Summary
Introduction: Tobacco is the most widely grown non-food crop in the world. Nicotine is the most abundant volatile alkaloid in tobacco leaves.
Objectives: This work aimed at measuring nicotine levels in the leaves of seven different varieties of Nicotiana tabacum, namely: Virginia, Burlip, Katrina, Shk al-bent, Zegrin, Basma and Burley, cultivated in Syria.
Methods: Nicotine was extracted according to approved method and its concentration was determined by LC/MS/MS in comparison with a standard material dilution series. The percentage of nicotine concentration was calculated manually. Statistical analysis was used to assess the significance of differences among variables and to perform multiple comparisons.
Results: The amount of nicotine in dry weight of tobacco leaves represented 6.7% in Virginia variety, 4.9% in Burlip, 4.84% in Katrina, 4.67% in Shk al-bent, 4% in Zegrin, 3.3% in Basma and <3% in Burley. Significant differences in nicotine concentration were found among the different varieties as determined by LSD test at a level of 0.05.
Conclusion: This study shows the importance of tobacco varieties grown in Syria, particularly Virginia, Burlip, Katrina, as a cheap and wealthy source for nicotine to be used in some industries.
The essential oil composition of Styrax officinalis L. was investigated by GC and GC-MS for the first time. Oil yields were low, whichever organ was hydrodistilled. Leaf, stem and flower oils consisted of 42.2%, 41.2% and 48.7% of terpenoids, respectively. Among all the identified terpenoids, oxygenated monoterpenes were predominant in all the plant organs. The major compounds in the leaf essential oils were (E )-2-hexenal (17.6%), linalool (11.9%) and geranial (5.5%). Linalool was the major compound (26.4%) in the volatile flower oil, followed by tridecanal (9.8%) and dodecane (9.6%), while α α α α α -terpineol (17%) and eugenol (9.9%) were the main compounds in the stem essential oil.
SummaryIntroduction:The potato tuber moth (PTM) is the major economic pest of potato. Different approaches were tried to prevent and control this pest including natural pesticides and synthetic fumigants.Objectives: This study was conducted to evaluate the insecticidal activity of the essential oils of thyme and myrtle. In addition to evaluating the insecticidal activity of carvacrol and eucalyptol against the different life stages of potato tuber moth using a fumigation bioassays.Methods:Thyme and myrtle oils were extracted from wildThymus syriacusBoiss. and wildMyrtus communisL. by hydrodistillation. Fumigation experiments were conducted on potato tuber moth of different stages of development (eggs, larvae, pupae, and adults), using standard methods. The potato tuber moth was treated for different periods using different concentrations of the essential oils. One-way analysis of variance (ANOVA) was applied on the mortality percentages data to estimate the significance of differences between treatments atp<0.05. Probit analysis was used to estimate the LC50, LC90and LT50.Results:Adult stage was the most sensitive to essential oils vapours with LC50value of 0.5μl/l air. Whereas, pupal stages were the most tolerant. The essential oil of thyme possessed the strongest fumigant toxicity against eggs with a LC50value of 6.1μl/l air. The two monoterpens showed varied fumigant toxicity against adult stage. Carvacrol achieved 100% mortality at 0.125μl/l air after 6 h, and 0.025μl/l air after 48h exposure with LT50period of 0.5 h.Conclusion:The present work demonstrated thatT. syriacusessential oil is a promising natural fumigant against the different developmental stages of PTM.
The objective of current study was to determine the chemical constituents and fumigant toxicity of essential oil isolated by hydro-distillation from dry fruit of bitter fennel (Foeniculum vulgare Miller). The chemical composition of the essential oil was assessed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Constituents of the oil were determined as α-pinene (1.6%) and limonene (3.3%), fenchone (27.3%), estragol (3.9%), and (E)-anethole (61.1%). The fumigant toxicity of the essential oil was tested on larvae of the stored product insect Trogoderma granarium Everts. The mortality of larvae was tested at different concentrations ranging from 31.2 to 531.2 μl/l air and at different exposure times (24 and 48 h). Probit analysis showed that LC50 and LC90 following a 48 h-exposure period for essential oil were 38.4 and 84.6 μl/l, respectively. These results showed that the essential oil from F. vulgare may be applicable to the management of populations of stored-product insects.
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