scholarly journals Influence of Oryzanols Concentrate on the Oxidation of Methyl Ester Linoleic Acid and Study of Their Oxidation Products

2019 ◽  
Vol 8 (4) ◽  
pp. 37
Author(s):  
Bruno Irigaray ◽  
Iván Jachmanián ◽  
María A. Grompone
Keyword(s):  
Linoleic Acid ◽  
Methyl Ester ◽  
Sunflower Oil ◽  
Rice Bran Oil ◽  
Methyl Esters ◽  
Acid Methyl Ester ◽  
Oxidation Products ◽  
Antioxidant Power ◽  
Linoleic Acid Methyl Ester ◽  
Acid Methyl

Oryzanols are frequently found in rice bran oil but almost completely removed in the neutralization step when the oil is chemically refined. In this way, oryzanols can be recovered from the soapstocks to generate a concentrate. Thereby, they could be used as antioxidants in lipids for specific purposes. In the present work the antioxidant power of oryzanols concentrate (33% purity) was studied together with pure oryzanols and butylhydroxytoulene (BHT). Methyl esters were prepared from regular sunflower oil without antioxidants to which the antioxidants before mentioned were added in an effective concentration of 3x10-3 M. The samples were oxidized in a heating block with oxygen flow and the hydroperoxides of linoleic acid methyl ester were analyzed. It was observed that all antioxidants were able to protect the sunflower oil methyl esters from oxidation with respect to methyl esters without antioxidants. Oryzanols presented a notoriously lower protection ability compared to BHT. However, the formation of the linoleic acid methyl ester hydroperoxides and their proportion, for the same oxidation stage, did not show differences between the antioxidants used. Therefore, the oxidation kinetics were similar between the different antioxidants studied.

scholarly journals Autoxidation of Conjugated Linoleic Acid Methyl Ester in the Presence of α-Tocopherol: The Hydroperoxide Pathway

Lipids ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 599-610 ◽  
Author(s):  
Taina I. Pajunen ◽  
Mikael P. Johansson ◽  
Tapio Hase ◽  
Anu Hopia
Keyword(s):  
Linoleic Acid ◽  
Methyl Ester ◽  
Conjugated Linoleic Acid ◽  
Acid Methyl Ester ◽  
Linoleic Acid Methyl Ester ◽  
Acid Methyl

Enzymic characterization of epidermis-derived 12-lipoxygenase isoenzymes

2001 ◽  
Vol 355 (1) ◽  
pp. 97-104 ◽  
Author(s):  
Malte SIEBERT ◽  
Peter KRIEG ◽  
Wolf D. LEHMANN ◽  
Friedrich MARKS ◽  
Gerhard FÜRSTENBERGER
Keyword(s):  
Arachidonic Acid ◽  
Catalytic Activity ◽  
Linoleic Acid ◽  
Methyl Ester ◽  
Docosahexaenoic Acid ◽  
Methyl Esters ◽  
Acid Methyl Ester ◽  
Dienoic Acid ◽  
Acidic Ph ◽  
Acid Methyl

Substrate selectivity and other enzymic characteristics of two epidermis-derived lipoxygenases (LOXs), the epidermis-type (e) (12S)-LOX and (12R)-LOX, were compared with those of the platelet-type (p) (12S)-LOX. In contrast with p(12S)-LOX, e(12S)-LOX and (12R)-LOX exhibited no or very low reactivity towards the customary substrates linoleic acid and arachidonic acid but metabolized the corresponding fatty acid methyl esters, which, in contrast, were not accepted as substrates by p(12S)-LOX. Other esters of arachidonic acid and linoleic acid, including propan-2-yl and cholesterol esters, 1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-linoleyl-sn-glycero-3-phosphoethanolamine, and ceramide 1 carrying an ω-linoleic acid ester, were not metabolized by these three LOX isoenzymes. Among various polyunsaturated fatty acids the isomeric eicosatrienoic acids were found to be oxygenated by e(12S)-LOX but not by (12R)-LOX. 4,7,10,13,16,19-Docosahexaenoic acid as a substrate was restricted to p(12S)-LOX. Variations in the pH and the Ca2+ content of the incubation medium affected the catalytic potential only slightly. Whereas (12R)-LOX activity increased in the presence of Ca2+ and with an acidic pH, Ca2+ had no effect on p(12S)-LOX and e(12S)-LOX; an acidic pH decreased the catalytic activity of the latter two. However, the catalytic activity of the epidermis-type isoenzymes, but not of p(12S)-LOX, was found to be markedly increased in the presence of DMSO. Under these conditions, e(12S)-LOX and (12R)-LOX oxygenated 4,7,10,13,16,19-docosahexaenoic acid to 14-hydroxy-4,7,10,12,16,19-docosahexaenoic acid and 13-hydroxy-4,7,10,14,16,19-docosahexaenoic acid respectively. In addition, (9R)-hydroxyoctadeca-10,12-dienoic acid methyl ester was generated from linoleic acid methyl ester by (12R)-LOX. Independently of the substrate, the catalytic activity of e(12S)-LOX and (12R)-LOX was always at most 2% of that of p(12S)-LOX with arachidonic acid as substrate.

Hydroperoxide formation during autoxidation of conjugated linoleic acid methyl ester

2001 ◽  
Vol 103 (9) ◽  
pp. 588-593 ◽  
Author(s):  
Taina I. Hämäläinen ◽  
Susanna Sundberg ◽  
Marjukka Mäkinen ◽  
Seppo Kaltia ◽  
Tapio Hase ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Methyl Ester ◽  
Conjugated Linoleic Acid ◽  
Acid Methyl Ester ◽  
Linoleic Acid Methyl Ester ◽  
Acid Methyl ◽  
Hydroperoxide Formation

Repellent and Insecticidal Activities of Melia azedarach L. against Cotton Leafworm, Spodoptera littoralis (Boisd.)

2011 ◽  
Vol 66 (3-4) ◽  
pp. 129-135 ◽  
Author(s):  
Mohamed Farag ◽  
Mohamed H. M. Ahmed ◽  
Heba Yousef ◽  
A.-H. Abdel-Rahman
Keyword(s):  
Oleic Acid ◽  
Methyl Ester ◽  
Growth Inhibition ◽  
Spodoptera Littoralis ◽  
Methyl Esters ◽  
Acid Methyl Ester ◽  
Melia Azedarach ◽  
Linoleic Acid Methyl Ester ◽  
Acid Methyl ◽  
Oleic Acid Methyl Ester

A crude acetone extract and oil of ripe fruits from Melia azedarach L. were evaluated against the 2nd and 4th instar larvae of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). Both oil and extract exhibited highly significant growth inhibition at all concentrations tested, while the oil of M. azedarach recorded higher insecticidal activity against both instars than the crude extract. GC-MS analysis of the oil revealed the presence of linoleic acid methyl ester, oleic acid methyl ester, and free oleic acid as the main components in addition to hexadecanol, palmitic acid, methyl esters of stearic acid and myristic acid. Fatty acids and their esters were not only the main constituents of essential oil from the ripe fruits of M. azedarach, but also mainly responsible for the insecticidal and growth inhibition activity against S. littoralis

scholarly journals Micropropagation and Screening of Phytocompounds Present among in vitro Raised and Wild Plants of Rauvolfia serpentine

2020 ◽  
Vol 17 (11) ◽  
pp. 1177-1193
Author(s):  
Varnika VARNIKA ◽  
Rohit SHARMA ◽  
Ajay SINGH ◽  
Shalini SHALINI ◽  
Nishesh SHARMA
Keyword(s):  
Linoleic Acid ◽  
Methyl Ester ◽  
Acid Methyl Ester ◽  
Wild Plants ◽  
Gas Chromatography Mass Spectrometry ◽  
Hexadecanoic Acid ◽  
Rauvolfia Serpentina ◽  
Linoleic Acid Methyl Ester ◽  
Acid Methyl

Rauvolfia serpentina, commonly known as Sarpgandha, is a plant well-known for being utilized for several medicinal purposes. Unrestricted collection from natural stands and overexploitation for medicinal and traditional purposes have rendered it endangered, hence there is necessary requirement for the development of cultivation protocols for mass propagation and sustained utilization of the plant. In the present study, in vitro culture of the apical parts of R. serpentina on MS (Murashige and Skoog) medium enriched with NAA resulted in development of callus, whereas multiple shoot regeneration along with callus development was achieved on medium combination MS + NAA + Kn and MS + NAA + BAP. MS + 4µM NAA + 4µM BAP was found to be most optimum media composition for regeneration of shoots and callus. Among different media combinations utilized for in vitro rooting, a maximum of 82.6 % explants developed in vitro roots on ½ MS + 12µM NAA. Gas chromatography-mass spectrometry (GC-MS) analysis of methanolic extract prepared from leaves of wild and micropropagated plants of R. serpentina revealed the presence of 38 and 48 phytocompounds, respectively. 9, 12-Octadecadienoic acid, Methyl linoleate, Methyl stearate, Hexadecanoic acid, methyl ester, Linoleic acid, Ergost-4, 7, and 22-trien-3.alpha.-ol were some of the major compounds found to be present in the leaves of wild plants, and Linoleic acid, methyl ester, Cis-Linoleic Acid Methyl Ester, Methyl elaidate, hexadecanoic acid, and methyl ester were major compounds found to be present in in vitro raised plants. Many of the compounds detected have been known to possess 1 or more biological or pharmacological activities.

scholarly journals Evaluation of 3-Methylbutanoic Acid Methyl Ester as a Factor Influencing Flavor Cleanness in Arabica Specialty Coffee

2021 ◽  
Vol 11 (12) ◽  
pp. 5413
Author(s):  
Keiko Iwasa ◽  
Harumichi Seta ◽  
Yoshihide Matsuo ◽  
Koichi Nakahara
Keyword(s):  
Methyl Ester ◽  
Methyl Esters ◽  
Acid Methyl Ester ◽  
Chemical Compounds ◽  
Gas Chromatography Mass Spectrometry ◽  
Arabica Coffee ◽  
Acid Methyl ◽  
Coffee Brew ◽  
Coffee Beans ◽  
Specialty Coffee

This paper reports on the chemical compounds in arabica coffee beans with a high Specialty Coffee Association (SCA) cupping score, especially those in specialty coffee beans. We investigated the relationship between the chemical compounds and cupping scores by considering 16 types of Coffea arabica (arabica coffee) beans from Guatemala (SCA cupping score of 76.5–89.0 points). Non-targeted gas chromatography-mass spectrometry-based chemometric profiling indicated that specialty beans with a high cupping score contained considerable amounts of methyl-esterified compounds (MECs), including 3-methylbutanoic acid methyl ester (3-MBM), and other fatty acid methyl esters. The effect of MECs on flavor quality was verified by spiking the coffee brew with 3-MBM, which was the top-ranked component, as obtained through a regression model associated with cupping scores. Notably, 3-MBM was responsible for the fresh-fruity aroma and cleanness of the coffee brew. Although cleanness is a significant factor for specialty beans, the identification of compounds that contribute to cleanness has not been reported in previous research. The chemometric profiling approach coupled with spiking test validation will improve the identification and characterization of 3-MBM commonly found in arabica specialty beans. Therefore, 3-MBM, either alone or together with MECs, can be used as a marker in coffee production.

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