Cyclopropenoid Acids Research Articles

Fatty acid composition of <i>Tilia</i> spp. seed oils

As part of a study of the seed oil fatty acid composition of Malvaceae plants, the seeds of seven Tilia species (lime or linden trees) were evaluated for their fatty acid profiles. Seeds were obtained from the Germplasm Research Information Network and from various commercial sources. After extraction of the seed oil with hexane, the glycerides were trans-methylated and analyzed by gas chromatography on two polar stationary phases. All of the seed oils analyzed were composed primarily of linoleic acid (49-60%) with lesser amounts of oleic (16-22%) and palmitic (8-10%) acids. The usual secondary components were also found. In addition, cyclopropenoid acids (i.e., sterculic and malvalic acids) were present at levels between 6 and 17%. In all samples, the level of malvalic acid was approximately twice the level of sterculic acid, indicating that considerable a-oxidation of sterculic acid had occurred in these seeds. Two additional a-oxidation products, 8-heptadecenoic acid and 8,11-heptadecadienoic acid were also detected. Combined, the level of these fatty acids was between 1.3 and 2.3%, roughly comparable to the levels of these acids recently reported in the seed oil of Thespesia populnea.

The lipids ofHibiscus seeds

The composition and amounts of various classes of lipids of the seeds of Hibiscus sp. have been investigated. Seven classes of neutral lipids, five of phospholipids, and five of glycolipids have been identified and their fatty-acid and triglyceride compositions have been established. The presence has been shown of 16 main types of triacylglycerols and 25 types of epoxyacyldiacylglycerols. An epoxy-18.0 and an epoxy-18:1 acid in a combined amount of 1.4% have been detected among the acids of the free lipids, together with 8.1% of cyclopropenoid acids.

Hydrogen bromide titration for soaps in fat products

AbstractSince none of the existing methods for determining soaps in fat products have been found to be entirely satisfactory, a method has been devised for the determination of alkali metal soaps by direct titration with Durbetaki reagent (hydrogen bromide dissolved in glacial acetic acid). When the titration was conducted at room temperature in acetic acid‐benzene solution with crystal violet as indicator, soaps of potassium, sodium and lithium could be determined accurately in anhydrous oils, monoglycerides, and sucrose esters. The presence of alcohols, glycerol and sucrose did not interfere in the direct titration. However, oxidized oils, epoxides, and cyclopropenoid acids, which are known to consume hydrogen bromide, did interfere. Products containing the interfering substances could be analyzed by a modified procedure in which the alkali metal cations were extracted from a mixture of amyl acetate andn‐butanol (1:3) into an aqueous solution of acetic acid, and titrated as the acetates.

Hydrogenation of cyclopropenoid fatty acids occurring in cottonseed oil

AbstractThe hydrogenation of cyclopropenoid acids and their relative reactivities during hydrogenation as compared to linoleic and oleic acids were examined. Pure methyl sterculate and purifiedSterculia foetida oil and its methyl esters, which have a cyclopropene content more than 60 times that of cottonseed oil, were used for the hydrogenation experiments. Nickel, palladium and platinum catalysts were used. The effect of temperature and type of catalyst were demonstrated in a series of hydrogenation experiments of safflower andS. foetida oil mixtures, and methyl oleate and methyl dihydrosterculate mixtures. Partial hydrogenation of methyl sterculate formed as many as twenty compounds in addition to the cyclopropenoid derivatives. Most of these compounds were monounsaturated. The cyclopropene group hydrogenated very readily compared to the 9,12‐diene system in linoleate. The cyclopropane group obtained by hydrogenating the cyclopropenoid acids group was quite resistant to further attack by hydrogen and nickel catalyst had little effect. With palladium catalyst, a temperature of 180 C was necessary for the reaction to go to completion. Platinum in acetic acid was a good system for hydrogenolysis of the cyclopropane group at 80 C.

Cyclopropenoid Acid and Fatty Acid Content of Ten Varieties of Hybrid Cotton Seed Oils

AbstractThe cyclopropenoid (Malvalic acid) fatty acid content of oils from ten varieties of cotton seeds has been determined range (0.7 to 1.3). Iodine values varied from 32.9 to 114.0. The fatty acid composition was in the following range: Myristic, 0.9‐3.0; palmitic, 18.3‐34.1; stearic, 2.2‐4.5; arachidic, 0.8‐1.4; behenic, 0.9‐1.2; oleic, 9.7‐22.1; linoleic, 42.4‐52.5. The oil content varied from 22.5% to 24.5%.

Gas chromatographic analysis of cyclopropenoid acids in cottonseed oils

AbstractA gas chromatographic method of analysis for cyclopropenoid acids in cottonseed oil, as the methyl esters, is described. With a glass column packed with a methyl silicone substrate on an inert support, methyl sterculate and methyl malvalate can be chromatographed without decomposition. Although methyl malvalate was not well resolved from methyl linoleate, it could be quantitated accurately at concentrations as low as 0.03% by a peak‐height method. Quantitation can be done manually with an internal standard, or with a data system without an internal standard. The method does not require calibration with a cyclopropenoid acid standard, i.e., it is a primary method. Results compare favorably with those obtained by HBr titration. Less than 1 mg of oil is required for an analysis.

Insect Growth Inhibitors in Crop Plants

Diverse classes of organic compounds showing growth-inhibitory activity toward lepidopterous larvae have been isolated from corn, cotton, tomato, sunflower, and soybean plants. These compounds include flavonoids, tannin, terpenoids, cyclopropenoid acids, and cyclitols. The structures of these compounds, their biological activities, and their possible role in the plant as a defense against insects are discussed.

Cyclopropenoid Fatty Acids of Sida grewioides and Hibiscus caesius (Malvaceae) Seed Oils

AbstractEvidence is provided that sterculic and malvalic acids occur together in seed oils of Sida grewioides and Hibiscus caesius. Sida grewioides oil contains 1.3% sterculic and 2.1 % malvalic acids; Hibiscus caesius oil contains 1.0 % sterculic and 5.7 % malvalic acids. The cyclopropenoid acids were characterised by gas liquid chromatography (GLC) of the silver nitrate‐methanol treated methyl esters using Sterculia foetida esters as a reference standard. A third unusual component, identified as epoxy acid, also occurs in Sida grewioides oil as a trace constituent.

Determination of oil and lipids in cottonseed meal

AbstractTwo simple methods for determining total oil equivalent in cottonseed meal are described. The meal is extracted with methanol, and the crude extract is either (a) saponified and subsequently acidified to find the weight of acids set free, or (b) subjected to methanolysis to determine the weight of esters formed. When applied to a meal previously extracted with petroleum ether, these methods determine lipids. Results obtained on three commercial cottonseed meals were in excellent agreement with those obtained by the more cumbersome method requiring direct saponification of the ground meal. The methods described should also be applicable to soybean and sunflower seed meals and to other systems containing lipids, such as flours, doughs, and leaf proteins. One of the methods is particularly useful as a preliminary step in the determination of cyclopropenoid acids in cottonseed meal because much larger lated as methyl esters.

Determination of the molecular structure of plant phosphatidylcholines taking cyclopropenoid acids into account

The molecular compositions of plant phospholipids have been determined experimentally with the presence of CPAs taken into account for the first time. It has been shown that the phosphatidylcholines of the seeds of the cotton plant of variety 5904-I consist of 45 species, among which the disaturated and saturated-unsaturated types predominate. It has been established that the CPAs form pairs both with the saturated (16:0) and with the unsaturated (18:1, 18:2) acids.

Cyclopropenoids and Fatty Acid Composition of Five Varieties of Cotton Seed Oils

AbstractFive varieties of cotton seed oils from Jayadhar, Bhagya, Mysore Vijaya, Hampi and 170 CO2 have been analysed for their fatty acid content and the results (Wt.%) are in the following range: Myristic 0.8–1.1; Palmitic 23.0–23.9; Stearic 2.7–4.2; Arachidic 0.3–0.7; Behenic 0.3–1.4; Oleic 11.9–22.8; Linoleic 47.5–58.1; and Cyclopropenoid acids 0.6–2.1. The oil content and iodine value from 20.2–22.5 percent and 104.3–115.3 respectively. Protein content ranges from 24.8–48.4 percent.

Studies on the inhibition of the desaturases by cyclopropenoid fatty acids.

Unwashed rat liver microsomes were used to study the inhibition of the delta6 and delta9 desaturases by cyclopropenoid fatty acids with the ring structure about the 9,10 or 6,7 carbon atoms. The 9,10 cyclopropenoid acid (sterculic acid) is shown to be an effective inhibitor of only delta9 desaturase and then only in the presence of MgCl2 and coenzyme A (presumably due to the formation of sterculoyl-CoA). Two 6,7 cyclopropenoid acids of different chain lengths showed no marked inhibition of either the delta6 or delta9 desaturase. By the use of [3H]-sterculic acid, it has been shown that under conditions of high inhibition of the delta9 desaturase the inhibitor is not covalently attached to the enzyme at any point. This disproves older ideas on the mechanism of inhibition that assumed reaction between the cyclopropenoid ring and sulphydryl groups on the enzymes.

The position of cyclopropenoid acids in a glyceride molecule

The position of cyclopropenoid acids in a glyceride molecule

Composition of the lipids of lupin seed (Lupinus angustifolius L. var. “uniwhite”)

AbstractThe total lipids (8.6%) extracted from whole lupin seeds (Lupinus angustifolius L. var. “Uniwhite”) were found to be comprised of triglycerides (71.1%), phospho‐lipids (14.9%), free sterols (5.2%), glycolipids (3.5%), sterol and wax esters (0.5%), free alcohols (0.4%), hydrocarbons (0.4%) and unidentified waxy material (4.0%). The main fatty acids in the total lipid extract were linoleic (48.3%), oleic (31.2%), palmitic (7.6%) and linolenic (5.4%). Erucic acid was not present, nor were cyclopropenoid acids. Seed coatings constituted 23.9% of the weight of the whole seeds and contained 1.5% lipids, the main classes of which were triglycerides (38.4%), free sterols (28.0%), phospholipids (9.7%), glycolipids (9.1%) and free alcohols (3.7%). The seed coatings and kernels contained the same fatty acid constituents, but the proportions of oleic, linoleic and linolenic acids were markedly different. β‐Carotene was present, although at low concentration. When evaluated on its lipid composition, “Uniwhite” lupin seed appears suitable as a supplement for pig, poultry and stock feeding.

Oil of the seeds of Hibiscus syriacus

The physical and chemical properties and the fatty acid and triglyceride compositions of the oil ofHibiscus syriacus L. have been investigated. The oil was found to contain 16.87% of the cyclopropenoid acids malvalic and sterculic acids.

Fatty Acid Composition of Crude and Refined Cottonseed Oils

Abstract The fatty acid composition of 20 cottonseed oils was determined by isothermal GLC analysis of the total esters. A urea fractionation procedure, combined with modified programmed temperature GLC, was used to detect esters present in trace amounts (0.001–0.1%) in four refined and three crude oils. The odd a n d even chain length saturated acids from C8 to C26 were present. Mono-unsaturated acids from C15 to C20 were also detected. The crude and refined oils did not differ markedly in their fatty acid composition. The presence of malvalic and sterculic acids and the possible presence of shorter and longer chain length cyclopropenoid acids with their interfering GLC peaks make it impossible to detect and quantitatively estimate the branched and multiple branched acids.

Analysis of cyclopropenoid acids by gas-liquid

Analysis of cyclopropenoid acids by gas-liquid

Cyclopropenoid fatty acid content and fatty acid composition of crude oils from twenty‐five varieties of cottonseed

AbstractThe cyclopropenoid acid content of oils extracted from 22 commercial varieties and 3 botanical species of cottonseed have been determined. The malvalic acid content determined by HBr titration varied from a low of 0.56% to a high of 1.17%. Iodine values of the oils ranged from 96.8 to 111.6 No definite correlation could be established between iodine value and malvalic acid content. Equations for regression lines for the major acids have been calculated from plots of fatty acid composition vs. iodine value. The high degree or correlation suggests that for commercial oils the fatty acid composition can be estimated from the iodine value. Oils of the 3 experimental types of different species showed wide variations in fatty acid composition and represented many of the maximum and minimum values reported.

Methods for the determination of cyclopropenoid fatty acids V. A spectrophotometric method for cottonseed oils based upon the Halphen‐test reaction

AbstractA spectrophotometric method of analysis for the quantitative estimation of cyclopropenoid fatty acids in cottonseed oil based upon the Halphen‐test reaction has been described. Various parameters involved in the reaction have been investigated and two pigment fractions responsible for the characteristic Halphen‐test cherry‐red color have been isolated. The method is applicable to relatively small amts of sample material. The average deviation from the actual cyclopropenoid acid contents as determined by the stepwise HBr titration method was less than ŷ0.02% in both the refined and crude oil series.

Analysis of cyclopropenoid and cyclopropanoid acids in fats and oils

AbstractThe analysis of cyclopropenoid acids may be considered, from a historical standpoint, to have started with the discovery of the Halphen test. Although this test as orginally conceived was utilized as a means of detecting adulteration of premium edible oils with cottonseed oil, it has since been shown to be a characteristic test for cyclopropenoid fatty acids and has been adapted with various modifications as a quantitative colorimetric test for these substances. More recently, spectrophotometric methods particularly in the IR region have been applied to the analysis of these substances. The 9.8 Ɓ band, characteristic of the cyclopropane, and the 9.91 Ɓ band, characteristic of the cyclopropene group, as well as the 11.0 Ɓ band, characteristic of some of the noncyclic degradation derivatives, have been utilized. Gasliquid chromatography (GLC) has been applied to the methyl esters of cyclopropanoid and hydrogenated cyclopropenoid acids. The reactivity of the cyclopropene ring toward hydrohalogens has been the basis of several analytical methods developed for use with cyclopropene acid‐containing oils. Both aqueous and nonaqueous solutions of hydrohalogens have been employed. The hydrohalogenation methods are the most precise methods currently available for these analyses but only GLC has the inherent potential of identifying the specific cyclopropenoid or cyclopropenoids involved.