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1.
The composition of the oils extracted from the acorn fruit of three species of Mediterranean oaks, Quercus ilex L., Q. suber L., and Q. faginea L., was characterized. Both major and minor components, including FA, TG, sterols, methyl sterols, triterpenic and aliphatic
alcohols, tocopherols, and hydrocarbons, were identified by standard methods and MS. High-resolution GLC and HPLC were used
for quantification. The FA profile, together with the equivalent carbon numbers and TG carbon numbers, was compared with data
for other edible vegetable oils. Oil yield, expressed as wet weight, was 5% (w/w). Sterol content was remarkable for the three
species (8,563–11,420 mg/kg), with β-sitosterol being the most abundant (80%). Oils were also high in tocopherol, with a wide
variation between species (165–456 mg/kg) but with γ-tocopherol predominating in all three oils (90% of the total tocopherol
content). Also, high terpenic alcohol contents were found (1527–2984 mg/kg), with dammaradienol and β-amyrin being the most
abundant (33–60% of the total alcohol content). Bioactive properties and industrial applications of this underutilized native
product are also discussed. 相似文献
2.
Chakra Wijesundera Claudio Ceccato Peter Fagan Zhiping Shen Wayne Burton Phil Salisbury 《Journal of the American Oil Chemists' Society》2008,85(8):693-699
Canola-quality Indian mustard (Brassica juncea) is being developed as a complimentary oilseed crop to canola (Brassica napus) for cultivation in hot and low-rainfall areas, where canola does not perform well. In Australia, several B. juncea breeding lines have been developed for commercial cultivation and for eventual processing as canola oil. However, there still
are significant species-based differences in the fatty acid composition with B. juncea containing lower levels of linoleic acid and higher levels of oleic and linolenic acids compared with B. napus. This has raised concern about possible oxidative stability differences between the oils. Oils (unrefined) extracted from
different breeding lines of each species were subjected to accelerated autoxidation, and development of oxidative rancidity
was assessed by four separate techniques: depletion of polyunsaturated fatty acids, depletion of tocopherol, development of
primary oxidation products, and development of secondary oxidation products (propanal and hexanal). All the tests showed that
the newly developed B. juncea oils are more stable to autoxidation than conventional canola (B. napus) oil, despite containing marginally higher linolenic levels. Oxidative stability does not appear to be a barrier to using
oils from these emerging lines of B. juncea for partial or full replacement of conventional canola oil. 相似文献
3.
Reaction selectivities were determined in multicompetitive reactions mediated by Burkholderia cepacia lipase (Amano PS-30) at a water activity of 0.19 in hexane. Saturated FA (C4–C18 even chain) and oleic acid (C18∶1) were
reacted with a single alcohol, glycerol, α-or β-MAG, containing C4, C10, C16, or C18∶1 individually as alcohol cosubstrate.
Similar odrinal patterns of FA selectivity, with C8, C10, and C16 preferred over others, were generally observed for incorporation
of FA into specific acylglycerol (AG) pools of the 24 specific cases evaluated. The three exceptions were enrichment of C14
and C18 in the MAG pool with α-C16-MAG, substrate, and a general suppression of >C8 incorporation into the TAG pool for reactions
with α-C10- and α-C16-MAG. PS-30 lipase selectivity toward MAG was in descending order: α/β-C4-MAG>β-C10-MAG>β-C16-MAG>α/β-C18∶1-MAG>α-C10-MAG>α-C16-MAG.
Selectivity in channeling CX of the original CX-MAG substrates into higher AG species was in descending order: α-C10-MAG∼α-C16-MAG>α-C18∶1-MAG>β-C10-MAG∼β-C16-MAG∼β-C18∶1-MAG
>α/β-C4-MAG. Generally, MAG were better acyl donors than FA for esterification reactions leading to DAG formation. These observations
are relevant to the design of biocatalytic processes intended to yield specifically structured TAG. 相似文献
4.
Néstor M. Carballeira Michelle Cartagena Deniz Tasdemir 《Journal of the American Oil Chemists' Society》2008,85(7):605-611
This study describes work aimed at the rapid evaluation of the fatty acid (FA) composition of Turkish Rhododendron species, particularly the leaves and the flowers of the toxic plants, R. ponticum and R. luteum. The FA profiles of the available parts of three other nonpoisonous Rhododendron species were also investigated. Subtotal extracts obtained (using n-hexane, chloroform and methanol) from total chloroform:methanol (1:1) extracts were analyzed and compared to each other.
Palmitic acid was found to be the most abundant FA in almost all Rhododendron extracts, and the majority of leaf and flower extracts contained significant portions of C18 unsaturated FAs (18:1n-9, 18:2n-6,
18:3n-3). The n-hexane extracts of R. ponticum leaves and R. luteum flowers were unique, as they contained an unusual series of even-chain iso FAs (C16–C24). Especially the n-hexane extracts were found to comprise uncommon FAs with odd-numbered carbons (C13–C29). Overall, n-hexane proved to be the best solvent by representing the richest FA profile, whereas chloroform or methanol appeared less
suitable for FA analyses. Appreciable intra-species variations in FA compositions among the leaves as well as other anatomical
parts examined were observed. This study highlights the chemotaxonomical importance of the FAs for the genus Rhododendron. 相似文献
5.
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
6.
Hiromi Yoshida Yuka Tomiyama Masayuki Saiki Yoshiyuki Mizushina 《Journal of the American Oil Chemists' Society》2007,84(11):1031-1038
The positional distribution of fatty acids (FA) of triacylglycerols (TAG) and major phospholipids (PL) prepared from four
cultivars of peas (Pisum sativum L.) were investigated as well as their tocopherol contents. The lipids extracted from these peas were separated by thin-layer
chromatography (TLC) into seven fractions. The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while the
other components were also present in minor proportions (5.6–9.2%). γ-Tocopherol was present in the highest concentration,
and α- and δ-tocopherols were very small amounts. The main PL components isolated from the four cultivars were phosphatidylcholine
(42.3–49.2%), followed by phosphatidylinositol (23.3–25.2%) and then phosphatidylethanolamine (17.7–20.5%). Small but significant
differences (P < 0.05) in FA distribution existed when different pea cultivars were determined. However, the principal characteristics of
the FA distribution in the TAG and the three PL were evident among the four cultivars; unsaturated FA were predominantly located
in the sn-2 position, and saturated FA primary occupied the sn-1 or sn-3 position in the oils of the peas. These results suggest that the regional distribution of tocopherols and fatty acids in
peas is not dependent on the climatic conditions and the soil characteristics of the cultivation areas during the growing
season. 相似文献
7.
The contents of total trans FA of sunflower oils at different stages of refining processes were determined by capillary GLC. The contents of 18∶1, 18∶2,
and 18∶3 trans acids were 0.22±0.03, 2.31±0.23, and 0.03±0.01%, respectively, in physically refined sunflower oils, and 0.05±0.01, 0.69±0.26,
and 0.02±0.01%, respectively, in chemically refined sunflower oils. The total trans FA contents drastically increased at the end of the physical refining process. The total trans FA contents of chemically refined sunflower oils were <1%. Because of the high temperature applied in the last stage of physical
refining, the content of total trans FA was higher than in chemically refined sunflower oils. The last-stage conditions should be carefully evaluated to reduce
the formation of trans FA during physical refining. 相似文献
8.
Abdalbasit Adam Mariod Bertrand Matthäus I. H. Hussein 《Journal of the American Oil Chemists' Society》2009,86(9):857-865
This study investigated the fatty acid, tocopherol, sterol and total phenolic compounds of Salvadora percica seeds as well as the potential antioxidant activity of the leaves, bark and seedcake extracts. Two samples of S. persica seed collected from Kordofan (sandy soil) and Gezira (heavy clay soil) states in Sudan were used. The predominant fatty acids
were 14:0, 16:0 and 18:1 representing 45.50, 35.12 and 10.20% for Kordofan and 45.20, 34.49 and 10.66% for Gezira samples.
Gamma-tocopherol was the predominant tocopherol in both samples representing 61.3 and 61.7% of the total tocopherols, respectively,
followed by α-tocopherol at 21.1 and 20.2%, respectively. Total sterol content was 3399.6 and 3385.3 mg/kg for Kordofan and
Gezira samples, respectively. Beta-sitosterol, campesterol, stigmasterol and Δ5-avenasterol were predominant. The content
of total phenolic compounds was determined in S. persica bark (SPB), S. persica leaves (SPL), and S. persica seedcake (SPC) extracts of each sample according to the Folin–Ciocalteau method as 111.70, 132.60, and 66.10 mg GAE/g extract
for the Kordofan sample. They were found to be 105.90, 129.10 and 62.90 mg GAE/g extract in the Gezira sample, respectively.
The two samples were significantly (P < 0.05) different in total phenolic content with SPL as the highest in both samples. The methanolic extracts of SPL, SPB, and
SPC in both samples were markedly effective in inhibiting the oxidation of linoleic acid and subsequent bleaching of β-carotene
in comparison with the control. But they were less effective than butylated hydroxyanisole. 相似文献
9.
Sequestration of Furostanol Saponins by <Emphasis Type="Italic">Monophadnus</Emphasis> Sawfly Larvae
Prieto JM Schaffner U Barker A Braca A Siciliano T Boevé JL 《Journal of chemical ecology》2007,33(3):513-524
Sawfly larvae of the tribe Phymatocerini (Hymenoptera: Tenthredinidae), which are specialized on toxic plants in the orders
Liliales and Ranunculales, exude a droplet of deterrent hemolymph upon attack by a predator. We investigated whether secondary
plant metabolites from Ranunculaceae leaves are sequestered by phymatocerine Monophadnus species, i.e., Monophadnus alpicola feeding upon Pulsatilla alpina and Monophadnus monticola feeding upon Ranunculus lanuginosus. Moreover, two undescribed Monophadnus species were studied: species A collected from Helleborus foetidus and species B collected from Helleborus viridis. Comparative high-performance liquid chromatographic–photodiode array detection–electrospray ionization–mass spectrometric
analyses of plant leaf and insect hemolymph extracts revealed the presence of furostanol saponins in all samples. Larvae of
species A and B actively sequestered (25R)-26-[(α-l-rhamnopyranosyl)oxy]-22α-methoxyfurost-5-en-3β-yl O-β-d-glucopyranosyl-(1→3)-O-[6-acetyl-β-d-glucopyranosyl-(1→3)]-O-β-d-glucopyranoside (compound 1). This compound occurred at a 65- to 200-fold higher concentration in the hemolymph of the two species (1.6 and 17.5 μmol/g
FW, respectively) than in their host plant (0.008 and 0.268 μmol/g FW, respectively). In M. monticola, compound 1 was found at a concentration (1.2 μmol/g FW) similar to that in the host plant (1.36 μmol/g FW). The compound could not be
detected consistently in M. alpicola larvae where, however, a related saponin may be present. Additional furostanol saponins were found in H. foetidus and H. viridis, but not in the two Monophadnus species feeding on them, indicating that sequestration of compound 1 is a highly specific process. In laboratory bioassays, crude hemolymph of three Monophadnus species showed a significant feeding deterrent activity against a potential predator, Myrmica rubra ant workers. Isolated furostanol saponins were also active against the ants, at a concentration range similar to that found
in the hemolymph. Thus, these compounds seem to play a major role for chemical defense of Monophadnus larvae, although other plant secondary metabolites (glycosylated ecdysteroids) were also detected in their hemolymph. Physiological
and ecological implications of the sequestered furostanol saponins are discussed.
Dedicated to the memory of Professor Ivano Morelli (1940–2005) 相似文献
10.
Members of the Daphne genus have been of interest owing to their excellent medicinal value. In this work, we describe the results of phytochemical
analysis and the antioxidant activity of the methanol extracts from leaves and stems of D. gnidium L. grown wild in Sardinia, Italy. Four coumarins (daphnetin, daphnin, acetylumbelliferon, and daphnoretin), nine flavonoids
(apigenin, luteolin, quercetin, orientin, isoorientin, luteolin 7-O-glucoside, apigenin 7-O-glucoside, genkwanin, and 5-O-β-d-primeverosyl genkwanine), and α-tocopherol were isolated. We investigated the ability of the two extracts and five pure compounds
(daphnetin, daphnoretin, apigenin, luteolin, and α-tocopherol) to protect linoleic acid against free radical attack in simple
in vitro systems by autoxidation and iron- or EDTA-mediated oxidation. Pure compounds were the most active antioxidants. During autoxidation,
daphnetin, luteolin, and α-tocopherol were effective at a molar ratio of 1∶1600, 1∶2500, and 1∶2000, respectively. Daphnoretin
was active only at high concentrations. During the iron-catalyzed oxidation of linoleic acid, all the materials tested showed
activity in the following order: luteolin>daphnetin>α-tocopherol >leaf extract>stem extract>daphnoretin. Apigenin was not
active in any of the experimental systems used. 相似文献
11.
Reaction selectivities were determined in multicompetitive reactions mediated by Rhizomucor miehei (RM) lipase at water activity of 0.19 in hexane. Saturated FA (C4–C18 even chain) and oleic acid (C18∶1) were reacted with
a single alcohol, glycerol, or α-or β-MAG containing C4, C10, C16, or C18∶1 individually as alcohol cosubstrate. Similar patterns
of broad FA selectivity toward C8–C18 FA were generally observed for esterification into specific acylglycerol (AG) pools
with the different α/β-CX-MAG cosubstrates. Exceptions were enrichment of C18 in the MAG pool with α-C16-MAG substrate, and
a general suppression of C4/C6 FA reactivity and a specific discrimination toward >C8 FA incorporation into the TAG pool,
both for reactions with α-C10- and α-C16-MAG. RM lipase selectivity toward MAG was in descending order: β-C18∶1-MAG>α/β-C4-MAG∼β-C10-MAG∼β-C16-MAG>α-C18∶1-MAG
>α-C10-MAG∼α-C16-MAG. Selectivity in channeling CX of the original CX-MAG substrates into higher AG species was in descending
order: α-C10-MAG∼α-C16-MAG>β-C10-MAGβ-C16-MAG>α-C18∶1-MAG>β-C18∶1-MAG∼ α/β-C4-MAG. Aside from their characteristic FA selectivity,
Burkholderia cepacia (PS-30) and RM lipases behaved similarly in terms of MAG selectivity as well as a general conservation of FA selectivity
throughout the sequential steps of TAG assembly from FA and glycerol for processes designed to yield specifically structured
TAG. 相似文献
12.
The purification of tocopherols and phytosterols (referred to as sterols) from soybean oil deodorizer distillate (SODD) was
attempted. Tocopherols and sterols in the SODD were first recovered by short-path distillation, which was named sODD tocopherol/sterol
concentrate (SODDTSC). The SODD-TSC contained MAG, DAG, FFA, and unidentified hydrocarbons in addition to the two substances
of interest. It was then treated with Candida rugosa lipase to convert sterols to FA steryl esters, acylglycerols to FFA, and FFA to FAME. Methanol (MeOH), however, inhibited
esterification of the sterols. Hence, a two-step in situ reaction was conducted: SODDTSC was stirred with 20 wt% water and 200 U/g mixture of C. rugosa lipase at 30°C, and 2 moles of MeOH per mole of FFA was added to the reaction mixture after 16h. The lipase treatment for
40 h in total achieved 80% conversion of the initial sterols to FA steryl esters, complete hydrolysis of the acylglycerols,
and a 78% decrease in the initial FFA content by methyl esterification. Tocopherols did not change throughout the process.
To enhance the degree of steryl and methyl esterification, the reaction products, FA steryl esters and FAME, were removed
by short-path distillation, and the resulting fraction containing tocopherols, sterols, and FFA was treated with the lipase
again. Distillation of the reaction mixture purified tocopherols to 76.4% (recovery, 89.6%) and sterols to 97.2% as FA steryl
esters (recovery, 86.3%). 相似文献
13.
This study utilized γ-linolenic acid (18∶3n−6; GLA)-rich borage oil (BO) and evening primrose oil (EPO) for the synthesis
of structured lipids (SL) and compared the oxidative stability of the products with those of unmodified BO and EPO as controls.
Immobilized Novozym 435 lipase from Candida antarctica was used as the biocatalyst for SL production. BO or EPO eas enzymatically modified with docosahexaenoic acid (22∶6n−3; DHA),
as the acyl donor, to produce SI. The SI were characterized and their oxidative stabilities evaluated. Among the oils examined,
SL gave rise to higher quantities (P≤0.05) of conjugated dienes, TBARS, and headspace volatiles as compared to their unmodified counterparts. Results indicated
that modified oils were less stable than their unmodified counterparts. The double bond index (DBI) and methylene bridge index
(MBI) of oils decreased (P<0.05) during oxidation in the more unsaturated oils. An attempt was made to correlate various parameters of oxidation with
DBI and MBI of oils; correlation coefficients (−r) were within the range of 0.574–0.973. This suggests that indicators such as DBI and MBI can reflect oxidative stability
of oils. 相似文献
14.
The seeds of cultivated Hibiscus spp. were extracted with supercritical carbon dioxide, and the resulting extracts were analyzed to identify the major TG
components as the corresponding FAME. The seed oils were composed predominantly of oleic and linoleic FA (69.6–83.4%) with
lesser amounts of palmitic acid (14.8–27.0%). Minor amounts of C14, C18, and C20 saturated FA were also detected. The oil
content of the seeds was determined to be between 11.8 and 22.1 wt% for hybrid varieties and between 8.9 and 29.5 wt% for
the native species from which the hybrid varieties were developed. The protein content of the defatted seed meal averaged
20% for the hybrid varieties. The composition of the extracted hibiscus seed oils suggests potential edible applications. 相似文献
15.
The FA composition in the sn-2 position of TAG is routinely determined after porcine pancreatic lipase hydrolysis. However, the content of saturated FA
increased when a pancreatic lipase preparation with higher specific activity was used. Lipase from Rhizopus delemar was selected as a potential replacement lipase for the following reasons: (i) The FA specificity is nearly equivalent in
hydrolysis activity toward FA such as lauric, myristic, palmitic, palmitoleic, stearic, oleic, linoleic, and α-linolenic acids;
and (ii) lipase from R. delemar hydrolyzes fatty acyl residues at the sn-1,3 positions of TAG. Acyl migration products were present at less than 0.8% in lipase hydrolysates containing 6–14% of sn-2 MAG. A reproducibility CV of less than 5% was obtained in a collaborative study in which the compositions of the main FA
at the sn-2 position in olive oil were determined using lipase from R. delemar.
This article was presented in part at the Biocatalysis Symposium, 94th AOCS Annual Meeting & Expo, Kansas City, Missouri,
May 2003. 相似文献
16.
Marine lipid-based liposomes increase <Emphasis Type="Italic">in vivo</Emphasis> FA bioavailability 总被引:1,自引:0,他引:1
Liposomes made from an extract of natural marine lipids and containing a high n-3 PUFA lipid ratio were envisaged as oral
route vectors for FA supplements in order to increase PUFA bioavailability. The absorption of FA in thoracic lymph duct-cannulated
rats, after intragastric feeding of dietary fats in the form of liposomes or fish oil, was compared. Lipid and FA analyses
were also performed on feces. Five mole percent α-tocopherol was added to fish oil and incorporated into the liposome membrane.
The influence of α-tocopherol on FA lymph recovery was also investigated. In vivo, FA absorption in rats was favored by liposomes (98±1%) compared to fish oil (73±6%). In the same way, the DHA proportion
in lymph was higher after liposome ingestion (78%) than after fish oil ingestion (47%). However, phospholipid (PL) concentration
in lymph was not affected by the kind of dietary fat ingested, suggesting a PL regulation due to de novo TAG synthesis. The influence of the intramolecular distribution of n-3 PUFA in dietary lipids (TAG and PL) on the intramolecular
FA distribution in TAG of chylomicrons was also investigated. The results obtained showed that the distribution of n-3 PUFA
esterified on the sn-2 of chylomicron TAG depended on the lipid source administered. All these results correlated, at least partly, with in vitro liposome behavior under conditions that mimic those of the gastrointestinal tract. As a whole, this study pointed out that
marine PL may constitute an attractive material for the development of liposomes as oral PUFA supplements. 相似文献
17.
J. C. Evans D. R. Kodali P. B. Addis 《Journal of the American Oil Chemists' Society》2002,79(1):47-51
The optimal concentration for tocopherols to inhibit soybean oil oxidation was determined for individual tocopherols (α-,
γ-, and δ-tocopherol) and for the natural soybean oil tocopherol mixture (tocopherol ratio of 1∶13∶5 for α-, γ-, and δ-tocopherol,
respectively). The concentration of the individual tocopherols influenced oil oxidation rates, and the optimal concentrations
were unique for each tocopherol. For example, the optimal concentrations for α-tocopherol and γ-tocopherol were ∼100 and ∼300
ppm, respectively, whereas δ-tocopherol did not exhibit a distinct concentration optimum at the levels studied (P<0.05). The optimal concentration for the natural tocopherol mixture ranged between 340 and 660 ppm tocopherols (P<0.05). The antioxidant activity of the tocopherols diminished when the tocopherol levels exceeded their optimal concentrations.
Above their optimal concentrations, the individual tocopherols and the tocopherol mixture exhibited prooxidation behavior
that was more pronounced with increasing temperature from 40 to 60°C (P<0.05). A comparison of the antioxidant activity of the individual tocopherols at their optimal concentrations revealed that
α-tocopherol (∼100 ppm) was 3–5 times more potent than γ-tocopherol (∼300 ppm) and 16–32 times more potent than δ-tocopherol
(∼1900 ppm). 相似文献
18.
Jazia Sriti Wissem Aidi Wannes Thierry Talou Baya Mhamdi Muriel Cerny Brahim Marzouk 《Journal of the American Oil Chemists' Society》2010,87(4):395-400
Coriander (Coriandrum sativum L.) seeds were harvested from the region of Korba (North-East Tunisia) in order to characterize their fatty acids, phytosterols,
tocopherols and tocotrienols (tocols) profiles. Nine fatty acids, with petroselinic acid accounting for 76.6% of the total
fatty acids, followed by linoleic, oleic and palmitic acids, accounting for 13.0, 5.4 and 3.4%, respectively, of the total
fatty acids were identified. Neutral lipids (NLs) were mainly composed of triacylglycerols (98.4%). Polar lipids were mainly
composed of phosphatidylcholine as the major phospholipid (PL) subclass, whereas digalactosyldiacylglycerol was the major
galactolipid (GL). Total sterols content was estimated to be 36.93 mg/g oil. Stigmasterol accounted for 29.5% of the total
sterols. Other representative sterols were β-sitosterol, Δ7-stigmasterol and Δ5, 24-stigmastadienol, which accounted for 24.8, 16.3 and 9.2%, respectively. Gamma-tocotrienol was the predominant tocol at
238.40 μg/g seed oil. This was equivalent to 72.8% of the total tocols followed by γ-tocopherol (8.06%) and α-tocopherol (7.6%). 相似文献
19.
Synthesis of FAME from Brassica carinata oil to produce biodiesel was accomplished using potassium hydroxide as the catalyst. A factorial design of experiments and
a central composite design were used. The variables chosen were: type of Brassica carinata oil, initial catalyst concentration, and temperature; and the responses were FAME purity and yield. The type of B. carinata oil included high-erucic B. carinata (HEBC) and lowerucic B. carinata (LEBC) varieties. The results show that the type of B. carinata oil does not affect the purity and yield of FAME. However, HEBC oil is more suitable for biodiesel production because its
iodine value is lower and within the European Union specifications. The initial catalyst concentration is the most important
factor, having a positive influence on FAME purity but a negative effect on FAME yield. The temperature has a significant
positive effect on FAME purity and a significant negative influence on FAME yield. Second-order models were obtained to predict
FAME purity and yield as a function of catalyst concentration and temperature for HEBC oil methanolysis. The best conditions
for this process are 25°C, and 1.2–1.5 wt% for the catalyst concentration. 相似文献
20.
The pinewood nematode (PWN), Bursaphelenchus xylophilus, the most important invasive species in pine forests of Asia, is transported to new pine hosts by beetles of the genus Monochamus. Third-stage dispersal juveniles (JIII) aggregate in pupal chambers around the vector as it matures. We demonstrated that the ratio of three terpenes (α-pinene,
β-pinene, and longifolene at 1:2.7:1.1) released by larval Monochamus alternatus strongly attract JIII, whereas the different ratio (1:0.1:0.01) of these three terpenes found in healthy xylem of Pinus massoniana attracts only the propagative stage (Jn) of the nematode. We suggest that the volatiles produced by the host plants could be the basis of a chemoecological relationship
between plant parasitic nematodes and their vector insects. Capture of JIII with terpene-baited trap tubes deployed for 2 hr in the field was demonstrated. This technique may lead to the development
of rapid sampling methodologies for use at either ports-of-entry or in the field. 相似文献