Malvalic Acid Research Articles

Fatty acid composition of seed oils from sixAdansonia species with particular reference to cyclopropane and cyclopropene acids.

The oil content of sixAdansonia species (Bombacaceae family) of Madagascar (Adansonia grandidieri, A. za, A. digitata, A. fony, A. madagascariensis andA. suarenzensis) and Africa (A. digitata) ranges from 8 to 46%. All the oils give a positive response to the Halphen test. Malvalic, sterculic and dihydrosterculic acids were detected using gas liquid chromatography-mass spectrometry (GLC-MS). Epoxy or hydroxy fatty acids were not found in these oils. Fatty acid composition was determined by GLC using glass capillary columns coated with BDS and Carbowax 20 M. Results obtained for cyclopropenic fatty acids (CPEFA) were compared to those given by glass capillary GLC after derivatization with silver nitrate in methanol, by hydrogen bromide titration and by proton magnetic resonance (PMR). Good agreement was observed for the results given by the various methods. Malvalic acid content ranges from 3 to 28%, sterculic acid from 1 to 8% and dihydrosterculic acid from 1.5 to 5.1%. Odd-numbered fatty acids (Pentadecanoic and hepatadecanoic) were also observed in minute amounts (0.1-1.1%). Among the normal fatty acids, we observed mainly palmitic (21-46%), oleic (15-40%) and linoleic (12-32%). The relationship between fatty acid composition andAdansonia species is 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.

Cyclopropenoid Fatty Acids of Sterculia Oils by Gas Liquid Chromatography

AbstractSilver nitrate treated methyl esters of the seed oils of Sterculia alata, Sterculia foetida, Sterculia guttata and Sterculia villosa were subjected to gas liquid chromatography and were found to contain sterculic and malvalic acids (4.0, 17.6; 55.7, 11.4; 5.8, 2.1 and 3.2, 2.5%, respectively), besides the conventional fatty acids. IR and NMR of the oils confirmed the cyclopropenoid moiety in these oils. Seed oil of Sterculia foetida was used as a standard reference.

Eriolaena hookeriana seed oil: A rich source of malvalic acid

The seed oil of Eriolaena hookeriana (Sterculiaceae) contains malvalic (25.8%) and sterculic (6.0%) acids in addition to normal fatty acids. Eriolaena hookeriana is the second known species of the Sterculiaceae plant family whose seed oil contains more malvalic acid than sterculic acid. Gas chromatography-mass spectrometry (GS-MS) study of the silver nitrate-methanol treated methyl esters has been carried out for unequivocal characterisation of the individual cyclopropene acids. Genesis of diagnostic fragment ions is discussed.

Isolation and identification of constituents of Jasminum auriculatum (Vahl) leaves

AbstractJasminum auriculatum (Vahl) (family: Malvaceae) widely grown in India was analysed for its fatty acids and waxy constituents. Straight‐chain hydrocarbons (C20‐C34), fatty acids (C14‐C23) and fatty alcohols (C21‐C32) were found in the 95% aqueous ethanol extract of the leaves of the plant. Malvalic acid was the only cyclic acid identified. Hydrocarbons (C29 and C31), fatty acids (C16, C18, C18:1, C18:2, C18:3 and C22) and fatty alcohols (iso‐C26, C28 and C30) were the major components. Four polyalcohols, namely D‐mannitol, xylitol, inositol and sorbitol, have also been found in the alcoholic extract of the leaves.

Cyclopropenoid fatty acids in seed oils ofSida acuta andSida rhombifolia (malvaceae)

AbstractSeed oils ofSida acuta andSida rhombifolia were found to contain sterculic (11.0, 10.8%) and malvalic (1.7, 2.0%) acids respectively, in addition to the normal fatty acids. Co‐occurrence of these acids was established by gas liquid chromatography of the silver nitrate‐methanol‐treated methyl esters usingSterculia foetida esters as a reference standard. This gas liquid chromatography technique of quantitation was found most suitable to estimate these acids in low level cyclopropenoid acid‐containing seed oils.

Cyclopropenoic acids ofPavonia sepium seed oil

AbstractThe seed oil ofPavonia sepium (Malvaceae) contains sterculic (7%) and malvalic (4%) acids. Countercurrent distribution in a hexane‐acetonitrile system concentrated and resolved the homologus cyclopropenoid methyl esters. Reductive ozonolysis of selected countercurrent distribution fractions gave β‐diketoesters, which were identified by gas chromatography‐mass spectrometry as derivatives of sterculic and malvalic acids.Pavonia sepium is the first known species in the plant family Malvaceae whose seed oil contains more sterculic than malvalic acid.

Changes in lipids of maturing Ceiba pentandra seeds

Lipids were extracted with chloroform-methanol from Ceiba pentandra seeds at different stages of maturity, separated by TLC and tested for the Halphen response. Cyclopropene fatty acids (CFA) were absent from mono- and diglycerides and phospholipids. Free fatty acids, diglycerides and phospholipids were maximum on the 23rd, 65th and 65th day respectively and minimum on the 96th day (mature) after flowering. The fatty acid compositions were determined by GLC. Dihydromalvalic acid reached a maximum value on the 81st day, while malvalic acid remained almost constant from the 38th day and sterculic acid steadily increased. Dihydrosterculic acid was noticed only in the free fatty acids and phospholipids. The positional distribution in the triglycerides was determined by lipolysis. Since CFA inhibited lipolysis partially the triglycerides were dissolved in chloroform and treated with methanolic silver nitrate prior to lipolysis. CFA were found in the 2-position, though to a lesser extent than in the primary positions, indicating rearrangement of glycerides during maturation.

The distribution of cyclopropane and cyclopropene fatty acids in higher plants (Malvaceae)

AbstractThe occurrence and distribution of cyclopropane and cyclopropene fatty acids has been investigated in seeds, leaves and other tissues of several species of Malvaceae. Sterculic and malvalic acids and their dihydro‐analogs were present in all the plant tissues examined, the highest proportions generally being in immature seeds. The cyclic acids were mainly concentrated in the neutral lipids with lesser proportions in phospholipid or glycolipid classes. The occurrence of these acids in all tissues of some species offered the attractive possibility of establishing callus tissue cultures capable of synthesizing cyclopropane and cyclopropene fatty acids and thereby providing a more convenient and reproducible system for biosynthetic studies. Substantial proportions of these cyclic acids were found in callus tissue cultures propagated from twoMalva species.

Syntheses of C-14 labeled methyl malvalates

Malvalic acid, the principle cyclopropene acid in cottonseed oil, has been synthesized with carbon-14 at the 1-position, at the ring methano-position, and at the 10-position. A method for reaching malvalic-9- 14C acid has also been worked out. These labeled compounds should prove useful in studies on the biochemical reactions and degradation of malvalic acid.

Some reactions of sterculic and malvalic acids. A new source of malvalic acid.

Oxidation of sterculic acid by aqueous alkaline permanganate gave 9,11-dioxononadecanoic acid. Oxidation of sterculic acid by peracetic acid gave a mixture of 9-oxononadec-10-enoic and 11-oxononadec-9-enoic acids. Acetolysis of malvalic acid gave a mixture of 8-hydroxy-9-methylene-heptadecanoic and 9-hydroxy-8-methylene-heptadecanoic acids. Seed oil of Pterospermum acerifolium Willd. (family Sterculiaceae) contained malvalic acid as its major cyclopropenoid component. It comprised about 16% of the total fatty acids.

Syntheses of methyl malvalate and methyl 5-6-methano-5-undecenoate

This invention relates to the preparation of methyl malvalate, methyl 5,6-methano-5-undecenoate and the preparation of some new intermediates. Malvalic acid, the major cyclopropene component in cottonseed oil, has been synthesized. When 1-chloro-7-hexadecyne reacts with diazoacetic ester in the presence of copper bronze, the ester of 1-chloro-7,8-carboxymethano-7-hexadecene is formed. Treating the corresponding acid chloride with zinc chloride causes loss of carbon monoxide. Either sodium borohydride or lithium aluminum hydride reduces the resulting cyclopropenium compound to 1-chloro-7,8-methano-7-hexadecene. Replacing the chloro group with cyano yields malvalonitrile, which can be converted to methyl malvalate. An analogous sequence of steps has been applied to 1-chloro-4-decyne to produce methyl 5,6-methano5-undecenoate. An alternate synthesis of methyl malvalate starts by using 1-chloro-7-hexadecyne as the precursor for methyl 8heptadecynoate. This acetylenic ester is converted to 8,9carboxymethano-8-heptadecenoic acid, the diacid chloride of which decarbonylates selectively in the presence of metallic chlorides to form the cyclopropenium-acid chloride. After esterification the resulting cyclopropenium-ester is reduced with borohydride to methyl malvalate.

Reaction of cyclopropene esters with hydrogenation catalysts

AbstractMethyl esters of stereulic and malvalic acids were heated under nitrogen in the presence of various hydrogenation catalysts, and the effect on the cyclopropene moiety was established. Similar tests were conducted with cottonseed oil, which contains glycerides of sterculic and malvalic acids. Palladium catalysts, and some palladium compounds which were tested, readily gave cyclopropene‐free products, while nickel and platinum catalysts did not. Palladium catalysts freshly activated with hydrogen were not as active as those freed of adsorbed hydrogen. The catalysts could be reused. Heating cottonseed oil (0.73% cyclopropenes, calculated as trimalvalin) with 0.02% palladium, as a 10% palladium‐on‐carbon catalyst, gave a cyclopropene‐free oil after 2 hr at 150 C. The treated oil was unaltered in appearance, and the noncyclopropene components were unaffected. Heating methyl sterculate with palladium catalyst produced a mixture of unsaturated condensation products and a number of unsaturated monoesters of practically unchanged molecular weight. The palladium treatment was shown to cleave the cyclopropene ring and produce methyl and methylene substituted fatty acid groups.

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.

Fatty acid desaturase systems of hen liver and their inhibition by cyclopropene fatty acids.

AbstractHen liver preparations which desaturate stearic acid at the 9,10 position to form oleic acid have been found to desaturate other saturated fatty acids of carbon chain length from 12 to 20 and 22. The 9,10‐monoenoic fatty acid of the same chain length as the substrate fatty acid is the major product formed. Minor amounts of the 10,11‐ and 11, 12‐monoenoic acids are also formed. Maximum desaturation occurred with the C14 fatty acid substrate and with the fatty acids C17 and C18, suggesting the presence of at least two desaturating systems. The cyclopropene fatty acids, sterculic and malvalic acids, inhibited the desaturation of all thefatty acids at the 9,10 position but desaturation at the 10,11 and 11, 12 positions was affected only slightly. The effect is not due to inhibition of the primary activating enzyme, the long chain acyl CoA synthetase. Sterculic acid is a more effective inhibitor than either malvalic acid or sterculyl alcohol, probably because these cyclopropene compounds do not block the desaturating site of the enzyme as completely as sterculic acid.

Inhibition by cyclopropene fatty acids of the desaturation of stearic acid in hen liver

The mechanism of the hardening of body fats of animals by dietary lipids which contain cyclopropene fatty acids has been studied. Dietary methyl sterculate increased the stearic acid content of egg yolk lipid and decreased the activity of the stearic acid desaturase system of hen liver. The cyclopropene fatty acids were specific inhibitors of the stearic acid desaturase system of hen livers since other fatty acids, including two possible metabolites of sterculic acid, failed to inhibit the system at equivalent concentrations. Sterculic acid was a more effective inhibitor of the system than malvalic acid. Kinetic studies have shown that the inhibition is irreversible. Apparent kinetic constants were determined for the system.The results support the hypotheses that cyclopropene fatty acids inactivate an essential component of the desaturase system, probably by combination with-SH groups, and that this inhibition causes many of the effects of dietary cyclopropene fatty acids, including permeability disorders of eggs.

Selective hydrogenation of the cyclopropene acid groups in cottonseed oil

AbstractThe cyclopropene acid groups in cottonseed oil can be modified by a light hydrogenation which will not produce large amounts oftrans isomers or lower the iodine value to a significant extent. Optimum conditions, as indicated by this investigation, are 105–115C, 20 psig hydrogen pressure, 0.1% electrolytic nickel as catalyst, and a low hydrogen‐dispersion rate. Under milder conditions of hydrogenation the elimination of the cyclopropenes was accompanied by a lower formation oftrans isomers and a lower hydrogenation of noncyclopropenes, but the time required increased. In one hydrogenation carried out with commercial nickel catalyst, the 0.4% of malvalic acid groups in the cottonseed oil was hydrogenated completely whereas the iodine value was reduced by only 1.7 units and only 2.1% oftrans isomers was formed. AVinterization of cottonseed oils which had been hydrogenated to the point of eliminating their response to the Halphen test and in which only small amounts of saturated acid groups andtrans isomers had been formed gave yields equal to or better than those of the original oil. Hydrogȳnation actually increased the ease of winterization.

The biosynthesis of cyclopropane and cyclopropene fatty acids in plant tissues

The biosynthesis of cyclopropane and cyclopropene fatty acids was investigated in seeds of several species of the order Malvales, including species with a high content of sterculic acid, a high content of malvalic acid, and a low content of these cyclopropene fatty acids. The fatty acid composition of the lipids in young and developing seeds is compared with particular attention to variations in cyclopropane and cyclopropene fatty acid contents.Incubation studies employing several(14)C compounds indicate that the methyl group of methionine is the most likely precursor of the ring-methylene carbon. A pathway for the synthesis of the cyclopropane and cyclopropene fatty acids is postulated. The origin of malvalic acid is also considered.

Pink Egg Discoloration with Methyl Dihydrosterculate

The formation of pink whites during storage of eggs from hens that had been fed sterculic and malvalic acid derivatives has been amply documented (reviews: Carter and Frampton, 1964; Shenstone et al., 1965; Phelps et al., 1965). Destruction of the cyclopropene ring in these compounds gave normal eggs when the treated materials were incorporated into the diets of laying hens.Although small amounts of cyclopropane derivatives had no deleterious effects on egg quality (Masson et al., 1957; Shenstone and Vickery, 1959), large quantities have never been fed to hens. Wood and Reiser (1965) fed methyl cis and trans-9, 10-methylene octadecanoate (I) to rats at a level of 0.54% of a fat free diet and observed that the cyclopropane acids are incorporated into the rat adipose tissue and are also oxidized to the 3, 4-methylene dodecanoic acids (II).▪▪Chung (1966), working with rat liver mitochondria, showed that the methylene carbon …

Studies with Acidulated Cottonseed-Oil Soapstock: 3. Its Use as a Fat Supplement in Layer Rations

COTTONSEED products are involved in the discoloration of cold stored eggs, by producing (a) olive or brown yolks (Lamon and Lee, 1917; Schaible et al., 1934); and (b) pink whites and salmon colored yolks (Sherwood, 1928, 1931). The dark yolk discoloration was reported to be caused by free gossypol (Heywang et al., 1955), and the pink color of the egg albumen by sterculic and malvalic acids (Shenstone and Vickery, 1959), fatty acids of Sterculia foetida oil and of cottonseed oil, respectively, having a cyclopropene ring and giving the Halphen color reaction.Discolorations of both yolk and albumen appear closely related to the enhanced rates of diffusion caused by cyclopropenoid fatty acids. As a result, yolk iron diffuses into the albumen and chelates with the protein conalbumin to give the pink iron-conalbumin complex, and more rapid transmission into the yolk sac of albumen alkaline fluids causes the gossypol in the yolk …