Volatile constituents and fatty acid composition of lipids in Durio zibethinus

The predominating flavour compounds in the fruit pulp of Durio zibethinus were hydrogen sulfide, ethyl hydrodisulfide and several dialkyl polysulfides, particularly (C₂H₅)₂S_n, where n = 2 or 3. Ethyl acetate, 1,1-diethoxyethane and ethyl 2-methylbutanoate contribute to an additional fruity odour note. Hydrodisulfides are probably the precursors of the dialkyl sulfides. In the pericarp and seed no volatile sulfur compounds could be detected. The fatty acid composition of the lipids in pericarp, pulp and seed depended on the origin and/or harvest season of the fruit. The main components were oleic and palmitic acids or arachidic acid together with appreciable quantities of palmitoleic, stearic, linoleic and linolenic acids.     

Surface lipids of Trifolium species

Fatty acids comprised 27.7 and 30.3% of the surface lipids of Trifolium pratense and T. resupinatum, respectively. The hydrocarbons contained 1     

Free and bound lipids of Neurospora crassa

Extraction of light and dark grown cells of Neurospora crassa with chloroform-methanol gave a free lipid extract in which the relative amounts and compositions of sterols, fatty acid and carotenoid fractions were determined. Further extraction of the cells with methanolic potassium hydroxide solution liberated a bound lipid fraction from the cells. The levels of the bound lipid fraction were much lower than those of the free lipids but analysis showed that the composition was similar to that of the free lipids.     

Extracellular fungal polyol lipids: A new class of potential high value lipids

Extracellular fungal glycolipid biosurfactants have attracted attention because productivities can be high, cheap substrates can be used, the molecules are secreted into the medium and the downstream processing is relatively simple. Three classes of extracellular fungal glycolipid biosurfactants have provided most of the scientific advances in this area, namely sophorolipids, mannosylerythritol lipids and cellobioselipids. Polyol lipids, a fourth class of extracellular fungal glycolipid biosurfactants, comprise two groups of molecules: liamocins produced by the yeast-like fungus Aureobasidium pullulans, and polyol esters of fatty acids, produced by some Rhodotorula yeast species. Both are amphiphilic, surface active molecules with potential for commercial development as surfactants for industrial and household applications. The current knowledge of polyol lipids highlights an emerging group of extracellular fungal glycolipid biosurfactants and provides a perspective of what next steps are needed to harness the benefits and applications of this novel group of molecules.     

Neutral lipids of leaves and stems of Trifolium repens

The neutral lipids of white clover leaves and stems have been separated into wax esters, free fatty acids, free fatty alcohols, free sterols, triglycerides and hydrocarbons. The wax esters were mainly of C₁₈ di- and tri-unsaturated fatty acids and C₃₀ fatty alcohol. Linolenic acid was the predominant free fatty acid and triacontanol was the principal free fatty alcohol. Of the hydrocarbons, C₂₉ and C₃₁ were present in the largest amounts.     

Comparative analysis of diacylglyceryl-trimethylhomoserine in Ochromonas danica and in Chlamydomonas reinhardtii 137+

The fatty acid compositions of the ether lipid 1(3),2-diacylglyceryl-(3)-O-4′-(N,N,N-trimethyl)homoserine (DGTS) from Ochromonas danica a     

Hexane soluble non-volatiles in flowering to fruiting stages of Fatsia japonica

The n-hexane soluble non-volatile fraction of the acetone extracts from the flower buds, the flowers and the immature and the mature fruits of Fatsia japonica were all found to contain fatty acids, fatty acid methyl esters, squalene, β-amyrin and sterols. At all the stages between budding to the mature fruit, the major fatty acids were palmitic and linoleic acids and the major phytosterol was stigmasterol. In addition steryl and β-amyrenyl esters were found in the flowers and the immature and the mature fruits, but these esters were not present in the flower buds. Sitosteryl ester was the major constituent of the steryl ester fraction in the fruiting stages. Phytol was found in only the flowering stage and triglycerides in only the mature fruits. The variations in the lipid constituents is discussed in relation to the stages from budding to the mature fruit.     

Free Fatty Acids of Surface Film of Water in the Sydinsky Bay of the Krasnoyarsk Reservoir

During the summer of 1990 composition and concentrations of free fatty acids (FFA) in the surface film of water were investigated. 23 FFA species were identified. Using cluster analysis in conjunction with ANOVAR correspondence of FFA contents in the surface film with seasonal patterns of pelagic plankton was proved. Three different groups of FFA were revealed, acids of every group had similar seasonal dynamics and presumably were of similar origination. Data obtained gave a chance to suppose that main part of FFA were originated by exudation of living cells of phytoplankton as well as postmortal exudation of bacterioplankton. On the basis of FFA contents in a single sample from the surface film identification of sign of derivatives of phytoplankton biomass was suggested. This express-assay may be useful for monitoring.     

The fatty acid composition of Ulothrix aequalis lipids

Fatty acid composition of the total lipids isolated from the fresh-water green alga Ulothrix aequalis shows that they resemble marine green algal lipids in having a high proportion of 16:4 ω-3 but differ in having only trace amounts of 18:4 ω-3. The distribution of ω-3 acids in the MGDG and DGDG fractions resembles that in green seaweeds and higher plants with the 16:4 ω-3 distribution in the Ulothrix fractions resemblmg that of 18:4 ω-3 in the corresponding fractions of the seaweeds.     

Identification of a phospholipase B encoded by the LPL1 gene in Saccharomyces cerevisiae

Phospholipids also play a major role in maintaining the lipid droplet (LD) morphology. In our current study, deletion of LPL1 resulted in altered morphology of LDs and was confirmed by microscopic analysis. LPL1/YOR059c contains lipase specific motif GXSXG and acetate labeling in the LPL1 overexpressed strains depicted a decrease in glycerophospholipids and an increase in free fatty acids. The purified Lpl1p showed phospholipase activity with broader substrate specificity, acting on all glycerophospholipids primarily at sn-2 position and later at sn-1 position. Localization studies precisely revealed that Lpl1 is exclusively localized in the LD at the stationary phase. Site directed mutagenesis experiments clearly demonstrated that the lipase motif is vital for the phospholipase activity. In summary, our results demonstrate that yeast Lpl1 exerts phospholipase activity, plays a vital role in LD morphology, and its absence results in altered LD size. Based on the localization and enzyme activity we renamed YOR059c as LPL1 (LD phospholipase 1).     

Contrasting effects of anoxia on rhizome lipids in Iris species

A 14-day period of anoxia resulted in losses of polar lipids, particularly their saturated fatty acid components, from the anoxia-tolerant species Iris pseudacorus. By complete contrast, the anoxia-intolerant, closely related species I. germanica, although possessing a highly similar lipid profile, exhibited no changes in lipid composition in response to anoxia. The consequences of the lipid alterations in I. pseudacorus for membrane function and their possible role in adaptation to anoxia are discussed.     

Sterol esters of Phycomyces blakesleeanus

The sterol esters of Phycomyces blakesleeanus are based on ergosterol, episterol, ergosta-7-en-3β-ol, ergosta-7,22-dien-3β-ol, cholesterol, lan     

Lipid composition of Sporendonema epizoum

Triglycerides, free fatty acids, free and esterified ergosterol, Q₉, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, lysophosphatidylethanolamine, and three different acylglycoses were identified in the soluble lipids of Sporendonema epizoum mycelium. The same compounds as well as a sterol glycoside were also found in conidia. The mycelium is richer than the conidia in phospholipids, Q₉ and free and esterified ergosterol but contains less glycolipids. The most abundant fatty acid in all non-polar fractions is C_18:2. The prevalent fatty acid of the phospholipids is C_18:1, except for conidial phosphatidylethanolamine and mycelial lysophosphatidylethanolamine.     

Epicuticular wax of Pinus radiata needles

Epicuticular wax isolated from the cotyledons and primary needles of 10-week-old Pinus radiata seedlings is similar in composition and contains 86% neutral compounds, viz. alkyl esters (25%, C₂₄–C₆₄), nonacosan-10-ol (52%), heptacosane-5,10-diol (2%), nonacosane-4,10-diol, nonacosane-5,10-diol, and nonacosane-10,13-diol (total 12%) and estolides, MW ca 800 (2%), MW ca 1100 (6%), and MW ca 1500 (1%). The acidic fraction (14%) contains n-acids (78%, C₁₂–C₃₂) and diterpene acids (22%, mainly abieta-8,11,13-trien-18-oic, with lesser amounts of pimara-8(14),15-dien-18-oic, isopimara-7,15-dien-18-oic and hydroxylated aromatic, diene and mono-ene acids). Wax isolated from primary needles of 1-yr-old seedlings had a similar neutral fraction composition, but the acidic fraction contained predominantly the diterpene acid mixture, with only trace amounts of n-acids. The wax from 1-yr-old secondary, needles from P. radiata forest trees aged 5 yr and 40 yr contained an acid fraction (12% 5 yr, 17% 40 yr trees) comprising the diterpene acid mixture, with trace amounts of n-acids together with ω-hydroxy acids (C₁₂, C₁₄ and C₁₆). The neutral fraction from both young and old trees had a similar composition containing alkyl esters (7%, C₂₄–C₆₆), estolides (90%, MW 566-ca 1500), nonacosan-10-ol (2%) and the heptacosane and nonacosane diols (1%). During growth and maturation of P. radiata, the nonacosan-10-ol content of the needle wax decreases while the proportion of estolides and diterpene acids increases, the latter probably being located around the stomatal pore.     

Mobilization of steryl esters from lipid particles of the yeast Saccharomyces cerevisiae

In the yeast as in other eukaryotes, formation and hydrolysis of steryl esters (SE) are processes linked to lipid storage. In Saccharomyces cerevisiae, the three SE hydrolases Tgl1p, Yeh1p and Yeh2p contribute to SE mobilization from their site of storage, the lipid particles/droplets. Here, we provide evidence for enzymatic and cellular properties of these three hydrolytic enzymes. Using the respective single, double and triple deletion mutants and strains overexpressing the three enzymes, we demonstrate that each SE hydrolase exhibits certain substrate specificity. Interestingly, disturbance in SE mobilization also affects sterol biosynthesis in a type of feedback regulation. Sterol intermediates stored in SE and set free by SE hydrolases are recycled to the sterol biosynthetic pathway and converted to the final product, ergosterol. This recycling implies that the vast majority of sterol precursors are transported from lipid particles to the endoplasmic reticulum, where sterol biosynthesis is completed. Ergosterol formed through this route is then supplied to its subcellular destinations, especially the plasma membrane. Only a minor amount of sterol precursors are randomly distributed within the cell after cleavage from SE. Conclusively, SE storage and mobilization although being dispensable for yeast viability contribute markedly to sterol homeostasis and distribution.     

Inhibition of lipolysis may contribute to the acute regulation of plasma FFA and glucose by FGF21 in ob/ob mice

FGF21 is a unique member of the fibroblast growth factors (FGFs) and a novel hormone that regulates glucose, lipid, and energy homeostasis. The beneficial effects of FGF21 reported thus far have mostly been from chronic treatments. In order to better understand the mechanism for FGF21 action, we evaluated the acute effects of FGF21 in vivo and in vitro. Here we report that a single injection of FGF21 acutely reduced plasma free fatty acid levels similar to its acute effects on plasma glucose in ob/ob mice. In vitro, FGF21 inhibited lipolysis in adipocytes during a short treatment and reduced total lipase activity. These results demonstrate the potential importance of adipocyte lipolysis to the observed acute improvements in plasma parameters.     

In vivo incorporation of acetate into the acyl moieties of polar lipids from etiolated leek seedlings

Seven-day-old leek seedlings actively synthesize lipids in vivo from [1-¹⁴C]acetate, both in the light and in the dark. In the dark, phospholipid synthesis is more effective than galactolipid synthesis. Whatever the time of acetate incorporation by the etiolated seedlings, very long chain fatty acids having from 20 to 26 carbon atoms are found in all the polar lipids, including the acyl-CoAs. All of the labelled very long chain fatty acids incorporated into the polar lipids are saturated. On the other hand, the labelled C₁₈-fatty acids are unsaturated in phospholipids and galactolipids and almost no label is found in the saturated or unsaturated C₁₈-fatty acids of the acyl-CoAs.     

Incorporation of free fatty acids into acylthioesters and lipids of developing sunflower seeds

The synthesis of lipids from radioactive fatty acids in developing sunflower seeds has been examined. Lauric, palmitic, stearic and oleic acids were us     

Conjugated fatty acids from latex of Euphorbia lathyris

The fatty acids esterified with triterpene and diterpene alcohols from the latex of Euphorbia lathyris were analyzed. 77% of the fatty acids esterified with triterpenes were conjugated, the main components of which were decadienoic and decatrienoic acids. Of the acids esterified with diterpenes, 81% were decatrienoic and dodecatrienoic acids.