Lipid metabolism ofAgaricus bisporus (Lange) sing.: I. Analysis of sporophore and mycelial lipids

The lipid components of four strains ofAgricus bisporus (Lange) Sing., the cultivated mushroom, were analyzed. Both sporophore and mycelial samples were obtained from beds in normal production. A method for obtaining mycelium free of compost was developed. Neutral lipids were separated from polar lipids by silicic acid column chromatography. Each fraction was separated by thin layer chromatography. Fatty acid methyl esters were analyzed by gas liquid chromatography and mass spectrometry. Sporophore extracts contained free sterol, free fatty acid, triglycerides, phosphatidyl choline and phosphatidyl ethanolamine. High amounts of linoleic acid were found in both neutral and polar lipid fractions. Mycelial extracts contained free fatty acids, triglycerides, phosphatidylcholine and phosphatidyl ethanolamine. No free sterol could be detected. Linoleic acid was also present in large amounts. Paper 3798 in the Journal Series of The Pennsylvania Agricultural Experiment Station.     

Neutral lipids in snail-conditioned water fromBiomphalaria glabrata (Gastropoda: Planorbidae)

Thin-layer chromatography was used to study neutral lipids in snail-conditioned water (SCW) fromBiomphalaria glabrata snails. A major lipid fraction in SCW at 2 and 4 hr after snail incubation contained free fatty acids. Fatty acids released per snail per milliliter of water when 10 snails were incubated in 5 ml of deionized water for 4 or 2 hr was 2.4±0.4 µg/ml and 0.9±0.1 µg/ml (mean ± SE), respectively. The amount released at 4 hr was significantly greater than at 2 hr. Snails also released free sterols, a sterol ester-hydrocarbon fraction, methyl esters, and other unidentified lipid fractions into the water. The potential of these neutral lipids to serve as chemoattractants for larval trematodes or snails remains to be determined.     

Lipid composition of 30 species of yeast

The detailed composition of cellular lipid of more than 23 species of yeast has been determined quantitatively by thinchrography on quartz rods, a method previously used for estimating cellular lipids of seven species of yeast. That data was fortified by neutral and phospholipid quantitations on 30 species of yeast cells. Most of the test organisms contained 7–15% total lipid and 3–6% total phospholipid per dry cell weight, except for the extremely high accumulation of triglycerides in two species ofLipomyces. Qualitatively, 30 species of yeast cells contained similar neutral lipid constituents (triglyceride, sterol ester, free fatty acid, and free sterol) and polar lipid components (phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, cardiolipin, and ceramide monohexoside) without minor constituents. Based on the quantitative composition of neutral lipids, the 30 species of yeast were divided into two groups, the triglyceride predominant group and the sterol derivative group. These groupings were fairly well overlapped from the standpoint of the distribution characteristics of fatty acid. The relative polar lipid compositions also grossly resembled each other. Only one exception of polar lipid composition in yeast cells was found inRhodotorula rubra species which contained phosphatidyl ethanolamine as the most abundant phospholipid. Fatty acid distribution patterns in yeast cells consistently coincided with other reports concerning fatty acid composition of yeast cells. Correlation of lipid composition and classification of yeasts are suggested and discussed. A part of this investigation has been reported at the 14th conference of the Japan Oil Chemists' Society, Nagoya, Japan, October 1975.     

Relationship between embryonic and tumor lipids: I. Changes in the neutral lipids of the developing chick brain,heart and liver

Organ dry weight, per cent total lipid, per cent neutral lipid, per cent phospholipid, and neutral lipid class composition of embryonic and mature brain, heart and liver were determined at 10, 13, 16, 19, 22, 27 and 53 days after incubation was initiated. All three tissues showed an increase in total lipids from the 10th day to hatching (21st day). The 10th day brain showed relatively high levels of sterol esters which decreased with increased development while free sterol levels increased. Heart free sterol and sterol ester percentages decreased with increassed time, while triglyceride levels increased dramatically after the 16th day. Liver showed a massive accumulation of neutral lipid after the 17th day. The neutral lipid was not triglyceride, as might have been expected, but sterol ester. Liver sterol, sterol ester and triglyceride levels were approximately equal at the 10th and 13th days, after which time sterol ester rose rapidly to more than 90% of the total neutral lipids by the 19th day. The neutral lipid class distributions were characteristically different for each tissue throughout embryonic development. The relative high sterol ester levels in each of the tissues early in development suggests that the high level of sterol esters in neoplastic tissue may be related to the growth process of increasing cell numbers. On the other hand, the absence or the presence of only trace amounts of glyceryl ether diesters in any of the embryonic tissues suggests that the elevated levels of this lipid class in most tumors may be related to the neoplastic process or to conditions resulting from neoplasia.     

Effect of extraction methods on lipid yield and fatty acid composition of lipid classes containing γ-linolenic acid extracted from fungi

The effect of extraction procedures on the lipid yield and fatty acid composition of total lipid and main lipid structures (phospholipids, diacylglycerols, triacylglycerols, free fatty acids, and sterol esters) of fungal biomass (Mucor mucedo CCF-1384) containing γ-linolenic acid (GLA) was investigated. Seventeen extraction methods, divided into three groups, were tested: six with chloroform/methanol, five with hexane/alcohols, and six with common solvents or mixtures. The chloroform/methanol procedure (2∶1) was selected as standard, where lipid yield (TL/DCW, total lipid per dry cell weight) was 17.8%, considered to be 100% of lipids present. All chloroform/methanol extractions yielded more than 83% recorvey of lipids. Use of hexane/isopropanol solvent systems led to a maximum of 75% recovery. The best lipid yield was achieved by a two-step extraction with ethanol and hexane (120%). Extraction efficiency of the other solvent systems reached a maximum of 73%. Triacylglycerols were the main structures of lipid isolated; only methanol-extracted lipid contained 58.5% phospholipids. The fatty acid content of total recovered lipid was variable and depended on both the lipid class composition and the solvent system. GLA concentrations in total lipids isolated by hexane/alcohol procedures (7.3–10.7%) are comparable with classical chloroform/methanol systems (6.5–10.0%). The maximal GLA yield was obtained with chloroform/methanol/n-butanol/water/0.1 M ethylenediaminetetraacetic acid (EDTA) (2∶1∶1∶1∶0.1, by vol) and after two-step extraction with ethanol and hexane (14.3 and 13.7 g GLA/kg DCW, respectively). The highest GLA content was analyzed in the phospholipid fraction (16.1%) after using chloroform/methanol/n-butanol/water/0.1 M EDTA (2∶1∶1∶1∶0.1, by vol). Remarkably low concentrations of polyunsaturated fatty acids were determined in the free fatty acid fraction.     

Effect of excessive fatty acid ingestion upon composition of neutral lipids and phospholipids of snailHelix pomatia L.

The effect of an excessive intake of oleic acid on the lipids of the Roman snail (Helix pomatia L.) was studied. The total lipid content increased by 30% which was fully attributable to a marked elevation in the neutral esters and free fatty acids, as phospholipid and free sterol contents remained unaffected. The fatty acid composition of the phospholipids, characterized by high amounts of stearic, linoleic, homolinoleic, and, particularly, arachidonic acids, appeared to be nearly insensitive to this excessive oleic acid ingestion. By contrast, the effect of oleic acid upon the depot lipids was striking: active intestinal resorption of the acid from the dietary supply was shown by the fourfold level of lleic acid in the free fatty acid fraction, whereas a fivefold level of this acid in the glyceride and sterol ester fraction was proof of a substantial esterification. These data support the view that the composition of the structural lipids is specifically species oriented, whereas both the content and the composition of the depot lipids are highly governed by dietary fat intake.     

Chemoattraction ofBiomphalaria glabrata (Gastropoda: Planorbidae) to lipid standards and lipophilic factors in leaf lettuce and Tetramin

Chemoattraction of individualBiomphalaria glabrata snails for lipid standards and lipophilic fractions of leaf lettuce and Tetramin were studied in a Petri dish bioassay. Snails were more significantly attracted to a whole Tetramin lipophilic fraction than that of leaf lettuce. Thin-layer chromatography showed that major neutral lipid fractions in Tetramin were triacylglycerols, free fatty acids, and free sterols, and in leaf lettuce were free fatty acids and a mixed free sterol-chlorophyll fraction. Snails were significantly attracted to both the free fatty acid and free sterol fractions from Tetramin, but only to the free fatty acid fraction from leaf lettuce. Snails were significantly attracted to a mixed lipid standard containing equal amounts of phosphatidylcholine, cholesterol, oleic acid, triolein, and cholesteryl oleate. Of four individual neutral lipid standards tested, i.e., cholesterol, oleic acid, triolein, and cholesteryl oleate, snails were only attracted to cholesteryl oleate.     

Distribution of neutral lipids in the tissues of the oysterCrassostrea virginica

The content of neutral lipids was determined in the tissues of oysters (Crassostrea virginica Gmelin) collected in June, July and March. The lipid content of starved March oysters was also determined. Oyster tissue from the June harvest contained the highest quantities of triglyceride; starved and July (late spawning) oysters had decreased levels of triglycerides in all tissues except the digestive diverticula/gonad. Free sterol content of all the tissues averaged 1.21 mg equivalent cholesterol/g wet weight tissue, and the steryl ester concentration averaged about 10% of this value. Findings of this investigation indicate that the triglyceride content of oyster tissue fluctuates seasonally and is there-fore keyed to the physiological state of the animal. Furthermore, triglycerides may be an important energy reserve for reproductive tissue.     

Lipid composition of perilla seed

The composition of lipids and oil characteristics from perilla [Perilla frutescens (L.) Britt.] seed cultivars are reported. Total lipid contents of the five perilla seed cultivars ranged from 38.6 to 47.8% on a dry weight basis. The lipids consisted of 91.2–93.9% neutral lipids, 3.9–5.8% glycolipids and 2.0–3.0% phospholipids. Neutral lipids consisted mostly of triacylglycerols (88.1–91.0%) and small amounts of sterol esters, hydrocarbons, free fatty acids, free sterols and partial glycerides. Among the glycolipids, esterified sterylglycoside (48.9–53.2%) and sterylglycoside (22.1–25.4%) were the most abundant, while monogalactosyldiacylglycerol and digalactosyldiacylglycerol were present as minor components. Of the phospholipids, phosphatidylethanolamine (50.4–57.1%) and phosphatidylcholines (17.6–20.6%) were the major components, and phosphatidic acid, lysophosphatidylcholine, phosphatidylserine and phosphatidylinositol were present in small quantities. The major fatty acids of the perilla oil were linolenic (61.1–64.0%), linoleic (14.3–17.0%) and oleic acids (13.2–14.9%). Some of the physicochemical characteristics and the tocopherol composition of perilla oil were determined.     

Sterol and fatty acid composition of neutral lipids ofParatenuisentis ambiguus and its host eel

The sterol composition of free sterol and steryl ester fractions of the fish parasiteParatenuisentis ambiguus was determined. In addition, the fatty acid composition of various neutral lipid classes, i.e., wax esters, steryl esters, triacylglycerols and free fatty acids, as well as the composition of the 1-O-alkyl moieties of total ether glycerolipids of the parasite, were investigated. The results of these studies were compared with those obtained on the intestinal tract tissue of its host, the eel (Anguilla anguilla). Cholesterol is the major sterol in bothP. ambiguus andA. anguilla. However, the sterols ofP. ambiguus contain high proportions (>20%) of other sterols, such as campesterol and various dehydrosterols. [e.g., 7-dehydrocholesterol and cholesta-5,22(E)-dienol]. The presence of these minor sterols agrees with the known biotransformations of exogenous sterols in various helminths. Considerable differences are found in the fatty acid composition of neutral lipid fractions, as well as the total lipid extract from the endoparasite as compared to the host tissue. In particular, eicosapentaenoic acid (20∶5n−3), other polyunsaturated fatty acids, such as 20∶4n−6, 22∶5n−3 and 22∶6n−3, as well as long-chain saturated fatty acids, such as 20∶0, are generally enriched in the neutral lipid fractions of the parasite as compared to those of infected eel intestine. The analysis of ether glycerolipids revealed that 1-O-hexadecyl (16∶0) and 1-O-hexadecenyl (16∶1) moieties were present in similar proportions in the ether lipids of bothP. ambiguus and eel intestine, whereas 1-O-octadecyl (18∶0) moieties are more prominent in the parasite and 1-O-octadecenyl (18∶1) moieties in the eel. The results of these studies show thatP. ambiguus has specific mechanisms for the regulation of the sterol and fatty acid composition of its neutral lipids. Dedicated to Professor Helmut K. Mangold on the occasion of his 70th birthday.     

Quantitative isolation of lipids of partially defatted and whole peanuts by a dry column method

A dry column method of lipid extraction was found to be applicable to peanuts—partially defatted as well as whole. Total lipid was obtained from the peanut/sodium sulfate/Celite 545 columns by isocratic elution with dichloromethane/methanol 9:1. Moreover, neutral lipids were obtained by sequential elution that were completely free from polar lipids. First, dichloromethane eluted the neutral lipids, then the 9:1 solvent eluted the polar lipids—at times containing small quantities of neutral lipids. Total lipid values obtained by the column extraction method were slightly higher than those obtained by the standard Soxhlet extraction procedure. This was due in part to the more complete polar lipid isolation produced by the column method. In partially defatted peanuts produced by mechanical pressing, 99% of the polar lipids remained in the retained oil, and these were shown to be slightly less unsaturated than the neutral lipids.     

Neutral lipid composition ofCulex quinquefasciatus andCulex tritaeniorhynchus cells at two phases of growth

The mosquito cellsCulex quinquefasciatus andCulex tritaeniorhynchus were grown in spinner cultures. The fatty acid profiles of the neutral lipid classes were analyzed, and comparisons were made between the two species at logarithmic and stationary phases of growth and between the species and the medium. The results from the data suggest an increase in the average chain length of the fatty acids in the free fatty acid and sterol ester fractions of theCulex quinquefasciatus cells with aging. From the logarithmic to stationary phase, both Culex cells showed some increase in desaturation of acids in the di- and triglyceride and free fatty acid fractions. TheCulex tritaeniorhynchus cells also showed some increase in desaturation of acids in the monoglyceride fraction. Differences between the twoCulex species at the logarithmic phase of growth were observed in the fatty acid profiles of all the neutral lipid fractions examined and at the stationary phase of growth in the free fatty acid, triglyceride, and sterol ester fractions.     

Neutral lipids in non‐starch lipid and starch lipid extracts from Portuguese sourdough bread

This research effort was aimed at assessing the changes in extractable neutral lipids (NL) throughout the baking process of Broa, a Portuguese traditional sourdough bread. NL were accordingly isolated, purified and quantitated – starting from non‐starch lipid (NSL) and starch lipid (SL) extracts of maize and rye flours, as well as fermented dough and bread. NSL accounted for the major fraction of extracted lipids; furthermore, the NSL/SL ratio evolved throughout processing in agreement with the phenomena prevailing during dough preparation, fermentation, and baking. An analytical method based on resolution by normal‐phase HPLC coupled with detection by evaporative light scattering was accordingly developed for quantitation of the aforementioned NL classes. Distinct NL classes correlated well with the stage of bread making. The main NL in NSL were triacylglycerols (ca. 75% of the total), but relatively high concentrations of sterol esters and diacylglycerols were also found. Conversely, free fatty acids were the dominant component of SL, whereas monoacylglycerols and free sterols were comparable to those in NSL.     

Excretion of lipids by the liver fluke (Fasciola Hepatica L)

Adult liver flukes kept in a glucoseenriched medium were found to excrete lipids. Analysis of the incubation medium showed that both neutral lipids (including cholesterol and its esters) and polar lipids were released. The rate of lipid excretion was greatly reduced when the excretory pores and mouths of the flukes were ligated. Histochemical examination of the flukes indicated that such lipids, released through the excretory pores, originate in the cells lining the excretory ducts.     

Evidence of pheromonal constancy among sexual and asexual females in a population of fall cankerworm,Alsophila pometaria (Lepidoptera: Geometridae)

The compounds (Z,Z,Z)-3,6,9-nonadecatriene (I), (Z,Z,Z,E)-(II), and (Z,Z,Z,Z)-3,6,9,11-nonadecatetraene (III) have been implicated as components of the female sex pheromone of the fall cankerworm. Chromatographie determination of the proportions of these compounds in individual females of sympatric asexual and sexual reproductive forms of the species, with concurrent analysis of the electrophoretic profiles of the same females, showed that the I: II: III proportion of compounds was constant across electrophoretically differing asexual genotypes and between these and the sexual form. Life-history characters, in contrast, typically show great variation among these genetic groups. The results indicate that pheromonal constancy is maintained in a reproductive system that is theoretically vulnerable to selective pressures that would lead to heterogeneity in the species' pheromonal communication channel.     

Composition of neutral lipid classes and content of fatty acids throughout sourdough breadmaking

Broa is an example of bread that is a good candidate for inclusion in functional diets, so it deserves further in‐depth study of its chemical composition—namely with regard to evolution of the lipid profile throughout breadmaking, in order to assess whether mixing, fermentation, or baking affect its nutritional value (in terms of unsaturated fatty acids, UFA) based on the assumption that neutral lipids (NL) can be protein‐ or carbohydrate‐bound. Hence, constituent fatty acids in NL of maize (Zea mays) and rye flour (Secale cereale), and in sourdough and final broa manufactured from a mixture therefrom were quantitated. Methodologies of esterification of fatty acids, as well as of transesterification of acyl lipids and sterol esters (SE) were improved. The n‐hydrocarbons containing between 4 and 24 carbon atoms were then resolved and identified by gas–liquid chromatography. Regarding total neutral lipids (TNL) in all samples, 79–89% were TAGs, and 87–93% were TAGs and DAGs in the case of free lipids (FL). Furthermore, 73–85% of TNL in bound lipids (BL) and 65–80% of TNL in starch lipids (SL) were TAG and free fatty acids (FFA). Conversely, only 4–5%, 6–16%, and 7–10% of TNL in FL, BL, and SL, respectively, were SE and MAGs. TAGs and DAGs underwent partial hydrolysis during fermentation and baking; palmitic, oleic, and linoleic acids were dominant as products released. The nutritional value of broa lipids was apparent owing to their proportions of SE (4%) and DAG (9%), coupled with 52% of linoleic acid in all samples—as well as to the high contents of polyunsaturated versus monounsaturated or saturated fatty acids, and to the general dominance of UFA.     

Fat-Soluble Bioactives,Fatty Acid Profile and Radical Scavenging Activity of <Emphasis Type="Italic">Semecarpus anacardium</Emphasis> Seed Oil

Semecarpus anacardium (family Anacardiaceae) has many applications in the Ayurvedic and Siddha systems of medicine in India. Detailed knowledge on the composition of S. anacardium oil, in consideration of potential utilization, is of major importance. In this investigation, column chromatography, gas chromatography, thin layer chromatography and liquid chromatography techniques were performed to analyze lipid classes, fatty acids and fat-soluble bioactives of S. anacardium crude seed oil. The amount of neutral lipids in the crude seed oil was the highest, followed by glycolipids and phospholipids, respectively. Linoleic followed by palmitic and oleic were the major fatty acids. The ratio of unsaturated fatty acids to saturated fatty acids was higher in neutral lipid classes than in the polar lipids. The main sterol compounds were β-sitosterol, campesterol and stigmasterol. δ-Tocopherol followed by β-tocopherol were the main tocopherols. When S. anacardium seed oil and extra virgin olive oil were compared for their radical scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl radical and galvinoxyl radical (by electron spin resonance spectrometry), S. anacardium seed oil exhibited a stronger RSA.     

Canavalia ensiformis neutral lipids,a rich source of lupeol

The composition of the neutral lipids ofCanavalia ensiformis, which represent 2.21% of whole seeds, has been investigated. The fatty acid composition is characterized by the presence of palmitic (15%), oleic (54%), linoleic (7%) and linolenic (8%) acids. The unsaponifiable matter (7.9% of the neutral lipids), was examined for sterol, 4α-methylsterol and triterpene alcohols. The occurrence of lupeol in high amount in the last fraction (96%) constitutes an interesting source for this compound.     

Lipids of cultured hepatoma cells: VIII. Utilization of D-[1-14C] glucose for lipid biosynthesis

Minimal deviation hepatoma 7288C cells (HTC) were incubated in serum-supplemented and serum-free Swim’s 77 medium in the presence of D-[1-¹⁴C] glucose for 1, 2, 4, 8, 12 and 24 hr. Glucose oxidation to CO₂, incorporation into total cell mass, and incorporation into cell and medium lipids were determined. The percentage distribution of total cell lipid radioactivity in individual neutral and polar lipid classes was followed as a function of time. Degradation studies of individual lipid classes were performed to ascertain the percentage of radioactivity in acyl and glycerol moieties. The percentage of D-[1-¹⁴C] glucose oxidized to¹⁴CO₂, incorporated into cell matter and cell lipids was elevated in cells incubated in serum-free medium as opposed to serum-supplemented medium. The percentage distribution of total cell lipid radioactivity into individual neutral lipid classes from both serum-free and serum-supplemented cultures was as follows: sterols > triglycerides > free fatty acids > sterol esters. The percentage distribution of total cell lipid radioactivity into individual polar lipid classes of serum-supplemented cultures was as follows: phosphatidylcholine > phosphatidylinositol > sphingomyelin > phosphatidylethanolamine > phosphatidylserine. The distribution of glucose radiolabel into individual polar lipid classes of serum-free HTC cells was different from their serum-supplemented counterparts: sphingomyelin > phosphatidylcholine > phosphatidylinositol > phosphatidylethanolamine > phosphatidylserine. Glycerol from glyceride classes contained a higher percentage of radioactivity than the acyl moieties, with this percentage significantly elevated in serum-free cultures. The data indicate that, although glucose is a substrate for HTC cell lipids, other precursors present in the culture system also contribute to the lipid constituency of this hepatoma cell line.     

Lipid composition of millet (Pennisetum americanum) seeds

The composition of lipids extracted from a sample of millet seeds by each of 8 solvent systems is reported. Lipid components were separated by silicic acid column and thin layer chromatography (TLC) and quantitated by analysis of fatty acid methyl esters by gas liquid chromatography (GLC), with heptadecanoic acid as internal standard. Best results were obtained by extraction with hot water-saturated butanol. Lipids extracted amounted to 7.2% of the seed dry weight and consisted of 85% neutral lipids, 12% phospholipids and 3% glycolipids. Neutral lipids contained mostly (85%) triacylglycerols and small amounts of mono- and diacylglycerols, sterols and free fatty acids. Sterols consisted of campesterol, stigmasterol and 2 unidentified sterols, occurring in the same proportions in free and esterified forms. Ten glycolipid and 10 phospholipid components were separated and characterized. Contrary to previously published observations, lysophosphatidylcholine was the major phospholipid (42%) in millet seeds; smaller amounts of phosphatidylcholine (24%), lysophosphatidylethanolamine (21%) and trace amounts of phosphatidylglycerol, phosphatidic acid, phosphatidylserine and phosphatidylinositol also were present. The major glycolipids were esterified sterol glycoside, sterol glycoside, monogalactosyldiacylglycerol, digalactosyldiacylglycerol and cerebrosides (ceramide monohexosides).