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71.
The biological screening of 44 marine sponge extracts for the research of bioactive molecules, with potential application in the treatment of age-related diseases (cancer and Alzheimer’s disease) and skin aging, resulted in the selection of Scopalina hapalia extract for chemical study. As no reports of secondary metabolites of S. hapalia were found in the literature, we undertook this research to further extend current knowledge of Scopalina chemistry. The investigation of this species led to the discovery of four new compounds: two butenolides sinularone J (1) and sinularone K (2), one phospholipid 1-O-octadecyl-2-pentanoyl-sn-glycero-3-phosphocholine (3) and one lysophospholipid 1-O-(3-methoxy-tetradecanoyl)-sn-glycero-3-phosphocholine (4) alongside with known lysophospholipids (5 and 6), alkylglycerols (7–10), epidioxysterols (11 and 12) and diketopiperazines (13 and 14). The structure elucidation of the new metabolites (1–4) was determined by detailed spectroscopic analysis, including 1D and 2D NMR as well as mass spectrometry. Molecular networking was also explored to complement classical investigation and unravel the chemical classes within this species. GNPS analysis provided further information on potential metabolites with additional bioactive natural compounds predicted.  相似文献   
72.
在大气CO2体积分数为700×10-6条件下,对油桐和烟草的光合CO2同化速率、光呼吸18O2吸收速率、光合色素、叶的脂类和脂肪酸组成等进行了比较分析.结果表明:大气CO2体积分数为700×10-6时油桐和烟草的光合速率有所增加,并抑制光呼吸18O2的吸收,但是,油桐对CO2浓度升高比烟草敏感,它的光合速率在700×10-6CO2时增加了2倍,而光呼吸18O2吸收则完全消失;油桐在700×10-6CO2下生长,光合色素合成量增加较多,其中叶绿素b及类胡罗卜素等属于捕光色素系统的色素增加尤其明显,叶绿素a/b值显著下降,在同样条件下,烟草的叶绿素含量还略有减少,类胡罗卜素含量则明显减少;高浓度CO2影响这两种植物叶的脂类和脂肪酸的组成,700×10-6CO2下生长的这两种植物叶的饱和脂肪酸和磷脂含量有所增加,但油桐叶的糖脂含量有所下降,烟草的糖脂含量则不受CO2浓度升高的影响.  相似文献   
73.
This study determined the profile of hydrophobic phytochemicals (steroid-like components and lipophilic phenolics) and antioxidant potential (DPPH and Rancimat tests) of wheat grain in relation to sowing date (standard vs. delayed) using six cultivars of Triticum aestivum wheat grown in Poland. The study found that “sowing time” generally had a low impact on sterols, carotenoids, squalene and total lipophilic phenolics in wheat grain. The highest impact of “sowing time” was noted for α-tocopherol, C19:0 alkylresorcinol and campesterol. Delayed sowing reduced their content by up to 9%. The antioxidant potential of grain extracts obtained by the use of water-saturated butanol (WSB) was mostly cultivar-dependent (depending on assay: DPPH 56.3% and Rancimat 75.1% of explained variation, respectively). Wheat grain WSB extracts increased rapeseed oil induction time by up to 21% and their antioxidant capacity was up to 1.24 μM TEg−1.  相似文献   
74.
本试验旨在研究日粮中添加屎肠球菌对AA肉鸡生产性能、免疫器官指数和血液脂质代谢相关指标的影响,探讨屎肠球菌替代抗生素在肉鸡日粮中应用的可行性及其最适添加量。试验选取1日龄AA肉鸡公仔鸡600只(50 g/只),随机分成5组,每组6个重复,每个重复20只鸡。对照组(CON)饲喂基础日粮;抗生素组(ANT)饲喂基础日粮+0.1%金霉素;3个屎肠球菌试验组(LEF、MEF和HEF组)在基础日粮中分别添加50、100、200 mg/kg屎肠球菌。试验分2期,分别为1~21日龄(前期)和22~42日龄(后期)。结果显示:①各试验组肉鸡生长性能与CON组相比均无显著差异(P>0.05);从饲养全期看,MEF组和HEF组AA肉鸡的死淘率最低。②在饲养后期,与CON组相比,MEF组胸腺指数显著提高(P<0.05),MEF组脾脏指数有提高的趋势(0.05 < P < 0.1)。③在饲养前期,与CON组和ANT组相比,LEF组和HEF组血清总胆固醇(TC)含量极显著降低(P<0.01);与ANT组相比,LEF组和MEF组血清甘油三酯(TG)含量极显著降低(P<0.01);与CON组相比,MEF组和HEF组血清高密度脂蛋白(HDL)含量极显著提高(P<0.01);与ANT组相比,添加屎肠球菌试验组的低密度脂蛋白(LDL)含量极显著降低(P<0.01)。在饲养后期,与CON组和ANT组相比,LEF组肉鸡血清中TG含量极显著降低(P<0.01),LEF组和MEF组HDL含量极显著提高(P<0.01)。综上所述,在肉鸡饲养中,添加屎肠球菌可以在一定程度上降低死淘率,并有促进免疫器官发育的趋势,还具有一定的降低血脂的作用。综合考虑,建议在AA肉鸡日粮中添加100 mg/kg屎肠球菌。  相似文献   
75.
The order of aluminum (Al) tolerance in triticale lines (ST2>ST22) after re-elongation in an Al-free 0.2 mM calcium (Ca) solution for 9 h (Ca period) following 1 h pretreatment with 20 μM Al (Al period) agreed with that after 24 h of Al treatment. Permeability of the plasma membrane (PM) of root-tip cells after the Ca period was significantly increased in Al-sensitive ST22. Al was accumulated more heavily in the root-tip portion of ST22 than in that of ST2, although similar amounts of malic and citric acid anions were released from both triticale lines. We established a new system examining lipid permeability using synthesized nylon-2,8 ultrathin and porous capsules trapped previously with 0.1% (w/v) methylene blue solution and coated thereafter with PM lipid isolated from root tips by a newly developed technique. Permeability of the PM lipid measured with time in 0.2 mM Ca with or without 50 μM Al photometrically ( A 680) was significantly greater in Al-sensitive ST22 after 5 min of Al treatment. This is the first report to directly show the primary and early role of PM lipid in Al tolerance in triticale.  相似文献   
76.
A. M. Thro  K. J. Frey 《Euphytica》1985,34(2):251-263
Summary The potential for breeding for high groat-oil content in oats was investigated by (a) conducting generation means analyses on data from three matings among adapted Avena sativa L. cultivars, (b) practicing one cycle of phenotypic recurrent selection in a segregating population derived from eight species backcrosses (Avena sativa x (A. sativa x A. sterilis)) among 24 parents, and (c) identifying transgressive segregates from interspecific (A. sativa x A. sterilis) matings.Additive gene action was the most important component in explaining the variation among generation means for groat-oil content. Dominance and epistatic interactions involving dominance were not significant in any mating. Significant residual genetic variation occurred in one mating, even after additive, dominance, and three digenic interactions were fitted. The importance of additive genes action implies that desired allelic combinations for high groat-oil content can be obtained in pure-line cultivars.One cycle of phenotypic recurrent selection using single plants as the selection units resulted in a genetic gain of 1.7 to 2.1% in groat-oil content. Individual plants selected for initiating the second cycle had from 9.5 to 12.6% groat oil.Over all 12 interspecific matings, the F2 progeny means were similar to the midparent values. Only two were significantly deviant. Transgressive segregates for high and low groat-oil content from these matings provided evidence that A. sterilis possesses alleles for high and low groat-oil content that are different from those in the gene pool of cultivated oats.Journal Paper No. J-11340 of the Iowa Agric. and Home ECon. Exp. Stn., Ames, Iowa 50011. Project 2447. This study was supported in parts by grants from the Iowa Committee for Agricultural Development and the International Harvester Company.  相似文献   
77.
家兔日粮中的脂质能够影响兔肉的品质,科学利用日粮脂质,能够克服兔肉多不饱和脂肪酸组成不平衡和易氧化的缺点,提高兔肉的营养价值和肉品质。文章简述了日粮脂质在兔肉中的蓄积及对兔肉脂肪酸成分、抗氧化性、系水力和嫩度的影响。  相似文献   
78.
The fatty acid compositions of fish tissue lipids usually reflect those of the feed lipids, but few attempts have been made to predict the way in which the profiles change or assess the time required for the fatty acid profile to stabilize following a dietary change. The present focus on the influences of vegetable oils and fish oils on the fatty acid compositions and sensory attributes of fish fillets increases the interest in the ability to make such predictions. A dilution model was tested using data for the influences of feed oils (rape/linseed (V) vs. sand‐eel (F)) and dietary fat concentrations (ca. 30% (H) vs. ca. 20% (L)) on the body growth and fatty acid compositions of the fillets of Atlantic salmon, Salmo salar L., parr and post smolt. Fish given HV or LV feeds during freshwater rearing (mass increase from ca. 19 g to ca. 130 g) were switched to HF and LF feeds following parr–smolt transformation. The changes in fillet percentages of 18:1, 18:2 (n‐6) and 18:3 (n‐3) during 98 days of on‐growing in seawater (mass increase from ca. 130 g to ca. 380 g) conformed closely to predictions made on the basis of the dilution model. Model applications require information about the proportionate increase in fillet fat over time, but the relative changes in body mass can be used as a surrogate provided that both fillet yield (as a % of body mass) and fillet fat percentage change little over time. This is not the case for small salmon, but does seem to apply to larger salmon as they approach harvest size. This means that, for large salmon, ratios of changes in body mass can be substituted for ratios in the quantitative change in fillet fat without the introduction of a large error in the prediction of the change in fillet fatty acid profile following the introduction of a novel feed.  相似文献   
79.
We assessed growth in subyearling chinook salmon (Oncorhynchus tshawytscha) during the 1998 El Niño and 1999 La Niña in the Gulf of the Farallones, a region of the continental shelf off central California seaward of the Golden Gate and the southernmost ocean entry point for the species in North America. Juvenile salmon demonstrated greater growth during this strong El Niño, when water temperature anomalies of more than +3°C were recorded at local buoys, than during the similarly strong 1999 La Niña. Slopes of regressions of weight on length, length on age, and weight on age were all significantly greater for juvenile salmon during the 1998 El Niño compared with those in the 1999 La Niña. Daily otolith increment widths, an estimator of somatic growth, corroborated population data. Between June 1 and August 9, mean increment widths for juvenile chinook salmon in 1998 were 3.54 ± 0.03 μm, significantly larger than the 3.13 ± 0.03 μm found in juveniles during the same time interval in 1999. Condition factor for juvenile chinook salmon entering the ocean at the Golden Gate was the same in both years, but became significantly greater in ocean fish during the 1998 El Niño than in ocean fish during the 1999 La Niña. Energy storage was significantly greater in ocean juvenile salmon during the 1998 El Niño as well. Mean triacylglycerol/cholesterol ratios increased following ocean entry in 1998, whereas they declined in ocean juveniles during 1999. Thus, not only was growth better in the El Niño period compared with La Niña, but lipid accumulation was also better. Oceanographic data for 1998 indicated elevated temperatures, lower salinity, greater freshwater outflow from San Francisco Bay, northerly flowing coastal currents, and positive upwelling index anomalies. This combination of environmental factors resulted in greater zooplankton productivity that, in conjunction with higher temperatures, allowed metabolic processes to enhance growth. Although El Niño events have certainly produced large-scale, and often adverse, effects on ecosystems, the results of this study emphasize the importance of local oceanographic conditions to growth and other physiological and ecological processes.  相似文献   
80.
The fatty acid composition of pikeperch (Sander lucioperca) was determined according to their physiological status, during starvation (10 days) and feeding (28 days). In starved larvae, polyunsaturated, monounsaturated and saturated fatty acids were utilized as metabolic substrates until day 9. At day 10, all fatty acid levels remained stable or, at least, increased in larval body. Among fatty acids, docosahexaenoic acid 22:6 n-3 was used preferentially (20.3% from total fatty acids utilized) followed by palmitoleic acid 16:1 n-7 (13.9%) and then by oleic 18:1 n-9 (12.3%), linoleic 18:2 n-6 (10.1%), linolenic 18:3 n-3 (9.7%) and eicosapentaenoic 20:5 n-3 (9.1%) acids. On the other hand, arachidonic acid 20:4 n-6 was utilized very lowly (0.3%). In fed larvae, no utilization of body fatty acids was observed during the experiment. It seems that energy requirements (and others) of fed larvae were satisfied by feed.  相似文献   
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