Changes in Volatile Fatty Acids and Free Amino Acids during Air-Tobacco Stalks

In our searching program for novel sorbicillin related compounds, three novel compounds, spirosorbicillinols A (1), B (2), and C (3), were isolated from the fermentation broth of the USF-4860 strain isolated from a soil sample. The planar structures of compounds 1–3 were determined from spectroscopic evidence and degradation reaction, and that of 1 was the same as that of 2. The relative stereochemistries of compounds 1–3 were determined by ¹H-¹H coupling constants, the elucidation of HMBC and NOESY spectra in detail. 1 and 2 were stereoisomers at C8 position, each other. We propose that compounds 1 and 2 were formed by exo and endo intermolecular Diels-Alder reaction between sorbicillinol as a diene and scytolide (proposed precursor-1) as a dienophile, respectively. Similarly, we propose that compound 3 was formed by an endo intermolecular Diels-Alder reaction between sorbicillinol and proposed precursor-2.     

Comparison of Free and Bound Amino Acids in White and Green Tissues of Variegated Tobacco Plants

Qualitative and quantitative comparisons of free and bound aminoacids and soluble proteins in white and green tissues of variegatedtobacco leaves were made. White tissue contained more free andless bound amino acids than green tissue, although the sum ofthe total amino acids did not differ significantly between thetwo tissues. The major free amino acids in white tissue wereglutamine and asparagine, whereas those in green tissue wereglutamic acid, aspartic acid and -aminobutyric acid. The contentsof fraction 1 protein and 70 S ribosomes in white tissue werenegligible in comparison with those found in green tissue, butthe amounts of other soluble protein components and the 80 Sribosomes were at the same level in both tissues. (Received October 21, 1981; Accepted January 28, 1982)     

外源氨基酸胁迫下植物体内游离氨基酸的测定

目的：通过检测外源氨基酸胁迫下植物体内的游离氨基酸含量,探讨氨基酸胁迫下植物生长受抑制的机制。方法：小麦胚接种在加入D-丙氨酸、D-丝氨酸和L-缬氨酸等3种外源氨基酸的培养基中,其发芽和生长会受到强烈抑制。取材胁迫植株和对照植株,提取并用HPLC方法检测游离氨基酸含量,分析主要氨基酸特征的改变。结果：作为处理的胁迫氨基酸在体内有数倍到数十倍的增高,其他氨基酸,尤其是同族及相近族氨基酸的量也出现较大改变,有增加也有减少,有些氨基酸甚至检测不出。结论：在外源氨基酸胁迫下,植物可直接吸收这些氨基酸,胁迫氨基酸在体内的积累。至少影响到了部分氨基酸的合成,使细胞内正常游离态氨基酸的数量增加或减少,这些变化引起代谢失调,进而引起生长抑制。     

Hippocampal Free Amino Acids in Alzheimer's Disease

The free amino acid content of the hippocampus, obtained at postmortem, has been analysed in cases of Alzheimer's disease and compared with normal cases. There were no significant differences in the levels of 23 amino acids including the transmitter candidates γ-aminobutyric, glutamic or aspartic acids. This finding is interpreted in relation to present knowledge of transmitter pathways in the region of the hippocampus. A tendency for some amino acids to be increased in the Alzheimer group reached statistical significance for arginine. This observation is consistent with increased proteolytic or peptidase activity in Alzheimer's disease.     

Accumulation of Prolamines and Glutelins during Rice Seed Development: a Quantitative Evaluation

The levels of prolamines and glutelins, the storage proteinsof rice, were quantified during seed development by immunoblotanalysis. Although both storage proteins were first detectedin 10 day old seeds and their amounts steadily increased throughoutseed development, the relative proportions of glutelins andprolamines were not constant. The molar ratio of glutelins toprolamines was 1.7 in 10 day old seeds and this ratio steadilydecreased to 1.2 in 25 day old seeds due to the increased synthesisand accumulation of prolamines specifically during the latterstages of seed development. In vivo pulse chase labelling studiesconfirmed that the rate of prolamine synthesis as compared tothat evident for glutelin increased during the latter half ofseed development and that protein turnover was not the basisfor the differences in accumulation patterns of these storageproteins. These results indicate that the storage proteins exhibitdifferent temporal accumulation patterns during seed developmentand, moreover, demonstrate that prolamines comprise a much largerproportion of the total storage protein fraction than previouslyrecognized. (Received August 31, 1992; Accepted November 27, 1992)     

Changes in Serum Free Amino Acids and Muscle Fatigue Experienced during a Half-Ironman Triathlon

The aim of this study was to investigate the relationship between changes in serum free amino acids, muscle fatigue and exercise-induced muscle damage during a half-ironman triathlon. Twenty-six experienced triathletes (age = 37.0 ± 6.8 yr; experience = 7.4 ± 3.0 yr) competed in a real half-ironman triathlon in which sector times and total race time were measured by means of chip timing. Before and after the race, a countermovement jump and a maximal isometric force test were performed, and blood samples were withdrawn to measure serum free amino acids concentrations, and serum creatine kinase levels as a blood marker of muscle damage. Total race time was 320 ± 37 min and jump height (-16.3 ± 15.2%, P < 0.001) and isometric force (-14.9 ± 9.8%; P = 0.007) were significantly reduced after the race in all participants. After the race, the serum concentration of creatine kinase increased by 368 ± 187% (P < 0.001). In contrast, the serum concentrations of essential (-27.1 ± 13.0%; P < 0.001) and non-essential amino acids (-24.4 ± 13.1%; P < 0.001) were significantly reduced after the race. The tryptophan/BCAA ratio increased by 42.7 ± 12.7% after the race. Pre-to-post changes in serum free amino acids did not correlate with muscle performance variables or post-race creatine kinase concentration. In summary, during a half-ironman triathlon, serum amino acids concentrations were reduced by > 20%. However, neither the changes in serum free amino acids nor the tryptophan/BCAA ratio were related muscle fatigue or muscle damage during the race.     

Free Amino Acids and Phosphorylethanolamine in Milk Whey of Cow

Free amino acids in the milk of cow were investigated in comparison with those in the plasma. The concentrations of most free amino acids in the milk except for a few amino acid were lower than those in the plasma. It appears that the percentage of each amino acid in the milk against the corresponding amino acid in the plasma is the reflexion of casein synthesis in the mammary gland. Nutritional alteration influenced on the level of some amino acids in the milk. Free phosphorylserine, glycerylphosphorylethanolamine, and phosphorylethanolamine were observed in the milk. Phosphorylethanolamine was present in significantly high concentration in one animal as control, whereas was almost absent in another animal as experimental.     

Dependence of Seed Vigor during Germination on Carbohydrate Source in Endosperm Mutants of Maize

Differences in seed vigor of four genotypes of maize (Zea mays L.), brittle-1 (bt1), shrunken-2 (sh2), sugary (su), and normal, in an isogenic background, were investigated. Excised whole embryos and axes were grown on Murashige and Skoog (MS) media containing various carbohydrate sources. Of the four genotypes examined, sh2 seeds had the lowest vigor, especially under germination stress conditions. Embryo dry weights of sh2 were less than su and normal but equal to bt1 and made up nearly 25% of the whole seed weight. The sh2 seeds and whole embryos had low starch levels compared with the other three genotypes. Sugar levels were comparable in the three endosperm mutants, which were two times higher than normal. Optimum growth of excised embryos of all genotypes was obtained on MS medium containing 5% sucrose. However, this concentration did not totally overcome poor germination and growth of sh2 embryos and axes. Axes of su and normal had greater growth rates than sh2 and bt1 on sucrose-free medium, although the difference between genotypes decreased when whole embryos were used. When ground endosperm was employed as the carbohydrate source, sh2 embryos germinated and grew poorly, particularly on normal endosperm. With a commercial corn starch as the carbohydrate source, sh2 germlings were shorter in length and displayed a greater loss in dry weight than the other genotypes. The poor growth of sh2 embryos on ground endosperm and starch media may indicate a dysfunction of the scutellum or axis in relation to carbohydrate metabolism and utilization.     

Respiratory Transition during Seed Germination

Experiments with germinating seeds of Wayne soybean (Glycine max Merr.) show that between the 4th and the 8th hour of germination, respiration experiences a transition from predominantly “alternate” respiration, which is sensitive to salicylhydroxamic acid, to a cyanide-sensitive respiration. The dependence of early germination stages on alternate respiration is reflected in several types of seed functions, including subsequent root growth rate, chlorophyll synthesis, and germination itself. The early period of germination is shown to require a normal O₂ tension, which is no longer a requirement at later stages. The changing sensitivity to cyanide and to salicylhydroxamic acid is found to be common to seven different types of germinating seeds. It is proposed that the alternate pathway of respiration provides something essential for the completion of the earliest stages of seed germination.     

Free Radicals Developed in the Amino-Garbonyl Reaction of Sugars with Amino Acids

GA_l5, GA₃, GA₅, GA₁₉, GA₂₀ and GA₂₃ were identified by GC-MS in the acidic ethyl acetate-soluble fraction from the seeds of sweet potato (Ipomoea batatas Lam.). GA₁₉ and GA₂₃ were major GAs in the mature seeds, their contents being about 200 and 160 μg/kg fresh weight, respectively, while those of GA₁₉ and GA₂₃ in immature seeds were below 100 μg/kg fr. wt. The occurrence of glycosyl conjugates of GA₃, GA₅, GA₈, GA₁₇, GA₁₉, GA₂₀, GA₂₃ and GA₄₄ in the butanol fraction from mature seeds was shown by GC/MS analysis after enzymatic hydrolysis.

Besides the endogenous GAs in sweet potato, those in immature seeds of several other Convolvulaceae plants were investigated. The species of endogenous GAs were discussed in terms of chemotaxonomy.     

Changes in the Levels of Free Amino Acids in Various Regions of Cuscuta during Growth

The angiospermous plant parasite Cuscuta derives reduced carbonand nitrogen compounds primarily from its host. Free amino acidsalong Cuscuta vines in three zones, viz., 0 to 5 cm, 5 to 15cm, and 15 to 30 cm, which in a broad sense represent the regionof cell division, cell elongation and differentiation and vasculartissue differentiation respectively, were quantitatively estimated.The free amino acid content was the highest in the 0 to 5 cmregion and progressively decreased along the posterior regionsof the vine. The haustorial region showed the lowest contentof free amino acids. In general, the free amino acid contentin samples collected at 7 p.m. was found to be higher than thatin the samples collected at 7 a.m. Three basic amino acids,histidine, the uncommon amino acid -hydroxyarginine, and arginineconstituted more than 50% of the total free amino acids in allthe zones studied except the haustorial region. Aspartic acidand glutamic acid constituted the major portion in the acidicand neutral fraction of amino acids. Glutamine, asparagine,threonine, and serine were eluted together and occurred in substantialamounts. -Hydroxyarginine constituted the largest fraction inthe cut end exudate of Cuscuta and presumably appeared to bethe major form of transport amino acid. -Hydroxyarginine wasalso a major constituent of the basic amino acids in Cuscutavines parasitizing host plants from widely separated families,suggesting that this amino acid is a biosynthetic product ofthe parasite rather than that of the hosts. Also, U-¹⁴C argininewas converted to -hydroxyarginine by cut Cuscuta vines, suggestingthat -hydroxyarginine is synthesized de novo from arginine byCuscuta. (Received March 30, 1987; Accepted June 7, 1988)     

HNPCC家系血清中游离氨基酸及矿物质测定

目的 :探讨HNPCC家族血清游离的氨基酸与矿物质的变化 ,为HNPCC家族的监测提供论据 ;方法 :用HPLC及原子吸收分光光度法检测正常人与HNPCC家族成员血清中游离氨基酸及Cu、Ca、Fe、Zn的含量 ;结果 :HNPCC组血清中Glu、Cys、Val高于正常对照组 ;而His、Pro、Leu、Phe低于正常对照组 ,血清Fe比正常人高 ,血清Ca低于正常人。结论 :血清中的部分游离氨基酸及Fe、Ca可作为HNPCC家族监测的间接指标。     

Effect of some Flavonoids and Phenolic Acids on Seed Germination and Rooting

Nandakumar, L. and Rangaswamy, N. S. 1985. Effect of some flavonoidsand phenolic acids on seed germination and rooting.Mdash;J.cxp. Bot. 36: 1313–1319. Effects of isovitexin (isolated from leaves of Rhynchosia minima),leucocyanidin, gallic acid, and protocatechuic acid on seedgermination and subsequent seedling growth of a crucifer Brassicacampestris, and two legumes Lens esculenta and R. minima, aswell as effects of isovitexin on rooting of onion bulbs aredescribed. Neither of the flavonoids affected seed germinationin any of the three systems studied. However, both the flavonoidspromoted seedling growth in B. campestris and L. esculenta;the promotion of root growth was more marked. At 10^–5and 10^–7M, isovitexin also promoted rooting of onion bulbs.In the range of 2.27 ? 10^–4M to 3.28 ? 10^–3M, leucocyanidinpromoted growth of both root and shoot in L. esculenta, whereasin the range 3.28 ? 10^–3M to l.64?lO^–3M it suppressedseedling growth. In contrast to the flavonoids, the two phenolicacids tested inhibited seed germination at 10^–3M, andat lower concentrations they suppressed seedling growth. The promotive effects of the flavonoids isovitexin and leucocyanidin,especially on root growth, hold promise for the use of suchnaturally occurring plant substances in studies on the physiologyof plant growth and development. Key words: Flavonoids, phenolic acids, seed germination, rooting     

Changes in the Contents of Free and Protein Amino Acids in Tobacco Seeds and Placentae during Maturation

Changes in the levels of protein and free amino acids in theseeds and placentae of Nicotiana tabacum were studied duringseed development. Seed maturation was completed 24 days afteranthesis. During maturation, protein rapidly accumulated inthe seeds between the 6th and 18th day, along with an appreciablecompositional change in the protein amino acids as the proportionsof glutamic acid and arginine increased. The amount of freeamino acids in the seeds gradually decreased throughout maturation.The major free amino acid on the 6th day after anthesis wasglutamine, which then drastically decreased between the 6thand 12th day with increases of glutamic acid, proline, arginineand alanine. The latter amino acids decreased thereafter untilthe 24th day. On the other hand, the amount and composition of the proteinsin the placentae did not change significantly throughout seedmaturation. In the early stage of development, the major freeamino acids in the placentae were glutamine, asparagine andglutamic acid, while in the later stage asparagine was mostabundant. (Received March 12, 1982; Accepted August 16, 1982)     

外源一氧化氮供体浸种对玉米种子萌发和幼苗生长的影响

外源一氧化氮供体硝普钠浸种可以提高玉米种子的发芽率,浓度为10、100、1000、2000μmol·L-1时,促进幼苗地上部和根的伸长生长,且有利于玉米侧根发生,幼苗叶片中的硝酸还原酶的活性也提高.以100μmol·L-1的硝普钠处理的综合效果最好.     

Free Amino Acids in Serine-Antagonized Cells of Tetrahymena pyriformis.

Wragg, June B. (Agricultural Research Service, Beltsville, Md.), Howard Reynolds, and Michael J. Pelczar, Jr. Free amino acids in serine-antagonized cells of Tetrahymena pyriformis. J. Bacteriol. 90:748-754. 1965.-Growth inhibition of Tetrahymena pyriformis by l-serine in a chemically defined medium was reversed by l-arginine in a manner which resembled competitive antagonism. Composition of the free amino acid pools from cells grown in either a balanced amino acid mixture or a mixture with serine concentrations which inhibited growth suggested an antagonism by serine with energy-yielding reactions. Growth in media with excess serine resulted in the accumulation of higher concentrations of free cellular amino acids and an apparent increase in the rate of conversion of arginine to ornithine, as compared with growth in the balanced medium. The results suggested that serine or a metabolic product of serine interferes with the formation of pyruvic acid. In the presence of high levels of serine, arginine appeared to be metabolized more rapidly and to be spared when alanine, aspartic acid, or glutamic acid was added to the unbalanced medium.     

种子萌发过程中贮藏油脂的动员

对植物种子萌发过程中贮藏油脂动员的研究进展进行了综述。不同种子的贮藏油脂的降解途径不同。目前提出有3条途径:传统的脂酶直接水解途径;新近发现的酰基-CoA-二酯酰甘油酰基转移酶途径和脂氧合酶(LOX)途径。前两条途径不依赖于LOX。这3条途径可能在贮藏油脂动员过程中是并存的,但目前尚不知道在种子萌发过程中油脂降解是以那一条降解途径为主,以及不同的种之间是否存在差异。此外,3条降解途径目前都缺乏分子生物学的直接证据。     

Changes in Free Amino Acids in White and Green Tissues of Variegated Tobacco Leaves during Water Stress

Variegated tobacco leaves, white on one side of the midrib andgreen on the other, were detached from the stem and incubatedunder water stress or turgid conditions for 4 days to determineany changes in the levels of free amino acids. Drastic changes in the free amino acid composition occurredin the green tissue during the water stress period, but onlyvery small changes in the white tissue. During that time, themost striking difference between the two tissues was the largeamount of proline accumulated in the green tissue, but not inthe white. An exogenous supply of sucrose increased the prolinecontent in both tissues during water stress. An exogenous supplyof glutamic acid increased the proline and asparagine contentsin the green tissue, but it increased only the asparagine contentin the white tissue during water stress. (Received May 4, 1982; Accepted August 12, 1982)