much lower MNTDs [(60.0±2.0) μg/ml for methanol extracts and (8.0±1.0) μg/ml for water extracts] were recorded for var. angustifolia. Studies revealed that the methanol extracts of both varieties and the water extracts of var. angustifolia at either MNTD or 1/2MNTD significantly inhibited the maturation of preadipocytes. Conclusions: The inhibition of the formation of mature adipocytes indicated that leaf extracts of F. deltoidea could have potential anti-obesity effects.  相似文献   

13.
通过对湖北海棠种子甲醇浸提液的生物测定,探讨湖北海棠种子休眠与种子内源抑制物质的关系。结果表明,湖北海棠种子不同浓度的甲醇浸提液对白菜种子发芽率及幼苗的高生长、根生长均有抑制作用,浓度越高抑制作用越明显。方差分析结果表明,不同处理组之间白菜种子发芽率、苗高和根长存在显著差异。其中用0%、25%、50%、75%和100%的浸提液处理白菜籽,其发芽率分别为82.5%、72%、64%、34%和18%,根长分别比对照大约降低了6%、11%、18%和26%,苗高分别比对照大约降低了22%、38%、52%和66%,表明湖北海棠种子含有抑制种子萌发和幼苗生长的成分。  相似文献   

14.
Chemical composition of Gongronema latifolium leaves was determined using standard methods. Aqueous and methanol G. latifolium extracts were tested against thirteen pathogenic bacterial isolates. Crude protein, lipid extract, ash, crude fibre and nitrogen flee extractives obtained are: 27.2%, 6.07%, 11.6%, 10.8% and 44.3% dry matter respectively. Potassium, sodium, calcium, phosphorus and cobalt contents are 332, 110, 115, 125 and 116 mg/kg respectively. Dominant essential amino acids are leucine, valine and phenylalanine. Aspartic acid, glutamic acid and glycine are 13.8%, 11,9% and 10.3% respectively of total amino acid. Saturated and unsaturated fatty acids are 50.2% and 39.4% of the oil respectively. Palmitic acid makes up 36% of the total fatty acid. Extracts show no activity against E. faecalis, Y. enterolytica, E. aerogenes, B. cereus and E. agglomerans. Methanol extracts were active against S, enteritidis, S. cholerasius ser typhimurium and P. aeruginosa (minimum inhibitory concentration (MIC) 1 mg; zone of growth inhibition 7, 6.5 and 7 mm respectively). Aqueous extracts show activity against E. coli (MIC 5 mg) and P. aeruginosa (MIC 1 mg) while methanol extracts are active against P. aeruginosa and L. monocytogenes. G. lafifolium has potential food and antibacterial uses.  相似文献   

15.
利用莱氏野村菌对亚洲玉米螟二龄幼虫的室内毒力测定,最高死亡率达86.52%,致死中时间为5.62d,致死中浓度为7.93×105个/ml.莱氏野村菌对亚洲玉米螟幼虫具有较强的毒力效果.  相似文献   

16.
长柄石杉中黄酮类物质的提取研究   总被引:1,自引:0,他引:1  
以甲醇为溶剂,采用索氏提取法研究长柄石杉中黄酮类物质的提取工艺,考察了提取温度、提取时间及溶剂浓度对提取效果的影响。经正交试验结果表明,长柄石杉中黄酮类物质的提取条件为甲醇浓度100%、提取温度80℃、提取时间8 h时提取量较高,在此条件下黄酮提取量为23.15 mg/g。  相似文献   

17.
桐花树嫩叶浸出液对绿豆下胚轴不定根生长的影响   总被引:1,自引:0,他引:1  
本试验研究了桐花树嫩叶浸出液对绿豆下胚轴不定根生长的影响.七个浓度梯度处理分别是:原液(0.078 9 g/mL)、稀释5倍(0.0157 8 g/mL)、稀释10倍(0.007 89 g/mL)、稀释15倍(0.005 26 g/mL)、稀释20倍(0.003 95 g/mL)、稀释30倍(0.002 63 g/mL)、稀释40倍(0.001 97 g/mL),以蒸馏水为对照组.分别简记为T1、T2、T3、T4、T5、T6、T7、CK.结果表明:T1~T6组对绿豆下胚轴不定根数目和生根范围均有显著促进作用,且随浸出液浓度的增大而呈上升趋势,其中T1、T2组的不定根数目和生根范围均显著大于其他组;T4和T5组的不定根根粗为最大,且显著大于其他组;T4组的不定根最长根长、鲜重和干重最大,分别比对照组显著提高14.69%、30.00%和55.56%.试验表明,桐花树嫩叶浸出液对绿豆下胚轴不定根生长具有较明显的化感效应,表现为过高浓度起抑制作用,较高浓度起促进作用,而过低浓度的促进效果不明显.  相似文献   

18.
Antimicrobial activity of organic and aqueous extracts from fruits, leaves and roots of Tribulus terrestris L., an Iraqi medicinal plant used as urinary anti-infective in folk medicine, was examined against 11 species of pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Corynebacterium diphtheriae, Escherichia coli,Proteus vulgaris, Serratia marcescens, Salmonella typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans using microdilution method in 96 multiwell microtiter plates. All the extracts from the different parts of the plant showed antimicrobial activity against most tested microorganisms. The most active extract against both Gram-negative and Gram-positive bacteria was ethanol extract from the fruits with a minimal inhibitory concentration (MIC) value of 0.15 mg/ml against B. subtilis,B. cereus, P. vulgaris and C. diphtheriae. In addition, the same extract from the same plant part demonstrated the strongest antifungal activity against C. albicans with an MIC value of 0.15 mg/ml.  相似文献   

19.
采用高效液相色谱法对小麦中尿囊素含量进行测定.色谱柱为Kromasil C18,流动相为V甲醇∶V水=5∶95,柱温30℃,流速0.5 mL/min,HPLC测定尿囊素含量变异系数小于1.1%,回收率为95.80%~105.4%,最低检出限0.5μg/mL.  相似文献   

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