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1.
The essential oils of the leaves of Cupressus dupreziana and Cupressus sempervirens were compared. The composition of the hydrocarbon fraction showed a great similarity between the two species.  相似文献   

2.
Heartwood extractives of C. dupreziana were investigated. Carvacrol methyl ether, cedrol and α-cedrene are present, together with sesquiterpene hydrocarbons. A comparison is made with those found in C. sempervirens and other Cupressus species.  相似文献   

3.
Sixteen major components have been detected in woody tissues of Eucalyptus polyanthemos. The components identified include 2,3- and 4,6-(hexahydroxydiphenoyl)-glucose, a di-(hexahydroxydiphenoyl)-glucose known as pedunculagin, an ellagitannin which appears to be a cyclic di-(hexahydroxydiphenoyl)-diglucose, 3,4,3′-tri-O-methylellagic acid and its 4′-glucoside, 3,4,3′,4′-tetra-O- and 3,3′-di-O-methylellagic acids. A 3,3′-di-O-methylellagic acid glucoside and 2 gallotannins are possibly present in addition to the unidentified ellagitannin D-13. The distribution of these components in the woody tissues is discussed in relation to heartwood formation. The trimethylellagic acid glucoside was also present in the heartwood of other members of the red-box group of eucalypts.  相似文献   

4.
Twenty-three major components were detected in the methanol extractives of the heartwood of Eucalyptus sideroxylon. The components identified include resveratrol, resveratrol-β-glucoside, 3,3′-di- and 3,3′,4-tri-o-methylellagic acids and their glucosides. The 3,3′-di-o-methylellagic acid 4′-glucoside isolated had properties significantly different from those previously reported for this compound. Also present were gailic acid, catechin, ellagic acid, an unidentified stilbene, the ellagitannins D-6 and D-13, polymerized leucocyanidin and an oily material. The sapwood contained gailic acid, small amounts of ellagitannins and ellagic acids and traces of other components. The heartwood extractives of related eucalypt species were also examined.  相似文献   

5.
Nonpolar volatile extractives of Cupressus stephensonii heartwood amounting to 1·3% (drywood weight basis) were analyzed for their constituents and the main component was found to be carvacrol (78%). Tropolones (17%) were composed largely of β-thujaplicin and nootkatin with γ-thujaplicin in secondary quantities. Acids were low (1·7%). Neutral constituents (3·4%) contained α-pinene (8%), 4-terpinenol (27%), and methyl 4-trans-dehydrogeranate (45%).  相似文献   

6.
From the neutral fraction of the hexane extract of Halimium viscosum the following components were isolated; 7-labdene-3β,l5-diol, 15-acetoxy-7-labden-3β-ol and a new diterpene-lactone with a rearranged ent-labdane skeleton, 13S-ent-9, 1-friedo-labd-1(10)-en-15-acetoxy-2R,18-olide. From the non-saponifiable part, beside 7-labdene-3β, 15-diol and 7, 13E-labdadiene-3β, 15-diol, the new diterpene 8(17)-labdene-3β, 7α, 15-triol was extracted. The structures were elucidated by spectroscopic methods, correlations or synthesis.  相似文献   

7.
Fourteen mono-, 13 sesqui-, 16 diterpenes, dodecanal, sitosterol and desoxypodophyllotoxin were identified in the seed of T. dolabrata var. dolabrata. Sabinene and α-pinene were found to be the main components of the volatile oil. From the diterpenoid fraction, two new abietane-type compounds (ar-abietatrien-12,16-oxide and 16-hydroxyferruginol) were isolated and their structures were elucidated. Significant differences were observed in the seed diterpenoids when these results were compared with those obtained earlier with T. dolabrata var. hondae.  相似文献   

8.
In stems of woody angiosperms responding to mechanical stress, imposed for instance by tilting the stem or formation of a branch, tension wood (TW) forms above the affected part, while anatomically distinct opposite wood (OW) forms below it. In poplar TW the S3 layer of the secondary walls is substituted by a “gelatinous layer” that is almost entirely composed of cellulose and has much lower hemicellulose contents than unstressed wood. However, changes in xylan contents (the predominant hemicelluloses), their interactions with other wall components and the mechanisms involved in TW formation have been little studied. Therefore, in the study reported here we determined the structure and distribution of xylans, cloned the genes encoding the xylan remodeling enzymes β-xylosidases (PtaBXLi), and examined their expression patterns during tension wood, normal wood and opposite wood xylogenesis in poplar. We confirm that poplar wood xylans are substituted solely by 4-O-methylglucuronic acid in both TW and OW. However, although glucuronoxylans are strongly represented in both primary and secondary layers of OW, no 4-O-methylGlcA xylan was found in G-layers of TW. Four full-length BXL cDNAs encoding putative β-xylosidases were cloned. One, PtaBXL1, for which xylosidase activity was confirmed by heterologous expression in Escherichia coli, exhibited a wood-specific expression pattern in TW. In conclusion, xylan as PtaBXL1, encoding β4-xylosidase activity, are down-regulated in TW.  相似文献   

9.
Sensitization to Cupressaceae pollen has become one of the most important causes of pollinosis in Western countries during winter and early spring. However, the characterization of the extracts, the allergens involved and the cross-reactivity with other pollen sources still remain poorly studied; in the case of Cupressus arizonica only two allergens have been described so far. A new allergen from C. arizonica pollen, Cup a 4, was cloned and expressed in Escherichia coli as an N-terminally His-tag recombinant protein that was characterized biochemically, immunologically and by circular dichroism spectroscopy. The new allergen has high sequence identity with Prickly Juniper allergen Jun o 4 and contains four EF-hand domains. The recombinant protein has structural similarities with other calcium binding allergens such as Ole e 3, Ole e 8 and Phl p 7. Cup a 4 is expressed in mature pollen grains and shares antigenic properties with the recombinant form. Sera from 9.6% C. arizonica allergic patients contain specific IgE antibodies against recombinant Cup a 4.  相似文献   

10.
The matrix metalloproteinases MMP9 and MMP13 catalyze the degradation of extracellular matrix (ECM) components in the growth plate and at the same time cleave and release biologically active molecules stored in the ECM, such as VEGFA. In mice, ablation of Mmp9, Mmp13, or both Mmp9 and Mmp13 causes severe distortion of the metaphyseal growth plate. We report that mutations in either MMP9 or MMP13 are responsible for the human disease metaphyseal anadysplasia (MAD), a heterogeneous group of disorders for which a milder recessive variant and a more severe dominant variant are known. We found that recessive MAD is caused by homozygous loss of function of either MMP9 or MMP13, whereas dominant MAD is associated with missense mutations in the prodomain of MMP13 that determine autoactivation of MMP13 and intracellular degradation of both MMP13 and MMP9, resulting in a double enzymatic deficiency.  相似文献   

11.
Fossil wood collections at the Natural History Museum, London, were searched for the type material of two important species, described as early as 1831 by Witham, on the basis of material at least partly furnished by Nicol and collected in the Liassic of Whitby (Yorkshire, UK). The names given to these two species by Witham are the basionyms for more than ten other species names, while these species names also provide syntypes for several generic names. Despite this, the original material has been only rarely and partly revised, leading to much confusion.We managed to locate some of the original material. Several topotypes were also studied. On the basis of this review we propose here a neotypification for Peuce huttoniana Witham, a lectotypification for Cupressinoxylon barberi Seward and a lectotypification for Tiloxylon Hartig. We evidence several taxonomical and nomenclatural synonymies, assign Peuce lindleyana Witham to Protocedroxylon and P. huttoniana to Xenoxylon Gothan, and introduce the new combination Xenoxylon huttonianum (Witham) nov. comb. as the correct name for Xenoxylon ellipticum Gottwald & Holleis ex Schultze-Motel.A topotype of Araucariopitys americana Hollick & Jeffrey was also reviewed, which, together with previous results, leads us to suggest that Araucariopitys Hollick & Jeffrey, Protocedroxylon Gothan and Planoxylon Stopes should not be considered as taxonomical synonyms. This point is crucial to the interpretation of the fossil record of Early Abietinae.  相似文献   

12.
The geographical distribution and analysis of the essential oils of species from three sections of Hypericum L. (Guttiferae/Clusiaceae/Hypericaceae) from Portugal are presented. Hypericum perfoliatum (section Drosocarpium) grows wild in the centre and south of Portugal; Hypericum humifusum and Hypericum linarifolium are both from section Oligostema, the former occurring throughout the country, while the second is distributed mainly in the north and centre; Hypericum pulchrum (section Taeniocarpium) is confined to the littoral north of Portugal. The essential oils were obtained by distillation–extraction, hydrodistillation and distillation in a modified Marcusson apparatus from the dried aerial parts of the different populations and were analysed by GC and GC–MS. Monoterpene hydrocarbons constituted the main fraction in all oils (43–69%, 53–85%, 28–45% and 48–65% for H. perfoliatum, H. humifusum, H. linarifolium and H. pulchrum, respectively). Sesquiterpene hydrocarbons (2–13%, 6–18%, 21–27% and 16–18%, respectively) and a third fraction of non-terpenic compounds (20–29%, 3–16%, 2–14% and 5–11%, respectively) from the four species attained relatively high amounts in all oils. Within each species, no major differences were detected in the essential oil composition, despite the fact that different locations, phenological phases and extraction methodologies were used. Notwithstanding the dominance of α-pinene in all four species' oils, cluster and principal components analysis on the identified components showed that the range of α-pinene, β-pinene and n-nonane supported a separation of the four species. The essential oil composition of the four species showed some qualitative resemblances, which correlate well with the taxonomical classification based on morphological characters.  相似文献   

13.
Five lignans have been isolated from wood of Larix leptolepis. They are identified as 1-(4-hydroxy-3-methoxyphenyl)-2-4-[2-formyl-(E)-vinyl]-2-methoxyphenoxy-propane- 1,3-diol, 1-(4-hydroxy-3-methoxyphenyl)-2-2-methoxy-4-[1-(E)-propen-3-ol]-phenoxy- propane-1,3-diol, 1-(4-hydroxy-3-methoxyphenyl)-2-(4-formyl-2-methoxyphenoxy)-propane-1,3-diol, 1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol and a trilignol, leptolepisol C.  相似文献   

14.
The fruit-coat fats of Rhopalostylis sapida, R. baueri (Palmae), Elaeocarpus dentatus (Elaeocarpaceae) and Nestegis cunninghamii (Oleaceae) and the seed fats of E. dentatus and N. cunninghamii contain as their major fatty acids palmitic 11–35%, oleic 13–68%, and linoleic 16–31%. The seed fat of E. dentatus contains 10% hexadecenoic acid and the fruit-coat fat of N. cunninghamii 13% linolenic acid.  相似文献   

15.
In this study, all the components of Jatropha curcus and Morus indica were chemically characterized and their biochemical methane potentials (BMP) were determined. From the variables that showed strong influence on the ultimate methane yield (Bo) of J. curcus, a multiple regression Jatropha model was developed. This model comprised of total carbohydrates, protein, lipid, acid-detergent fiber (ADF), cellulose and ash in ADF as independent variables, with r2 value of 0.943. The Jatropha model was validated on 7 samples of M. indica parts and wastes from silkworm rearing trays of this study and 13 samples of heterogeneous organic wastes of earlier studies, to judge the prediction quality. It was found that most of the predicted values differed by less than 15% of their experimental Bo.  相似文献   

16.
B. González  J.L. Chávez  N.A. Castro  S. Gómez  C. Kennedy 《BBA》2006,1757(12):1614-1622
In highly aerobic environments, Gluconacetobacter diazotrophicus uses a respiratory protection mechanism to preserve nitrogenase activity from deleterious oxygen. Here, the respiratory system was examined in order to ascertain the nature of the respiratory components, mainly of the cyanide sensitive and resistant pathways. The membranes of G. diazotrophicus contain Q10, Q9 and PQQ in a 13:1:6.6 molar ratios. UV360 nm photoinactivation indicated that ubiquinone is the electron acceptor for the dehydrogenases of the outer and inner faces of the membrane. Strong inhibition by rotenone and capsaicin and resistance to flavone indicated that NADH-quinone oxidoreductase is a NDH-1 type enzyme. KCN-titration revealed the presence of at least two terminal oxidases that were highly sensitive and resistant to the inhibitor. Tetrachorohydroquinol was preferentially oxidized by the KCN-sensitive oxidase. Neither the quinoprotein alcohol dehydrogenase nor its associated cytochromes c were instrumental components of the cyanide resistant pathway. CO-difference spectrum and photodissociation of heme-CO compounds suggested the presence of cytochromes b-CO and a1-CO adducts. Air-oxidation of cytochrome b (432 nm) was arrested by concentrations of KCN lower than 25 μM while cytochrome a1 (442 nm) was not affected. A KCN-sensitive (I50 = 5 μM) cytochrome bb and a KCN-resistant (I50 = 450 μM) cytochrome ba quinol oxidases were separated by ion exchange chromatography.  相似文献   

17.
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19.
The major components of the essential oil from roots of Pimpinella diversifolia, gathered in the Kumaun Region of India, have been identified as the (+)-Z-2-methyl-2-butenoate (angelate) and (+)-isobutyrate esters of 4-methoxy-2-(E-3-methyloxiranyl)phenol. Aromatic 13C NMR resonances of these compounds and their synthetic acetate analog, as well as those of 2-methoxy-4-(E-3-methyloxiranyl)phenyl acetate prepared from isoeugenol, were found to be in excellent agreement with calculated values. Comparison of the EIMS of the natural and synthetic products with those reported for compounds previously identified as 2-methoxy-4-(E-3-methyloxiranyl)phenyl esters indicates that they also have the 4-methoxy-2-(E-3-methyloxiranyl)phenyl structure.  相似文献   

20.
Purified acetyl-CoA: choline O-acetyltransferase (EC 2.3.1.6) from Drosophila melanogaster has been shown to contain two major polypeptides of 67 and 54 K Daltons. However, all enzyme activity is found in a single molecular weight form of approx 67 K Daltons as determined by sucrose gradient sedimentation and molecular exclusion chromatography. The latter showed both the 67 and 54 K Dalton polypeptides on polyacrylamide gel electrophoresis in sodium lauryl sulfate (10% acrylamide). Analysis of purified choline acetyltransferase on polyacrylamide gel electrophoresis in sodium lauryl sulfate (15% acrylamide) revealed the presence of an additional polypeptide at 13 K Daltons. Tryptic-peptide maps of the 67, 54 and 13 K Dalton components showed all three to be structurally related. In addition to several common tryptic peptides, the 13 K Dalton polypeptide contained three tryptic-peptides that were also found in the 67 K Dalton polypeptide, but were absent from the 54 K Dalton polypeptide. This evidence suggests that native Drosophila choline acetyltransferase may exist in two forms, one a single polypeptide chain with a molecular weight of 67 K Daltons and the other consisting of two noncovalently bound polypeptide chains with molecular weights of 54 and 13 K Daltons. The latter form is the major one isolated and may be generated by limited proteolysis of the single chain 67 K Dalton form.  相似文献   

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