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Mary T. Fletcher Lynette M. Lowe William Kitching Wilfried A. König 《Journal of chemical ecology》2000,26(10):2275-2290
Investigation of the strikingly aposematic Leichhardt's grasshopper revealed a number of host-plant-derived components. Chemical study of the three known host plants revealed a diverse array of components. Pityrodia ternifolia and P. pungens contain predominantly sesquiterpenes and sesquiterpene glycosides and P. jamesii is rich in cineole, dihydrochalcones, chalcones, and monoterpene glycosides. Feces from grasshoppers feeding on P. jamesii contain a mixture of hydroxycineoles, of which 3-hydroxycineole is the predominant isomer (68%). No evidence for previously suspected "alkaloidal" toxins was found in either the insect or host plant. 相似文献
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This study determines the occurrence and concentration levels of artificial low-calorie sweeteners (LCSs) in food and food supplements on the Italian market. The analysed sample set (290 samples) was representative of the Italian market and comprised of beverages, jams, ketchups, confectionery, dairy products, table-top sweeteners and food supplements. All samples were analysed via UPLC-MS/MS. The method was in-house validated for the analysis of seven LCSs (aspartame, acesulfame-K, saccharin, sucralose, cyclamate, neotame and neohesperidin dihydrochalcone) in food and for five LCSs (aspartame, acesulfame-K, saccharin, cyclamate and sucralose) in food supplements. Except for cyclamate in one beverage which exceeded the maximum level (ML) with 13%, all concentrations measured in food were around or below the ML. In food supplements, 40 of the 52 samples (77%) were found to be above the ML, with exceedances of up to 200% of the ML. 相似文献
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Fraser L. Courts Gary Williamson 《Critical reviews in food science and nutrition》2015,55(10):1352-1367
The human diet contains a wide variety of plant-derived flavonoids, many of which are glycosylated via an O- or less commonly a C-glycosidic linkage. The distribution, quantity, and biological effects of C-glycosyl flavonoids in the human diet have received little attention in the literature in comparison to their O-linked counterparts, however, despite being present in many common foodstuffs. The structural nature, nomenclature, and distribution of C-glycosyl flavonoids in the human diet are, therefore, reviewed. Forty-three dietary flavonoids are revealed to be C-glycosylated, arising from the dihydrochalcone, flavone, and flavan-3-ol backbones, and distributed among edible fruits, cereals, leaves, and stems. C-linked sugar groups are shown to include arabinose, galactose, glucose, rutinose, and xylose, often being present more than once on a single flavonoid backbone and occasionally in tandem with O-linked glucose or rutinose groups. The pharmacokinetic fate of these compounds is discussed with particular reference to their apparent lack of interaction with hydrolytic mechanisms known to influence the fate of O-glycosylated dietary flavonoids, explaining the unusual but potentially important appearance of intact C-glycosylated flavonoid metabolites in human urine following oral administration. Finally, the potential biological significance of these compounds is reviewed, describing mechanisms of antidiabetic, antiinflammatory, anxiolytic, antispasmodic, and hepatoprotective effects. 相似文献
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以橙皮苷为原料,经化学处理,可转化成具有纯正甜味的,非营养性的题示甜味剂。本文阐述了它的原料来源,产品性能,合成原理及制备方法。 相似文献
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采用循环伏安法和线性扫描伏安法研究了新橙皮苷二氢查尔酮在玻碳电极上的电化学行为。在pH=4.8的醋酸/醋酸钠缓冲溶液中,新橙皮苷二氢查尔酮的循环伏安图上呈现出一对氧化还原峰,其电化学过程表现出良好的可逆性。实验结果表明,电化学过程中新橙皮苷二氢查尔酮的电子转移数n为2,参与反应的质子数也为2。新橙皮苷二氢查尔酮的还原峰峰电流与其浓度在2.8×10^-7mol·L^-1至3.1×10^-6mol·L^-1范围内呈现出良好的线性关系。对1.1×10^-6mol·L^-1新橙皮苷二氢查尔酮溶液连续6次测定的RSD为2.2%,检出限为1.1×10^-7mol·L^-1 相似文献
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