Neutral lipids of chickpea flour and protein isolates

The neutral lipids composition of defatted chickpea flour and two types of protein isolates has been studied. The main compounds in neutral lipids are triacylglycerols, free fatty acids, and diacylglycerols. Other compounds present are wax esters, free fatty alcohols, and free sterols. The main fatty acids in neutral lipids are C_18:2 and C_18:1 among the unsaturated, and C_16:0 and C_18:0 among the saturated acids. Free and esterified alcohols range from C_16:0 to C_28:0, the majority being those with an even number of carbon atoms. Sterols observed are β-sito-sterol, campesterol, stigmasterol, and δ-5-avenasterol. Triacyl-glycerols are partially hydrolyzed, and the amounts of unsaturated sterols and unsaturated fatty acids are reduced as a result of the chemical treatment during production of the protein isolates.     

Interactions oftrans-cinnamic acid,its related phenolic allelochemicals,and abscisic acid in seedling growth and seed germination of lettuce

Phenolic compounds have been identified as the most common allelochemicals produced by higher plants. Inhibitions of cinnamic acid, its related phenolic derivatives, and abscisic acid (ABA) on seedling growth and seed germination of lettuce were studied.trans-Cinnamic acid, ando-,m-, andp-coumaric acids inhibited the growth of etiolated seedlings of lettuce at concentrations higher than 10^–4 M and seed germination above 10^–3 M. Coumarin inhibited seedling growth and seed germination at 10^–5 M or above. Chlorogenic acid inhibited seedling growth above 10^–4 M, but did not inhibit seed germination at 10^–5–5×10^–3 M. Low concentrations (below 10^–3 M) of caffeic and ferulic acids promoted the elongation of hypocotyls, but higher concentrations (over 10^–3 M) inhibited seedling growth and seed germination. These phenolic compounds and abscisic acid had additive inhibitory effects both on seedling growth and seed germination. The inhibition on lettuce was reversed by caffeic and ferulic acids at concentrations lower than 10^–3 M except for the inhibition of germination by coumarin. These results suggest that in naturetrans-cinnamic acid,o-, m-, p-coumaric acids, coumarin, and chlorogenic acid inhibit plant growth regardless of their concentration. However, caffeic and ferulic acids can either promote or inhibit plant growth according to their concentration.     

Characterization of <Emphasis Type="Italic">Pentadesma butyracea sabine</Emphasis> Butters of Different Production Regions in Benin

Pentadesma butter (Pentadesma butyracea, sabine, clusiaceae) is an extract of the kernels of tree fruits in West Africa and similar to shea butter. The study of the fatty acid composition, triacylglycerols, sterols and tocopherols of Pentadesma butter was carried out on seeds collected in ten production areas in Benin. The results obtained show that the composition in fatty acids is characterized by the presence of stearic acid and oleic acid, which represent nearly 96% of the total fatty acids. The triacylglycerols profile of the different butters is marked by the overwhelming presence of the triacylglycerols SOS and SOO. The unsaponifiable fraction shows, for the sterolic composition, a predominance of stigmasterol (nearly 68% of the total sterols) whilst the β-tocopherol is the main tocopherol.     

The content and composition of sterols and sterol esters in sunflower and poppy seed oils

The composition and proportion of free sterols and sterol esters in crude sunflower and poppy seed oils were determined, using preparative thin layer chromatography followed by gas chromatography with cholesterol as an internal standard. Free sterols and sterol esters were also isolated in a liquid fraction obtained by low temperature crystallization (−80 C) of the oils and enriched with minor lipid classes. This enrichment procedure provided a liquid fraction suitable for studies of minor components in the oils. However, selectivity towards sterol esters was observed since sterols esterified to very long chain fatty acids (C₂₀–C₂₄) were preferentially retained in the precipitate. The proportions of free and esterified sterols were found to be 0.34 and 0.28%, respectively, in the sunflower oil, whereas the corresponding figures for poppy seed oil were 0.33% and 0.05%. Sunflower oil was characterized by a relatively high percentage of Δ7-sterols, preferentially obtained in the esterified fraction, and by very long chain saturated fatty acids of sterol esters. The sterols in poppy seed oil were composed almost entirely of campesterol, stigmasterol, sitosterol and Δ5-avenasterol, although their percentage distributions were remarkably different in the free and esterified fraction.     

Synergistic inhibitory effects ofp-coumaric and ferulic acids on germination and growth of grain sorghum

The data support the hypothesis that there is a synergistic phytotoxic effect whenp-coumaric and ferulic acids are found together. Equimolar mixtures of both acids showed greater reduction in sorghum seed germination, shoot elongation, and total seedling growth than either phytotoxin caused when alone. Repeated experiments showed mixtures containing 5×10^–3 Mp-coumaric and 5×10^–3 M ferulic acids reduced germination to 34% of controls after 24 hr and 59% by 48 hr. The same concentration of either phenol-treated seeds alone showed 69 and 92% germination at comparable times. The phytotoxic action of the combination approximated the inhibitory effect on germination of 10^–2 M ferulic acid and was a greater reduction than caused by 10^–2 Mp-coumaric treatments. Sorghum seedling growth was more sensitive than germination, with an equimolar mixture of 2.5×10^–4 Mp-coumaric and 2.5×10^–4 M ferulic acids reducing seedling dry weight significantly below weights of seedlings treated separately with 2.5×10^–4 Mp-coumaric or ferulic acids. Further dilutions showed a 1.25×10^–4 M concentration of either phenol was stimulatory to seedling growth, whereas a mixture of these two produced inhibition.     

Steryl esters in a cell suspension culture of celery (Apium graveolens)

Arange of analytical techniques was used to investigate the composition of the steryl fatty acyl esters in a cell suspension culture of celery (Apium graveolens). Gas chromatography (GC) and GC-mass spectrometry (GC-MS), using electron ionization (EI) and negative ion chemical ionization (NICI), were employed to characterize the intact steryl esters. Assignments were supported by analysis of the sterol and fatty acid moieties released from the intact molecular species by alkaline hydrolysis. A selectivity for sterol esterification was noted, with the major free sterol, stigmasterol, occurring only in a very small amount in the esterified form. Instead, the precursors to Δ⁵-phytosterols, particularly cycloartenol, predominated in the ester fraction. The pentacyclic triterpene, β-amyrin, was also found as the palmitate and linoleate esters. Changes in composition and abundance of the steryl esters during the different growth phases of a celery cell suspension culture were investigated. The total amount of esterified sterols exceeded that of free sterols throughout the growth cycle. The changes observed during growth highlighted differences between the esters of precursor sterols and those of the 4-desmethyl-sterols, and it is postulated that the various steryl esters perform different functions in cell metabolism.     

Fatty acid composition of individual plasma steryl esters in phytosterolemia and xanthomatosis

The bulk of the plasma plant sterol in phytosterolemia occurs in the esterified form and is carried mostly in the low and high density lipoproteins. We have determined the fatty acid composition of the individual plasma steryl esters from a newly discovered subject with phytosterolemia and xanthomatosis. For this purpose the intact steryl esters were subject to high temperature gas liquid chromatography (GLC) on a polar capillary column, which separated the major esters on the basis of molecular weight and degree of unsaturation of the fatty acids. The saturated and unsaturated sterols esterified to saturated, monoenoic, dienoic and tetraenoic fatty acids were identified by GLC analysis of the sterol moieties of the corresponding AgNO₃-TLC fractions of the steryl esters. The GLC results were confirmed by reversed phase high performance liquid chromatography combined with mass spectrometry via direct liquid inlet interface. It was found that, in general, each fatty acid was esterified to the same complement of sterols, and that the esterified sterols possessed a composition comparable to that of the free plasma sterols, which was comprised of about 75% cholesterol, 6% campesterol, 4% 22,23-dihydrobrassicasterol and 15% β-sitosterol. The fatty acid composition of the steryl esters differed from that of the 2-position of the plasma phosphatidylcholines, which contained significantly less palmitic and oleic and more linoleic acid. On the basis of these results and a review of the literature it is suggested that the plasma cholesteryl and plant steryl esters in phytosterolemia originate from both synthesis in plasma via the lecithin-cholesterol acyltransferase and synthesis in tissues via the acylCoA-cholesterol acyltransferase.     

The Effect of processing on the content and composition of free sterols and sterol esters in soybean oil

The content and composition of free sterols and sterol esters in crude soybean oil and in oils from different stages of two continuous refining systems were determined. The sterols were isolated by preparative thin layer chromatography and analyzed by gas chromatography with cholesterol as an internal standard. The free sterols in one of the degummed oils amounted to 3.1 mg/g and were diminished to 1.8 mg/g oil by the De Laval Short-Mix refining process. The content of free sterols of the other degummed oil was reduced from 3.4 to 1.6 mg/g oil by the Zenith process. The greatest reduction of sterol content was caused by the treatment with bleaching earth. The sterol esters accounted for 0.6 mg/g of the degummed oil, and only very small changes were observed during the processes. However, changes in the composition of fatty acids of the sterol esters were found. These changes might indicate a selective deacylation of sterol esters or an interesterification during the refining processes. The composition of sterols in free and esterified form were different. Campesterol, stigmasterol and sitosterol were obtained in both free and esterified form, but Δ7 stigmasterol was only found in esterified form. Only small changes in the percentage distribution of the sterols occurred during the processes. Present adress Food Technology Division, ALFA-LAVAL,S-14700 Tumba, Sweden     

Fatty acid and sterol specificity of cholesterol esterifying enzyme in developing rat brain

The properties and fatty acid and sterol specificity of cholesterol-esterifying enzyme (EC 3.1.1.13) in rat brain were studied. The enzyme utilized free fatty acid for esterification, and activity was maximal at pH 5.6. Exogenous ATP and CoA did not stimulate the incorporation of free fatty acids into sterol esters. Substrates dispersed in Tween 20 or Triton X-100 were just as effective as the substrates dissolved in acetone solution, while dispersion in propylene glycol or sodium taurocholate was not as effective. Snake venom phospholipase A₂ (EC 3.1.1.4) increased the esterification of cholesterol in the absence of added fatty acid. The fatty acid specificity data indicated that oleic and palmitic acids were the preferred fatty acids. Little or no esterification occurred in the presence of long chain fatty acids (C₂₀–C₂₄). Esterification of cholesterol with palmitate or stearate was not affected by the presence of oleic acid in the mixture. Thus, the nonrequirement of the brain-esterifying enzyme for a bile acid or for an amphiphile such as an unsaturated fatty acid suggests that micellar solubilization of the substrate is not essential for activity. Although the brain enzyme catalyzed the esterification of desmosterol, cholesterol was the preferred substrate. Neither lanosterol (C₂₉ sterols) nor Δ7-dehydrocholesterol was esterified to any significant extent. The presence of low concentrations of desmosterol increased cholesterol esterification slightly, while there was a concentration-dependent inhibition of demosterol esterification by cholesterol. These data on fatty acid and sterol specificity of the esterifying enzyme correlate well with the composition of sterol esters present in developing rat brain.     

Synergistic inhibitory effects of vanillic andp-hydroxybenzoic acids on radish and grain sorghum

Radish and grain sorghum germination and sorghum growth were inhibited in a synergistic manner by combinations of vanillic andp-hydroxybenzoic acids. At threshold inhibition levels, 2.5 × 10^–3 M vanillic acid-treated radish seeds had 71 % of control germination after 24 hr and 2.5 × 10^–3 Mp-hydroxybenzoic acid-treated radish yielded 95% germination. A mixture of 2.5 × 10^–3 M of each of these two phytotoxins showed 52% germination after 24 hr. Equimolar mixtures of 5 × 10^–3 M vanillic andp-hydroxybenzoic acids allowed sorghum germination of 60% of untreated seeds after 24 hr, whereas separate treatments of individual phenols had 93% and 96% of control seed germination. Sorghum root and shoot elongation and total seedling growth were more sensitive than germination to vanillic andp-hydroxybenzoic acid treatments, and synergistic effects also were apparent. A combination of 5 × 10^–3 M vanillic with 5 × 10^–3 Mp-hydroxybenzoic reduced root length more than either did individually, and a mixture of 5 × 10^–4 M vanillic with 5 × 10^–4 Mp-hydroxybenzoic acid reduced sorghum seedling growth to approximately that resulting from a 10^–3 M concentration of either phenol alone. Phytotoxin levels inhibitory to sorghum growth caused small increases in lower leaf surface diffusive resistance, but did not close stomates, and this effect was not judged to be the cause of reduced sorghum growth.     

Phytosterol Ester Constituents Affect Micellar Cholesterol Solubility in Model Bile

Plant sterols and stanols (phytosterols) and their esters are nutraceuticals that lower LDL cholesterol, but the mechanisms of action are not fully understood. We hypothesized that intact esters and simulated hydrolysis products of esters (phytosterols and fatty acids in equal ratios) would differentially affect the solubility of cholesterol in model bile mixed micelles in vitro. Sodium salts of glycine- and taurine-conjugated bile acids were sonicated with phosphatidylcholine and either sterol esters or combinations of sterols and fatty acids to determine the amount of cholesterol solubilized into micelles. Intact sterol esters did not solubilize into micelles, nor did they alter cholesterol solubility. However, free sterols and fatty acids altered cholesterol solubility independently (no interaction effect). Equal contents of cholesterol and either campesterol, stigmasterol, sitosterol, or stigmastanol (sitostanol) decreased cholesterol solubility in micelles by approximately 50% compared to no phytosterol present, with stigmasterol performing slightly better than sitosterol. Phytosterols competed with cholesterol in a dose-dependent manner, demonstrating a 1:1 M substitution of phytosterol for cholesterol in micelle preparations. Unsaturated fatty acids increased the micelle solubility of sterols as compared with saturated or no fatty acids. No differences were detected in the size of the model micelles. Together, these data indicate that stigmasterol combined with saturated fatty acids may be more effective at lowering cholesterol micelle solubility in vivo.     

Chemical Evaluation of Rapeseed

The seed chemical composition and oil physical and chemical constants of two imported rapeseed German varieties and one locally produced in Egypt were studied. Rapeseeds are characterized by high lipid and protein contents. The fatty acid analysis indicated that palmitic and oleic acids were the most prevalent saturated and unsaturated acids, respectively. Also, the rapeseed oils under study were free from long-chain fatty acids (>C₁₈). The unsaponifiables were fractionated by GLC into 36 different compounds of which 26 hydrocarbons were identified. The hydrocarbons having carbon atoms between C₂₀ and C₂₄ represent the most common compounds. Campesterol, stigmasterol and β-sitosterol were present in appreciable amounts in German varieties while these compounds occurred as trace substances in the seeds produced in Egypt.     

Just how insoluble are monoterpenes?

Prior generalizations about the ecological roles of monoterpenes may be misleading if based on the presumed insolubility of monoterpenes in water. We determined the aqueous solubility of 31 biologically active monoterpenes by gas chromatography. While hydrocarbons were of low solubility (< 35 ppm), oxygenated monoterpenes exhibited solubilities one or two orders of magnitude higher, with ranges of 155–6990 ppm for ketones and of 183–1360 ppm for alcohols. Many monoterpenes are phytotoxic in concentrations under 100 ppm, well below the saturated aqueous concentrations of oxygenated monoterpenes. Therefore, even dilute, unsaturated solutions of monoterpenes, occurring naturally in plant tissues and soil solutions, may act as potent biological inhibitors.     

Supercritical CO2 extraction of oil, carotenoids, squalene and sterols from lotus (Nelumbo nucifera Gaertn) bee pollen

The high-quality oil, abundant in carotenoids, squalene and sterols (mainly consisting of campesterol, stigmasterol, β-sitosterol and β-amyrin), was extracted by supercritical CO₂ from lotus bee pollen for its potential nutraceutical use. The effects of extraction pressure and temperature on the yields and the compositions of the extracts were investigated by using a two-factor central composite rotatable design experiment. ANOVA for response surface model demonstrated that the data were adequately fitted into four polynomial models. The yields of the oil, carotenoids, squalene and sterols were significantly influenced by the experimental variables. It was predicted that maximum oil yield obtained at the extraction pressure of 38.2 MPa and temperature of 49.7 °C contained the maximum amount of carotenoids, squalene and sterols. GC-FID analysis of the fatty acid composition of lotus bee pollen oil showed that polyunsaturated fatty acids accounted for approximately 22% of the total fatty acids.     

Changes in lipids of pigeon “milk” in the first week of its secretion

Pigeon “milk” (PM) collected from the crop of 1- to 5-day-old squabs was analyzed to examine whether there were changes in lipid composition during the first week of secretion. The high PM fat content (9–11%) remained fairly constant in the first 5 days of secretion. The mean percentage of neutral lipids, glycolipids and phospholipids was 80, 12 and 8%, respectively. Unlike the content of neutral lipids, glycolipid and phospholipid levels increased significantly between day 1 and day 5 of secretion. Triglycerides, the major neutral lipids, decreased by 24% between day 1 and day 5, while free sterols, monoglycerides and hydrocarbons increased by 8%, 11% and 2.5%, respectively, during the same period; diglycerides and sterol esters, however, remained unchanged. The ratio of saturated to unsaturated fatty acids was 0.27 and it remained unchanged. Medium-chain (C₁₀, C₁₂ and C₁₄) and oddchain (C₁₅ and C₁₇) fatty acid contents were low. Fatty acids longer than C₂₀ were absent. Palmitic acid, the major saturated fatty acid, increased by 42% from day 1 to day 5, whereas stearic acid decreased by 48% during the same period. Oleic acid, the predominant unsaturated fatty acid, also decreased from 51 to 45% between the first and fifth day of PM secretion. Polyunsaturated acids (18∶2, 18∶3 and 20∶4) accounted for 26% and 30% of the total fatty acids on day 1 and day 5, respectively. Although lipid changes in the crop of squabs prior to collection of samples cannot totally be ruled out, the nature of lipid changes is likely to reflect cellular breakdown that precedes PM secretion by parent pigeons.     

Minor components ofLesquerella fendleri seed oil

Routine analysis of fatty ester fractions ofLesquerella fendleri oil suggested the presence of epoxy compounds and other minor components. By a combination of open silica column and high performance liquid chromatography (HPLC) fractionations of the methyl esters prepared from the oil, these constitutents were isolated and then characterized by thin-layer chromatography-mass spectrometry (GC-MS—electron ionization, EI, and chemical ionization, CI) and nuclear magnetic resonance (NMR—¹H and¹³C). Three epoxy acids, 15,16-epoxy-9,12-octadecadienoic, 9,10-epoxy-12-octadecenoic and 9,10-epoxy-octadecanoic, were found. Hydroxy acids present included a C-22 homologue of lesquerolic acid (16-hydroxy-12-docosenoic acid) and 14,15-dihydroxy-tricosanoic acid. Other minor ocmponents included four sterols, brassicasterol, campesterol, β-sitosterol and stigmasterol, and a series of saturated and unsaturated fatty acids up to C30. Visiting postdoctoral scientist sponsored by the government of India.     

Sources of Variation in Concentration and Composition of Foliar Monoterpenes in Tamarack (Larix laricina) Seedlings: Roles of Nutrient Availability, Time of Season, and Plant Architecture

The effects of foliage class, time of season, and nutrient availability on monoterpene composition and concentration were evaluated. In the first experiment, we compared foliar monoterpenes of long shoots versus short shoots, which differ in age and origin, and differences due to nutrient availability and time of season. Both the concentrations and compositions of these monoterpenes were higher in the foliage of the long shoots. The only exceptions were the concentration of -3-carene and the composition of -pinene. Within a foliage class, the concentrations of seven monoterpenes and the percentages of five monoterpenes changed over the season. Of these, almost all declined, with the exceptions of -pinene and an unknown. Nutrient availability significantly affected the concentration or composition of some monoterpenes, but only to a slight extent. -Pinene and the unknown increased with nutrient availability, whereas -pinene and myrcene decreased. A more comprehensive analysis of four foliage classes on a separate cohort of trees showed that all monoterpenes, except sabinene and terpinolene, differed between foliage classes, but there were few general patterns. Overall, within-tree variation in tamarack monoterpenes related to foliage class and age appears more important than between-tree variation due to nutrient availability. These results suppport the view that products of mevalonic acid biosynthesis, such as terpenes, do not follow predictions of the carbon–nutrient balance and growth differentiation hypotheses. Our overall results show that individual hosts need to be considered as phytochemical mosaics when interpreting herbivore–plant interactions.     

Phospholipid synthesis inS. cerevisiae strain GL7 grown without unsaturated fatty acid supplements

In the absence of exogenous unsaturated fatty acids (UFA),Saccharomyces cerevisiae strain GL7 synthesizes low levels of UFA and large amounts of decanoic, dodecanoic and tetradecanoic fatty acids. Supplementation with hemin leads to slightly higher levels of UFA, but synthesis of the medium-chain saturated fatty acids (SFA) continues. Under these conditions of limited UFA availability, strain GL7 incorporates most of its UFA into phosphatidylethanolamine (PE), whereas phosphatidylcholine (PC) and phosphatidylserine+phosphatidylinositol (PS+PI) are enriched with the mediumchain SFA. The association of specific fatty acids with the various phospholipids is not accompanied by changes in the proportions of newly synthesized phospholipids, demonstrating that the fatty acid composition of PE can be modulated independently of the other phospholipids. The effect of sterol structure on the fatty acid composition of cells grown with limiting UFA was also examined. Yeast cells grown with either ergosterol or stigmasterol contained less UFA and more medium-chain SFA in their phospholipids than did cholesterol-grown cells, suggesting that the former sterols allow strain GL7 to grow with a lower UFA content. Portions of this paper were presented at the AOCS 72nd Annual Meeting, New Orleans, May 1981.     

The Sterols and Fatty Acids of Delphinium denudatum Roots

The content and composition of sterols and fatty acids of Delphinium denudatum roots, which are used in the Indian Unani system of medicine, were determined. The sterols were composed almost entirely of campesterol, stigmasterol and sitosterol. Trace amounts of cholesterol and Δ⁵-avenasterol were also detected. Characteristic higher plant fatty acids were also present.     

Antagonistic effects ofMyxococcus xanthus on fungi: II. Isolation and characterization of inhibitory lipid factors

The chemical composition of the lipophilic excretion ofMyxococcus xanthus inhibitory to the germination of fungal spores and growth has been investigated. The inhibitory effect was attributed to a mixture of fungistatically acting fatty acids and a component of antibiotic character. The fatty acid mixture has been fully characterized and found to constitute a mixture of saturated (68%) and unsaturated (32%) structures in the C₁₃–C₁₇ range. The major part is methylbranched of theiso-type, with 13-methyltetradecanoic acid being the main component (33% of the total). The fungistatic activity of the fatty acid mixture on spore germination is attributed to the structures withiso-configuration. The presence of unsaturation is of minor importance. Observed morphological changes of the spores and hyphae in the presence ofiso-fatty acids suggest that they act on the plasma membrane.