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1.
The investigation of seven Bolivian Senecio species afforded in addition to known compounds five new furanoeremophilanes, two C10-amides, a new isoeugenol ester and the isomer of pterophorin. The structures are elucidated mainly by spectroscopic methods. While most of the new compounds are closely related to those isolated before from Senecio species, four of them are unusual. Another is a new type of a furanoeremophilane; its biogenesis however, can be explained easily from known types.  相似文献   

2.
The investigation of four Helianthus species afforded, in addition to known compounds, four new atisirenic acid derivatives, a new ent-kaurenic acid derivative, three new labdane derivatives and an unknown C15-acetylenic compound. The structures of the diterpenes were elucidated by intensive NMR studies and some chemical transformations. An unusual fragmentation in the mass spectra of the atisirenes is discussed briefly.  相似文献   

3.
Reinvestigation of the polar fractions of the aerial parts of Centaurea ruthenica afforded, in addition to known compounds, more than 20 new ones, mostly in very small quantities, which in many cases could only partly be separated even after acetylation. The structures, however, could be elucidated by spectroscopic methods. Besides additional C13-acetylenes, several new C14- and C10-acetylenes are present. The compounds isolated are of special interest in view of the proposed biosynthetic scheme of acetylenic compounds of this type.  相似文献   

4.
The investigation of Calea urticifolia afforded eight new germacranolides. While five are heliangolides, three are of a new type and have some unusual structural features. The structures are elucidated by extensive 1H-NMR studies and some chemical transformations. In addition, a new isoeugenol and an unusual phloroglucinol derivative were isolated; the structure of the latter could only be established after some chemical transformations. Other Calea species contain typical C17 acetylenes only, also present in other species of the subtribe Galinsoginae. So far, the results on Calea indicate that the genus is chemically heterogenous.  相似文献   

5.
The roots of C. rugosa afforded, in addition to known compounds, a C17-acetylenic epoxide and five new guaianolides, four of them being hydroperoxides. The structures were elucidated by extensive NMR studies. The aerial parts only contain triterpene mixtures, as those of C. hieronymi. The compounds isolated confirm that Cacosmia is unrelated chemically to true members of the tribe Senecioneae.  相似文献   

6.
The investigation of several members of the South African genus Cineraria affords, in addition to known compounds, several new eremophilene derivatives together with modified types all derived from a carbon skeleton where the 5-methyl has migrated to C-6. Some of these compounds are transformed to unusual enol lactones. Furthermore some derivatives of himachalene are present. All species also contain C11-acetylenes, most of which are new. Senecio deltoideus also contains some of these compounds. The chemotaxonomic situation is discussed.  相似文献   

7.
Asclepias eriocarpa and A. labriformis contain three new cardenolides, the structures of which have been partially assigned by their spectral properties and comparison with the known cardenolides of A. curassavica. They include labriformin (C31H39O10NS), labriformidin (C29H31O11) and eriocarpin.  相似文献   

8.
The hexane extract of Wyethia mollis contains the n-alkanes C15-C18, C20-C25, C27 and C29. Linoleic acid was the only detectable acidic component. A mass spectral analysis of the wax ester fraction indicated that it was a mixture of homologues, the saturated even-carbon acids n-C16-C30 esterfield with the saturated even-carbon alcohols n-C18-C26. The chloroform extract yielded the known isoflavones santal and 3′-O-methylorobol along with a new lanostane-type triterpene, 22,25-epoxy-lanosta-7:9(11)-dien-3-one. The wide distribution of n-alkanes and the decreased odd-even carbon ratio are consistent with the proposed primitive nature of this plant.  相似文献   

9.
The investigation of three South African and a North American Conyza species afforded, in addition to known compounds, a new eudesmane ketone and five new scopoletin derivatives. The structures are elucidated by spectroscopic methods and by some chemical transformations. Two of the scopoletin enol ethers have very unusual structures. While most of the Conyza species investigated so far contain typical C10-acetylenes, also present in related genera, there are some with different chemistry. The relationship of the genus to Aster and Erigeron, however, is clearly indicated.  相似文献   

10.
From the culture medium of a strain of Metarhizium anisopliae, 14 depsipeptides have been isolated. Five of them were identified as known destruxins A, B, C, D and desmethyldestruxin B. The structures of the new compounds, named destruxins E, A1, A2, B1, B2, C2, D1, D2 and E1,were established mainly from the mass spectral analysis of their corresponding open-chain derivatives.  相似文献   

11.
Artemisia douglasiana afforded, in addition to known compounds, two new C14-acetylenes, five longipinene derivatives, three nerolidol derivatives, a lactone and a ketone with a new carbon skeleton and lavendulol-2-methylbutyrate. The structures were elucidated by spectroscopic methods and some chemical transformations. The configurations of several oxo longipinene-7, 9-di- and 7, 8, 9-triesters isolated previously were corrected. The biogenesis of the new lactones is discussed briefly.  相似文献   

12.
13.
The Laxa group of the Panicum genus contains species which have CO2 exchange and anatomical characteristics intermediate to C3 and C4 photosynthetic types (C3/C4), and also species characterized as C3. Hybrids were made between two of the C3/C4 species and two C3 species. Carbon dioxide exchange and morphological, leaf anatomical, and cytogenetic characteristics of F1 hybrids between Panicum milioides Nees. ex Trin (C3/C4) and P. laxum Mez. (C3), P. spathellosum Doell (C3/C4) and P. boliviense Hack. (C3), and P. spathellosum and P. laxum were studied. There were no consistent differences in apparent photosynthesis, although two of the three hybrids had higher net CO2 uptake than the C3 parent. Values of inhibition of apparent photosynthesis by 21% O2, CO2 loss in the light, and CO2 compensation concentration for the hybrids were between those of the parents. All three hybrids showed leaf anatomical traits, especially organelle quantities in the bundle sheath cells, between those of their respective parents. Linear regression of CO2 compensation concentration on the percentage of mitochondria and chloroplasts in vascular bundle sheaths of the parents and hybrids gave correlation coefficients of −0.94. This suggests that the reduction in CO2 loss in the C3/C4 species, and to a lesser degree in the F1 hybrids, was due to development of organelles and perhaps a higher proportion of leaf photorespiration in bundle sheaths. The overall morphology of the hybrids was so different from the parents that they could be described as new taxonomic forms. The chromosomes in the hybrids were mainly unpaired or paired as bivalents indicating possible homology between some parental genomes.  相似文献   

14.
Addition to Bacillus acidocaldarius of acids which can act as primers for fatty acid synthesis promote the synthesis of corresponding fatty acids competitively. The effective acids are n?C5 to -?7 (not C4 or C8), iso- and anteiso-C, and ?C, (not C4), and a range of cyclic acids from cyclobutylacetic and cyclopentanecarboxylic to cycloheptylacetic. New non-natural ω-cyclobutyl-, ω-cyclopentyl-, and ω-cycloheptyl-fatty acids are obtainable. The range of acceptable primers and the range of fatty acids produced therefrom indicate, respectively, the substrate specificities of the transacylase which introduces acyl species into fatty acids synthesis and the one which removes them. The specificity of the primer transacylase may be similar to that in some rumen anaerobes.  相似文献   

15.
Zinaflavins A-F, six new H, C14α, elemanolides were isolated from Zinnia flavicoma. Their structures and stereochemistry were determined by spectroscopic techniques and confirmed by X-ray analysis of zinaflavin F. Zinaflavins G and H, two new H, C14β elemanolides were also isolated from this species.  相似文献   

16.
The early history of Panorpidae (Mecoptera) is poorly known due to sparse fossil records. Up to date, only nine fossil species have been described, all from the Paleogene, except the Early Cretaceous Solusipanorpa gibbidorsa Lin, 1980. However, we suggest S. gibbidorsa is too incompletely preserved to permit even family classification. A new genus with two new species, Jurassipanorpa impunctata gen. et sp. n. and Jurassipanorpa sticta sp. n., are described based on four well-preserved specimens from the late Middle Jurassic Jiulongshan Formation of Daohugou, Inner Mongolia, China. These two new species are the earliest fossil records of Panorpidae. The new genus is erected based on a combination of forewing characters: both R1 and Rs1 with two branches, 1A reaching posterior margin of wing distad of the forking of Rs from R1, and no crossveins or only one crossvein between veins of 1A and 2A. In all four specimens, long and robust setae ranging from 0.09 to 0.38 mm in length and pointing anteriorly, are present on anal veins of forewings. The function of these setae is enigmatic.  相似文献   

17.
Complementary to our previous project on the molecular phylogeny of Camphorosmeae, the leaf anatomy of ca. 35 species including all non-Australian and selected Australian species was studied by use of light microscopy. Nine anatomical leaf types were described, compared to previous classifications, and discussed with regard to their putative evolution on the background of phylogenetic trees. Particular emphasis was given to the relationships between the C3 and C4 leaf types: Chenolea type (C3), Eokochia type (C3), Neokochia type (C3), Sedobassia type (C3/C4 intermediate), Bassia prostrata type (C4), B. muricata type (C4), B. eriantha type, B. lasiantha type (C4), Camphorosma type (C4). The main results and conclusions were: (1) Two unusual new C3 leaf types: Chenolea with microfenestrate chlorenchyma, Eokochia with unique complex vascular bundles; (2) Sedobassia interpreted as anatomically C3/C4 intermediate by kranz-like bundle sheath cells is the first C3/C4 intermediate in Camphorosmeae and found in a derived position; (3) Neokochia type detected as the likely starting point for all four C4 leaf types and for the C3/C4 intermediate; (4) hypodermis of C4 types originated from outermost chlorenchyma layer of C3 types and lost multiple times during further evolution; (5) atriplicoid Bassia. lasiantha type without water storage tissue evolved from kochioid B. muricata type; (6) two independent gains of C4 photosynthesis, one in Bassia and one in Camphorosma; (7) depending on the lineage, leaf architecture remains comparatively stable (Australian Camphorosmeae) or shows an unexpected plasticity (Bassia scoparia group).  相似文献   

18.
The cuticular hydrocarbons (CHs) and morphology of two Ceratitis rosa Karsch (Diptera: Tephritidae) populations, putatively belonging to two cryptic taxa, were analysed. The chemical profiles were characterised by two-dimensional gas chromatography with mass spectrometric detection. CHs of Ceratitis rosa that originated from the lowlands and highlands of Kenya comprised of n-alkanes, monomethylalkanes, dimethylalkanes and unsaturated hydrocarbons in the range of the carbon backbone from C14 to C37. Hydrocarbons containing C29, C31, C33 and C35 carbon atoms predominated in these two populations. 2-Methyltriacontane was the predominant compound in both populations. Quantitative differences in the distribution of hydrocarbons of different chain lengths, mainly the C22, C32, C33 and C34 compounds of these two populations, were observed despite indistinct qualitative differences in these hydrocarbons. Morphological analyses of male legs confirmed that the flies belong to different morphotypes of Ceratitis rosa previously labelled as R1 and R2 for lowland and highland populations, respectively. A statistical analysis of the CH compositions of the putative R1 and R2 species showed distinct interspecific identities, with several CHs specific for each of the lowland and highland populations. This study supports a hypothesis that the taxon Ceratitis rosa consists of at least two biological species.  相似文献   

19.
Samples of the green colonial alga Botryococcus braunii, collected from various localities, were grown in the laboratory and examined for their hydrocarbon content and morphology. Although few differences appeared between the ultrastructures of the samples, the nature of their hydrocarbons, which remains unchanged at any stage of growth, allows the distinction of two physiological races viz algae producing odd-numbered unbranched alkadienes and trienes (C25C31) (the A race) and those producing polymethylated triterpenes CnH2n-10 (C30C37), the botryococcenes (the B race). In laboratory culture, the hydrocarbon content of these new strains is very high, from 30 to 60% of the dry biomass. For the two races the greatest hydrocarbon productivity takes place during the active growth phase. The important variability observed in botryococcene distribution could originate both from genetic and environmental factors.  相似文献   

20.
The carotenoids of unialgal cultures originating from symbiotic zooxanthellae of two molluscan (Tridacna crocea, a giant clam, and Pteraeolidia ianthine a nudibranch) and one cnidian (Pseudopterogorgia bipinnata, a gorgonian coral) host have been analysed by HPLC or TLC procedures combined with several spectroscopic techniques including MS and NMR. A high total carotenoid content (0.45-0.63% of the dry wt) was obtained. The carotenoid pattern with C37-norcarotenoids (peridinin and pyrrhoxanthin) comprising around 80% of total carotenoids, and β,β-carotene (2%), the ailenic dinoxanthin (3–4%) and the acetylenic diatoxanthin (1–3%) and diadinoxanthin (7–9%) representing minor C40-carotenoids, corresponds to that of peridinin-producing free-living dinoflagellates. Supplementary 1H NMR and 13C NMR data are reported for peridinin and pyrrhoxanthin. A polar, minor carotenoid, P447, was partly characterized as containing a disaccharide glycosidically bound to an allenic carotenoid aglycone. Re-evaluation of previous reports suggests the wide-spread occurrence of related carotenoid disaccharides in Dinophyceae for which they are considered a new chemosystematic marker.  相似文献   

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