Long-term Adaptation to Fatty Acids by the Phytoflagellate, Polytoma uvella

SUMMARY. The adaptation to fatty acids by Polytoma depends upon two mechanisms: 1. The induced synthesis of fatty acid oxidase which precedes growth. 2. A long-term physiological adaptation spanning several cell generations which results in an increase of the initial rate of growth.
Analysis of the long-term adaptation shows that the adaptation does not result from the selection of fast-growing mutants. The generation time on butyrate of unadapted cells is initially ca. 24 hours and it is reduced to ca. 10 hours after the second subculture in butyrate medium. Adaptation to butyrate results in a simultaneous adaptation to caproate.     

Sugars and Organic Acids of Vitis vinifera

Glucose, fructose, galactose, sucrose, maltose, melibiose, raffinose, and stachyose were identified in the leaves, bark, roots, and berries of Vitis vinifera L. var. Thompson Seedless. In addition to these sugars, verbascose and manninotriose were found in the leaves and bark.

Malic, tartaric, citric, isocitric, ascorbic, cis-aconitic, oxalic, glycolic, glyoxylic, succinic, lactic, glutaric, fumaric, pyrrolidone carboxylic, α-ketoglutaric, pyruvic, oxaloacetic, galacturonic, glucuronic, shikimic, quinic, chlorogenic, and caffeic acids were identified in the leaves, bark, roots, and berries.

Glucose, fructose, sucrose, malate, tartrate, and citrate were determined quantitatively in the leaf, petiole, xylem, bark, tendril, bud, puduncle pedicel, berry, lateral roots, and main roots at 4 separate physiological stages of growth. In addition, changes in the concentrations of fructose, glucose, malate, and tartrate in leaves were measured during a 36-day period starting from budburst.

     

Fatty Acids in Chloroplasts and Leaves

The fatty acid composition of green and white leaf tissue inAcer negundo, Zea mais, and Ilex aquifolium, of green and yellowtissue in Ligustrum ovatifolium and of etiolated and green tissuein Vicia faba has been determined. The mesophytic green leavesexamined show a general similarity in fatty acid composition,characterized by a high concentration of non-conjugated octadecatrienoicacid. Chloroplasts were isolated from Vicia and Acer and containan even higher concentration of this acid and only traces ofnon-conjugated octadecadienoic acid. Conjugated diene and trieneacids occur in traces in chioroplasts, but are also found innon-green leaf tissue. The fats of non-green leaves are in generalmore saturated than those from green tissue but vary considerablyin composition. The relationship between fat composition andplastid development is discussed.     

Zinc and Fatty Acids in Depression

Polyunsaturated Fatty acids (PUFAs) seem to be helpful in the therapy of depression. Zinc (Zn) may be one co-factor contributing to their antidepressive effect. Zn acts lipid protective and is a constituent of fatty acid metabolism enzymes. In animals, an antidepressive effect of Zn was already demonstrated. Therefore, if and how Zn and PUFAs correlate in depressive patients or in individuals from the general population was investigated. Blood samples were collected from 88 depressive in-patients and 88 volunteers from the general population matched for age-group and gender (each 32 men and 56 women, 21–70 years) for measurement of Zn (colorimetric) and of 12 fatty acids (FAs) (by capillary gas-chromatography). Severity of depression in patients was assessed by Beck Depression Inventory (BDI) and Hamilton Depression Rating Scale (HDRS). Zn concentration was independent of age, gender and body-mass-index and significantly correlated with the severity of depression measured by BDI (r = 0.26; P = 0.034) in depressive patients,. HDRS was inversely correlated with gammalinolenic acid concentration (r = −0.24; P = 0.029). Median serum Zn concentration in depressive patients did not differ from control individuals. Zn was correlated with myristic acid concentration (r = 0.22; P < 0.05) in controls from the general population; and a negative correlation between Zn and dihomogammalinolenic acid concentration (r = −0.26; P < 0.05) was found in depressive inpatients. FA composition in serum significantly differed between depressive and healthy persons: Depressive patients had higher stearic and arachidonic acid (AA) concentration. Relative to AA, their eicosapentaenoic and docosapentaenoic acid concentration were diminished compared to the general populations group. These results do not confirm the hypothesis of a general lack of Zn in depressive disorders, but Zn concentrations differed dependent on comorbid disorders and severity of depression. In depressive patients and control persons Zn concentration is associated with different FAs indicating diverging metabolic pathways.     

Variability for Free Sugars and Organic Acids in Capsicum chinense

Variability in the concentrations of the chemical constituents that contribute to fruit flavor in Capsicum chinense is poorly documented in the scientific literature. We surveyed fruit of 216 landraces and cultivated varieties of Capsicum chinense acquired from North, Central, and South America, and analyzed these for concentrations of the simple sugars sucrose, glucose, and fructose, and citric, malic, succinic, fumaric, and ascorbic acids. Concentrations (mg/100 g Fresh Weight (FW) of whole fruit) of sucrose, glucose, and fructose in fruit of this species ranged from 0.0 to 150, 68 to 701, and 101 to 823, respectively. The total of these sugars (sucrose+glucose+fructose) ranged from 198 to 1543 mg/100 g FW. Concentrations of organic acids ranged from 0.0 (not detected) to 818, 430, 340, and 232 mg/100 g FW for citric, malic, fumaric, and succinic acids, respectively. However, the relative ranking in the concentrations of the individual acids was genotype‐dependent. Total ascorbic‐acid values ranged from 30 to 1466 mg/100 g FW. These data serve to document the range in the concentrations of individual sugars and acids present in mature C. chinense fruit and suggest that this variability may lend itself to studies involving the synthesis and/or metabolism of compounds associated with fruit flavor.     

多不饱和脂肪酸的研究进展

多不饱和脂肪酸(PUFA)是人类的必需脂肪酸,对人体有重要的生理功能,能调节人体的脂质代谢、治疗和预防心脑血管疾病、抗癌、对抗肥胖,促进生长发育和提高幼体的成活率等．综述了PUFA的生理作用和来源的研究进展,特别是在对抗肥胖、促进生长发育、提高幼体的成活率等方面的研究情况进行了阐述．     

Transgenic Mice Convert Carbohydrates to Essential Fatty Acids

Transgenic mice (named “Omega mice”) were engineered to carry both optimized fat-1 and fat-2 genes from the roundworm Caenorhabditis elegans and are capable of producing essential omega-6 and omega-3 fatty acids from saturated fats or carbohydrates. When maintained on a high-saturated fat diet lacking essential fatty acids or a high-carbohydrate, no-fat diet, the Omega mice exhibit high tissue levels of both omega-6 and omega-3 fatty acids, with a ratio of ∼1∶1. This study thus presents an innovative technology for the production of both omega-6 and omega-3 essential fatty acids, as well as a new animal model for understanding the true impact of fat on human health.     

Patterns of Effective Permeability of Leaf Cuticles to Acids

Plants in the field are frequently exposed to anthropogenic acid precipitation with pH values of 4 and below. For the acid to directly affect leaf tissues, it must pass through the leaf cuticle, but little is known about the permeability of cuticles to protons, or about the effect of different anions on this permeability. We investigated the movement of protons through isolated astomatous leaf cuticles of grapefruit (Citrus X paradisi Macfady.), rough lemon (Citrus limon [L.] Burm. fils cv Ponderosa), and pear (Pyrus communis L.) using hydrochloric, sulfuric, and nitric acids. Cuticles were enzymically isolated from leaves and placed in a diffusion apparatus with pH 4 acid on the morphological outer surface of the cuticle and degassed distilled water on the inner surface. Changes in pH of the solution on the inner surface were used to determine rates of effective permeability of the cuticles to the protons of these acids. Most cuticles exhibited an initial low permeability, lasting hours to days, then after a short transition displayed a significantly higher permeability, which persisted until equilibrium was approached. The change in effective permeability appears to be reversible. Effective permeabilities were higher for sulfuric acid than for the others. A model of the movement of protons through the cuticle is presented, proposing that dissociated acid groups in channels within the cutin are first protonated by the acid, accounting for the low initial effective permeability; then protons pass freely through the channels, resulting in a higher effective permeability.     

Separation and Identification of Fatty Acids

For the characterization of fatty acids, 2, 4-dinitrophenylhydrazones of p-bromophenacyl esters of even-numbered saturated fatty acids from C₂ to C₂₀ and several unsaturated fatty acids from monoethenoid to triethenoid were prepared. The derivatives of linoleic and linolenic acids as well as those of the other unsaturated and saturated acids, were successfully obtained in crystalline forms which showed sharp and high melting points, 72° and 69°, respectively. It was found that the derivatives of unsaturated acids were valuable for characterizing the parent acids, while those of saturated acids were unsuitable for this purpose owing to the similarity of their melting points.     

Separation and Identification of Fatty Acids

An improved method is described for separating saturated fatty acids by reversed-phase paper chromatography. The 2,4-dinitrophenylhydrazides prepared from saturated fatty acids from C₂ to C₂₂ are run upward on paper impregnated with tetralin, using 90% methanol—acetic acid—tetralin, 80% ethanol—acetic acid—tetralin, or 90% methanol—tetralin as the moving solvent. The simultaneous separations of all even-carbon acids from C₆ to C₂₂, all odd-carbon acids from C₇ to C₁₉, and also all odd- and even-carbon acids from C₇ to C₁₉ can be successfully performed by means of this paper chromatography. The method is useful for the detection of component saturated fatty acids in natural fats.     

Spin Label Motion in Fatty Acids

Spin labels dissolved in highly purified fatty acid systems exhibit nearly identical tumbling rates in liquid and solid phases. Even though the spin labels do not have the same molecular geometry as the lipid matrix the melting point of the matrix can be inferred by measurements of the temperature dependency of molecular motion.     

Very Long-Chain Fatty Acids in Yeast

Novel fatty acids ranging from 20 to 30 carbons have been found in Saccharomyces cerevisiae. These comprise 1 to 2% of the total fatty acid fraction.     

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.     

Fatty Acids of Mycobacterium kansasii

The cellular fatty acids of 35 strains of Mycobacterium kansasii isolated from clinical material were analyzed to establish properties by which we could identify and characterize these acid-fast microorganisms. The fatty acids were extracted from cells grown in liquid synthetic media, and they were analyzed as methyl esters by gas-liquid chromatography. The fatty acid profiles of all strains were similar. They differed from fatty acid profiles of other mycobacteria by their content of a saturated fatty acid with a methyl group at C2.