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1.
Cortical oleoresins from 352 Abies magnifica and A. procera trees, collected in 35 localities, were analysed for composition of their monoterpene fractions. The monoterpenes were composed primarily of -pinene, β-pinene, limonene and β-phellandrene, with camphene and 3-carene appearing only sporadically in larger amounts. Limonene, β-phellandrene, -pinene and 3-cerene were used to study the transitional populations in northern California and southern and central Oregon and the transitional-like populations in southern Sierra Nevada. The populations segregated latitudinally into three related clusters—above 44° (A.procera), between 44° and 40° (transitional), and below 40° (A.magnifica). A.magnifica from southern Sierra Nevada and A.magnifica from Mtn. Shasta differed in a number of parameters, with southern Sierra Nevada populations being chemically much closer to typical A. magnifica from central and northern Sierra Nevada. While monoterpene and morphological data did not allow a clear Interpretation of the status of the transitional and southern populations, the paleobotanical evidence favored the recent evolution over introgression. The desirability of additional studies was indicated.  相似文献   

2.
Variation of terpenes and resin acids in needles of young Scots pine (Pinus sylvestris L.) seedlings from nine different provenances in Turkey was investigated. The provenances represent 1200-km West to East and 400-km South to North transects. Seven monoterpenes and two sesquiterpenes were reported in the needles of pines studied. Generally, the kinds of terpenes were similar but the relative amount of some compounds differed among the origins. The major components of the monoterpene fraction in Turkish sources were α-pinene (84.8%), β-pinene (4.1%) and limonene (3.0%), corresponding to 91.9% of the crude needle extract. In a PCA-analysis, 3-carene, myrcene and terpinolene in seedlings from Turkish provenances were quite low and thus, they were clearly different from a Northern European Scots pine provenance from Finland. In the resin acid fraction, abietic acid (62.4%) and dehydroabietic acid (16.1%) were the most abundant constituents in the needles of the Scots pine from Turkish provenances.  相似文献   

3.
The impact of spruce spider mite (SSM) (Oligonychus ununguis Jacobi, Acari: Tetranychidae) feeding on needle compounds of young dwarf white spruce (Picea glauca ‘Conica’), important in defence against pests, was determined. It was shown that the direction and intensity of changes in chemical composition of spruce needles was related to the density of spruce spider mite population. Relative to uninfested controls, needles of trees infested by 2–6 mites per 5 cm oftwig during 8 weeks contained markedly higher concentration of soluble proteins, total phenolics and essential oil volatiles (linalool, β-phellandrene, β-myrcene, δ-3-carene, p-cymene, limonene, α-pinene, β-pinene, borneol, methyl salicylate, geranyl acetate). Feeding of a three times larger population of mites (18 specimens per 5 cm of twig) caused either reduction of concentration of those compounds, or no significant difference in comparison to the control. The results of our study show that O. ununguis at relatively low density (not exceeding 2–6 specimens per 5 cm of twig per 8 weeks) stimulates even susceptible host-plant to alter metabolism, however induced responses are suppressed as mite density increases. Findings are discussed in relation to the importance of changes in the concentration of needle primary and secondary metabolites to white spruce defence against O. ununguis.  相似文献   

4.
Aureobasidium pullulans grown on arabinoxylan accumulates β-xylanase, p-nitrophenyl xylosidase, - -arabinofuranosidase and acetyl esterase activity in the culture fluid. The pH and temperature optima of these arabinoxylan-degrading enzymes were determined. The temperature optima of β-xylanase and p-nitrophenyl xylosidase were between 45 and 50°C whereas the optima for acetyl esterase and - -arabinofuranosidase were 55 and 60°C, respectively. β-xylanase, p-nitrophenyl xylosidase and - -arabinofuranosidase were stable over 3 h at 35°C, 35°C and 60°C, respectively, whereas acetyl esterase remained stable at 55°C for h. The enzymes were inactivated at higher temperatures. The pH optima for β-xylanase, p-nitrophenyl xylosidase and - -arabinofuranosidase were pH 4·0, between 4·0 and 7·0 and 5·0, respectively. β-xylanase, p-nitrophenyl xylosidase, - -arabinofuranosidase and acetyl esterase were most stable at pH 5·0 4·0–5·0, 6·0 and 5·0–6·0, respectively. The most suitable conditions for the use of the enzymes together to hydrolyze arabinoxylan would be 35 °C and pH 5.  相似文献   

5.
油松萜烯成分变化与红脂大小蠹的反应特性   总被引:1,自引:0,他引:1  
采用顶空采样方法,比较健康油松、人工损伤油松以及抗性油松在单萜烯成分组成上的差异。GC-MS分析表明,在自然状况下,油松树干释放的萜烯类成分很少,以α-蒎烯占绝对优势(>97%);人工损伤后,油松萜烯类成分明显增多,除α-蒎烯为主要成分外,还包括β-蒎烯、月桂烯、柠檬烯、萜品油烯、β-水芹烯、长叶烯等;而抗性油松萜烯类成分更为复杂。对3类油松主要单萜类成分的相对含量方差分析表明,α-蒎烯的相对含量呈显著降低;3-蒈烯在损伤寄主中相对含量最高,在抗性寄主中相对含量与自然状态下没有差异。柠檬烯、莰烯、萜品油烯在抗性寄主中相对比率显著增加。而β-蒎烯、月桂烯、β-水芹烯相对含量在3个处理中变化不大。在此基础上,比较红脂大小蠹Dendroctonus valens LeConte对油松主要单萜类成分的触角电位及嗅觉行为反应。结果表明,室内触角电位、嗅觉试验与先前林间试验结果相一致,即红脂大小蠹对(+)-3-蒈烯表现出最强的电生理和行为反应。对R-(+)-α-蒎烯和S-(-)-α-蒎烯研究发现,红脂大小蠹对α-蒎烯2个对映体的触角电位、嗅觉行为无显著不同。结合油松单萜类含量变化特点与红脂大小蠹行为反应,认为3-蒈烯相对含量上升可能作为易感寄主特点;而柠檬烯、莰烯、萜品油烯相对比率增加则代表了抗性或者非适合寄主的特征。  相似文献   

6.
Sweet basil (Ocimum basilicum L.), one of the most popular aromatic plants, shows great variation in both morphology and essential oil components. In this study, the composition of 18 Turkish basil essential oils was investigated by GC and GC–MS. Variation of essential oils in the landraces was subjected to cluster analysis, and seven different chemotypes were identified. They were (1) linalool, (2) methyl cinnamate, (3) methyl cinnamate/linalool, (4) methyl eugenol, (5) citral, (6) methyl chavicol (estragol), and (7) methyl chavicol/citral. Methyl chavicol with high citral contents (methyl chavicol/citral) can be considered as a “new chemotype” in the Turkish basils. Because methyl eugenol and methyl chavicol have structural resemblance to carcinogenic phenylpropanoids, chemotypes having high linalool, methyl cinnamate or citral contents and a mixture of these is suitable to cultivate for use in industry.  相似文献   

7.
The chemical composition of essential oil samples from needles of six species of five-needle pines (Pinus pumila, Pinus sibirica, Pinus parviflora, Pinus armandii, Pinus koraiensis, and Pinus cembra) and one natural interspecific hybrid Pinus sibirica × Pinus pumila has been studied by the chromato-mass spectrometry method. Essential oils have been prepared by simultaneous steam distillation-extraction. The analysis of the samples?? composition showed that the main constituents of the essential oils were the following mono- and sesquiterpenic compounds: ??-pinene (5?C63%), camphene (0.7?C3.6%), ??-pinene (0.7?C7%), ??-myrcene (0.5?C3.4%), 3-carene (0?C16%), limonene (0.6?C7.9%), ??-phellandrene (0.7?C5.3%), terpinolene (0.4?C6.7%), bornyl acetate (0.2?C12%), ??-terpenyl acetate (0?C4.6%), caryophyllene (0.4?C24%), humulene (0.1?C4%), germacrene D (0.1?C24%), bicyclogermacrene (0.1?C3.6%), ??-cadinene (0.9?C2.3%), ??-cadinene (2.2?C6.1%), germacrene D-4-ol (0?C6.8%), T-cadinol (0.7?C2.9%), and ??-cadinol (0.7?C6.0%).  相似文献   

8.
Starch-poly (ethylene-co-acrylic acid) (EAA) complexes were prepared by jet-cooking mixtures of either cornstarch, waxy cornstarch or high amylose cornstarch with aqueous ammonia dispersions of EAA (4% EAA based on the weight of starch). Viscosities (η) were determined at temperatures ranging from 80°C to 22°C, and plots of log η versus 1/T (K−1) were prepared. When cooked with EAA, cornstarch and waxy cornstarch showed major changes in viscous behavior between 50°C and 60°C. Above 50–60°C, viscosity increased markedly with a reduction in temperature; however, viscosity increased slowly below 50–60°C with an apparent activation energy for the process approximating that of water itself. The temperature dependence of the measured viscosity from 80°C to 60°C could be attributed to the large increase in size and complexity of the flowing particles as individual amylopectin molecules were bound together by complexed EAA. Apparently, complexing is essentially complete at 50°C. When high amylose cornstarch was cooked in the absence of EAA, retrogradation produced a sharp increase in log η at temperatures below about 50°C. However, if EAA is present, association between amylose molecules apparently takes place via complex formation rather than retrogradation, since log η increases sharply at about 70–80°C. Also, in contrast to cornstarch and waxy cornstarch, log η versus 1/T plots for high amylose cornstarch did not level off at low temperatures. In general, viscosities increased with the pH of the system, particularly when η was measured at high temperatures. This could result from improved complexing ability of EAA under high pH conditions, possibly due to reduced micelle size and maximum extension of polymer chains from micelle surfaces.  相似文献   

9.
Monoterpene hydrocarbons from phloem and cortex of sixty-eight trees of Abies lasiocarpa var. lasiocarpa and var. arizonica were analysed by GLC. While the same terpenes were present in either bark tissue, cortical terpenoids were found to be higher in limonene, but lower in -pinene, β-pinene, 3-carene and myrcene. Statistical calculations indicated that although control of terpene levels by the plant was generally similar in cortex and phloem, small but definite differences were present in some instances. It is concluded that the two oleoresins should be analysed separately in chemosystematic work.  相似文献   

10.
This short paper presents preliminary results on the ‘zero-shear’ specific viscosity ηsp0 of a commercial hydroxyethylmethylcellulose (Tylose MH-4000) in water, at the temperatures 10, 25 and 40·5°C, over a wide range of concentrations. At the two higher temperatures, two regions are found in the plot of logC[η]0 against logηsp0 with a C*[η]0 value of about 2·5. This is consistent with the behaviour of other random-coil polymers. At 10°C however, there is an interesting ‘upward shift’ in this plot in the dilute region. It is suggested that this is related to the different degree of hydration of the oligo(ethyleneoxide) side chains at this temperature.  相似文献   

11.
Summary Monoterpenes in needles of Picea abies (L.) Karst. were studied to reveal whether or not the symptoms of forest decline observed in three mountain regions of South Germany (Bavaria) — needle loss and needle yellowing — are related to changes in the amounts of all or individual terpenes. The nutrient supply of the needles was examined in addition to the terpene concentrations, since the disease symptom montane yellowing is often associated with mineral deficiency. At two of the eight locations, trees exhibited Mg-deficiency, at one location K-deficiency was observed, and at another location the S-content of the needles indicated SO2-pollution. Using various statistical methods of analysis, no correlation was observed between the mineral element content of the needles, the percentage of needle loss and either the absolute or percentile terpene amounts stored within the needles. This finding is independent of needle age, date of sampling and terpene pattern. Concerning needle yellowing, the data show a tendency towards a reduction of the terpene concentrations in needles originating from branches with partly yellow needles compared to needles from exclusively green-needled branches. In spite of the fact that only 2-year-old and older needles show the disease symptom of yellowing, the terpene level is reduced even in still green, juvenile and 1-year-old needles. No terpene was found to be an indicator for early recognition of injury.  相似文献   

12.
Two new copper(II) complexes, Cu(L1)(ClO4)2 (1), {[(μ-oxalate)Cu(L1)] · 5H2O}n (2), and a zinc(II) complex, {[(μ-oxalate)Zn(L2)] · 3H2O · 0.5DMF}n (3) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane), have been synthesized and characterized by X-ray crystallography. In 1, the ligand conformation is planar, and the octahedral coordination about the copper(II) ion is completed by weakly interacting ions. In 2 and 3, bridging oxalate ligands coordinate to copper(II) or zinc(II) ions in an unusually twisted bis-monodentate (trans-1,1′-bicoordination) mode.

The rigidity and steric hindrance of macrocycles L1 and L2 by the introduction of two cyclohexane rings and methyl groups on a cyclam (1,4,8,11-tetraazacyclotetradecane) skeleton cause the bridging oxalate ligands to adopt such unusual geometries in 2 and 3.  相似文献   


13.
用马尾松老叶、新叶,湿地松老叶、新叶,当年生马尾松新叶、湿地松新叶和当年生以20%和40%β-蒎烯处理过的马尾松新叶作食料饲养马尾松毛虫。结果表明:马尾松毛虫幼虫在第1代发生期取食马尾松老叶、马尾松新叶、湿地松老叶和湿地松新叶等4种不同质量的食料后,因其食料中10种必需氨基酸含量和挥发性物质β-蒎烯含量的不同,导致幼虫的存活率差异显著。其中,取食马尾松老叶的幼虫成活率最高(44%),依次为马尾松新叶(32.7%)、湿地松老叶(4%),而取食湿地松新叶的幼虫全部死亡。通过马尾松针叶增加外援β-蒎烯喂养马尾松毛虫实验,表明增加了外源β-蒎烯的松针饲养的马尾松毛虫幼虫与用同样松针未增加外源β-蒎烯饲养的幼虫相比,死亡率明显提高;松树中β-蒎烯含量的增加与幼虫成活率呈显著负相关。由此,我们阐明了马尾松与湿地松对马尾松毛虫的抗虫机制。  相似文献   

14.
Physicochemical properties of native and dilute acid pretreated (0.6% H2SO4, 10 min, and either 170°C or 180°C) poplar were investigated before and during simultaneous saccharification and fermentation (SSF). SSF duration was 5 days and employed Trichoderma reesei cellulases and Saccharomyces cerevisiae fermentation. Chemical composition (glucan, xylan, lignin), enzyme-accessible surface area (based on solute exclusion), crystallinity index, particle size distribution, particle shape, and enzyme adsorption (cellulase, β-glucosidase) were compared to cellulose conversion. Cellulose conversion varied from 8% for native poplar to 78% for the 180°C-pretreated poplar. The physicochemical properties of native poplar changed little during SSF. In contrast, the physicochemical properties of the 180°C-pretreated feedstock changed markedly. Enzyme-accessible surface area and β-glucosidase adsorption increased by 83% and 65%, respectively, as cellulose was removed from the feedstock. Crystallinity index and particle size (large fraction) decreased by 65% and 93%, respectively. Cellulase adsorption per unit weight increased initially (+45%) followed by a slight decrease (−13%). The same trends were observed, although to a lesser extent, for 170°C-pretreated feedstock.  相似文献   

15.
茴香菖蒲精油化学成分的研究   总被引:3,自引:0,他引:3  
程菊英  唐改福   《广西植物》1985,(1):38-42
利用色谱—质谱联用方法,结合薄层层析、气相层析、红外和核磁共振光谱等鉴定了茴香菖蒲全株的精油成分为:α-派烯,β-水芹烯,伪柠檬烯,异龙脑,胡椒酚甲醚,大茴香脑,榄香烯,β-石竹烯等17种以上。为进一步开发利用茴香菖蒲精油提供科学依据。  相似文献   

16.
Partial hydrolysates of (1→3)(1→4)-β- -glucan from oats were produced by three hydrolysis methods: acid, cellulase or lichenase. The molecular weights ranged from 31 000 to 237 000 g/mol. Six percent solutions of small molecular weight β-glucans formed elastic gels after 4 days at 4 °C whereas larger molecular weight β-glucans remained viscous liquids after 7 days. The melting temperature of the gels increased as they aged and the peak heat flow temperature, measured by differential scanning calorimetry, was 62±2 °C. Partial hydrolysates produced with cellulase, which was shown to preferentially cleave regions of the molecule with longer contiguous β-(1→4)-linked -glucopyranosyl units, tended to produce more elastic gels with stronger junction zones than partial hydrolysates produced with lichenase which cleaves the β-(1→4) glycosidic 3-o-substituted glucose links. This suggests that β-(1→3)-linked cellotriose sections of the polymer are probably the segments which form the junction zones in the gel network rather than cellulose-like segments.  相似文献   

17.
Wetting of the upper needle surface of Abies grandis Lindl. by aqueous solutions of different pH values was investigated. With increasing needle age, contact angles decreased significantly from about 75° on current-year needles to values lower than 30° on 4-year-old needles. On older needles, contact angles were significantly lower, by more than 10°, when aqueous solutions of pH9-0 were used compared with those of pH3-0. On the surfaces of older needles, contact angle titrations were carried out, contact angles being measured with aqueous solutions covering a pH range from 3.0 to 11.0. Measured titration curves showed clear inflection points around pH 7.0, indicating the existence of ionizable carboxylie groups in the interface between needle surface and atmosphere. The evidence seems convincing that the pronounced pH dependence of wetting is mainly due to the presence and/or activity of epiphyllic micro-organisms, whereas the cuticular wax composition of Abies grandis needles does not appear to contribute significantly to this phenomenon. Thus, the results presented here allow the general conclusion that changes of contact angles measured on leaf surfaces may not always be due to changes in the leaf surface chemistry and/or the fine structure of leaf surface waxes, but may also be due to increased amounts of epiphyllic micro-organisms significantly altering the leaf surface wetting properties.  相似文献   

18.
The role of microzooplankton in waters adjacent to Australia's North West Cape (21°49'S 114°14'E) was studied during the austral summers 1997/1998 and 1998/1999. We estimated microzooplankton abundance and biomass at a shallow (∼20 m) shelf station and at a shelf break station (∼80 m). Microzooplankton were placed into six categories: four ciliate groups (strombidiids, strobilidiids, tintinnids, “other ciliates”), dinoflagellates, and sarcodines. Total microzooplankton abundances ranged between 0.14×103 l-1 and 3.4×103 l-1. The most abundant groups were the dinoflagellates (mean 459±73 standard error l-1) and strombidiids (mean 334±42 standard error l-1). Total microzooplankton biomass ranged between 0.03 and 1.70 µg C l-1 (mean 0.33±0.05 standard error l-1). Redundancy analysis indicated differences in microzooplankton community composition between stations and sampling years but no differences with sampling depth. The microzooplankton community showed considerable variability between adjacent sampling dates, reinforcing the conclusion of earlier studies that this area is a dynamic environment. Ciliate production on the shelf was estimated to be 1.05 µg C l-1day-1 (∼20 mg C m-2 day-1) and 0.79 µg C l-1 day-1(∼70 mg C m-2 day-1) at the shelf break. Ciliate production near North West Cape was two- to six-fold higher than the rate of secondary production by juvenile copepods. Despite this, ciliate grazing appears to account for only ∼5% of primary production and ciliates do not appear to be a major conduit between primary producers and higher trophic levels in these waters.  相似文献   

19.
Reaction of RuCl(η5-C5H5(pTol-DAB) with AgOTf (OTf = CF3SO3) in CH2Cl2 or THF and subsequent addition of L′ (L′ = ethene (a), dimethyl fumarate (b), fumaronitrile (c) or CO (d) led to the ionic complexes [Ru(η5-C5H5)(pTol-DAB)(L′)][OTf] 2a, 2b and 2d and [Ru(η5-C5H5)(pTol-DAB)(fumarontrile-N)][OTf] 5c. With the use of resonance Raman spectroscopy, the intense absorption bands of the complexes have been assigned to MLCT transitions to the iPr-DAB ligand. The X-ray structure determination of [Ru(η5-C5H5)(pTol-DAB)(η2-ethene)][CF3SO3] (2a) has been carried out. Crystal data for 2a: monoclinic, space group P21/n with A = 10.840(1), b = 16.639(1), C = 14.463(2) Å, β = 109.6(1)°, V = 2465.6(5) Å3, Z = 4. Complex 2a has a piano stool structure, with the Cp ring η5-bonded, the pTol-DAB ligand σN, σN′ bonded (Ru-N distances 2.052(4) and 2.055(4) Å), and the ethene η2-bonded to the ruthenium center (Ru-C distances 2.217(9) and 2.206(8) Å). The C = C bond of the ethene is almost coplanar with the plane of the Cp ring, and the angle between the plane of the Cp ring and the double of the ethene is 1.8(0.2)°. The reaction of [RuCl(η5-C5H5)(PPh)3 with AgOTf and ligands L′ = a and d led to [Ru(η5-C5H5)(PPh3)2(L′)]OTf] (3a) and (3d), respectively. By variable temperature NMR spectroscopy the rottional barrier of ethene (a), dimethyl fumarate (b and fumaronitrile (c) in complexes [Ru(η5-C5H5)(L2)(η2-alkene][OTf] with L2 = iPr-DAB (a, 1b, 1c), pTol-DAB (2a, 2b) and L = PPh3 (3a) was determined. For 1a, 1b and 2b the barrier is 41.5±0.5, 62±1 and 59±1 kJ mol−1, respectively. The intermediate exchange could not be reached for 1c, and the ΔG# was estimated to be at least 61 kJ mol. For 2a and 3a the slow exchange could not be reached. The rotational barrier for 2a was estimated to be 40 kJ mol. The rotational barier for methyl propiolate (HC≡CC(O)OCH3) (k) in complex [Ru(η5-C5H5)(iPr-DAB) η2-HC≡CC(O)OCH3)][OTf] (1k) is 45.3±0.2 kJ mol−1. The collected data show that the barrier of rotational of the alkene in complexes 1a, 2a, 1b, 2b and 1c does not correlate with the strength of the metal-alkene interaction in the ground state.  相似文献   

20.
Water-soluble non-starch polysaccharides were extracted from a Canadian malting barley (cv. Harrington) by sequential treatment with water at 40 °C (WE40) and 65 °C (WE65). The yields were 1.4 and 1.3% (w/w), respectively, of the dry barley grist. The WE40 extract was composed of 82.5% glucose, 8.9% xylose, and 7.0% arabiose residues, whereas WE65 contained 93.3% Glc, 3.3% Xyl, and 2.5% Ara. Only minute amounts of mannose and galactose residues were found in either fraction. Both extracts were further fractionated by stepwise (NH4)2SO4 precipitation into several polysaccharide populations. Subfractions from both extracts, obtained up to 45% saturation with (NH4)2SO4, contained mostly β-glucans, whereas subfractions precipitated at increasing saturation levels of (NH4)2SO4 (45–100%) contained progressively more arabinoxylans and less β-glucans. Compared to WE40, the WE65 extract was enriched in β-glucan populations with higher molecular size, higher limiting viscosity values, and higher content of β-(1 → 4) linkages. The ratio of tri-/ tetrasaccharide oligomers was also higher in β-glucans extracted at 65 °C than those extracted at 40 °C. Arabinoxylans in both extracts, WE40 and WE65, were highly substituted and contained large proportions of doubly substituted xylose residues.  相似文献   

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