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1.
Five Japanese liverworts (Bazzania sp.) were examined for sesquiterpenes. B. japonica and B. pompeana contained two new drimane-type sesquiterpene esters, albicanyl 3,4-dihydroxycinnamate and albicanyl 2,4dihydroxycinnamate. Tridensenone, a new aromadendrane-type sesquiterpene ketone was isolated from B. tridens. The stereostructures of these new sesquiterpenes were elucidated mainly by spectrometry. Barbatane-, bazzanane- and cuparane-type sesquiterpenes were found in all of the five species investigated. These sesquiterpenes, along with the new drimane- and aromadendrane-type sesquiterpenes are useful chemosystematic markers. 相似文献
2.
Christopher T. Lefèvre Marian L. Schmidt Nathan Viloria Denis Trubitsyn Dirk Schüler Dennis A. Bazylinski 《Applied and environmental microbiology》2012,78(20):7238-7248
Vibrioid- to helical-shaped magnetotactic bacteria phylogenetically related to the genus Magnetospirillum were isolated in axenic cultures from a number of freshwater and brackish environments located in the southwestern United States. Based on 16S rRNA gene sequences, most of the new isolates represent new Magnetospirillum species or new strains of known Magnetospirillum species, while one isolate appears to represent a new genus basal to Magnetospirillum. Partial sequences of conserved mam genes, genes reported to be involved in the magnetosome and magnetosome chain formation, and form II of the ribulose-1,5-bisphosphate carboxylase/oxygenase gene (cbbM) were determined in the new isolates and compared. The cbbM gene was chosen for comparison because it is not involved in magnetosome synthesis; it is highly conserved and is present in all but possibly one of the genomes of the magnetospirilla and the new isolates. Phylogenies based on 16S rRNA, cbbM, and mam gene sequences were reasonably congruent, indicating that the genes involved in magnetotaxis were acquired by a common ancestor of the Magnetospirillum clade. However, in one case, magnetosome genes might have been acquired through horizontal gene transfer. Our results also extend the known diversity of the Magnetospirillum group and show that they are widespread in freshwater environments. 相似文献
3.
《Phytochemistry》1986,25(4):891-897
The aerial parts of Artemisia iwayomogi afforded, in addition to already known terpenes, eleven new cudesmanolides whereas four new guaianolides were found in A. gmelinii. No sesquiterpene lactones were detected in the aerial parts of A. santolinifolia which afforded two new nerolidol derivatives besides several other already known compounds. From A. caerulescens var. cretacea six eudesmanolides were isolated, one of which has not been reported previously. The structures were elucidated by high field 1H NMR spectroscopy and chemical transformations. The chemotaxonomic significance of sesquiterpene lactones within the section Abrotanum and the subgenus Seriphidium is briefly discussed. 相似文献
4.
Besides an apigenin- and a luteolin-di-C-glycoside, 5 previously unknown di-C-glycosides of tricetin were identified in the gametophytic and sporophytic tissues of Plagiochila asplenioides. Two of them were new 6,8-di-C-hexopyranosyltricetins, and two were new 6-C- hexopyranosyl-8-C-pentopyranosyltricetins. 6-C-Hexopyranosyl-8-C-pentopyranosyltricetin-5′-methyl ether was also found. 相似文献
5.
《Phytochemistry》1987,26(2):515-517
Two new polyphenols, 4,6-di-O-galloylarbutin and 2,4,6-tri-O-galloyl-D-glucose, were isolated from the root of Bergenia purpurascens, which also contains 6-O-galloylarbutin, bergenin and its gallates, and five other phenolic compounds. The structures of the new compounds were determined by chemical and spectroscopic methods. 相似文献
6.
7.
《Phytochemistry》1987,26(12):3281-3283
A new neo-clerodane dilactone, desoxyarticulin, and dihydrotucumanoic acid, together with other known compounds, were isolated from Baccharis pedicellata and Baccharis marginalis. The structures of the new compounds were elucidated by spectroscopic methods. 相似文献
8.
A new ent-secoaromadendrane-type sesquiterpene hemiacetal, plagiochiline G, was isolated from Plagiochila ovalifolia. Four new ent-sesquiterpene hemiacetals, plagiochiline H and I, and two pungent methoxyplagiochilines A1, A2 and non-pungent methoxyplagiochiline C were also isolated from P. yokogurensis. The methoxylated plagiochilines A1, A2 and C were derived from the plagiochilines A and C during the extraction procedure. A new germacrene, ent-3α-acetoxybicyclogermacrene, ent-maaliol and the previously known ent- aromadendrane-type sesquiterpenes have been obtained from P. yokogurensis. The structures of the new compounds were elucidated by 1H NMR spectral data and by chemical correlation. 相似文献
9.
10.
Three new plant constituents were isolated from the primary leaves of Vigna radiata (= Phaseolus aureus) and their structures elucidated and characterized with the aid of negative-ion fast atom bombardment mass spectrometry (FAB MS), 1H NMR and UV spectroscopy, thin-layer, gas-liquid and high performance liquid chromatography. The new conjugates are (E)-p-coumaroyl-, (E)-caffeoyl- and (E)-feruloyltartronic acids. Their structures were unequivocally confirmed by comparison with synthetic material. The metabolism of the new hydroxycinnamic acid conjugates in young plants of Vigna radiata is described. 相似文献
11.
From the rhizomes of Polypodium formosanum, new triterpenoids of the cycloartane group, (24R)-cyclolaudenol and (24R)-cyclomargenol, were isolated as the corresponding acetates, alcohols and ketones, and their structures were established. Also, from the rhizomes of P. niponicum eight acetates of cycloartane derivatives and two acetates of new methyl sterols were isolated and characterized. 相似文献
12.
Robert T. Sherwood Maurice Shamma Jerome L. Moniot Julius r. Kroschewsky 《Phytochemistry》1973,12(9):2275-2278
One new and 5 known flavone C-glycosides were isolated from leaves and stems of Coronilla varia. The new compound was shown to be isoorientin 2″-O-rhamnoside. The known compounds were isovitexin, isoorientin, isovitexin 4′-O-glucoside, isoorientin 4′-O-glucoside, and isoorientin 7-O-glucoside. 相似文献
13.
Yan-Yan Long Ji-Guang Wei Xiang Sun Yue-Qiu He Ji-Tong Luo Liang-Dong Guo 《Mycological Progress》2012,11(3):689-698
In an investigation of Pythium species in lawn grassland of south China, two new species, Pythium breve and P. baisense, were identified based on morphological characteristics and DNA sequence data. These two new species differ morphologically from the other Pythium species by the oogonia encompassed by many antheridia and with 1?C3 antheridia on the wavy and curved stalks. Furthermore, P. baisense with complexly lobed antheridial stalks differs from P. breve with antheridial stalks entwining the hyphae nearby the oogonia with several turns. Results of phylogenetic analyses showed that these two new species were clearly separated from morphologically similar Pythium species based on the internal transcribed spacer region (ITS1, 5.8S, ITS2) and cytochrome c oxidase subunit I (COXI) gene sequences using maximum parsimony and Bayesian methods. These two new species are described and illustrated in detail. 相似文献
14.
The investigation of several South African species of the tribe Inuleae afforded in addition to known compounds 16 new constituents. From Leontonyx a group of 9 new phloroglucinol derivatives, from Stoebe species two new p-hydroxyacetophenone, two thymol and two coumaric acid derivatives and from Relhania a new euparine-derivative were isolated. The structures are elucidated mainly by spectroscopic methods. The chemotaxonomic aspects are discussed briefly. The phloroglucinol derivatives, which in part are derived from geraniol, seem to be especially characteristic. 相似文献
15.
Eleven of the major non-polar constituents of the dried bark of Virola elongata were isolated. A new neolignan, virolongin, two new lignans, dihydrosesartemin and β-dihydroyangambin, as well as the neolignan, eusiderin, the lignans, epi-sesartemin, epi-yangambin and yangambin, the cis and trans isomers of 3,5,4′-trimethoxystilbene and sitosterol were identified. The structures of virolongin, dihydrosesartemin and β-dihydroyangambin were determined. 相似文献
16.
Ferdinand Bohlmann Pahup Singh Christa Zdero Annette Ruhe Robert M. King Harold Robinson 《Phytochemistry》1982,21(7):1669-1673
The investigation of Eremanthus crotonoides afforded in addition to known compounds three new furanoheliangolides, while from E. glomerulatus six new furanoheliangolides and eremantholides were isolated. From the aerial parts of Chresta sphaerocephala a new guaianolide was obtained, while the roots contained known furanoheliangolides. The chemotaxonomy of the subtribe Lychnophorinae is discussed briefly. 相似文献
17.
《Mycoscience》2020,61(3):116-121
Five Simplicillium isolates were obtained from foam generated in an aquarium in Minato-ku, Tokyo, Japan. Using a combination of micro-morphological characteristics and multigene (ITS, SSU, LSU, TEF) phylogenics, the isolates were identified as S. subtropicum and a new species which were previously undescribed. Simplicillium spumae, which is a new species, differs from known Simplicillium species in the morphology of their conidia and conidiophores. 相似文献
18.
Five new cis-ent-clerodanes, linarenones A–E (1–5) and two known compounds (6 and 7) were isolated from whole plant of Linaria japonica. The structures of these compounds were determined by various spectroscopic analyses (UV, IR, HR–ESI–MS, 1D and 2D NMR). The absolute configuration of five new diterpenoids was confirmed by circular dichroism (CD) analysis and chemical conversion. Cytotoxicity of the isolated compounds against A549 cell lines and Leishmania major were evaluated. The new cis-ent-clerodane 3 was found to be moderately active against A549 cell lines, and new cis-ent-clerodanes 1, 6 and desacetyl-linarienone (7) were active against L. major. 相似文献
19.
We examined the role of sleep-related memory consolidation processes in learning new form-meaning mappings. Specifically, we examined a Complementary Learning Systems account, which implies that sleep-related consolidation should be more beneficial for new hippocampally dependent arbitrary mappings (e.g. new vocabulary items) relative to new systematic mappings (e.g. grammatical regularities), which can be better encoded neocortically. The hypothesis was tested using a novel language with an artificial grammatical gender system. Stem-referent mappings implemented arbitrary aspects of the new language, and determiner/suffix+natural gender mappings implemented systematic aspects (e.g. tib
scoiffesh
+ ballerina, tib
mofeem + bride; ked
jorool + cowboy, ked
heefaff + priest). Importantly, the determiner-gender and the suffix-gender mappings varied in complexity and salience, thus providing a range of opportunities to detect beneficial effects of sleep for this type of mapping. Participants were trained on the new language using a word-picture matching task, and were tested after a 2-hour delay which included sleep or wakefulness. Participants in the sleep group outperformed participants in the wake group on tests assessing memory for the arbitrary aspects of the new mappings (individual vocabulary items), whereas we saw no evidence of a sleep benefit in any of the tests assessing memory for the systematic aspects of the new mappings: Participants in both groups extracted the salient determiner-natural gender mapping, but not the more complex suffix-natural gender mapping. The data support the predictions of the complementary systems account and highlight the importance of the arbitrariness/systematicity dimension in the consolidation process for declarative memories. 相似文献
20.
The isolation is reported of the new germacrolide, 11,13-dehydroeriolin, the new melampolide schkuhrioidin and schkuhriolide from Schkuhria schkuhrioides. 11,13-Dehydroeriolin is also a constituent of S. virgata. The structure and stereochemistry of the new compounds were established on chemical and spectroscopic grounds. 相似文献