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991.
Diterpenes from Salvia broussonetii transformed roots and their insecticidal activity 总被引:2,自引:0,他引:2
Fraga BM Díaz CE Guadaño A González-Coloma A 《Journal of agricultural and food chemistry》2005,53(13):5200-5206
The new diterpenes brussonol (1) and iguestol (6alpha,11-dihydroxy-12-methoxy-abieta-8,11,13-triene) (2) with an icetexane and a dehydroabietane skeleton, respectively, have been isolated from hairy root cultures of Salvia broussonetii. Other previously known diterpenes, 7-oxodehydroabietane, 11-hydroxy-12-methoxyabietatriene, taxodione, inuroyleanol, ferruginol, deoxocarnosol 12-methyl ether, cryptojaponol, pisiferal, sugiol, isomanool, 14-deoxycoleon U, 6alpha-hydroxydemethylcryptojaponol, demethylsalvicanol, and demethylcryptojaponol, were also obtained from these roots. The insect antifeedant and toxic effects of several of these compounds were investigated against the insect pests Spodoptera littoralis and Leptinotarsa decemlineata. Additionally, their comparative cytotoxic effects were tested on insect Sf9 and mammalian CHO cells. Demethylsalvicanol (4) was a moderate antifeedant to L. decemlineata, whereas brussonol (1) was inactive. 14-Deoxycoleon U (15) was the strongest antifeedant, whereas demethylcryptojaponol (11) was toxic to this insect. None of these compounds had antifeedant or negative effects on S. littoralis ingestion or weight gains after oral administration. Demethylcryptojaponol (11) was cytotoxic to mammalian CHO and insect Sf9 cell lines, followed by the icetexane derivative brussonol (1), with moderate cytotoxicity in both cases. The remainder of the test compounds showed a strong selective cytotoxicty to insect Sf9 cells, with demethylsalvicanol (4) being the most active. 相似文献
992.
Díaz-Maroto MC Díaz-Maroto Hidalgo IJ Sánchez-Palomo E Pérez-Coello MS 《Journal of agricultural and food chemistry》2005,53(13):5385-5389
Volatile oil extracts of fennel seeds (Foeniculum vulgare Mill.) and thyme leaves (Thymus vulgaris L.) were obtained by simultaneous distillation-extraction (SDE) and supercritical fluid extraction (SFE) and analyzed by gas chromatography-mass spectrometry (GC-MS). In general, fennel oil extracted by SDE and SFE showed similar compositions, with trans-anethole, estragole, and fenchone as the main components. In contrast, thymol and p-cymene, the most abundant compounds in thyme leaves, showed big differences, with generally higher amounts of monoterpenes obtained by SDE. However, in this case, the differences between the extracts were higher. Key odorants of fennel seeds determined by gas chromatography-olfactometry (GC-O) showed similar patterns when applying SDE and SFE. trans-Anethole (anise, licorice), estragole (anise, licorice, sweet), fenchone (mint, camphor, warm), and 1-octen-3-ol (mushroom) were the most intense odor compounds detected in fennel extracts. Thymol and carvacrol, with oregano, thyme, and spicy notes, were identified as key compounds contributing to the aroma of thyme leaves. 相似文献
993.
Núñez-Delicado E Serrano-Megías M Pérez-López AJ López-Nicolás JM 《Journal of agricultural and food chemistry》2005,53(15):6087-6093
Dominga grape polyphenol oxidase (PPO) was extracted using phase partitioning with Triton X-114. The enzyme was obtained in latent state and could be optimally activated by the presence of 0.2% sodium dodecyl sulfate (SDS) at pH 6.0. In the absence of SDS, the enzyme showed maximum activity at acid pH. The kinetic parameters of the enzyme at pH 3.0 and 6.0 in the presence of SDS were calculated. The effect of several inhibitors was studied, tropolone being the most effective with a K(i) value of 18 muM. The effect of cyclodextrins was also studied, and the complexation constant K(c) between G(2)-beta-cyclodextrins and 4-tert-butylcatechol was calculated using the enzymatic method (K(c) = 13960 M(-)(1)). The evolution of the color parameters (L, a, b) of liquefied grape berries was inhibited by inhibitors of PPO activity, such as diethyldithiocarbamate, metabisulfite, and G(2)-beta-cyclodextrins, indicating that enzymatic browning by PPO is the main process involved in the browning of Dominga grape juice at room temperature. 相似文献
994.
Real-time polymerase chain reaction based assays for quantitative detection of barley, rice, sunflower, and wheat 总被引:1,自引:0,他引:1
Quality assurance is a major issue in the food industry. The authenticity of food ingredients and their traceability are required by consumers and authorities. Plant species such as barley (Hordeum vulgare), rice (Oryza sativa), sunflower (Helianthus annuus), and wheat (Triticum aestivum) are very common among the ingredients of many processed food products; therefore the development of specific assays for their specific detection and quantification are needed. Furthermore, the production and trade of genetically modified lines from an increasing number of plant species brings about the need for control within research, environmental risk assessment, labeling/legal, and consumers' information purposes. We report here the development of four independent real-time polymerase chain reaction (PCR) assays suitable for identification and quantification of four plant species (barley, rice, sunflower, and wheat). These assays target gamma-hordein, gos9, helianthinin, and acetyl-CoA carboxylase sequences, respectively, and were able to specifically detect and quantify DNA from the target plant species. In addition, the simultaneous amplification of RALyase allowed bread from durum wheat to be distinguished. Limits of detection were 1 genome copy for barley, sunflower, and wheat and 3.3 copies for rice real-time PCR systems, whereas limits of quantification were 10 genome copies for barley, sunflower, or wheat and approximately 100 haploid genomes for rice real-time PCR systems. Real-time PCR cycling conditions of the four assays were stated as standard to facilitate their use in routine laboratory analyses. The assays were finally adapted to conventional PCR for detection purposes, with the exception of the wheat assay, which detects rye simultaneously with similar sensitivity in an agarose gel. 相似文献
995.
Nunez YP Carrascosa AV González R Polo MC Martínez-Rodríguez AJ 《Journal of agricultural and food chemistry》2005,53(18):7232-7237
Five mutants (obtained by UV mutagenesis) and the parent strain were selected to produce sparkling wines following the traditional or champenoise method. The wines were aged with the yeast for 9 months, with samples being taken each month for analytical and sensory determinations. The wines elaborated with mutant strain IFI473I demonstrated an accelerated release of protein, amino acids, and polysaccharides. An analysis of the secreted polysaccharides revealed that mannose was the major sugar present. The effects of the products released by yeasts on the foaming properties of the wines were determined by both sensory and instrumental analysis. In all cases, the wines elaborated with mutant strain IFI473I showed improved foaming properties as compared to wines fermented without this strain. Similar results were obtained at a decreased aging time of 6 months, thereby confirming the capacity of IFI473I strain to carry out an accelerated autolysis. These results demonstrate that mutant strain IFI473I can significantly reduce production times of high-quality sparkling wines. 相似文献
996.
Noeleen T. McDonald Miguel A. Dionisio Fernández David P. Wall 《Communications in Soil Science and Plant Analysis》2016,47(22):112-121
ABSTRACTA reliable and practical test that can provide timely measurements of the levels of mineralizable nitrogen (MN) in soil is critical for improving the accuracy of N fertilizer applications for grassland and crops. The Illinois soil N test (ISNT) is considered to be a good estimate of MN, once soils are grouped according to soil characteristics such as the drainage type and sampling depth. To date, development and evaluation of the ISNT method has been conducted using arable soils mainly in North America where, in general, soils have lower levels of soil organic matter (SOM) compared to temperate grassland soils. We evaluated the effects of two pre-treatment soil aggregate sizes of <1 mm and <2 mm on the yield and recovery of MN (1) across temperate grassland soil types, and (2) across a 6-h interval diffusion period. No significant difference existed in the concentrations of ISNT-N between the two soil aggregate sizes of each soil type. For both aggregate sample sizes, the recovery of spiked amino sugar-N glucosamine from a temperate grassland soil was generally linear until hour 5, after which the quantities of recovered N diminished. Although N recovery after 6 h of diffusion at 50°C (±1°C) was less than 100% in both aggregate size samples, the response models indicated that the standard ISNT protocol using a 5-h diffusion period is appropriate for temperate grassland soils. The incomplete recovery of N in these mineral soils suggested that the protocol could be further optimized for temperate soils with high organic matter content and additional evaluation of the temperature during diffusion within an enclosed environment may be required using N (spiked glucosamine-N) recovery studies. 相似文献
997.
Vallejo F García-Viguera C Tomás-Barberán FA 《Journal of agricultural and food chemistry》2003,51(13):3776-3782
Changes in phenolic compounds, total glucosinolates, and vitamin C were monitored during the productive period along five inflorescence development stages of three broccoli commercial cultivars (Marathon, Monterrey, and Vencedor). In an attempt to identify differences due to agronomic factors, broccoli cultivars were grown under different sulfur fertilization with poor (15 kg/ha) and rich (150 kg/ha) rates. Phenolic compounds and vitamin C concentrations showed, in all broccoli cultivars, a rising trend from the first stage until the over-maturity stage, both for rich and poor sulfur fertilization. Significant differences were detected in the first two stages between rich and poor sulfur fertilization in total glucosinolates for all broccoli cultivars, where the highest concentration was always observed in the second development stage (used as minimally processed product) during poor fertilization. With regard to the last three stages, the glucosinolate concentration in the poor sulfur fertilization started to slope down until the over-maturity stage. Where rich sulfur fertilization is concerned, the highest level was reached during the third stage (used as minimally processed product also), and after that, glucosinolate concentration decreased until the fifth stage. 相似文献
998.
Fernández M Picó Y Girotti S Mañes J 《Journal of agricultural and food chemistry》2001,49(8):3540-3547
Pesticides applied in extended agricultural fields may be controlled by means of bioindicators, such as honeybees, in which are the pesticides bioaccumulate. Liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) experiments with positive (PI) and negative (NI) ion modes were optimized for the analysis of 22 organophosphorus pesticides in honeybee samples. The extraction required 3 g of sample, which was extracted with acetone. The extract was purified with coagulating solution and reextracted with Cl(2)CH(2). Pesticides studied could be detected by both ionization modes except for parathion, parathion-methyl, and bromophos, which did not give signals in PI mode, and triazophos, which was not detected in NI mode. Fragmentation voltage and vaporizer temperature were optimized to achieve the highest sensitivity. The spectra profile of each pesticide in PI mode showed the [M + H](+) ion as the main signal, whereas in NI mode only fragment ions were shown. The detection limit obtained in selected ion monitoring mode ranged from 1 to 15 microg kg(-1). The average recoveries from spiked honeybees at various concentration levels (0.5-5 mg kg(-1)) exceeded 65% with relative standard deviations of 4-15%. The method was applied to real samples, in which residues of coumaphos and dimethoate were detected. 相似文献
999.
M. B. Halitligil Ali Akın Nesteren Bilgin Yusuf Deniz Karani Öğretir Bülent Altınel Yusuf Işık 《Biology and Fertility of Soils》2000,31(2):175-182
In order to evaluate the influence of different N rates on percent N derived from fertilizer (%Ndff) at different growth stages, on yields and the percent N use efficiency (%NUE) values of two winter wheat varieties (durum and bread), field experiments on fallow were carried out at four different locations in Central Anatolia, in the 1991–1992 and 1992–1993 growing seasons. At each site the rates of N (0, 40, 80 and 120?kg N/ha) were applied as ammonium sulphate [(NH4)2SO4] using a Latin Square experimental design with four replicates. The total amounts of N fertilizer were applied once after seedling emergence at all experimental sites. Labelled (15NH4)2SO4 fertilizer was applied to sub-plots from which %Ndff values were determined at tillering, booting, grain filling, and harvest stages. Yield sub-plots received unlabelled (NH4)2SO4 from which total dry matter (seed and straw) and N yields were determined. Also the %NUE values were calculated by the 15N and "difference" methods at the harvest stage. Stored soil moisture at 0–90?cm depth, evapotranspiration and water use efficiency values were calculated as well. The results obtained showed that (1) Gerek-79 variety used both the applied N fertilizer and the available soil moisture more efficiently, (2) the percent NUE values obtained overall were generally less than 20 for both varieties and (3) with the 15N method, less variable %NUE values were obtained in comparison to the difference method. 相似文献
1000.