<i>Vernonia anthelmintica</i> (L.) Willd. trivernolin, 1,3‐divernolin and vernolic (Epoxyoleic) acid from the seed oil

Krewson, C. F.; Ard, J. S.; Riemenschneider, R. W.

doi:10.1007/bf02638798

Cited by 44 publications

(12 citation statements)

References 23 publications

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“…Spore breakage in an aqueous medium appears to activate the lipase, whether or not germination has been initiated. This situation is similar to that observed with some seed lipases (10)(11)(12).…”

Section: Methodssupporting

confidence: 75%

Some Characteristics of a Lipase Preparation from the Uredospores of Puccinia graminis tritici

Knoche¹,

Horner²

1970

Plant Physiol.

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The characteristics of a lipase preparation fronm the uredospores of Puccinia graminis (pers.) f. sp. tritici (Eriks. and Henn.) have been investigated. The majority of the lipolytic activity in disrupted uredospores was found to be associated with a lipid-containing, particulate fraction which sedimented at 5000g. With triolein as a substrate, both 1,3-and 1,2-diglycerides were formed. Ethylenediaminetetraacetate, p-chloromercuribenzoic acid, and Hg2+ strongly inhibited the activity. A pH optimum of 6.7 was observed. The sensitivity of the preparation to higher temperatures was indicated by a complete loss of activity when the preparation was preincubated at 25 C or above for 30 minutes. A temperature optimum of 13 C for the enzyme is strikingly similar to the temperature optimum for germination of the uredospores. The possible relationship between the sensitivity of the enzyme and the germination process is discussed.Relatively large quantities of lipids are present in the uredospores of many obligately parasitic fungi such as the plant rusts, and it is currently accepted that these stores provide much of the energy necessary for spore germination (1,3,8,15,18). While recent studies with the uredospores of Puccinia graminis tritici have shown that carbohydrates are utilized more rapidly than lipids, especially during the initial stages of germination, lipids are extensively metabolized (4).In spite of the apparent importance of lipid metabolism during the germination of spores, little experimental data are available to indicate the exact metabolic pathways or the characteristics of enzymes involved in the utilization of endogenous lipids by obligately parasitic fungal spores.Several studies have also shown the rapid utilization of exogenous lipids, especially the short chain fatty acids, by spores (13,14,16,19,20). The conversion of cis-9 , 1O-epoxyoctadecanoic acid to 9,10-dihydroxyoctadecanoic acid has been shown to be effected by enzymes present in the uredospores of P. graminis tritici and Melampsora lini (6,22). During the isolation of cellfree preparations capable of catalyzing the hydration of cis-9,10-epoxyoctadecanoic acid to form 9,10-dihydroxyoctadecanoic acid (unpublished work from our laboratory) it was observed 'This study was supported by the National Science Foundation University of Nebraska, Lincoln, Nebraska 68503 that a very active lipase was present in the uredospores of P. graminis tritici. The time necessary for disruption of the uredospores in an aqueous medium allowed essentially total conversion of the endogenous triglycerides to mono-and diglycerides. This observation and the assumption that triglyceride utilization must begin with a hydrolysis of esterified fatty acids led us to question whether the lipase activity in uredospores might be intimately involved not only in the control of lipid utilization but in the germination process as well. Therefore, it was the purpose of this work to determine some of the characteristics of the active lipase in the uredospores of P. gram...

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Section: Methodssupporting

confidence: 75%

Some Characteristics of a Lipase Preparation from the Uredospores of Puccinia graminis tritici

Knoche¹,

Horner²

1970

Plant Physiol.

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“…[18] The usual work-up was undertaken and the yield of the oil was on average 35.6%. Vernolic acid was obtained by reacting vernonia oil with NaOH at room temperature and purified according to Smith et al [19] Trivernolin and divernolin were obtained by the method described by Krewson et al [20] The yield for trivernolin was 49% and that for divernolin, 9.3%. Trivernolin was obtained as an oil, whereas divernolin was a colorless powder with a melting point of 54 8C.…”

Section: Synthesismentioning

confidence: 99%

“…Obtaining Trivernolin (1) from Vernonia Oil (Scheme 1) Trivernolin was obtained by washing vernonia oil dissolved in petroleum ether with an aqueous solution of sodium carbonate and then water from which divernolin and vernolic acid had been separated as explained by Krewson et al [20] Low temperature crystallization was then performed. The obtained oil had a purity of 92% with an oxirane oxygen value of 5.01% (theory: 5.18%).…”

Section: Synthesismentioning

confidence: 99%

Polymeric Antioxidants from Vernonia Oil

Kimwomi

Koßmehl²,

Zeinalov

et al. 2001

Macromol. Chem. Phys.

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The antioxidative activity of the title stabilizers has been studied by the initiated oxidation of cumene as a model reaction. The new model compounds prepared from vernonia oil and the conventional phenolic antioxidant 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionic acid (DTBH) and, copolymerized with styrene, showed that the rate constant of inhibition, k7, weakly depends on the size and the nature of the radical, R∗︁, whose magnitude was found to be k7 = 107.0±0.5 exp(4 200 ± 700)/RT L/mol·s. The antioxidative activities of the new compounds compare favorably with the commercial product used in technology. These phenolated vernonia oil derivatives were incorporated chemically to polystyrene and polyurethanes, forming polymeric antioxidants useful for master batches for the named polymeric materials.

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“…Air-dried seeds of the plant contain about 30% oil, whose major fatty acid is vernolic (cis-12,13-epoxy-cis-9-octadecenoic) acid (70-80%) (6). The high vernolic acid content of this oil makes it a viable starting material in oligoethylene glycol synthesis.…”

mentioning

confidence: 99%

Synthesis of oligoethylene glycol ethers from the seed oil of Vernonia anthelmintica

Singh

1997

J Americ Oil Chem Soc

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The seed oil of Vernonia anthelmintica on reaction with diols (mono-, di-, tri-, or tetraethylene glycols) in the presence of boron trifluoride etherate, followed by saponification and esterification (methanol/H + ), gives the oligoethylene glycol ethers: methyl 12(13)-hydroxy-13 (12) [2-hydroxy-ethyl-1-oxy]-octadec-9-enoate; methyl 12(13)-hydroxy-13(12)-[5-hydroxy-3-oxapentyl-1-oxy]-octadec-9-enoate; methyl 12(13)-hydroxy-13(12)-[8-hydroxy-3,6-dioxaoctyl-1-oxy]-octadec-9-enoate; and methyl 12(13)-hydroxy-13(12)-[11-hydroxy-3,6,9-trioxaundecyl-1-oxy]-octadec-9-enoate. Methyl 12,13-dihydroxyoctadec-9-enoate is a co-product in all reactions. JAOCS 74, 609-611 (1997). KEY WORDS:Boron trifluoride etherate, ethylene glycols (mono-, di-, tri-, and tetra-), methyl esters, seed oil, synthesis, trivernolein, Vernonia anthelmintica.Oligoethylene glycols (1,2) are important building blocks in the synthesis of nonionic surfactants, crown ethers (3), di-and tetraester ligands (4), and aza-crown ethers (5).Vernonia anthelmintica is an annual herb. Air-dried seeds of the plant contain about 30% oil, whose major fatty acid is vernolic (cis-12,13-epoxy-cis-9-octadecenoic) acid (70-80%) (6). The high vernolic acid content of this oil makes it a viable starting material in oligoethylene glycol synthesis.Ayorinde et al. (7) reported that alkali-catalyzed transesterification of vernonia oil gave epoxy esters and that saponification of the oil with potassium hydroxide gave epoxy acids. In both reactions, the epoxy ring remained intact.In contrast, Kleiman et al. (8,9) reported that acid-catalyzed transesterification of the oil with methanol resulted in epoxide ring opening and gave the hydroxy methoxy methyl ester derivatives. Ayorinde and coworkers (10) also reported the synthesis of 12-hydroxy-13-alkoxy isomer as the major product in the acid-catalyzed alcoholysis of V. galamensis oil.In the present study, V. anthelmintica oil has been used for the synthesis of oligoethylene glycol ethers. Scheme 1 represents the reactant trivernolein, which is the major triacylglycerol present in V. anthelmintica oil. EXPERIMENTAL PROCEDURESIn Scheme 2, crude V. anthelmintica oil (1) was obtained by chloroform extraction of the crushed seeds. Mono-, di-, tri-, and tetraethylene glycols (2a-d) were procured from a commercial supplier (Sisco Chem., Bombay, India) and were dried in an oven at a temperature of 103 ± 2°C for 4 h and then cooled and stored in a dessicator. BF 3 -etherate was ob-

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Vernonia anthelmintica (L.) Willd. trivernolin, 1,3‐divernolin and vernolic (Epoxyoleic) acid from the seed oil

Cited by 44 publications

References 23 publications

Some Characteristics of a Lipase Preparation from the Uredospores of Puccinia graminis tritici

Some Characteristics of a Lipase Preparation from the Uredospores of Puccinia graminis tritici

Polymeric Antioxidants from Vernonia Oil

Synthesis of oligoethylene glycol ethers from the seed oil of Vernonia anthelmintica

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