红豆杉细胞两液相耦合培养过程中细胞凋亡与紫杉醇含量的关系

以油酸作为有机相与改良B5液体培养基组成耦合培养体系 ,研究了在该体系中悬浮培养的红豆杉细胞凋亡与紫杉醇含量的关系 .结果表明 ,紫杉醇的总含量随凋亡率呈抛物线规律变化 ;耦合培养法有效地促进了胞内紫杉醇向胞外释放 ,绝大部分储存于有机相中 ,从而降低了紫杉醇影响细胞凋亡发生的可能性 ,因此推测是细胞凋亡促进了紫杉醇的大量合成     

真菌诱导子对悬浮培养南方红豆杉细胞次生代谢的影响

在悬浮培养的南方红豆杉细胞体系中 ,细胞进入指数生长期末期时 ,加入真菌诱导子 (即尖孢镰刀菌胞壁成分的粗提出物 ,其主要成分为糖类和多肽 ) ,对几个主要的细胞次生代谢指标进行了监测 .实验结果表明 ,诱导子引起了南方红豆杉细胞次生代谢结构的变化 ,胞内酶蛋白的含量呈先上升后下降的趋势 ,而胞外酶蛋白的含量显著上升 ;苯丙烷类代谢途径中重要的酶PAL的活性显著升高 ;次生代谢产物中 ,酚类物质的含量增加 ,且于 4天后急速上升 ,同时多酚氧化酶的活力也加强 ,萜类产物中紫杉烷类的生物合成均得到了加强 ,其中紫杉醇的含量得到了大幅度的提高 ,达到对照组的 5倍左右 .     

电刺激对红豆杉悬浮培养细胞产紫杉醇的影响

以红豆杉悬浮培养细胞为材料产紫杉醇,在细胞生长的不同时期分别用脉冲电刺激及微交流电刺激处理。结果表明,两种电刺激均不同程度促进了红豆杉悬浮培养细胞的生长、紫杉醇的产生,其中脉冲电刺激效果优于微交流电刺激。最佳作用时间是在红豆杉细胞生长的衰亡期,微交流电刺激的紫杉醇含量较对照提高3倍多,脉冲电刺激的紫杉醇含量约为对照的7~9倍,最高达到12.24 mg.L-1。脉冲电刺激可有效提高紫杉醇的胞外释放率,达对照的4~5倍。     

寡聚糖诱导悬浮培养红豆杉细胞生理态势的改变

运用顺磁共振、电镜、能谱等手段研究了寡聚糖对红豆杉细胞氧化还原生理态势的影响 .结果表明 ,诱导前红豆杉细胞处于相对稳定的生长态势 ,细胞完整 ,细胞器发达 ;氧化还原电势较低 ,活性氧相关酶系统相对稳定 ,细胞初生代谢旺盛 ,紫杉醇合成速率很低 .诱导后红豆杉细胞向产物合成态势转移 ,SOD酶活性迅速提高 ,CAT和POD酶活被强烈抑制 ;细胞出现活性氧迸发 ,4h达最大值 ;细胞的氧化还原电势增高 ,细胞膜上离子通道被激活 ,H⁺ 和Ca^{2 +} 内流 ,Cl^-外流 ;液胞内出现大量含Ca^{2 +} 离子的高电子致密区并呈规律性变化 ,培养环境碱化 ;细胞生长被抑制 ,紫杉醇合成速率升高 ,其产量提高了 5.5倍 ,达 76.1mg·L^-1.     

外加紫杉醇后南方红豆杉细胞的耐受性及其凋亡的研究

利用显微照相和DNA提取等技术，研究了外源紫杉醇作用于服浮培养南方红豆杉细胞（Taxus chinensis var.Mairei)的凋亡和对紫杉醇（taxol）的耐受性。利用荧光显微照相技术观察到，外源紫杉醇作用下，随培养时间延长，南方红豆杉细胞发生明显核分化，应用DNA电泳观察到细胞DNA断裂形成典型的180bp及其整数倍梯形条带（DNA.ladders) ,应用TUNEL检测发现DNA的3'-OH断端可被特异性标记，证实了加入紫杉醇后南方红豆杉细胞发生了凋亡。研究结果说明南方红豆杉细胞对紫杉醇的耐受性是有限度。并证明了植物细胞有类似于动物细胞的凋亡特征，也表明该体系可以作为研究植物细胞凋亡的实验模型。     

红豆杉植物和愈伤组织培养物中紫杉醇含量的检测

采用UV和HPLC两种方法,对南方红豆杉(Taxuschinensisvar.mairei)、曼地亚红豆杉(Taxusmediacv.Hicksii)天然植物和组织培养物中紫杉醇含量进行了检测。检测结果:南方红豆杉天然植物中未能检测出紫杉醇,南方红豆杉愈伤组织培养物中紫杉醇含量最高,为万分之4.09,是曼地亚红豆杉愈伤组织培养物中的2～27倍,是曼地亚红豆杉天然植物中的6～8倍。     

正常小鼠和肿瘤小鼠毛发中长链脂肪酸含量测定及比较

以正十七酸为内标 ,氯化氢 甲醇抽提和酯化 ,对正常、肿瘤、抗肿瘤小鼠毛发中长链脂肪酸——豆蔻酸、棕榈酸、棕榈油酸、油酸、硬脂酸和亚油酸进行毛细管柱气相色谱定量分析和比较。结果显示 :肿瘤小鼠或抗肿瘤小鼠毛发中长链脂肪酸含量明显升高 ,不饱和长链脂肪酸比例升高而饱和长链脂肪酸比例下降 ,提示毛发中不饱和长链脂肪酸尤其亚油酸与生物体内肿瘤的发生和存在有密切关系。本实验方法简单 ,所需样品量少 ,实验重现性好 ,回收率达定量分析要求。     

灵芝孢子油脂肪酸组分分析

脂肪酸含量差异是目前油种真伪鉴别的主要方法,采用气相色谱(GC)法对灵芝孢子油脂肪酸组分进行了分析。结果显示:灵芝孢子油中检出15种脂肪酸,其中饱和脂肪酸占22.931%,主要为棕榈酸(15.729%)、硬脂酸(3.734%)和十七碳酸(1.402),不饱和脂肪酸占76.977%,主要为油酸(63.027%)和亚油酸(12.809%)。同时对市售5个不同品牌灵芝孢子油(100%)软胶囊中油的脂肪酸组分进行了分析,发现其脂肪酸组成及含量比较接近,棕榈酸、十七碳酸、硬脂酸、油酸和亚油酸含量占95%以上,其中棕榈酸平均含量为15.181%,十七碳酸平均含量为1.423%,硬脂酸平均含量为3.722%,油酸平均含量为63.444%,亚油酸含量为13.189%。     

外源紫杉醇作用下南方红豆杉细胞凋亡及其动力学研究

利用光学显微照相技术、细胞总DNA琼脂糖凝胶电泳和TUNEL标记等手段 ,研究了外源紫杉醇(Taxol)作用下南方红豆杉细胞的凋亡及其动力学。研究结果表明 ,外源紫杉醇能显著提高南方红豆杉细胞凋亡的速率和发生率 ,表明高浓度紫杉醇不利于细胞的生长。凋亡动力学研究对指导大规模植物细胞培养生产紫杉醇具有重要意义     

释香过程中茉莉净油组成与含量变化规律研究

有机溶剂浸提制备茉莉净油,经GC、GC/MS分析,内标法定量,鉴定了27个主要组分.组分中由苯甲醇、苯甲酸、顺-3-己烯醇为基本结构单元酯类化合物种类较多且含量高;与头香相比,净油中还含有脂肪酸及其甲酯、苯甲酸苯甲酯等5个高沸点组分;释香过程中,净油、酯类、Ⅱ区组分总量和主要香气组分含量呈低-高-低变化趋势,而醇类、Ⅰ、Ⅲ区组分含量变化与之相反;6种组分与净油香气浓度变化呈显著正相关;用香气品质指数AI(∑Ⅱ/∑Ⅰ Ⅲ)评价了净油品质,具正常茉莉花香特征的香精油AI值以大于2.5为宜.提出了茉莉花酯类香气组分形成的可能途径.     

Effect of dietary saturated fatty acids and linoleic acid upon the structures of triglycerides in rabbit tissues

Five groups of rabbits were given a diet supplemented with safflower seed oil and safflower seed oil partially replaced by lauric, myristic, palmitic, and stearic acids respectively. After 10 weeks, plasma samples were taken from the animals in the fasted and nonfasted state; the animals then were killed, and the livers and samples of adipose tissue were removed. Lipids were extracted from the tissues, then separated into classes; and the fatty acid composition of each class was determined. In addition, the triglycerides were isolated and the structures determined by stereospecific analysis. There were marked differences in the compositions and structures of the triglycerides in the plasma from fasted and nonfasted animals. Feeding specific dietary fatty acids also greatly changed the metabolism of linoleic acid by the animals. The results are discussed in terms of the biosynthesis of triglycerides in plasma, liver, and adipose tissue.     

The variation of triglyceride structure with fatty acid composition in pig adipose tissue

Forty-five triglyceride samples with a wide range of fatty acid compositions were selected from a large number of pig adipose tissue samples (inner and outer back fats and perenephric fat) available from nutritional experiments. These samples were subjected to stereospecific analysis to determine the changes occurring in the positional distribution of the component fatty acids. The oleic acid content of the triglycerides was taken as the standard of comparison and as this increased, the proportions of the other unsaturated fatty acids also increased in a linear manner and the concentrations of the saturated components decreased proportionately. In position 1, the palmitic acid concentration remained constant while the stearic acid concentration decreased linearly and the concentrations of the unsaturated fatty acids increased. In position 2 the stearic acid concentration remained almost constant while the palmitic acid concentration decreased linearly in response to increases in the concentrations of the unsaturated acids. The least change occurred in position 3 where there were slight decreases in the concentrations of saturated acids as the concentrations of unsaturated acids increased. The precise quantitative relationships depended on the tissue examined. Constant proportions of the available myristic and palmitoleic acids were found in all three positions and constant proportions of the available stearic and oleic acids were found in position 1. These results are discussed in relation to possible pathways of triglyceride biosynthesis in pig adipose tissues.     

Definite influence of location and climatic conditions on the fatty acid composition of sunflower seed oil

Percentages of linoleic, oleic and stearic acids present significant differences between growing areas, whereas palmitic acid content remains practically constant, or at least presents no significant relation to the growing area. Nevertheless, palmitic acid appears to follow a pattern that relates its content to the total content of the other three major fatty acids. Seeds grown in the northern part of Spain presented a higher linoleic content than seeds grown in the South, which is in agreement with the general theory found in prior studies. Although there is an inverse correlation between oleic and linoleic content, we have found that the total content of both is neither constant nor independent of temperature, and increases when temperature and oleic acid increase. However, stearic content increases when the combination of linoleic and oleic acid decreases, suggesting a total constant value for the combination of these three acids. The average temperature of the are during development of the seed and the local climatic conditions have the greatest influence over fatty acid composition, while the seed variety presents limited influence.     

Lipid composition of hepatocyte plasma membranes from geese overfed with corn

Twelve-week-old Landes male geese were overfed with corn for 21 d in order to induce liver steatosis (fatty liver). Lipid composition of hepatocyte plasma membranes from fatty livers was compared to that of lean livers obtained from geese fed a normal diet. The ratio cholesterol/phospholipids was higher in fatty hepatocyte plasma membranes (0.63 vs. 0.47), whereas the phospholipid/protein ratio was less than half. Overfeeding induced changes in fatty acid composition of hepatocyte plasma membranes, including a greater than twofold increase in the percentage of oleic acid (29.7 vs. 13.8%) and a somewhat lesser increase in lauric, palmitic, and palmitoleic acid contents of plasma membrane lipids of fatty livers. A concomitant reduction in the proportion of stearic acid (18.4 vs. 25.1%) was also observed. In fatty livers, the increased ratio of saturated to polyunsaturated fatty acids (PUFA) (1.5 vs. 1.0) was related to a significant decrease in PUFA content. Among all the PUFA, only the eicosatrienoic acid (20∶3n−9) percentage was increased by liver steatosis. Overfeeding with corn appeared to induce competition between de novo synthesized and dietary fatty acids incorporated in hepatocyte plasma membranes. This resulted in an accumulation of de novo synthesized monounsaturated and derived fatty acids in plasma membranes from overfed birds. A defect in the incorporation of linoleic acid and linoleic- and linolenic-derived PUFA was observed despite the high proportion of these essential fatty acids in the diet. It was conclued that in overfed palmipeds, de novo hepatic lipogenesis prevails over dietary lipid intake to modulate lipid composition of the fatty liver plasma membrane.     

Variation in Fatty Acid Compositions, Oil Content and Oil Yield in a Germplasm Collection of Sesame (Sesamum indicum L.)

The variation in oil content, oil yield and fatty acid compositions of 103 sesame landraces was investigated. The landraces varied widely in their oil quantity and quality. The oil content varied between 41.3 and 62.7%, the average being 53.3%. The percentage content of linoleic, oleic, palmitic and stearic acids in the seed oil ranged between 40.7–49.3, 29.3–41.4, 8.0–10.3 and 2.1–4.8%, respectively. Linolenic and arachidic acids were the minor constituents of the sesame oil. Linoleic and oleic acids were the major fatty acids of sesame with average values of 45.7 and 37.2%, respectively. The total means of oleic and linoleic acids as unsaturated fatty acids of sesame were about 83% which increases the suitability of the sesame oil for human consumption. The superiority of the collection was observed in oil content. The oil content of a few accessions was above 60%, proving claims that some varieties of sesame can reach up to 63% in oil content. The accessions with the highest oil content were relatively richer in the linoleic acid content while there were some landraces in which linoleic and oleic acid contents were in a proportion of almost 1:1. The results obtained in this study provide useful background information for developing new cultivars with a high oil content and different fatty acid compositions. Several accessions could be used as parental lines in breeding programmes aiming to increase sesame oil quantity and quality.     

Fatty acid compositions of human brain lecithin and sphingomyelin in normal individuals,senile cerebral cortical atrophy,alzheimer’s disease,metachromatic leucodystrophy,Tay-Sachs and Niemann-Pick diseases

The fatty acid compositions of whole brain lecithin and sphingomyelin were determined. Brain specimens from normal adults, a normal infant, and several disease states were examined. Normal adult brain lecithin has a very simple fatty acid composition (palmitic, stearic, and oleic acids) and infant brain lecithin contains more palmitic acid and less oleic acid than adult brain. The whole brain lecithin fatty acid compositions from metachromatic leucodystrophy, and Tay-Sachs and Niemann-Pick diseases are intermediate between that of normal infant and normal adult brain and no characteristic features attributable to specific disease states were detected. The fatty acids of whole brain lecithin from senile cerebral cortical atrophy and Alzheimer’s disease were similar to normal adult brain except that a greater variety of fatty acids was seen in both pathological states. No characteristic features attributable specifically to either pathological state were detected. The fatty acid composition of normal adult brain sphingomyelin differs from that of the normal infant in that longer chain fatty acids are more abundant in adult brain. The fatty acid compositions of whole brain sphingomyelins from Niemann-Pick disease and metachromatic leucodystrophy differed from that of normal infant and adult brain in that C₂₄ acids were not detected. No characteristic features attributable to a specific disease were detected. Fatty acid compositions of whole brain sphingomyelins in senile cerebral cortical atrophy and Alzheimer’s disease were found to be very similar to those of the normal adult.     

Current advances in sunflower oil and its applications

The fatty acid and triacylglycerol composition of a vegetable oil determine its physical, chemical and nutritional properties. The applications of a specific oil depend mainly on its fatty acid composition and the way in which fatty acids are arranged in the glycerol backbone. Minor components, e. g. tocopherols, also modify oil properties such as thermo‐oxidative resistance. Sunflower seed commodity oils predominantly contain linoleic and oleic fatty acids with lower content of palmitic and stearic acids. High‐oleic sunflower oil, which can be considered as a commodity oil, has oleic acid up to around 90%. Additionally, new sunflower varieties with different fatty acids and tocopherols compositions have been selected. Due to these modifications sunflower oils possess new properties and are better adapted for direct home consumption, for the food industry, and for non‐food applications such as biolubricants and biodiesel production.     

棉籽酸化油的理化性质及脂肪酸组成分析

采用气相色谱法分析了棉籽酸化油的脂肪酸组成,并对其理化性质进行了研究。分析结果表明,棉籽酸化油的含油率为91.33%,酸值为144.35mgKOH/g,碘值为116.58gI2/100g,皂化值为199.80mgKOH/g;其主要脂肪酸为棕榈酸(21.29%)、硬脂酸(2.29%)、油酸(23.72%)、亚油酸(50.23%)和亚麻酸(0.39%),其中不饱和脂肪酸的含量高达74%,具有很高的工业利用价值。     

Effects of Chain Length of Saturated Fatty Acids on Plasma Total,LDL- and HDL-Cholesterol Levels

We conducted two clinical studies to examine the effects of diets high in stearic acid and lauric + myristic acid on plasma lipids and lipoproteins of healthy young men. In the first study subjects (n = 15) were fed whole food diets high in cocoa butter, butter, olive oil and soybean oil. In the second study, subjects were fed diets very high in saturated fatty acids (> 20% of calories) that were high in either stearic acid (from cocoa butter or milk chocolate) or lauric + myristic acid (from butter). In the first study, cocoa butter elicited a neutral cholesterolemic effect, whereas the butter diet was hypercholesterolemic and the olive oil and soybean oil diets were hypocholesterolemic. In the second study, the diets high in stearic acid did not raise plasma total and LDL-cholesterol levels, whereas, as in the first study, butter was markedly hypercholesterolemic. Regression analyses performed on the individual data from these two clinical studies were conducted to establish the cholesterolemic effects of individual fatty acids. The bestfitting linear regression equations relating ΔTC (change in plasma total cholesterol) was: ΔTC = 2.3 ΔC_14:0 + 3.0 ΔC_16:0-0.8 ΔC_18:0-1.0 ΔPUFA, where Δ fatty acid = change in intake expressed as percent of calories. This predictive equation separates stearic acid from the other long-chain saturated fatty acids and suggests that it has an independent cholesterol-lowering effect. In conclusion, stearic acid is a unique long-chain saturated fatty acid.     

Membrane fatty acid modification in tumor cells: A potential therapeutic adjunct

The fatty acid compositions of several tumors have been modified sufficiently to alter some of their properties and functions. These modifications were produced in culture by adding specific fatty acids to the growth medium or by feeding fat-supplemented diets to tumor-bearing mice. The phospholipid fatty acid composition of the plasma membrane was modified, but there were no changes in membrane phospholipid or cholesterol content or in phospholipid head group composition. Each of the most abundant membrane phosphoglyceride fractions exhibited some degree of fatty acid modification. Electron spin resonance measurements with nitroxystearate spin probes indicated that the fatty acid modifications were sufficient to alter the physical properties of the plasma membrane. The K _m ^′ for methotrexate uptake was reduced when the L1210 leukemia cells were enriched in linoleic acid. Even when the kinetics of uptake at 37 C were not altered, such as for melphalan and phenylalanine uptake, the temperature transition of transport was modified, indicating that these transport systems also are responsive to the membrane fatty acid modifications. Enrichment with highly polyunsaturated fatty acid did not affect either the growth rate or radiosensitivity of the L1210 leukemia. However, the sensitivity of the L1210 cells to the cytotoxic effects of Adriamycin and hyperthermia was increased. These findings suggest the possibility that fatty acid modification of tumors may be a useful adjunct to certain currently available therapeutic modalities. Presented at the symposium on Lipids and Cancer held during the joint meeting of the AOCS-JOCS in Honolulu, May 1986.