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1.
The dependence of the limonene content of lemon (Citrus volkameriana) peel oil on the degree of ripeness of the fruit has been studied by using steam distillation and cold pressing to extract the oils from lemon fruit peel at different stages of maturation (green, greenish-yellow, and yellow-orange peel coloration). Samples of essential oils were analyzed by high resolution GC and GC-MS, using tetradecane as internal standard for quantitation. Forty components were detected; thirty eight were positively identified by comparison of their mass spectra (El, 70 eV) and Kováts retention indexes (determined using a non-logarithmic scale on capillary columns coated with both polar (DB-Wax) and non-polar (DB-1) stationary phases) with those of standards and with data reported in the literature. The limonene concentration reached a maximum level of 79.4% when the fruit was in the intermediate maturation stage characterized by greenish-yellow coloration.  相似文献   
2.
黄酮化合物是具有多种生物活性的物质,广泛存在于自然界中。单纯为甲氧基取代的多甲氧基黄酮PMF是芸香科多种桔类所特有的,特别是在其果皮中有较高的含量。近年来有关桔皮PMF抗癌的研究取得了很大进展。PMF作为桔皮中的抗癌活性成分,对多种癌细胞有较强的抑制作用,受到国内外的广泛关注。由于桔皮中PMF的主要成分随柑桔种类和产地的不同而有较大差异,所以,筛选含有较强抗癌活性的PMF成分的桔皮种类,是一项非常有意义的工作。文献报道的PMF的分析检测方法主要有液相色谱法、气相色谱-质谱法等。本文利用液相色谱-大气压化学电离化质谱联用技术定性分析了3种柑桔果皮中PMF的主要成分,并结合紫外吸收光谱进一步确证。  相似文献   
3.
Citrus aurantium L. (Rutaceae) fruit extracts have recently been used for weight loss. Among the adrenergic amines the most important active constituent is the sympathomimetic compound synephrine and commercially available extracts are standardized for their content of this active principle. A capillary electrophoresis method was developed for the quantitative and qualitative determination of d-synephrine, l-synephrine, d-octopamine, l-octopamine, tyramine, n-methyl tyramine and hordenine. The electrophoretic separation was performed using a 75 cm × 50 µm ID (66.5 cm effective length) fused silica capillary. The samples were injected by pressure for 5s at 50 mbar and the running voltage was 30 kV at the injector end of the capillary. The method developed was successively applied to the determination of the adrenergic amines in dietary supplements, in various Citrus species including Citrus aurantium, jams and juices. Synephrine was the main component and present in the levels from 0.02–0.17% in various Citrus species and 0.42–69.28 mg in dietary supplements claiming to contain Citrus aurantium. Parameters affecting the resolution between (+) and (−)-enantiomers, such as pH, cyclodextrin concentration, temperature, organic modifier, buffer concentration and capillary dimensions were reported.  相似文献   
4.
Mineral content and botanical origin of Spanish honeys   总被引:2,自引:0,他引:2  
Eleven elements (Zn, P, B, Mn, Mg, Cu, Ca, Ba, Sr, Na and K) were determined by inductively plasma coupled spectrometry in 40 honey samples from different places of Spain and four different botanical origins: Eucalyptus (Eucalyptus sp.), Heather (Erica sp.), Orange-blossom (Citrus sinensis) and Rosemary (Rosmarinus officinalis). K, Ca and P show the higher levels with average concentrations ranged between 434.1-1935 mg kg−1 for K; 42.59-341.0 mg kg−1 for Ca and 51.17-154.3 mg kg−1 for P. Levels of Cu (0.531-2.117 mg kg−1), Ba (0.106-1.264 mg kg−1) and Sr (0.257-1.462 mg kg−1) are the lowest in all honey samples. Zn (1.332-7.825 mg kg−1), Mn (0.133-9.471 mg kg−1), Mg (13.26-74.38 mg kg−1) and Na (11.69-218.5 mg kg−1) concentrations were found strongly dependent on the kind of botanical origin.Results were submitted to pattern recognition procedures, unsupervised methods such as cluster and principal components analysis and supervised learning methods like linear discriminant analysis in order to evaluate the existence of data patterns and the possibility of differentiation of Spanish honeys from different botanical origins according to their mineral content. Cluster analysis shows four clusters corresponding to the four botanical origins of honey and PCA explained 71% of the variance with the first two PC variables. The best-grouped honeys were those from heather; eucalyptus honeys formed a more dispersed group and finally orange-blossom and rosemary honeys formed a less distinguishable group.  相似文献   
5.
Physiologically dropped immature Citrus reticulata Blanco fruits are regarded as waste and discarded in the citrus orchard but are a good source of bioactive compounds including flavonoids, antioxidants and total phenols. A study was undertaken to identify and quantify these bioactive compounds and to investigate the influence of different drying techniques, namely freeze drying and hot air oven drying, on flavonoids namely flavanone glycosides, antioxidant potential and total phenol content in immature dropped fruits of Citrus reticulata Blanco. Flavonoids were quantified in high-performance liquid chromatography (HPLC). The antioxidant activity were investigated with three assays azino-bis [3-ethylbenzthiazoline-6-sulfonic acid]) (ABTS), 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), Ferric Reducing Ability of Plasma (FRAP) and total phenol content was determined. Freeze dried samples of 12 and 14 mm size retained maximum hesperidin flavonoid content (27.03% and 27.20%) as compared to the hot air dried samples (17.99%) and retained higher phenolic content ranged from 50.54–54.19 mg GAEL−1. The antioxidant activity in freeze dried fruits was from 12.21–13.55 mM L−1 Trolox and 15.27–16.72 mM L−1 Trolox with ABTS, DPPH assay and FRAP values ranging from 7.31–9.07 mM L−1 Trolox. Significant positive correlation was found between the flavonoid hesperidin with antioxidant assays and total phenolic content (TPC). The results showed that waste citrus fruits can act as potential source of bioflavonoids, especially hesperidin, and antioxidants for pharmaceutical as well as nutraceutical industry.  相似文献   
6.
The chemical composition of three Citrus limon oils: lemon essential oil (LEO), lemon terpenes (LT) and lemon essence (LE), and their influence in the virulence factors production and motility (swarming and swimming) of two Pseudomonas aeruginosa strains (ATCC 27853 and a multidrug-resistant HT5) were investigated. The main compound, limonene, was also tested in biological assays. Eighty-four compounds, accounting for a relative peak area of 99.23%, 98.58% and 99.64%, were identified by GC/MS. Limonene (59–60%), γ-terpinene (10–11%) and β-pinene (7–15%) were the main compounds. All lemon oils inhibited specific biofilm production and bacterial metabolic activities into biofilm in a dose-dependent manner (20–65%, in the range of 0.1–4 mg mL−1) of both strains. Besides, all samples inhibited about 50% of the elastase activity at 0.1 mg mL−1. Pyocyanin biosynthesis decreases until 64% (0.1–4 mg mL−1) for both strains. Swarming motility of P. aeruginosa ATCC 27853 was completely inhibited by 2 mg mL−1 of lemon oils. Furthermore, a decrease (29–55%, 0.1–4 mg mL−1) in the synthesis of Quorum sensing (QS) signals was observed. The oils showed higher biological activities than limonene. Hence, their ability to control the biofilm of P. aeruginosa and reduce the production of virulence factors regulated by QS makes lemon oils good candidates to be applied as preservatives in the food processing industry.  相似文献   
7.
以废弃柑橘皮渣为碳源,通过ZnCl2活化后高温煅烧制备了纳米多孔碳材料(NPC),将其作为吸附剂,建立了分散固相萃取净化、气相色谱法测定果蔬中有机磷农药残留的方法.扫描电子显微镜(SEM)、X射线衍射(XRD)、傅立叶红外光谱(FT-IR)、拉曼光谱及氮气吸附分析(BET)等表征显示,NPC是无定形的多孔碳材料,孔径大小为0~15 nm,比表面积和孔体积分别为1243 m2/g和1.28 cm3/g.以果蔬中14种有机磷类农药为分析对象,考察了吸附剂的用量和净化时间,并将NPC与商业化材料N-丙基乙二胺(PSA)、十八烷基硅胶键合相(C18)和石墨化碳黑(GCB)进行了对比.结果表明,NPC最佳使用量为0.01 g,净化时间只需2 min.NPC成本远低于C18、PSA和GCB,因具有丰富的孔道结构,NPC净化效果显著优于3种商业化材料.在最优条件下,14种有机磷农药在0.02~1.0 mg/L范围内的线性关系良好(R2>0.99),检出限(S/N=3)为0.63~5.30μg/kg.3个添加水平下的平均回收率为71.3%~114.7%,相对标准偏差(RSD)为0.9%~12.9%.本方法操作简便、快速、成本低,在果蔬样品前处理中具有广阔的应用前景.  相似文献   
8.
阿维菌素在柑桔和土壤中的消解动态研究   总被引:1,自引:0,他引:1  
利用高效液相色谱法,建立了阿维菌素在柑桔和土壤中的残留分析方法.研究了阿维菌素在柑桔和土壤中的残留消解动态,对影响残留分析方法的主要参数进行了优化.柑桔和土壤样品分别用乙腈和二氯甲烷提取,弗罗里硅土柱净化,高效液相色谱仪可变波长紫外检测器检测,外标法定量.结果表明,该方法在柑桔和土壤中的最低检测浓度均为0.01 mg/...  相似文献   
9.
Chemical investigation of the fruit peel of dietary plant Citrus hystrix offered two new flavones 5,6,4′-trihydroxypyranoflavone I and 5,4′-dimethyl-6-prenylpyranoflavone XIII besides 11 known compounds. The structures of all compounds were elucidated with the aid of suitable analytical methods like 1D, 2D-NMR, mass and single crystal X-ray analysis. An X-ray crystal study of compound II was done for the first time and the compounds I–VI, XI and XII are hitherto not reported from this plant. Biological studies revealed that compound I found to have a good antidiabetic and antiacetylcholinesterase activities meanwhile compounds II, III and V showed a significant free radical scavenging ability as well as antioxidant capacity. In addition, compounds I, IV, V and VI showed cytotoxicity against U87, A549 and MCF-7 cells. Overall, the new compound I showed valuable bioactive properties. Due to insufficient quantity of compound XIII, biological studies were not done.  相似文献   
10.
In the present study, high-performance liquid chromatography micro-fraction bioactive evaluation and high speed countercurrent chromatography were performed on screening, identification and isolation of antioxidants from Citrus peel. Three compounds were screened as antioxidants and tyrosinase inhibitors using 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) radical cation scavenging assay and tyrosinase activity test, then they were identified as eriocitrin, narirutin and hesperidin. Moreover, the solvent system ethyl acetate-n-butanol-water (6:4:10, v/v/v) was used for separation of ethyl acetate extract of Citrus peel by high speed countercurrent chromatography. In total, 0.45 mg of eriocitrin with 87.10% purity, 2.04 mg of narirutin with 95.19% purity and 1.35 mg of hesperidin with 95.19% purity were obtained from 20 mg of ethyl acetate extract of Citrus peel in a single run and then each component was subjected to 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) radical cation scavenging assay and tyrosinase inhibition assay. Eriocitrin showed great antioxidant activity (the half-maximum concentration: 3.65 µM) and tyrosinase inhibition activity (the half-maximum concentration: 115.67 µM), while narirutin and hesperidin exhibited moderate activity. Tyrosinase inhibition activity for eriocitrin in vitro was reported for the first time. Furthermore, molecular docking between eriocitrin and mushroom tyrosinase was also studied.  相似文献   
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