鱼鳞云杉种子油中顺-5,9,12-十八碳三烯酸的分离和鉴定

在东北松科鱼鳞云杉(Picea jezoensis Carr.)种子油脂肪酸的分析中,发现有三种不常见脂肪酸未予鉴定,其中一种含量高达25.9％。对此我们进行了分离鉴定,确证为顺-5,9,12-十八碳三烯酸。此酸芬兰Eero Elomaa已有报导。 本实验分析了东北松科其余11种种子油脂肪酸的组成,发现它们都含有顺-5,9,12-十八碳三烯酸,但在我们分析过的东北其他科属180种种子油的脂肪酸中,未发现上述不     

油松种子油中顺-5,11,14-二十碳三烯酸的分离鉴定

本实验从油松(Pinus tabulaeformis Carr.)种子油中用尿素包合法和柱层析结合的方法分离出一种不常见的脂肪酸,经GC、UV、MS、NMR和IR分析确证该酸为顺-5,11,14-二十碳三烯酸,此酸芬兰T.Lehtinen美国T.Takagl已有报道。     

木姜子属三种植物油的脂肪酸成分

山苍子、天目木姜子、桂北木姜子种子油中脂肪酸成分均主含月桂酸(34.6—75.4%)。桂北木姜子果肉油的脂肪酸成分与其种子油不同,主要成分是亚油酸。生长在不同地区(湖南、福建、杭州等省市)的山苍子种子含油量及其脂肪酸成分是有差异的。采用减压分馏、硝酸银硅胶桂层析和液液分配层析方法,从山苍子种子油脂肪酸中分离出 C_(10)—C_(14)烯酸。通过高碘酸钠、高锰酸钾氧化方法、红外光谱、核磁共振和质谱分析,确定它们是顺式4-十碳烯酸、顺式4-十二碳烯酸和顺式4-十四碳烯酸。     

曼陀罗种子油脂肪酸化学成分研究

以石油醚为溶剂提取曼陀罗种子中的脂肪酸,采用GC-MS技术测定其化学成分,并通过饲料混毒法测定了曼陀罗种子脂肪酸对小鼠的毒性.结果表明,曼陀罗种子中含有23.2%的脂肪酸,其主要化学成分为1,20-二十碳二酸(34.55%)、Crinan-3-ol,1,2-didehydro-,(3à)(13.41%)、8,11-十八碳二烯酸(4.56%)、8,11,14-二十碳三烯酸(Z,Z,Z)(4.39%)、2,3,3-三甲基辛烷(4.35%)、7,10-十八碳二烯酸(3.61%)、亚油酸乙脂(2.64%)、α-亚麻酸(2.34%)、cis-乙酸环己脂-2-丙酸(2.34%)等.采用饲料混毒法对小鼠的毒性测定结果表明,曼陀罗种子脂肪油对小鼠无胃毒作用.研究认为,曼陀罗种子中含有多种对人体有益的活性成分,可作为脂肪酸食用油来源或从中提取对人体有益的活性成分开发利用.     

小眼虫藻Δ8-脂肪酸脱氢酶基因的克隆及其在酿酒酵母中的表达

Δ8途径是合成多不饱和脂肪酸的替代途径,Δ8-脂肪酸脱氢酶是该途径的关键酶之一。根据已报道的Δ8-脂肪酸脱氢酶基因设计引物,分别从小眼虫藻基因组DNA和cDNA中扩增得到该基因片段,序列分析表明：结构基因长1 266 bp,编码421个氨基酸;该基因没有内含子,比已经报道的Δ8-脂肪酸脱氢酶基因长6 bp,并且N末端序列也有所不同。利用酿酒酵母的载体pYES2.0构建Δ8-脂肪酸脱氢酶表达载体pYEFD,并转化到营养缺陷型酿酒酵母菌株INVSc1中,在选择培养基中筛选得到酿酒酵母转化菌株YD8。YD8在合适的培养条件下,添加外源底物二十碳二烯酸和二十碳三烯酸并诱导基因表达。脂肪酸甲酯气相色谱分析表明小眼虫藻Δ8-脂肪酸脱氢酶基因在酿酒酵母中获得了高效表达,将二十碳二烯酸和二十碳三烯酸分别转化成二高-γ-亚麻酸和二十碳四烯酸,其底物转化率分别达到了31.2％和46.3％。     

△6-脂肪酸脱氢酶对n-6和n-3途径中脂肪酸底物的偏好

添加α-亚麻酸作为底物,经半乳糖诱导,在含有少根根霉△6-脂肪酸脱氢酶基因的酿酒酵母总脂肪酸中检测到十八碳四烯酸的生成;同时添加亚油酸和α-亚麻酸时,检测到γ-亚麻酸和十八碳四烯酸生成,而且十八碳四烯酸的含量是γ-亚麻酸含量的3.81倍,表明在酿酒酵母中少根根霉△6-脂肪酸脱氢酶不仅能催化α-亚麻酸生成十八碳四烯酸,而且偏好n-3途径中的底物α-亚麻酸.同样,在改变少根根霉△6-脂肪酸脱氢酶基因的转译起始密码子周边序列后所构建的转基因酵母中,也得到类似的结果,而且各种目的脂肪酸的含量均有明显提高.     

小眼虫藻△8-脂肪酸脱氢酶基因的克隆及其在酿酒酵母中的表达

△8途径是合成多不饱和脂肪酸的替代途径,△8-脂肪酸脱氢酶是该途径的关键酶之一.根据已报道的△8-脂肪酸脱氢酶基因设计引物,分别从小眼虫藻基因组DNA和cDNA中扩增得到该基因片段,序列分析表明:结构基因长1 266 bp,编码421个氨基酸;该基因没有内含子,比已经报道的△8-脂肪酸脱氢酶基因长6bp,并且N末端序列也有所不同.利用酿酒酵母的载体pYES2.0构建△8-脂肪酸脱氢酶表达载体pYEFD,并转化到营养缺陷型酿酒酵母菌株INVSc1中,在选择培养基中筛选得到酿酒酵母转化菌株YD8.YD8在合适的培养条件下,添加外源底物二十碳二烯酸和二十碳三烯酸并诱导基因表达.脂肪酸甲酯气相色谱分析表明小眼虫藻△8-脂肪酸脱氢酶基因在酿酒酵母中获得了高效表达,将二十碳二烯酸和二十碳三烯酸分别转化成二高-γ-亚麻酸和二十碳四烯酸,其底物转化率分别达到了31.2%和46.3%.     

Δ^6-脂肪酸脱氢酶对n-6和n-3途径中脂肪酸底物的偏好

添加α-亚麻酸作为底物,经半乳糖诱导,在含有少根根霉Δ^6-脂肪酸脱氢酶基因的酿酒酵母总脂肪酸中检测到十八碳四烯酸的生成;同时添加亚油酸和α-亚麻酸时,检测到γ-亚麻酸和十八碳四烯酸生成,而且十八碳四烯酸的含量是γ-亚麻酸含量的3．81倍,表明在酿酒酵母中少根根霉Δ^6-脂肪酸脱氢酶不仅能催化α-亚麻酸生成十八碳四烯酸,而且偏好n-3途径中的底物α-亚麻酸。同样,在改变少根根霉Δ^6-脂肪酸脱氢酶基因的转译起始密码子周边序列后所构建的转基因酵母,也得到类似的结果,而且各种目的脂肪酸的含量均有明显提高。     

Δ6-脂肪酸脱氢酶对n-6和n-3途径中脂肪酸底物的偏好*

添加α 亚麻酸作为底物 ,经半乳糖诱导 ,在含有少根根霉Δ⁶-脂肪酸脱氢酶基因的酿酒酵母总脂肪酸中检测到十八碳四烯酸的生成 ;同时添加亚油酸和α-亚麻酸时 ,检测到γ 亚麻酸和十八碳四烯酸生成 ,而且十八碳四烯酸的含量是γ 亚麻酸含量的3.81倍 ,表明在酿酒酵母中少根根霉Δ⁶-脂肪酸脱氢酶不仅能催化α-亚麻酸生成十八碳四烯酸 ,而且偏好n 3途径中的底物α 亚麻酸。同样 ,在改变少根根霉Δ⁶-脂肪酸脱氢酶基因的转译起始密码子周边序列后所构     

微孔草油中脂肪酸的分离和鉴定

微孔草[Microula sikkimensis(Clarke)Hemsl.]种子含油45%,其油中含有γ-亚麻酸,(顺式-6,9,12-十八碳三烯酸)8.1%。通过硝酸银硅胶柱层析和高压液相色谱分离,采用高碘酸钠、高锰酸钾氧化裂解的方法和红外光谱,紫外光谱,气相色谱分析,质谱分析,对油中的γ-亚麻酸,顺式-6,9,12,15-十八碳四烯酸,顺式-11-廿碳烯酸,顺式-13-廿二碳烯酸,顺式-15-廿四碳烯酸进行了分离、鉴定。     

EFFECT OF HYPERPHENYLALANINEMIA ON FATTY ACID COMPOSITION OF LIPIDS OF RAT BRAIN MYELIN

Abstract— We have studied the fatty acid compositions of cerebral myelin lipids in phenyl-alanine-treated and control rats. The proportion of long chain fatty acids and the ratio of unsaturated to saturated fatty acids of whole brain lipids was low in the penylalanine-treated animals. Both of these reductions were more pronounced in the myelin from phenylalanine-treated rats. The ratio of unsaturated to saturated fatty acids in ethanolamine phosphatides was markedly decreased in the hyperphenylalaninemic condition. The reduction in the proportion of long chain fatty acids was predominant in non-hydroxy fatty acids in cerebrosides and ethanolamine phosphatides. The lipid composition of the myelin expressed as mole percentages of individual phospholipid and sphingolipid components was not significantly different in the two groups of rats, nor did it change with age. Our results indicate a deficiency in the fatty acid elongation and desaturation system in the brains of phenylalanine-treated rats. We suggest that in hyperphenylalaninemic rats, a reduction in the amounts of unsaturated fatty acid and long chain fatty acid alters, respectively, the biochemical reactivity and the stability of the myelin.     

THE EFFECT OF DIFFERENT DIETARY LEVELS OF ESSENTIAL FATTY ACIDS ON LIPIDS OF RAT CEREBRUM DURING MATURATION1

Abstract— Three dietary levels of essential fatty acids, 30, 0-75 and 007 calorie-%, with a linoleic: linolenic acid ratio of 4:1, were fed to rats for two generations. In the third generation the weight of the cerebrum and the concentration of its lipids and the fatty acid composition of phosphoglycerides were determined from term to 120 days of age. The cerebral weights and the concentrations of phospholipids, cholesterol and cerebrosides differed only slightly between the three dietary groups. The accretion of fatty acids of the linoleic acid series was independent of the dietary essential fatty acid level while the accretion of fatty acids of the linolenic acid series was markedly reduced in the groups with low essential fatty acid supply. The sum of the total polyunsaturated fatty acids in ethanolamine phosphoglycerides differed only slightly between the groups. The proportion of the major polyunsaturated fatty acid of the linoleic acid series was equal between the groups while that of 22:6 (n-3) was much lower in the groups fed 007 calorie % essential fatty acids. In these latter groups the relative concentrations of 22:5 (n-6), 20:3 (n-9) and 22:3 (n-9) were increased. The differences in the fatty acid composition were dependent on the age of the rats. They were largest in newborn rats and diminished with age after weaning.     

COMPARISON OF THE FATTY ACIDS OF LIPIDS OF SUBCELLULAR BRAIN FRACTIONS

Abstract— Rat brain grey and white matter were fractionated to yield myelin, nerve terminal, synaptic vesicle, nerve terminal 'ghost', and microsomal fractions of white and grey matter. Ester-type glycolipids were found in all fractions except myelin, while cerebrosides occurred in significant concentrations only in myelin and white microsomes. Comparison of the fatty acid profile of the ethanolamine- and serine-containing phospholipids showed marked differences between myelin and the particles from grey matter, while the microsomes of white matter were of intermediate composition. Docosahexaenoic acid, a minor acid in myelin, was a major fatty acid in microsomes of grey and white matter. The fatty acid composition of sphingomyelin was distinctly different in the fractions derived from grey and white matter, clustering about stearate and nervonate in the latter, but only about stearate in the grey. Marked differences in the positional distribution of fatty acids were seen within phosphatidyl choline from myelin and nerve terminals. Ribonucleic acid was found in nerve terminal and synaptic vesicle fractions. The sphingosine found in the ganglioside from microsomes of both grey and white matter was similar with respect to distribution of the C₁₈ and C₂₀ homologues.
The possibility is discussed that microsomes furnish characteristic lipids for the synthesis or renewal of specific membranes, and that these lipids are accumulated somewhat before being released.     

RENEWAL OF FATTY ACIDS IN THE MEMBRANES OF VISUAL CELL OUTER SEGMENTS

The renewal of fatty acids in the visual cells and pigment epithelium of the frog retina was studied by autoradiographic analysis of animals injected with tritiated palmitic, stearic, or arachidonic acids. Most of the radioactive material could be extracted from the retina with chloroform-methanol, indicating that the fatty acids had been esterified in lipids. Analysis of the extracts, after injection of [³H]palmitic acid, revealed that the radioactivity was predominantly in phospholipid. Palmitic acid was initially concentrated in the pigment epithelium, particularly in oil droplets which are storage sites for vitamin A esterified with fatty acid. The cytoplasm, but not the nucleus of these cells, was also heavily labeled. Radioactive fatty acid was bound immediately to the visual cell outer segment membranes, including detached rod membranes which had been phagocytized by the pigment epithelium. This is believed to be due to fatty acid exchange in phospholipid molecules already situated in the membranes. Gradually, the concentration of radioactive material in the visual cell outer segment membranes increased, apparently as a result of the addition of new phospholipid molecules, possibly augmented by the transfer from the pigment epithelium of esterified vitamin A. Injected fatty acid became particularly concentrated in new membranes which are continually assembled at the base of rod outer segments. This localized concentration was short-lived, apparently due to the rapid renewal of fatty acid. The results support the conclusion that rods renew the lipids of their outer segments by membrane replacement, whereas both rods and cones renew the membrane lipids by molecular replacement, including fatty acid exchange and replacement of phospholipid molecules in existing membranes.     

牙龈卟啉菌内毒素的化学组成和SDS—PAGE的特性分析

应用气液色谱法对牙龈卟啉菌脂多糖（Ｐｇ－ＬＰＳ）和大肠杆菌脂多糖（Ｅ－ＬＰＳ）的单糖和脂肪酸进行了分析和比较。Ｐｇ－ＬＰＳ主要含有甘露糖、葡萄糖、氨基葡萄糖、半乳糖和鼠李糖。Ｅ－ＬＰＳ单糖组成与Ｐｇ－ＬＰＳ基本相似,但缺乏鼠李糖。Ｐｇ－ＬＰＳ主要含有羟基十五烷酸和羟基十七烷酸等奇数碳原子脂肪酸,Ｅ－ＬＰＳ则以羟基豆蔻酸、豆蔻酸和月桂酸等偶数碳原子脂肪酸为主。Ｐｇ－ＬＰＳ含有甲基化脂肪酸,Ｅ－ＬＰＳ则缺如。实验结果提示,Ｐｇ－ＬＰＳ和Ｅ－ＬＰＳ化学组成上的差异可能导致二者的ＳＤＳ－ＰＡＧＥ图谱明显不同。     

THE FATTY ACID COMPOSITION OF PHOSPHOLIPIDS AND GLYCOLIPIDS IN JIMPY MOUSE BRAIN

Abstract— Phospholipids and sphingolipids from brains of normal and Jimpy mice were isolated in a pure form by thin-layer chromatographic procedures. The fatty acid composition of the major phospholipids, i.e. ethanolamine glycerophospholipids, serine glycerophospholipids, choline glycerophospholipids and inositol glycerophospholipids, as well as sphingomyelin, cerebrosides and sulphatides was determined by gas-liquid chromatography. A specific fatty acid pattern for each of the four glycerophospholipids was found. The fatty acid composition of inositol glycerophospholipid, which has not previously been studied in mouse brain, was characterized by a high concentration of arachidonic acid. After 16 days of age, fatty acid analysis showed definite differences between the phospholipids from normal and mutant brains. A small increase of polyunsaturated fatty acids in glycerophospholipids of ethanolamine, serine and choline from the Jimpy central nervous system was found, which has been explained by the myelin deficiency. Sphingomyelin, cerebrosides and sulphatide analyses showed a wide distribution of saturated and mono-unsaturated fatty acids in both normal and mutant mice. A reduction in the amount of long-chain fatty acids was demonstrated in mutant brain sphingolipids; in sulphatides and cerebrosides, the amount of non-hydroxy fatty acids was reduced to a greater extent than in sphingomyelin. The distribution of fatty acids in sphingolipids from the myelin and microsomal fractions was also investigated in both types of mice. Cerebrosides were characterized by a high content of long-chain fatty acids in myelin as well as in microsomes. Sulphatides and sphingomyelin, on the other hand, showed a higher content of medium-chain fatty acids in microsomes than in myelin. In the mutant brain, the amount of long-chain fatty acids was reduced in both subcellular fractions. The deviation from normal in the pattern of fatty acid distribution in Jimpy brain is discussed in relation to the current concepts of glycolipid biosynthesis.     

冷冻干燥条件下酿酒酵母细胞脂肪酸组成变化的研究

以气相色谱法测定酿酒酵母(Saccharomyces cereuisiae) F159细胞膜类脂中脂肪酸的组成。结果表明,在低温干燥条件下,酿酒酵母细胞能自身调节脂肪酸的不饱和度,出现C_(16:1)脂肪酸含量增加,C_(16:0)脂肪酸含量略有所增,而C_(18:0)脂肪酸含量却有下降,不饱和直链脂肪酸之和与饱和直链脂肪酸之和的比值增加。说明这些变化使酿酒酵母细胞膜保持流动状态而维持细胞的稳定性和活性。初步探讨了冷冻干燥对酿酒酵母细胞脂肪酸组成的影响,为进一步探索和研究微生物抗冷冻干燥生理生化机制提供了依据。     

FATTY ACID COMPOSITION OF CEREBROSIDES IN MICROSOMES AND MYELIN OF MOUSE BRAIN

Abstract— The fatty acid composition of cerebrosides isolated from myelin and from light and heavy microsomes of adult mouse brain was determined. 2-Hydroxy fatty acids represented 80 per cent of the fatty acids in myelin cerebrosides and approximately 55 per cent of the fatty acids in both light and heavy microsomes. In myelin, the majority of the fatty acids, both normal and hydroxy, were of chain length > C-20; in microsomes, shorter chain acids (C-16 to C-20) predominated.     

INFLUENCE OF TEMPERATURE ON THE FATTY ACID PROFILE OF LISTERIA MONOCYTOGENES

Variation in the fatty acid profile of two Listeria monocytogenes strains grown at varying temperatures was determined. The fatty acid profiles varied greatly at different temperatures. General decreases in relative percentages of branched and medium chain (up to C16:0) fatty acids and variable changes in long chain fatty acids were found with increasing growth temperature. Individual fatty acid percentages between strains were variable. The relative percentages of unknown long chain fatty acids, detected in both strains at various temperatures, were greatest in Scott A (7.07%) and ATCC 19114 (13.15%) at 35C. Results demonstrated that L. monocytogenes had altered fatty acid profile in response to changes in growth temperature.     

DECOMPOSITION OF PHOSPHOLIPIDS DURING WALLERIAN DEGENERATION J. DOMONKOS

—Of the lipid metabolic changes in Wallerian degeneration, the decomposition of phosphatides was studied in the early stages, 2–14 days after the nerve had been cut. It was found that the decomposition of phosphatides begins only 6 days after section. The amounts of lipid-P and fatty acid ester decrease in parallel. However, a greatcr decrease in the amount of fatty aldehyde was observed than of the lipid-P and fatty acid ester; this indicates that the vinyl ether bonds of glycerophosphatides are more sensitive to the degenerative process than the fatty acid ester or phosphorus. The fatty acid ester: lipid-P ratio, calculated from the results, does not change; however, the fatty aldehyde: lipid-P ratio shows a marked decrease during this same period. The values of the ratios indicate that in the 2nd week following nerve section, decomposition of glycerophosphatides containing fatty aldehyde (i.e. plasmalogens), in contrast to glycerophosphatides of diacyl form, may be only partial. Thus, in the 2nd week of Wallerian degeneration the formation of lysophosphatides may be presumed to come from the plasmalogens.