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The deterrent and toxicity effects of mint, Mentha virdis L. and peppermint, Mentha piperita L. on Tetranychus urticae Koch were studied under laboratory conditions. M. virdis was more potent for T. urticae than M. piperita, with a significant increase in repellency. Leaf discs treated with increasing concentrations of both materials showed reduction in the total numbers of eggs laid. A high percentage of T. urticae mortality was recorded in case of M. virdis. The direct toxicity of both essential oils to the female of the predacious mites namely Typhlodromus athiase Porath and Swirski Phytoseius finitimus Ribaga, Amblyseius barkeri (Hughes), Amblyseius zaheri Yousef and El-Borolossy, Amblyseius yousefi Zaher and El-Borolossy and Amblyseius deleoni (Muma and Denmark) were tested. At LC 50 level, M. virdis was the most toxic to females A. yousefi and the least to females T. athiasae. With the exception of A. zaheri, M. piperita proved to be more toxic to the predacious mites tested than M. virdis. The results obtained chemically and biologically, may suggest that the higher percentage of the hydrocarbons of M. virdis were responsible for the toxic effect.

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The deterrent and toxic effect of two essential oils, Majorana hortensis. Moench and Rosma- rinus officinalis L. on the two tetranychid mites Tetranychus urticae Koch and Eutetranychus orientalis (Klein) were studied under laboratory conditions. Both materials used were more potent for E. orientalis than against T. urticae with a significant increase in repellency. Leaf discs treated with increasing concentrations of the two oils showed increased mortality of both spider mites and reduction in the total numbers of eggs laid. This result could be due to the oil of the higher oxygenated compounds content that was more effective in this respect.

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Two essential oils, namely Ocimum basilicum L. and Lavandula offi­ci­nalis Chaix, were tested for their repellency, toxicity and oviposition deterrence against two tetranychid mites, tetranychus urticae (Koch) and Eutetranychus orientalis (Klein). Fifty-seven and forty-seven compounds, comprising about 96.7 and 95.4% of sweet basil and French lavender oil, respectively, were positively identified using GC-MS technique. Oil analysis revealed the dominant occurrence of the oxygenated terpenes in either oils (91.172 and 64.317%), respectively. The essential oil of French lavender was more potent for E. orientalis than against T. urticae. The ODI of both oils was ranged between (100-80) for both mite species at conc. (2- 0.5%). For both oils, a significant reduction in the total number of eggs laid by both tetranychid species was recorded at all con­centrations used. A high percentage of E. orientalis mortality was recorded for both materials while oil of sweet basil was more effective than French lavender oil in case of T. urticae. The results obtained chemically and biologically may suggest that the dominant occurrence of the oxygenated hydrocarbon compounds (91.172% of oil content) in sweet basil were responsible for the toxic effect.

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The direct toxicity of some mineral and plant oils to the eggs and females of the two spotted spider mite Tetranychus urticae Koch was tested. KZ oil was toxic to the egg stage compared to adult female. In contrast, Natur'l oil has a close toxic effect for both stages of T. urticae. Bio-dux oil was proved to be toxic to adult female and relatively in toxic to egg stage. Females of T. urticae suffered a depression in reproduction and shortened longevity when kept on plant leaves previously treated with different oils. Laboratory studies indicated that the vegetable oil Natur'l oil was effective on all biological aspects of T. urticae studied.

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The direct toxicity of some mineral and plant oils to adult females of the predacious mites, Amblyseius barkeri (Hughes) and Amblyseius zaheri Yousef and El-Borolossy were tested. KZ oil was the most toxic to females of A. barkeri and A. zaheri (LC50 = 0.391 and 0.308%, respectively). In contrast, Natur'l oil was relatively intoxic to females A. zaheri and A. barkeri. Bio-dux, Capl-2 and Natur'l oils have a close toxic effect for both predacious mites. Females of A. barkeri and A. zaheri suffered a depression in reproduction when sprayed with conc. = LC50 of each oil and kept on plant leaves previously treated with different oils. Laboratory studies indicated that the vegetable oil Natur'l oil was the least effective oil on all biological aspects of both predacious mites A. barkeri and A. zaheri in the laboratory.

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Two novel, sensitive, and selective stability-indicating chromatographic methods were described for the analysis of zopiclone (ZOP) in the presence of its degradation products, namely, 7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-yl-4-methylpiperazine-1-carboxylate (hydrolytic DEG) and 5H-pyrrolo[3,4-b]pyrazine-5,7(6H)-dione (oxidative DEG), in drug substance and product. The first method was an isocratic reversed-phase high-performance liquid chromatography (RP-HPLC) using Inertsil ODS3 (250 × 4 mm, 5 μm) column. Upon using HPLC, the run time could be reduced, and actually, the solvents consumption decreased. Quantification was achieved by detection wavelength at 237 nm, based on peak area. Chromatographic separation was performed over the range of 1–10 μg mL−1 with limits of detection (LOD) and quantification (LOQ) of 0.18 and 0.55 μg mL−1 and a mean recovery of 99.98 ± 0.55. The analysis was achieved at 30°C using a mixture of acetonitrile and water (50:50 v/v) as the mobile phase. The second method was thin-layer chromatography (TLC) applied for the separation and analysis of zopiclone in the presence of its alkaline, acidic, and oxidative degradation products. Chromatography was performed on silica gel 60 F254 plates with ethyl acetate‒methanol‒ammonia 33% (17:2:1 v/v) as the mobile phase. Successful resolution was observed with significant difference in the R F values, followed by densitometric measurement at 303 nm. Evaluation was carried out over the range of 0.1–2 μg per spot with a mean recovery of 100.52% ± 0.24. The developed methods were successfully applied to the analysis of ZOP in bulk powder, laboratory-prepared mixtures containing different percentages of its degradation products, and pharmaceutical dosage form. The degradation products were separated by HPLC as well as identified by TLC, infrared (IR), and mass spectrometry (MS) to confirm its structures and elucidate degradation pathway. The developed methods were validated as per the International Conference on Harmonization (ICH) guidelines. The results obtained by the proposed methods were statistically compared with the reported methods revealing high accuracy and good precision.

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The direct toxicity of some essential, mineral and plant oils to the eggs and females of the predacious mite Neoseiulus cucumeris (Oudemans) was tested in the laboratory. Sweet basil oil was the most toxic essential oil to females N. cucumeris, while sweet marjoram oil was the least toxic one (LC50=2.315 and 7.021%, respectively). In contrast, rosemary oil was toxic to eggs of N. cucumeris, while sweet basil oil was the least effective oil against predator eggs (LC50 = 2.695 and 11.950%, respectively). The mineral oil capl-l 1was the most toxic one to adult females (LC50= 0.849%) while natur'l oil was the least (LC50= 4.691%), respectively. In contrast, natur'l oil was proved to be highly toxic to predator eggs while bio-dux oil was the least effective oil against the egg stage. Females of N. cucumeris suffered a depression in reproduction when females treated and fed on prey formerly kept on treated plant leaves with LC50 concentration of each oil used in our studies. Rosemary and sweet marjoram as well as bio-dux oils seem to be slightly harmful to N. cucumeris at (LC50) concentration of each oil.

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Abstract  

The effect of water-miscible alcohols and acetone on the extraction and separation of Cd and Zn chlorides by TOPO was systematically investigated. The maximum extraction of Zn chloride with 0.1 M TOPO decreases in the order: acetone>methanol>ethanol>2-propanol>2-butanol. For alcohols, the sequence of decreasing extractability is thus parallel to the order of their dielectric constants. This can be explained by the increase of HCl extraction by TOPO in the same direction. The presence of additives in the polar phase prevents the formation of a bulky white precipitate encountered during extraction of ZnCl2 from pure aqueous solutions. A decrease of Cd chloride extraction was generally noticed in presence of additives; this is more noticeable for the longer chain alcohols. The highest separation factor (E for ZnCl2 and CdCl2 in 0.48M HCl is obtained from 30% methanol (13.8 compared to about 3.8 in absence of methanol) and from 10–20% acetone where it reaches 30.

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Accurate, selective, and sensitive thin-layer chromatography (TLC)—densitometry and reversed-phase high-performance liquid chromatography (RP-HPLC) methods have been developed and validated for the simultaneous determination of vitamin E (VIT E) and vinpocetine (VINP) in the presence of the alkaline-induced degradation product of vinpocetine (DEG). The proposed TLC— densitometric method depends on the separation and quantitation of VIT E, VINP, and VINP alkaline-induced degradation product on TLC silica gel 60 F254 plates, using methanol—chloroform—ethyl acetate—glacial acetic acid—ammonia solution (6:2:2:0.5:0.1, by volume) as the developing system followed by densitometric measurement at 235 nm. The studied components were well resolved from each other with significantly different R f values of 0.81, 0.62, and 0.41 for VIT E, VINP, and DEG, respectively. On the other hand, the developed RP-HPLC method was based on the separation of the studied components using 0.05 M KH2PO4 (adjusted to pH = 3) and methanol in gradient elution mode on C8 column at a flow rate of 1.5 mL min−1 and ultraviolet (UV) detection at 235 nm. The studied components were well resolved from each other with significantly different R t values of 10.90, 2.89, and 1.90 min for VIT E, VINP, and DEG, respectively. The developed methods were validated according to the International Conference on Harmonization (ICH) guidelines demonstrating good accuracy and precision. The results were statistically compared with those obtained by the reported method, and no significant difference was found. The developed methods are the first developed stability-indicating assay methods (SIAMs) for the analysis of the studied binary mixture.

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Two parts of the plant Capparis aegyptia, leaves and fruits, were extracted successfully with 4 different solvents. These solvents namely n-hexane, diethyl ether, ethyl acetate and ethanol. These extracts were tested for their toxicity against eggs and adult females of the two-spotted spider mite, Tetranychus urticae Koch. Extracts of both parts of the plant, prepared from various solvents were affected the behavior, toxicity and fecundity of females under laboratory conditions. Ethyl acetate extract of leaves and fruits was the most potent extract tested against eggs and adult females of T. urticae. In contrast, ethanol extract of fruits was the least effective extract against both tested stages. The egg stage was less susceptible to most different extracts of both parts of C. aegyptia. Leaf discs treated with LC50 concentration of various extracts showed a high percentage of repellency in case of ethanol extract from leaves and fruits (86.67 and 96.42%), respectively. Treated females with LC50 concentration of different extracts showed a higher remarkable percentage of mortality as well as a reduction in the total number of eggs laid during 15 days with fruit extracts than that with leaves extract.

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