Seasonal variation of lipids in femoral gland secretions of male green iguanas (Iguana iguana)

Femoral gland secretions were collected from 21 captive adult male green iguanas (Iguana iguana) in Orotina, Costa Rica, and San Diego, California, during the breeding (November) and nonbreeding (March) seasons. Lipids were extracted with methylene chloride, weighed, separated by thin-layer chromatography, and analyzed by gas chromatography-mass spectrometry. Free and esterified C₁₄-C₂₆ fatty acids, 5-cholestan-3-ol (epico-prostanol), cholest-5-en-3-ol (cholesterol), cholest-5-en-24-methyl-3-ol (campesterol), cholesta-5,22-dien-24b-ethyl-3-ol (stigmasterol), cholesta-8,24(5)-dien-4,4,14-trimethyl-3-ol (lanosterol), cholest-5-en-24-ethyl-3-ol (-sitosterol), and two uncharacterized sterols were indicated. More lipids were recovered from femoral gland secretions obtained during the breeding than the nonbreeding months, indicating that secretion deposits may be more detectable during the mating season.     

Study of neutral lipids ofLupinus mutabilis meal and isolates

Two types of protein isolates have been obtained from defattedLupinus mutabilis meal. The isolates, MA and MB, were obtained by alkaline extraction with 0.2% NaOH and 0.25% sodium bisulfite, respectively, followed by precipitation at the isoelectric point (pH 4.8). Total associated lipids were extracted with 86% ethanol. Neutral lipids were separated in a Florisil column. The lipids in the isolates were similar to those found in the original meal. The following types of compounds were separated, identified, and quantitated: hydrocarbons, waxes, methyl esters, triacylglycerols, free fatty acids, diacylglycerols, and free sterols.     

Chemical composition of tobacco seeds (Nicotiana tabacum L.)

Chemical characterization of tobacco seeds is supposed to be an interesting tool in order to extend the knowledge on alternative products of this crop which is of great economic interest. This paper describes chemical composition of meals, fat, ash, protein, fiber and nitrogen-free-extract; furthermore, particular emphasis is given to the composition of lipid fraction, with a complete characterization of triglycerides, fatty acids, and unsaponifiable matter. Trilinolein and palmitodilinolein are the main triglycerides, while linoleic is the main fatty acid. Cholesterol, as in otherSolanaceae, is present in the sterol fraction. Cycloartenol is the main component of the triterpenic alcohols fraction. Amino acids and glucides composition is also reported.     

Biohydrogenation intermediates are differentially deposited between polar and neutral intramuscular lipids of lambs

The deposition of C₁₈ fatty acids (FA), especially in rumen biohydrogenation intermediates, was studied using 36 lambs fed four diets with graded proportions of sunflower oil (SO) and linseed oil (LO). Lambs were fed one of four diets consisting on dehydrated lucerne with either: 6% SO, 4% SO plus 2% LO, 2% SO plus 4% LO and 6% LO. The profile of C₁₈ FA was greatly affected by replacement of SO with LO in both lipid fractions. In PL, oil replacement led to an extensive substitution of 18:2n‐6 with 18:3n‐3 and cis‐9 18:1, resulting in a fairly constant degree of unsaturation of C₁₈ FA in membrane PL. C₁₈ FA were differentially incorporated in NL and PL. Cis‐isomers like cis‐11; cis‐12; cis‐15 18:1 and cis‐12, cis‐15 18:2 were preferentially incorporated in PL with the exception of cis‐9, cis‐15 18:2. Trans C₁₈ FA, including CLA isomers, were preferentially incorporated in NL with the exception of cis‐11, trans‐13 18:2. The preferential deposition of biohydrogenation derived trans C₁₈ FA, including CLA isomers in NL, suggests that their potential to change membrane FA composition and structure is low.     

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.     

Characteristic distributions of fatty acids in different lipids from Jack beans (Canavalia gladiata DC.)

Extracted lipids obtained from Jack beans (white and red) were fractionated by TLC into nine subfractions. The major components were TAGs (TAG: 43.8–45.7 wt%) and phospholipids (PL: 46.7–47.0 wt%), while other components were also present in minor proportions (0.3–2.7 wt%). The principal fatty acids (FA) are generally palmitic (18.8–28.8%), stearic (0.7–6.8%), oleic (42.0–51.8%), linoleic (16.2–22.8%), and α‐linolenic (3.0–8.2%) acids, the distribution of which differs according to these lipid classes. There were no significant differences (p>0.05) in the positional distribution of FA in the TAG; unsaturated FA (97.5%) were predominantly concentrated in the sn‐2 position while saturated FA (33.3%) primarily occupied the sn‐1 position or sn‐3 position. However, significant differences (p<0.05) in FA distribution existed when the individual PL were compared between the white and red beans. Based on the FA composition of these lipids, it seems that the two cultivars of Jack beans are very similar to each other with a few exceptions. The results could be useful to both producers and consumers for our daily diet to improve value of the Japanese diet. Practical applications : The lipid composition suggests that these beans could be a good source of nutraceuticals with providing heath benefits. The white and red beans may be well incorporated into our daily Japanese diets to improve nutritional value. The data obtained in this study provide valuable information for manufacturing functional drinks such as Jack bean tea in Japan.     

Triterpene alcohols and fatty acids in lipids and nonsaponifiable matter of Lapsana communis L. subspecies communis (Asteraceae)

The oil content of samples of aerial parts of Lampsana communis L. subsp. communis, harvested in Indre et Loire (France) at different periods, varies from 1.1 to 2.1%. Nonsaponifiable matter in these samples represents 36.0 to 65.7% of the oil. Yields of triterpene alcohols of nonsaponifiable matter (25.9 to 81.8%) were determined by preparative thin-layer chromatography after saponification. Seven of them were identified by gas chromatography-mass spectrometry (GC-MS). Six of the fatty acids in the aerial parts have also been identified by GC-MS. The seeds of L. communis contain 2.6% oil.     

Cryptolepis buchnani seed oil: A rich source of keto fatty acid

A keto fatty acid (9-oxo-cis-12-octadecenoic acid) has been isolated in appreciable amounts (45.9%) fromCryptolepis buchnani seed oil. The identification was based on chemical and spectroscopic methods.     

Trans-18:1 acid content and profile in human milk lipids. Critical survey of data in connection with analytical methods

This study presents an in-depth, critical survey of the current knowledge about trans- 18:1 acid content and profile in human milk lipids. Emphasis is placed on the analytical methods employed to quantitate trans- 18:1 acids, most of which lead to imprecise quantitative data. It is demonstrated that data obtained by single gas-liquid chromatography (GLC) on polar capillary columns are underestimates by 25–40%. Several experiments indicate that the total content of trans-18:1 acids in human milk is directly related to the quantities ingested the previous day(s), provided no gross weight loss occurs during breast-milk feeding. Equations have been proposed to describe this relationship, and apparently the percentage of trans-18:1 isomers, relative to total fatty acids, is approximately three-fourths the quantity (in g) ingested by lactating mothers. That is, the determination of the trans-18:1 acid percentage in human milk is a convenient means to estimate trans-18:1 acid consumption by corresponding populations. Adapted methods (i.e., silver-ion thin-layer chromatography, coupled with GLC on long polar capillary columns) allow accurate quantitation of most individual trans- 18:1 acids, more particularly of the trans-Δ16 isomer. This determination, along with a knowledge of the distribution of individual isomers in ruminant fats and partially hydrogenated oils, is a convenient means to estimate the relative contribution of these two dietary sources to the distribution of individual trans-18:1 isomers in human milk lipids. A comparison of human milk and infant formulas is made with regard to trans-18:1 acid content and profile. Important differences are noted between data from European countries and from North America.     

Unusual fatty acids inBrunfelsia americana seed oil: A rich source of oil

Brunfelsia americana Linn, belonging to the Solanaceae plant family, was found to contain ricinoleic acid together with cyclopropenoid and normal fatty acids. These fatty acids were characterized by infrared, nuclear magnetic resonance, mass spectrometry, gas-liquid chromatography techniques and chemical degradations.     

The seed oil ofBernardia pulchella (Euphorbiaceae) —A rich source of vernolic acid

The fatty acids from the seed oil ofBernardia pulchella (Euphorbiaceae) have been analyzed by gas chromatography (GC) and GC-mass spectrometry (MS) analysis of their methyl esters. Vernolic acid is the main compound (91%), along with other usual fatty acids. In addition to the quantitation by GC analysis,¹H-nuclear magnetic resonance (NMR) signals from the seed oil have been used to estimate the total epoxy fatty acid content. The structure of vernolic acid has been proven by spectroscopic methods (infrared,¹H, and¹³C-NMR) and by GC-MS analysis of the corresponding silylated hydroxy-methoxy derivative. The 4,4-dimethyloxazoline derivatives of the fatty acid mixture have also been examined by GC-MS, and it was shown that this derivazation reaction is not suitable for the structure analysis of vernolic acid.     

Jojoba wax: Its esters and some of its minor components

A lack of reliability in the usual determinations of fatty acids and fatty alcohols of jojoba wax prompted us to propose an original method of hydrolysis and extraction, making it possible to better determine the composition of fatty acids and alcohols of the wax. High-performance liquid chromatography fractionation of the wax allowed isolation of four main classes of esters (which differed by their partition number). The detailed study of these ester classes emphasized the way acids and alcohols are connected, and fourteen distinct esters were thus identified. Some triacylglycerols, free fatty alcohols and other minor components of jojoba wax were found and quantitated. Seven sterols were identified, four for the first time.     

Lipid composition and oxidative stability of oils in hazelnuts (Corylus avellana L.) grown in New Zealand

Hazelnut (Corylus avellana L.) samples were collected from six different cultivars of trees grown in an experimental orchard at Lincoln University. Three U.S. commercial cultivars (Butler, Ennis, and Barcelona), two European commerical cultivars (Tonda di Giffoni and Campanica), and one New Zealand selection (Whiteheart) were evaluated. The total oil, stability to oxidation of the oil, and fatty acid, tocopherol, and sterol composition were determined on samples of freshly extracted hazelnut oil. The total oil content of the seeds ranged from 54.6 to 63.2% while the stability of the oil, as measured by the Rancimat test ranged from 15.6 to 25.3 h. The content of the monounsaturated oleic acid in the oils ranged from 73.8 to 80.1% of the total fatty acids, while the tocopherol content ranged from 225.8 to 552.0 mg/g freshly extracted oil. The major desmethylsterols were sitosterol, ranging from 1416 to 1693 μg/g, campesterol, ranging from 78 to 114 μg/g, and Δ5-avenasterol, ranging from 110 to 170 μg/g. The oil extracted from the cultivar Whiteheart was more stable (measured by Rancimat) than the oil from all other cultivars grown at the same location and under the same conditions. Whiteheart contained higher levels of total and γ-tocopherol when compared to the other cultivars. The higher levels of tocopherol in Whiteheart help to explain the greater stability of the oil during the oxidative stress test. These results suggest that nuts from the cultivar Whiteheart could be stored longer than the other nuts tested. Presented as a poster at the 87th AOCS Annual Meeting, Indianapolis, Indiana, April 28–May 1, 1996.     

Association of particular systems with the release of neutral lipids inEchinostoma revolutum (Trematoda) adults

Since free sterol excretory-secretory (E-S) products are involved in pheromonal communication in adultEchinostoma revolutum (Trematoda), attempts were made to associate specific systems with the release of lipids from this organism. A micropipet design was used to isolate neutral lipids from the excretory system versus those obtained from both the alimentary and the reproductive systems. Tegumentary lipids were obtained by rubbing the surface of worms with gauze. As determined by thin-layer chromatography, the major neutral lipid obtained from all systems was free sterol. Additional minor neutral lipid fractions were obtained from the excretory, alimentary, and reproductive systems. Histochemical oil red O studies showed neutral lipids only in the excretory system. Neutral lipids released from all of the above-mentioned systems may play a role in pheromonal communication in this species.     

Polar and nonpolar lipids and their fatty acid composition of a fewFusarium species

A few species ofFusarium have been evaluated for their potential to produce lipids. The isolates under investigation exhibited wide variation with respect to the mycelial weight, total lipid content and percentage composition of polar and nonpolar lipids in which triglycerides were the major components (81–90%). Palmitic, stearic, oleic and linoleic acids were the major fatty acids in both the fractions. The polar lipids contained higher levels of linoleic acid, whereas nonpolar lipids contained oleic acid as the predominant acid. Nonpolar lipids were more saturated than polar lipids.     

Variation in fatty acid composition of the different acyl lipids in seed oils from fourSesamum species

Seeds from different collections of cultivatedSesamum indicum Linn. and three related wild species [specifically,S. alatum Thonn.,S. radiatum Schum and Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil content and fatty acid composition of the total lipids. The wild seeds contained less oil (ca. 30%) than the cultivated seeds (ca. 50%). Lipids from all four species were comparable in their total fatty acid composition, with palmitic (8.2–12.7%), stearic (5.6–9.1%), oleic (33.4–46.9%) and linoleic acid (33.2–48.4%) as the major acids. The total lipids from selected samples were fractionated by thin-layer chromatography into five fractions: triacylglycerols (TAG; 80.3–88.9%), diacylglycerols (DAG; 6.5–10.4%), free fatty acids (FFA; 1.2–5.1%), polar lipids (PL; 2.3–3.5%) and steryl esters (SE; 0.3–0.6%). Compared to the TAG, the four other fractions (viz, DAG, FFA, PL and SE) were generally characterized by higher percentages of saturated acids, notably palmitic and stearic acids, and lower percentages of linoleic and oleic acids in all species. Slightly higher percentages of long-chain fatty acids (20∶0, 20∶1, 22∶0 and 24∶0) were observed for lipid classes other than TAG in all four species. Based on the fatty acid composition of the total lipids and of the different acyl lipid classes, it seems thatS. radiatum andS. angustifolium are more related to each other than they are to the other two species.     

Temperature shifts in regulation of lipids accumulated byLipomyces starkeyi

The effect of temperature on the accumulating triglycerides ofLipomyces starkeyi was studied in 10-L fermentation experiments. The temperature during the growth, lipid accumulation and postaccumulation phases was altered. The cellular lipid content, the glucose conversion efficiency and the specific lipid production rate were highest when the growth phase temperature was 28°C, instead of 16–18°C. The temperature of the accumulation phase had an influence on the lipid quality at the end of the accumulation. Oleic acid content increased from 52 to over 60% when the accumulation phase temperature was decreased from 28 to 15°C and, concomitantly, palmitic acid decreased from 33 to 26%. The degree of fatty acid unsaturation was the highest (0.75 Δmol⁻¹) when the accumulation phase temperature was the lowest (15°C) andvice versa. The temperature shift after the lipid accumulation phase affected neither the composition nor the amount of the accumulated lipids. In conclusion, the temperature profile for the highest lipid yield with the most desired composition should be: (i) a growth phase temperature that gives the maximum growth rate and (ii) an accumulation phase temperature that produces the desired ratio of palmitic to oleic acid.     

Vernonia galamensis: A rich source of epoxy acid

A percolation extraction ofVernonia galamensis seed, affording 38.6% of crude vernonia oil is described. The dark colored crude oil was degummed with water, treated with activated charcoal and bleached with a neutral agent, to give a light colored oil (Lovibond: 0.9 red, 3.5 yellow). Gas chromatographic/mass spectrometric analysis of the refined oil indicates a relative fatty acid composition of 79–81% vernolic (cis-12,13-epoxy-cis-9-octadecenoic) acid, 11–12% linoleic acid, 4–6% oleic acid, 2–3% stearic acid, 2–4% palmitic acid, and a trace amount of arachidic acid.     

Chemical polymorphism of the cuticular lipids of the cabbage white Pieris rapae

The epicuticular composition of different body parts of the Cabbage White, Pieris rapae L., was investigated using GC and GC/MS. The major group of components, hydrocarbons, occurs in two distinct classes, which show different distributions on the cuticle of the insects. Unbranched shorter chain compounds (C₂₁ to C₃₁, linear group) dominate on body, head and wings, while longer chain, polymethyl-branched compounds (C₃₅ to C₃₉, branched group) are predominantly found on the antennae. Several other components like 1,3-pentacosadiene and oxygenated aliphatic compounds occur in minor amounts on the cuticle. The reason for this polymorphism is discussed.     

The effect of temperature on lipid classes and their fatty acid profiles inLipomyces starkeyi

The effect of environmental temperature on fatty acid contents of major lipid classes was determined inLipomyces starkeyi at 30, 20, and 10°C. When the temperature was reduced from 30 to 20°C, the linolenic acid content increased in phosphatidylcholine but fell with further reduction to 10°C. The relative contribution of phosphatidylcholine and phosphatidylethanolamine that contained the next lowest-melting fatty acids, palmitoleic and linoleic acids, increased on lowering the temperature from 20 to 10°C and, concomitantly, the combined phosphatidylinositol and phosphatidylserine fraction decreased, and triacylglycerols were accumulated.