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41.
42.
Kim JK Lee SY Chu SM Lim SH Suh SC Lee YT Cho HS Ha SH 《Journal of agricultural and food chemistry》2010,58(24):12804-12809
Flavonoids and carotenoids of pigmented rice ( Oryza sativa L.), including five black cultivars and two red cultivars, from Korea were characterized to determine the diversity among the phytochemicals and to analyze the relationships among their contents. Black cultivars were higher in flavonoids and carotenoids than the red and white cultivars. The profiles of eight phytochemicals identified from the rice grains were subjected to principal component analysis (PCA) to evaluate the differences among cultivars. PCA could fully distinguish between these cultivars. The Heugjinjubyeo (BR-1) and Heugseolbyeo (BR-2) cultivars were separated from the others based on flavonoid and carotenoid concentrations. Flavonoid contents had a positive correlation with carotenoid contents among all rice grains. The BR-1 and BR-2 cultivars appear to be good candidates for future breeding programs because they have simultaneously high flavonoid and carotenoid contents. 相似文献
43.
Sang S Kikuzaki H Lapsley K Rosen RT Nakatani N Ho CT 《Journal of agricultural and food chemistry》2002,50(16):4709-4712
One sphingolipid, 1-O-beta-D-glucopyranosyl-(2S,3R,4E,8Z)-2-[(2R)-2-hydroxyhexadecanoylamino]-4,8-octadecadiene-1,3-diol, and four other constituents, beta-sitosterol, daucosterol, uridine, and adenosine, have been isolated from the nuts of almond (Prunus amygdalus). Complete assignments of the proton and carbon chemical shifts for the sphingolipid were accomplished on the basis of high-resolution 1D and 2D NMR data. All of these compounds are being reported from almond nuts (P. amygdalus)for the first time. 相似文献
44.
New prenylated benzoic acid and other constituents from almond hulls (Prunus amygdalus Batsch). 总被引:2,自引:0,他引:2
Shengmin Sang Karen Lapsley Robert T Rosen Chi-Tang Ho 《Journal of agricultural and food chemistry》2002,50(3):607-609
One new prenylated benzoic acid derivative, 3-prenyl-4-O-beta-D-glucopyranosyloxy-4-hydroxylbenzoic acid, and three known constituents, catechin, protocatechuic acid, and ursolic acid, have been isolated from the hulls of almond (Prunus amygdalus). Complete assignments of the proton and carbon chemical shifts for the new prenylated benzoic acid derivative were accomplished on the basis of high-resolution 1D and 2D nuclear magnetic resonance data. All of these compounds except ursolic acid are being reported from almond hulls (P. amygdalus) for the first time. 相似文献
45.
Sato D Awad AA Chae SH Yokota T Sugimoto Y Takeuchi Y Yoneyama K 《Journal of agricultural and food chemistry》2003,51(5):1162-1168
A simple and rapid analytical method for strigolactones, germination stimulants for the root parasitic weeds witchweed (Striga spp.) and broomrape (Orobanche spp.), has been developed using high-performance liquid chromatography connected to tandem mass spectrometry (LC/MS/MS). The natural strigolactones (strigol, sorgolactone, orobanchol, and alectrol) were clearly separated and identified by LC/MS/MS. As low as 0.1 pg/microL of strigol and 0.5 pg/microL of sorgolactone could be quantified, whereas 1 pg/microL was needed for the quantification of orobanchol (S/N > 10). Using this method, it was found that red clover produces orobanchol and alectrol but not strigol. The roots of red clover seedlings were found to produce 13, 70, 58, and 65 pg of orobanchol/plant 1, 2, 3, and 4 weeks after germination, respectively. 相似文献
46.
47.
Ji-Hoon Kim Won Sik Shin Dong-Ik Song Sang June Choi 《Water, air, and soil pollution》2005,166(1-4):367-380
Single- and bi-solute sorption and desorption of 2,4-dichlorophenol (2,4-DCP) and 2,4,5-trichlorophenol (2,4,5-TCP) in montmorillonite modified with hexadecyltrimethylammonium (HDTMA) were investigated using multi-step sorption and desorption procedure. Effect of pH on the multi-step sorption and desorption was investigated. As expected by the magnitude of octanol-water partition coefficient, K ow , both sorption and desorption affinity of 2,4,5-TCP was higher than that of 2,4-DCP at pH 4.85 and 9.15. For both chlorophenols, the protonated speciation (at pH 4.85) exhibited a higher affinity in both sorption and desorption than the predominant deprotonated speciation (about 95% and 99% of 2,4-dichlorophenolate and 2,4,5-trichlophenolate anions at pH 9.15, respectively). Desorption of chlorinated phenols was strongly dependent on the current pH regardless of their speciation in the previous sorption stage. Freundlich model was used to analyze the single-solute sorption and desorption data. No appreciable desorption-resistant (or non-desorbing) fraction was observed in organoclays after several multi-step desorptions. This indicates that sorption of phenols in organoclay mainly occurs via partitioning into the core of the pseudo-organic medium, thereby causing desorption nearly reversible. In bisolute competitive systems, sorption (or desorption) affinity of both chlorophenols was reduced compared to that in its single-solute system due to the competition between the solutes. The ideal adsorbed solution theory (IAST) coupled to the single-solute Freundlich model successfully predicted bisolute multi-step competitive sorption and desorption equilibria. 相似文献
48.
地下水埋深对春玉米田土壤水分及产量的影响 总被引:17,自引:3,他引:17
通过6种地下水位控制处理和对照春玉米试验,探讨了地下水埋深对春玉米农田土壤水分、产量以及水分利用效率的影响。结果表明,地下水埋深对春玉米0~100cm层次土壤水分的影响较大。地下水位越浅这种影响显得越明显;无论地下水埋深深浅,田间累计地下水补给量变化规律可分为4个阶段,即稳定增长期、缓慢增长期、快速增长期和趋于稳定期。地下水位越高,累计地下水补给量越大,土壤排水量越大。较大降雨后土壤开始排水日期随着地下水埋深加深而滞后;地下水埋深1.0m时春玉米产量和水分利用率最高。地下水位在1.0m以下时,水分利用效率随地下水位加深而减少。 相似文献
49.
Anushka Upamali Rajapaksha Meththika Vithanage Sang Soo Lee Dong-Cheol Seo Daniel C. W. Tsang Yong Sik Ok 《Journal of Soils and Sediments》2016,16(3):889-895
Purpose
Sulfamethazine (SMT) is increasingly detected in environmental matrices due to its versatile use as antibiotics. We aimed to investigate the benefits and roles of steam activation of biochars with respect to SMT sorption kinetics and equilibrium sorption.Materials and methods
Biochars were produced from burcucumber plant and tea waste using a pyrolyzer at a temperature of 700 °C for 2 h. The biochar samples were treated with 5 mL min?1 of steam for an additional 45 min for post-synthesis steam activation. The SMT sorption on the unmodified and steam activated biochars were compared.Results and discussion
The time taken to reach equilibrium was significantly less for steam activated biochars (~4 h) than non-activated biochars (>24 h). Up to 98 % of SMT could be removed from aqueous solutions by steam activated biochars. The sorption kinetic behaviors were well described by the pseudo-second model and SMT sorption rates of steam activated biochars (k 2?~?1.11–1.57 mg g?1 min?1) were significantly higher than that of the unmodified biochars (k 2?~?0.04–0.11 mg g?1 min?1) because of increased availability of accessible porous structure with averagely larger pore diameters. Moreover, the equilibrium sorption on the unmodified biochars was significantly influenced by increasing solution pH (~30–50 % reduction) because of speciation change of SMT, whereas steam activated biochars manifested much stronger sorption resilience against pH variation (~2–4 % reduction only) because the enhanced porosity offset the effect of unfavorable electrostatic repulsion.Conclusions
The observed features of steam activated biochars would render their applications more versatile and reliable in field throughout changeable environmental conditions.50.
Four new steroidal saponins from the seeds of Allium tuberosum 总被引:3,自引:0,他引:3
Four new steroidal saponins, 26-O-beta-D-glucopyranosyl-(25S,20R)-20-O-methyl-5alpha-furost-22(23)-en-2alpha,3beta,20,26-tetraol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (1); 26-O-beta-D-glucopyranosyl-(25S,20R)-5alpha-furost-22(23)-en-2alpha,3beta,20,26-tetraol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L- rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (2); 26-O-beta-D-glucopyranosyl-(25S,20S)-5alpha-furost-22(23)-en-2alpha,3beta,20,26-tetraol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L- rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (3); and 26-O-beta-D-glucopyranosyl-(25S,20S)-5alpha-furost-22(23)-en-3beta,20,26-triol 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside (4), have been isolated from the seeds of Allium tuberosum. Their structures were established by spectroscopic studies such as MS, IR, NMR, and 2D-NMR and the results of acid hydrolysis and named tuberosides F, G, H, and I, respectively. 相似文献