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1.
Eduardo A. Rodríguez-Leyes Víctor L. González Canavaciolo David Marrero Delange Abel R. Sgambelluri Enríquez Yuliamny Adames Fajardo 《Journal of the American Oil Chemists' Society》2007,84(8):765-767
The present study targeted the whole-fruit oil yield and fatty acid composition from five of the most abundant Arecaceae species grown in Cuba. The oil yields (% dry weight), determined by the Soxhlet extraction technique with hexane, were 25.5,
5.3, 6.9, 5.4, and 6.4% for Roystonea regia, Colpothrinax wrightii, Sabal maritima, Sabal palmetto and Thrinax radiata, respectively. The free fatty acid (FFA) content varied from 2.7 to 6.8%. Fatty acid (FA) profiles of the oils indicated
that lauric acid (13.7–44.4%), myristic acid (9.4–22.4%) and palmitic acid (9.2–17.1%) as major saturated FA; whereas oleic
acid (9.6–42.7%) and linoleic acid (9.3–17.0%) as major unsaturated FA. R. regia fruit seemed the most promising among Arecaceae grown in Cuba because of its high oil yield and low oil FFA content. 相似文献
2.
Reis MG de Faria DA dos Santos IA Amaral Mdo C Marsaioli AJ 《Journal of chemical ecology》2007,33(7):1421-1429
Tetrapedia diversipes and other Apidae (Anthophoridae) may be deceived by floral similarities between Malpighiaceae and Orchidaceae of the Oncidiinae
subtribe. The latter do not usually exudate floral oils. Thus, visitors may pollinate the flowers in a deceit/food/pollination
syndrome. We studied the chemical compositions of Byrsonima intermedia (Malpighiaceae) floral oil and T. diversipes (Anthophoridae) cell provisions. From B. intermedia floral oil, we isolated a novel fatty acid (3R, 7R)-3,7-diacetoxy-docosanoic acid, here named byrsonic acid, and from T. diversipes cell provisions we isolated two novel fatty acid derivatives 3,7-dihydroxy-eicosanoic acid and 3,7-dihydroxy-docosanoic acid,
here named tetrapedic acids A and B, respectively. The three fatty acid derivatives have common features: possess long chains
(20 or 22 carbon atoms) with no double bond and either hydroxy or acetoxy groups at carbons 3 and 7. This characteristic was
also encountered in the fatty acid moiety of oncidinol (2S, 3′R, 7′R)-1-acetyl-2-[3′, 7′-diacetoxyeicosanyl)-glycerol, a major floral oil constituent of several Oncidiinae species (Orchidaceae).
Thus, both tetrapedic A (C20) and B (C22) could be the biotransformation products of oncidinol and byrsonic acid by T. diversipes hydrolases. These are the chemical clues for bee visitation and oil collecting from both plant species. The results indicate
that the deceit/pollination syndrome should not be applied to all Oncidiinae flowers. 相似文献
3.
Nanzad Tsevegsüren Kurt Aitzetmüller 《Journal of the American Oil Chemists' Society》1996,73(12):1681-1684
Seeds of nine Central Asian species of Boraginaceae were investigated for the first time for their oil content and for the
fatty acid composition of their seed oils by capillary gas chromatography. Levels of γ-linolenic acid ranged from 6.6 to 13.0%
and levels of stearidonic acid ranged from 2.4 to 21.4% of total seed fatty acids. The seed oil ofHackelia deflexa exhibited the highest stearidonic acid content (21.4%) that has been found so far in nature. Other high contents of this
fatty acid were in threeLappula species (17.2 to 18.1%). Seed oils ofCynoglossum divaricatum andAmblynotus rupestris contain considerable amounts ofcis-11-eicosenoic (5.3 to 5.8%) andcis-13-docosenoic acid (7.0 to 9.7%) besides γ-linolenic (10.2 to 13.0%) and stearidonic acid (2.4 to 6.5%), which distinguish
these oils from those of other Boraginaceae genera.
This paper was presented as a poster at 10th Minisymposium and Workshop on Plant Lipids, Sept. 3–6, 1995, in Berne, Switzerland. 相似文献
4.
Shigenobu Kishino Jun Ogawa Yoriko Omura Kenji Matsumura Sakayu Shimizu 《Journal of the American Oil Chemists' Society》2002,79(2):159-163
After screening 14 genera of lactic acid bacteria, Lactobacillus plantarum AKU 1009a was selected as a potential strain for CLA production from linoleic acid. Washed cells of L. plantarum with high levels of CLA production were obtained by cultivation in a nutrient medium with 0.06% (wt/vol) linoleic acid (cis-9,cis-12-octadecadienoic acid). Under the optimal reaction conditions with the free form of linoleic acid as the substrate, washed
cells of L. plantarum produced 40 mg CLA/mL reaction mixture (33% molar yield) from 12% (wt/vol) linoleic acid in 108 h. The resulting CLA was
a mixture of two CLA isomers, cis-9,trans-11 (or trans-9,cis-11)-octadecadienoic acid (CLA1, 38% of total CLA) and trans-9,trans-11-octadecadienoic acid (CLA2, 62% of total CLA), and accounted for 50% of the total FA obtained. A higher yield (80% molar
yield to linoleic acid) was attained with 2.6% (wt/vol) linoleic acid as the substrate in 96 h, resulting in CLA production
of 20 mg/mL reaction mixture [consisting of CLA1 (2%) and CLA2 (98%)] and accounting for 80% of total FA obtained. Most of
the CLA produced was associated with the cells (ca. 380 mg CLA/g dry cells), mainly as FFA. 相似文献
5.
The autoxidation of p-t-butyltoluene (TBT) at 80 °C in the liquid phase is carried out with an initial mixture of cobalt(III) and cobalt(II) acetate in an acetic acid solution. The autoxidation kinetics of TBT is appreciably accelerated by electrolysis with a anodic current density of 62.5 A m–2. The electrolysis increases the concentration of cobalt(III) acetate, the actual catalyst of the autoxidation reaction. The end product of oxidation is p-t-butylbenzoic acid (TBBA). p-t-Butylbenzaldehyde (TBBZ) is an intermediary whose concentration passes through a maximum. The oxidation experiments with TBT were performed with total cobalt acetate concentrations ranging from 0.0188 to 0.169 mol dm–3. An increase in total cobalt acetate concentration favours the electrochemical regeneration of CoIII and slightly improves the TBBZ selectivity. The duration of TBT oxidation into TBBA is reduced by a factor of 5 compared with a reaction without electrolysis. 相似文献
6.
David C. Taylor Samuel L. MacKenzie Alan R. McCurdy Peter B. E. McVetty E. Michael Giblin Eric W. Pass Scot J. Stone Rachael Scarth S. Roger Rimmer Mark D. Pickard 《Journal of the American Oil Chemists' Society》1994,71(2):163-167
Stereospecific analyses of triacylglycerols from selected high-erucic acid breeding lines or cultivars ofBrassica napus L. andB. oleracea L. have been performed. Initial lipase screening revealed that while allB. napus lines contained little or no erucic acid at thesn-2 position, several of theB. oleracea lines had significant proportions of erucic acid at this position. Detailed stereospecific analyses were performed on the
triacylglycerols from these lines by using a Grignard-based deacylation, conversion of thesn-1,sn-2 andsn-3 monoacylglycerols to their di-dinitrophenyl urethane (DNPU) derivatives, resolution of the di-DNPU-monoacylglycerols (MAGs)
by high-performance liquid chromatography on a chiral column, transmethylation of eachsn-di-DNPU MAG fraction and analysis of the resulting fatty acid methyl esters by gas chromatography. The findings unequivocally
demonstrate for the first time that, within the Brassicaceae, there existsB. oleracea germplasm containing seed oils with substantial erucic acid (30–35 mol%) at thesn-2 position. This has important implications for biotechnology and breeding efforts designed to increase the levels of erucic
acid in rapeseed beyond 66 mol% to supply strategic industrial feedstocks. In the first instance, the germplasm will be of
direct use in retrieving a gene encoding aBrassica lyso-phosphatidic acid acyltransferase with an affinity for erucoyl-CoA. In a breeding program, the germplasm offers promise for
the introduction of this trait intoB. napus by interspecific hybridization and embryo rescue. 相似文献
7.
Ching T. Hou 《Journal of the American Oil Chemists' Society》2006,83(8):677-681
Bacillus megaterium ALA2 produces many oxygenated FA from linoleic acid: 12,13-dihydroxy-9(Z)-octadecenoic acid; 12,13,17-trihydroxy-9(Z)-octadecenoic acid; 12,13,16-trihydroxy-9(Z)-octadecenoic acid; 12-hydroxy-13,16-epoxy-9 (Z)-octadecenoic acid; and 12,17;13,17-diepoxy-16-hydroxy-9 (Z)-octadecenoic acid. Recently, we studied the monooxygenase system of B. megaterium ALA2 by comparing its palmitic acid oxidation products with those of the well-studied catalytically self-sufficient P450
monooxygenase of B. megaterium ATCC 14581 (NRRL B-3712) and of B. subtilis strain 168 (NRRI B-4219). We found that their oxidation products are identical, indicating that their monooxygenase systems
(hydroxylation) are similar. Now, we report that strain ALA2 epoxidizes linoleic acid to 12,13-epoxy-9(Z)-octadecenoic acid and 9,10-epoxy-12 (Z)-octadecenoic acid, the initial products in the linoleic acid oxidation. The epoxidation enzyme did not oxidize specific
double bond of the linoleic acid. The epoxidation activity of strain ALA2 was compared with the above-mentioned two Bacillus strains. These two Bacillus strain also produced 12,13-expoxy-9 (Z)-octadecenoic acid and 9,10-epoxy-12(Z)-octadecenoic acid, indicating that their epoxidation enzyme systems might be similar. The ratios of epoxy FA production
by these three strains (A1 A2, NRRI B-3712, and NRRI B-4219) were, respectively, 5.56∶0.66∶0.18 for 12,13-epoxy-9(Z)-octadecenoic acid and 2.43∶0.41∶0.57 for 9,10-epoxy-12(Z)-octadecenoic acid per 50 mL medium per 48 h. 相似文献
8.
The nonprotein amino acids 2-amino-3-cyclopropylbutanoic acid and 2-amino-5-chloro-4-pentenoic acid were isolated from the mushroom Amanita cokeri. The cyclopropyl amino acid is toxic to the fungus Cercospora kikuchii, the arthropod Oncopeltus fasciatus (milk weed bug), and the bacteria Agrobacterium tumefaciens, Erwinia amylovora, and Xanthomonas campestris. Toxicity to bacteria was reversible by addition of isoleucine to the medium. No toxicity was observed for 2-amino-5-chloro-4-pentenoic acid. 相似文献
9.
Joseph Gresti Corinne Mignerot Jean Bézard Robert L. Wolff 《Journal of the American Oil Chemists' Society》1996,73(11):1539-1547
Purified triacylglycerols (TAG) fromPinus koraiensis andP. pinaster seed oils, which are interesting and commercially available sources of Δ5-olefinic acids (i.e.,cis-5,cis-9,cis-12 18:3 andcis-5,cis-11,cis-14 20:3 acids) were fractionated by reversed-phase high-performance liquid chromatography, and each fraction was examined
by capillary gas-liquid chromatography for its fatty acid composition. A structure could be assigned to more than 92% of TAG
from both oils. In both instances, ca. 48% of the TAG were shown to contain at least one δ5-olefinic acid. In the great majority
of TAG, our data showed that there is only one molecule of δ5-olefinic acid per molecule of TAG. This is compatible with theoretical
calculations based on the proportion of total δ5-olefinic in the oils. Thecis-5,cis-9,cis-12 18:3 acid (14.2 and 8.6% of total fatty acids in the seed oils ofP. koraiensis andP. pinaster, respectively) and thecis-5,cis-11,cis-14 20:3 acid (1.1 and 8.1% of total fatty acids in the seed oils ofP. koraiensis andP. pinaster, respectively) are preferentially associated with two molecules of linoleic acid, and to a lesser extent, to one molecule
of linoleic acid and one molecule of oleic acid, or two oleic acid molecules. However, several other combinations occur, each
in low amounts. The distribution of δ5-olefinic acids in TAG is evidently not random. Combining these results with the known
preferential esterification of δ5-olefinic acids to the 1,3-positions of TAG would suggest that most of these acids are present
at only one of these positions at a time. 相似文献
10.
J.-F. Butaud P. Raharivelomanana J.-P. Bianchini E. M. Gaydou 《Journal of the American Oil Chemists' Society》2008,85(4):353-356
The sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E-11-octadecen-9-oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry
(GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The
content in stearolic acid, octadec-9-ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic
acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species
belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content. 相似文献
11.
Robert L. Wolff Bernard Comps Laurent G. Deluc Anne M. Marpeau 《Journal of the American Oil Chemists' Society》1998,75(1):45-50
The fatty acid compositions of pine seed oils were determined from 11 species of the Banksiana subsection and three species of the Ponderosa subsection. All were collected in North America (United States, Mexico, and Cuba). These analyses also included the seed
oils from the unique European species of the Ponderosa-Banksiana section (Banksiana subsection), Pinus pinaster, and from three pine species of the Halepensis section, which are related to the Banksiana subsection. Emphasis was placed on their Δ5-olefinic acid content and profile. Principal-component analysis of fatty acid
compositions showed that all North American species constituted a fairly homogeneous group. However, P. jeffreyi was slightly eccentric, and P. pinaster, a west-Mediterranean species, was completely isolated from the North American group. Other species from the Banksiana and Ponderosa subsections could not be distinguished on the basis of their seed oil fatty acid compositions. With respect to Δ5-olefinic
acids, the North American species (except for P. jeffreyi) had 5,9-18:2, 5,9,12-18:3, 5,11-20:2, and 5,11,14-20:3 acid concentrations in the ranges 1.9 to 3.2, 17.7 to 22.9, 0.2 to
0.4, and 2.0 to 3.5%, respectively (sum, 22.7–28.5%). Levels of corresponding acids in P. pinaster were 0.9, 7.9, 0.9, and 7.0%, respectively (sum, 16.7%). Other differences were observed for linoleic acid (42.6 to 48.6%
vs. 52.2%) and α-linolenic acid (0.3 to 0.6% vs. 1.4%). Pinus pinaster was close to species of the Halepensis section (5,9-18:2, 0.5 to 1.0%; 5,9,12-18:3, 3.1 to 4.4%; 5,11-20:2, 0.4 to 0.5%; 5,11,14-20:3, 3.6 to 5.4%; sum, 8.6–11.1%),
which were clearly separated from the Ponderosa-Banksiana section. Among all pines analyzed, P. pinaster presented the highest level of sciadonic (5,11,14-20:3) acid, a component that has three ethylenic bonds in common with arachidonic
and eicosapentaenoic acids. 相似文献
12.
Multi-gram quantities of deuterium-labelled methyl linoleate (methyl cis-9,cis-12-octadecadienoate) and its geometric isomers
are readily synthesized fromCrépis alpina (70–80% cis-9-octadecen-12-ynoic acid) andVernonia galamensis (70–80% 12,13-epoxy-cis-9-octadecenoic acid) seed oils. Methylcis- 9,cis- 12- andtrans- 9,cis- – octadecadienoate-12,13-d2 were prepared by the Lindlar-catalyzed reduction (with D2 gas) of methylcis- 9- and trans-9-octadecen-12-ynoates, respectively. Methyltrans- 9- octadecen-12-ynoate was synthesized by thep-toluene-sulfinic acid-catalyzed isomerization of the corresponding cis isomer. Methylcis- 9fiis- 12., trans- 9fiis- 12;cis- 9,trans- 12- andtrans- 9, frans-12-octadecadienoate-d2, d4 and d6 were prepared by the Wittig coupling (with stereochemical control) of the appropriate d2-, d4- or de-alkyltriphenyl-phosphonium salt with methyl 12-oxo-cis-9- ortrans- 9- dodecenoate (prepared by the para-periodic acid cleavage of methyl 12,13-dihydroxy-cis-9- or trans-9-octadecenoate). Thecis dihydroxy ester was synthesized fromVernonia galamensis seed oil by acetolysis, saponification and then esterification. Thecis dihydroxy ester was isomerized by nitric acid/sodium nitrite to thetrans form and purified by silver resin chromatography. Isotopic purities ranged from 88% (for the d6 isomers) to 99% (for the d2 isomers).
The mention of firm names or trade products does not imply that they are endorsed or recommended over other firms or similar
products not mentioned. 相似文献
13.
The ripe fruit ofMorinda citrifolia, host plant forDrosophila sechellia is highly toxic for three closely related species (D. melanogaster, D. simulans, andD. mauritiana). Green and rotten fruits are not toxic for all species tested. Short fatty acids were found to be present in large quantities in the extract of the ripe fruit. The most abundant (octanoic acid) was tested pure for its toxicity in a dose-dependent manner;D. sechellia is five to six times more resistant thanD. melanogaster to octanoic acid. Octanoic acid alone seems to be sufficient to explain the toxic effect of the pulp. It is less abundant in the rotten fruit and absent in the green fruit. 相似文献
14.
Characterization of yam bean (Pachyrhizus spp.) Seeds as potential sources of high palmitic acid oil
W. J. Grüneberg F. D. Goffman L. Velasco 《Journal of the American Oil Chemists' Society》1999,76(11):1309-1312
Seeds from 22 accessions of the yam bean species Pachyrhizus ahipa (14 accessions), P. erosus (5), and P. tuberosus (3) were investigated for oil and protein contents, fatty acid composition of the seed oil, and the total tocopherol content
and composition. Plants from the accessions were grown under greenhouse conditions during one (P. erosus and P. tuberosus) or two years (P. ahipa). The pattern of the investigated seed quality traits was very similar in the three species. Yam bean seeds were characterized
by high oil (from about 20 to 28% in one environment) and protein contents (from about 23 to 34%). Seed oil contained high
concentrations of palmitic (from about 25 to 30% of the total fatty acids), oleic (21 to 29%), and linoleic acids (35 to 40%).
Levels of linolenic acid were very low, from about 1.0 to 2.5%. Total tocopherol content was relatively low in P. erosus (from 249 to 585 mg kg−1 oil) and P. tuberosus (from 260 to 312 mg kg−1 oil) compared with the levels found in P. ahipa grown under identical conditions (508 to 858 mg kg−1 oil). In all the samples, γ-tocopherol was predominant, accounting for more than 90% of the total tocopherol content. The
combination of high oil and protein contents, together with high palmitic acid, low linolenic acid, and high γ-tocopherol
concentration, makes these crops an interesting alternative as sources of high palmitic acid oil for the food industry. 相似文献
15.
Gerald P. McNeill Philip E. Sonnet 《Journal of the American Oil Chemists' Society》1995,72(2):213-218
Three lipases were compared for their ability to hydrolyze high erucic acid rapeseed oil, with the objective of concentrating
the erucic acid in a single glyceride fraction. Lipase fromPseudomonas cepacia released all fatty acids rapidly and did not result in selective distribution of erucic acid.Geotrichum candidum lipase released C20 and C22 fatty acids extremely slowly, resulting in their accumulation in the di- and triglyceride fractions.
Less than 2% of the total erucic acid was found in the free fatty acid (FFA) fraction. Lipase fromCandida rugosa released erucic acid more slowly than C20 and C18 fatty acids at 35°C but only resulted in a limited accumulation of the
erucic acid in the di- and triglyceride fractions. However, when hydrolysis catalyzed byC. rugosa lipase was carried out below 20°C, the reaction mixture solidified and was composed solely of FFAs and diglycerides. The
diglyceride fraction contained approximately 95% erucic acid while about 20% of the total erucic acid was found in the FFA
fraction. It is concluded that hydrolysis at low temperature withC. rugosa lipase results in a higher purity of erucic acid in the glyceride fraction than can be obtained withG. candidum lipase, but with considerable loss of erucic acid to the FFA fraction. 相似文献
16.
Fidèle P. Tchobo Armand K. Natta Bruno Barea Nathalie Barouh Georges Piombo Michel Pina Pierre Villeneuve Mohamed M. Soumanou Dominique C. K. Sohounhloue 《Journal of the American Oil Chemists' Society》2007,84(8):755-760
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. 相似文献
17.
Afaf Kamal-Eldin Lars Åke Appelqvist 《Journal of the American Oil Chemists' Society》1994,71(2):135-139
Seeds from different collections of cultivatedSesamum indicum Linn. and three related wild species [specifically,S. alatum Thonn.,S. radiatum Schum and Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil content and fatty acid composition of the total lipids. The wild seeds contained
less oil (ca. 30%) than the cultivated seeds (ca. 50%). Lipids from all four species were comparable in their total fatty acid composition, with palmitic (8.2–12.7%), stearic
(5.6–9.1%), oleic (33.4–46.9%) and linoleic acid (33.2–48.4%) as the major acids. The total lipids from selected samples were
fractionated by thin-layer chromatography into five fractions: triacylglycerols (TAG; 80.3–88.9%), diacylglycerols (DAG; 6.5–10.4%),
free fatty acids (FFA; 1.2–5.1%), polar lipids (PL; 2.3–3.5%) and steryl esters (SE; 0.3–0.6%). Compared to the TAG, the four
other fractions (viz, DAG, FFA, PL and SE) were generally characterized by higher percentages of saturated acids, notably palmitic and stearic
acids, and lower percentages of linoleic and oleic acids in all species. Slightly higher percentages of long-chain fatty acids
(20∶0, 20∶1, 22∶0 and 24∶0) were observed for lipid classes other than TAG in all four species. Based on the fatty acid composition
of the total lipids and of the different acyl lipid classes, it seems thatS. radiatum andS. angustifolium are more related to each other than they are to the other two species. 相似文献
18.
Cessation of polyunsaturated fatty acid formation in four selected filamentous fungi when grown on plant oils 总被引:6,自引:0,他引:6
Four fungi,Conidiobolus nanodes, Entomophthora exitalis, Mortierella isabellina, andMucor circinelloides, were grown on various oils (triolein, sesame, safflower, linseed, and oil fromM. isabellina) and produced lipids in which the fatty acids were predominantly the same as those of the original staring substrate. Only
in the first two cases was there evidence of a small amount of chain elongation and of fatty acid desaturation taking place.
The extent of this was only about 10% of that seen in glucose-grown cells. The apparent repression of the fatty acid desaturases
and elongases was not reversed by growing cells on glucose and oils as mixed substrates—the fatty acid profiles were the same
as when the fungi had grown in oils alone. Neither was the cessation of polyunsaturated fatty acid synthesis due to the presence
of nonoil components (NOC) in the oil. Only the NOC from sesame oil affected one single conversion, that of 20∶3n-3 to 20∶4n–6.
We conclude that fatty acid desaturase and elongase systems are repressed either partially or completely in a filamentous
fungi grown on triacylglycerol oils. 相似文献
19.
The pharmaceutically interesting Δ6-FA 18∶3Δ6c, 9c, 12c (γ-linolenic acid) and 18∶4Δ6c,9c,12c,15c (stearidonic acid) appear to have evolved independently several times during plant phylogenetic evolution. They typically
occur in “clusters” of a few closely related species or genera in about a dozen different plant families throughout the plant
kingdom. A hither-unknown “cluster of occurrence” has now been discovered in the New World plant family Loasaceae. γ-Linolenic
and stearidonic acids occur exclusively in representatives of the newly described genus Nasa at significance levels of between 3 and 10% each. Nasa had recently been separated from the older, more broadly circumscribed genus Loasa. The two Δ6-FA were not found in the closely related genus Loasa sensu stricto, nor in a number of other representatives of Loasaceae. 相似文献
20.
Rudrappa T Bonsall J Gallagher JL Seliskar DM Bais HP 《Journal of chemical ecology》2007,33(10):1898-1918
Phragmites australis is considered the most invasive plant in marsh and wetland communities in the eastern United States. Although allelopathy
has been considered as a possible displacing mechanism in P. australis, there has been minimal success in characterizing the responsible allelochemical. We tested the occurrence of root-derived
allelopathy in the invasiveness of P. australis. To this end, root exudates of two P. australis genotypes, BB (native) and P38 (an exotic) were tested for phytotoxicity on different plant species. The treatment of the
susceptible plants with P. australis root exudates resulted in acute rhizotoxicity. It is interesting to note that the root exudates of P38 were more effective
in causing root death in susceptible plants compared to the native BB exudates. The active ingredient in the P. australis exudates was identified as 3,4,5-trihydroxybenzoic acid (gallic acid). We tested the phytotoxic efficacy of gallic acid on
various plant systems, including the model plant Arabidopsis thaliana. Most tested plants succumbed to the gallic acid treatment with the exception of P. australis itself. Mechanistically, gallic acid treatment generated elevated levels of reactive oxygen species (ROS) in the treated
plant roots. Furthermore, the triggered ROS mediated the disruption of the root architecture of the susceptible plants by
damaging the microtubule assembly. The study also highlights the persistence of the exuded gallic acid in P. australis’s rhizosphere and its inhibitory effects against A. thaliana in the soil. In addition, gallic acid demonstrated an inhibitory effect on Spartina alterniflora, one of the salt marsh species it successfully invades.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献