Circulating levels of vitamin E in captive Asian elephants (Elephas maximus)

Circulating levels of α-tocopherol (vitamin E) were examined via high-performance liquid chromatography in four female Asian elephants (Elephas maximus) at the New York Zoological Park between 1983 and 1987. Plasma vitamin E averaged 0.08 μg/ml in 1983, and was considered deficient. Over a four-year period of dietary supplementation ranging from 0.7 to 3.7 IU vitamin E/kg body mass (approximately 50 to 250 IU/kg diet as fed), mean plasma α-tocopherol increased to 0.6 μg/ml. Plasma and dietary vitamin E were found to be significantly correlated (p < 0.025) in these animals. Serum or plasma vitamin E measured in an additional 20 elephants from eight other zoological institutions in the United States and Canada averaged 0.5 μg/ml, but values were not significantly correlated (p > 0.05) with calculated dietary levels of the vitamin. To achieve the mean value for circulating α-tocopherol in captive elephants (0.5 μg/ml), feed must provide at least 1.0, and more likely 2.0 to 2.5 IU vitamin E/kg body mass (approximately 130 to 167 IU/kg diet).     

南美白对虾饲料中沙蚕的营养成分分析

以南美白对虾饲料中的沙蚕为研究对象,通过气相色谱-质谱联用仪和氨基酸自动分析仪分析检测其体内的脂肪酸和氨基酸,之后对其营养价值进行了分析评价。结果表明:沙蚕体内检测出11种脂肪酸,多不饱和脂肪酸质量分数高达46.62%,其中EPA和AA的含量达16.20%和10.41%;沙蚕体内蛋白含量丰富,必需氨基酸含量为38.39%。通过营养评价,表明沙蚕对南美白对虾来说是一种高蛋白、低脂肪的优质饲料。     

Mapping the regioisomeric distribution of fatty acids in triacylglycerols by hybrid mass spectrometry

This study describes the use of hybrid mass spectrometry for the mapping, identification, and semi-quantitation of triacylglycerol regioisomers in fats and oils. The identification was performed based on the accurate mass and fragmentation pattern obtained by data-dependent fragmentation. Quantitation was based on the high-resolution ion chromatograms, and relative proportion of sn-1(3)/sn-2 regioisomers was calculated based on generalized fragmentation models and the relative intensities observed in the product ion spectra. The key performance features of the developed method are inter-batch mass accuracy < 1 ppm (n = 10); lower limit of detection (triggering threshold) 0.1 μg/ml (equivalent to 0.2 weight % in oil); lower limit of quantitation 0.2 μg/ml (equivalent to 0.4 weight % in oil); peak area precision 6.5% at 2 μg/ml concentration and 15% at 0.2 μM concentration; inter-batch precision of fragment intensities < 1% (n = 10) independent of the investigated concentration; and averaged accuracy using the generic calibration 3.8% in the 1–10 μg/ml range and varies between 1–23% depending on analytes. Inter-esterified fat, beef tallow, pork lard, and butter fat samples were used to show how well regioisomeric distribution of palmitic acid can be captured by this method.     

Gene transfer of the Caenorhabditis elegans n-3 fatty acid desaturase inhibits neuronal apoptosis

Previous studies have shown that n-3 polyunsaturated fatty acids (PUFAs) can exert an antiapoptotic effect on neurons. The present study was designed to investigate whether the Caenorhabditis elegans fat-1 gene encoding an n-3 fatty acid desaturase (an enzyme that converts n-6 PUFAs to corresponding n-3 PUFAs) can be expressed functionally in rat cortical neurons and whether its expression can change the ratio of n-6 : n-3 fatty acids in the cell membrane and exert an effect on neuronal apoptosis. Infection of primary rat cortical cultures with Ad-fat-1 resulted in high expression of the fat-1 gene. Lipid analysis indicated a decrease in the ratio of n-6 : n-3 PUFAs from 5.9 : 1 in control cells, to 1.45 : 1 in cells expressing the n-3 fatty acid desaturase. Accordingly, the levels of prostaglandin E2, an eicosanoid derived from n-6 PUFA, were significantly lower in cells infected with Ad-fat-1 when compared with control cells. Finally, there was a significant inhibition of growth factor withdrawal-induced apoptotic cell death in neurons expressing the fat-1 gene. These results demonstrate that expression of the fat-1 gene can inhibit apoptotic cell death in neurons and suggest that the change in the n-6 : n-3 fatty acid ratio may play a key role in this protective effect.     

构树种子化学成分研究

对构树种子的脂肪油、氨基酸、矿质元素进行分析,结果表明:种子含脂肪油40.18%,主要成分为:亚油酸(85.42%)、油酸(4.29%)、棕榈酸(7.35%)、亚麻酸(0.98%)等。此外,还含有17种氨基酸和24种矿质元素。     

The transfer of fatty acids in a freshwater planktonic foodweb of the Kuibyshevskoe reservoir (middle reaches of the Volga)

The fatty acid composition of seston (small-size fraction, < 50 m) and of Daphnia galeata, Bythotrephes longimanusand adult individuals of Leptodora kindtii was analysed in the summer of 1997. When comparing the eicosapentaenoic acid (EPA) content of seston with Daphnia, Daphnia with Bythotrephes; Daphniawith Leptodora, we found similarities in the dynamics of EPA accumulation, in most cases. The content of EPA in seston was found to be significantly correlated with numerical abundance of small diatoms (r =0.662).Maximally the % EPA increased from seston (traces – 4% of total fatty acids) to Daphnia (traces – 12.2%). Both the lower and upper relative EPA contents were higher in Bythotrephes (10.8–16%), whereas the maximum value was lower in Leptodora (0.4–6.3%) compared to Daphnia. Correlation coefficients between the EPA content of the organisms at different trophic levels were not significant. The existence of species-specific differences in accumulation and /or transformation of polyunsaturated fatty acids in freshwater crustaceans is proposed.     

不同细菌来源的3-酮脂酰ACP合成酶Ⅲ生物学特性分析

3-酮脂酰ACP合成酶Ⅲ(FabH)是催化细菌脂肪酸合成的起始反应.研究表明,革兰氏阳性细菌FabH对支链脂酰-CoA前体的选择性是其合成支链脂肪酸的关键.但部分革兰氏阴性细菌也产生一定量的支链脂肪酸,其合成机制还不清楚.为此,本研究选取了革兰氏阳性细菌枯草芽孢杆菌BsfabH1和BsfabH2、金黄色葡萄球菌SafabH、天蓝色链霉菌ScofabH、革兰氏阴性细菌茄科雷尔氏菌RsfabH、大肠杆菌EcfabH,以及产支链脂肪酸的水稻黄单胞菌XoofabH,共7种fabH同源基因进行生物学特性分析.异体遗传互补茄科雷尔氏菌fabH突变株RsmH,表明这7个基因编码蛋白都具有3-酮脂酰ACP合成酶Ⅲ活性.脂肪酸组成分析显示,4个革兰氏阳性菌fabH和XoofabH互补株类似,均能产生支链脂肪酸,而EcfabH和RsfabH互补株不产生支链脂肪酸,说明XooFabH不同于EcFabH,参与支链脂肪酸合成.体外酶学分析表明,XooFabH与4种革兰氏阳性菌FabH类似,对支链脂酰-CoA有较高的选择,但EcFabH和RsFabH对支链前体活性低.与革兰氏阳性细菌FabH不同,XooFabH对中短链长(C4~C10)脂酰-CoA也具有较高的活性.综合以上结果,不同细菌来源FabH的生物学特性差异明显,FabH能利用支链前体是细菌合成支链脂肪酸的关键因素.     

青葙子化学成分初步研究

本文报道青葙子的主要化学成分。经测定,青葙子氨基酸种类比较齐全,必需氨基酸含量较高,占总氨基酸含量的42.85%。种子含有丰富的脂肪油,主要成分为:棕榈酸(18.225%)、硬脂酸(2.459%)、油酸(27.995%)、亚油酸(44.522%)和亚麻酸(2.374%)等,不饱和脂肪酸的含量达79.276%。种子还含有种类较齐全的矿质元素,具有较高的营养价值。     

Recovery of brain docosahexaenoate leads to recovery of spatial task performance

Infants fed vegetable oil-based formulas may have poorer visual function, lower cognitive scores and acquire learning tasks more slowly in comparison with those breast fed or those fed formulas supplemented with docosahexaenoate. The aim of the present study was to determine the reversibility of losses in brain function associated with the loss of brain DHA. Rats were fed very low or adequate levels of n-3 fatty acids through three generations. The n-3 fatty acid deficient animals of the F3 generation were then given an n-3 adequate diet containing alpha-linolenic and docosahexaenoic acids (DHA) at birth, weaning (3 weeks) or young adulthood (7 weeks). The spatial task performance of these animals returned to the n-3 adequate diet was then compared using the Morris water at two different ages, at 9 or 13 weeks. Our results indicate that animals repleted since birth or at weaning were able to achieve nearly the same level of brain DHA and spatial task performance as animals maintained for three generations on an n-3 adequate diet. In the case of young adult animals, the degree of DHA and behavioral performance recovery depended upon the duration of dietary repletion with substantial recovery in animals after 6 weeks but little recovery of function after two weeks. The significance of these findings is that they indicate that at least some of the adverse effects of DHA deficiency during neurodevelopment may be reversible with an n-3 fatty acid supplemented diet.