Objective:To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L.(L...Objective:To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L.(L.sativa).Methods:The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L.sativa(lettuce)grown in Sultanate of Oman by hydro distillation method.The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity(DPPH)method.Results:About 20 chemical compounds of different concentration representing 83.07%and 79.88%respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves asα-pinene(5.11%and 4.05%).γ-cymene(2.07%and 1.92%),thymol(11.55%and 10.73%),durenol(52.00%and 49.79%),α-terpinene(1.66%and 1.34%),thymol acetate(0.99%and 0.67%),caryophyllene(2.11%and 1.98%),spathulenol(3.09%and 2.98%).camphene(4.11%and3.65%),limonene(1.28%and 1.11%)representing these major chemical compounds.However,some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including p-pinene,α-terpinolene,linalool,4-terpineol,α-terpineol,o-methylthymol,L-alloaromadendrene and viridiflorene.Conclusions:The chemical consliluents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes,sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons.Therefore,the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant,antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases.展开更多
The present investigation reports the soxhlet assisted solvent extraction technique to derive the oil from seeds of the rain tree.The optimization of the factors affecting the extraction process has been carried out b...The present investigation reports the soxhlet assisted solvent extraction technique to derive the oil from seeds of the rain tree.The optimization of the factors affecting the extraction process has been carried out by Response Surface Methodology(RSM)technique,and a Box-Behnken Design(BBD)consisting of three process variables has been developed to optimize the yield of oil.Using the RSM technique,the predicted optimum oil yield of 11.15%at an optimized condition of powder weight of 20 g,volume of solvent of 380 mL,and extraction time of 6 h.The physiochemical properties of the oil showed liquid greenish-yellow with 0.88,1.473 of specific gravity and refractive index,respectively.Similarly,the moisture content,free fatty acid,acid value,saponification value,iodine value,and peroxide value were found to be 0.16%,13.615,27.23,187.1 mg KOH per g oil,65.8 g I_(2) per 100 g,and 4.02 meq O_(2) per kg,respectively.From the obtained results,it was found that the extracted oil could be used for various applications.展开更多
基金Supported by Central Instrument Laboratory,College of Agriculture and Marine Sciences,Sultan Qaboos University,Grant No.507/SOP/OB/1/2013
文摘Objective:To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L.(L.sativa).Methods:The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L.sativa(lettuce)grown in Sultanate of Oman by hydro distillation method.The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity(DPPH)method.Results:About 20 chemical compounds of different concentration representing 83.07%and 79.88%respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves asα-pinene(5.11%and 4.05%).γ-cymene(2.07%and 1.92%),thymol(11.55%and 10.73%),durenol(52.00%and 49.79%),α-terpinene(1.66%and 1.34%),thymol acetate(0.99%and 0.67%),caryophyllene(2.11%and 1.98%),spathulenol(3.09%and 2.98%).camphene(4.11%and3.65%),limonene(1.28%and 1.11%)representing these major chemical compounds.However,some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including p-pinene,α-terpinolene,linalool,4-terpineol,α-terpineol,o-methylthymol,L-alloaromadendrene and viridiflorene.Conclusions:The chemical consliluents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes,sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons.Therefore,the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant,antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases.
文摘The present investigation reports the soxhlet assisted solvent extraction technique to derive the oil from seeds of the rain tree.The optimization of the factors affecting the extraction process has been carried out by Response Surface Methodology(RSM)technique,and a Box-Behnken Design(BBD)consisting of three process variables has been developed to optimize the yield of oil.Using the RSM technique,the predicted optimum oil yield of 11.15%at an optimized condition of powder weight of 20 g,volume of solvent of 380 mL,and extraction time of 6 h.The physiochemical properties of the oil showed liquid greenish-yellow with 0.88,1.473 of specific gravity and refractive index,respectively.Similarly,the moisture content,free fatty acid,acid value,saponification value,iodine value,and peroxide value were found to be 0.16%,13.615,27.23,187.1 mg KOH per g oil,65.8 g I_(2) per 100 g,and 4.02 meq O_(2) per kg,respectively.From the obtained results,it was found that the extracted oil could be used for various applications.
