1000 resultados para Ferrovias - Mirandópolis (SP)


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Investigation of a southern Australian marine sponge, Mycale sp., resulted in isolation of the known norsesterterpenes 1-3 as well as two new isomeric norsesterterpenes, mycaperoxide C methyl ester (4) and mycaperoxide D methyl ester (5), and six new norterpenes (6-11).

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A Sigmosceptrella sp. of sponge collected during trawling operations in the Great Australian Eight, Australia, has yielded a series of new norterpenes. These include a new bisnorditerpene, sigmosceptrin-A (5); two new norditerpenes, sigmosceptrin-B (14) and sigmosceptrin-C (15), isolated as their methyl esters (6) and (7) respectively; and an ethylated artefact, sigmosceptrin-B ethyl ester (8). Complete stereostructures were assigned to the sigmosceptrins by spectroscopic analysis, chemical degradation, derivatization, and by a single-crystal X-ray structural analysis. A biosynthetic pathway is proposed that requires a common biosynthetic precursor to both the sigmosceptrins and norterpene cyclic peroxides.

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Pholeohedra overstreeti n. g., n. sp. (Digenea: Haploporidae) is described from Girella zebra (Kyphosidae) in South Australia. The new genus is compared with all genera of Haploporidae sensu late (including Atractotrematidae, Megasolenidae and Waretrematidae) and has a unique bell-shaped concavity at its posterior end. The genus otherwise resembles Hapladena in the arrangement of the testis, vitellarium and gut but also resembles Megasolena, Metamegasolena and Vitellibaculum except in having a single testis. This is the first haploporid reported from kyphosid fishes in Australia.

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A specimen of the sponge Dendrilla sp. collected during commercial trawling operations in the Great Australian Eight, Australia, analyses for a very high natural abundance of the new amino acid cis-3-hydroxy-N-methyl-L-proline (1). The complete stereostructure for (1) was determined by spectroscopic analysis and chemical derivatization.

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Two species of Clinostomum previously described from Australia, C. hornum from Botaurus poiciloptilus (Australian bittern) and Nycticorax caledonicus (Nankeen night heros) and C. australiense from Pelecanus conspicillatus (Australian pelican), which have previously been synonymised with C. complanatum, are redescribed and recognised as valid species. In addition, C. complanatum is recorded from Egretta alba (large egret), E. garzetta (little egret), E. intermedia (plumed egret), N. caledonicus and Ardea novaehollandiae (white-faced heron). C. wilsoni n. sp. is described from E. intermedia from Queensland. C. wilsoni differs from the other three species in size and shape of the body and in the oral collar, oral sucker, intestinal caeca, caecal diverticula and position of testes. Taxonomic problems within the genus Clinostomum are discussed.

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A Spongosorites sp. collected during trawling operations off the southern coast of Australia returned the new alkaloid dragmacidin E (3), the structure of which was secured by detailed spectroscopic analysis. Dragmacidin E (3), and its co-metabolite dragmacidin D (1) have been identified as potent inhibitors of serine-threonine protein phosphatases.

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A Callyspongia sp. collected by SCUBA off Barwon Heads, Australia, has afforded two new polyacetylenic lipids, callyspongynes A and B, the structures of which were assigned by spectroscopic analysis and chemical derivatization.

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2D-NMR spectroscopic data is reported for the haliclonacyclamines A - D (1)-(4) and for two bismethiodide adducts (5) and (6). The structures of two new alkaloids, haliclonacyclamines C (3) and D (4), which are the 15,16-dihydro analogues of the haliclonacyclamines A (1) and B (2) are described. Revised assignments deduced by 2D-INADEQUATE spectroscopy are presented for (1) and (2). The alkene substituent in the C,, spacer group of (2) and (4) is positioned between C27-C28 by NMR, and confirmed by x-ray structural analysis for (2). Metabolite (3) has a C25-C26 double bond. (C) 1998 Elsevier Science Ltd. All rights reserved.

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Ten Australian representatives from seven of the 10 genera presently constituting the family Cystolcloniaceae have been analyzed for their cell-wall galactans. Included in our survey are the monotypic Australian-endemic genera Austroclonium, Gloiophyllis, Erythronaema, and Stictosporum, one species of Craspedocarpus, three species of Rhodophyllis, and two species of Calliblepharis. As one of the species of the latter genus is endemic to Western Australia and presently undescribed, we illustrate its habit and anatomical features in formally proposing to name it Calliblepharis celatospora Kraft, sp. nov. All the species surveyed essentially produce typical iota (iota)-carrageenans, with the exception of Austroclonium. The sulfated galactans from Austroclonium predominantly contain the repeating units of iota-, alpha (alpha)-, and 6'-O-methylated iota- and alpha-carrageenans; whether these exist as discrete polysaccharides or a complex hybrid structure was not resolved. Thus, Austroclonium carrageenans resemble the polysaccharides from Rhabdonia, Areschougia, and Erythroclonium. Although these latter three genera are currently included in the large gigartinalean family Solieriaceae, all produce significantly different carrageenans from Solieria itself and related genera such as Eucheuma, Kappaphycus, Betaphycus, Sarcodiotheca, Agardhiella, Sarconema, and Callophycus. In consideration of these findings, as well as of significant anatomical similarities, we provisionally recommend reestablishment of the family Rhabdoniaceae Kylin (as the family Areschougiaceae J. Agardh) for Rhabdonia, Areschougia, Erythroclonium, and Austroclonium.

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A Latrunculia sp, collected off Port Phillip Bay, Victoria, returned three new norsesterterpene cyclic peroxides. Trunculins G (9), H (10) and I (11) were isolated as their methyl esters (12), (13) and (14) respectively. Gross structures for these new trunculins were assigned on the basis of spectroscopic analysis, while the absolute stereochemistry about the cyclic peroxide terminus was established by application of the Horeau and Mosher procedures.

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Light-microscopic and electron-microscopic studies of the tropical marine sponge Haliclona sp. (Or der: Haplosclerida Family: Haliclonidae) from Heron Island, Great Barrier Reef, have revealed that this sponge is characterized by the presence of dinoflagellates and by nematocysts. The dinoflagellates are 7-10 mu m in size, intracellular, and contain a pyrenoid with a single stalk, whereas the single chloroplast is branched, curved, and lacks grana. Mitochondria are present, and the nucleus is oval and has distinct chromosomal structure. The dinoflagellates are morphologically similar to Symbiodinium microadriaticum, the common intracellular symbiont of corals, although more detailed biochemical and molecular studies are required to provide a precise taxonomic assignment. The major sponge cell types found in Haliclona sp, are spongocytes, choanocytes, and archaeocytes; groups of dinoflagellates are enclosed within large vacuoles in the archaeocytes. The occurrence of dinoflagellates in marine sponges has previously been thought to be restricted to a small group of sponges including the excavating hadromerid sponges; the dinoflagellates in these sponges are usually referred to as symbionts. The role of the dinoflagellates present in Haliclona sp. as a genuine symbiotic partner requires experimental investigation. The sponge grows on coral substrates, from which it may acquire the nematocysts, and shows features, such as mucus production, which are typical of some excavating sponges. The cytotoxic alkaloids, haliclonacyclamines A and B, associated with Haliclona sp. are shown by Percoll density gradient fractionation to be localized within the sponge cells rather than the dinoflagellates. The ability to synthesize bioactive compounds such as the haliclonacyclamines may help Haliclona sp. to preserve its remarkable ecological niche.

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A Sigmosceptrella sp. from the Great Australian Eight, Australia, has yielded the new norditerpene cyclic peroxide, nuapapuin A (2a), and the norsesterterpene cyclic peroxide sigmosceptrellin D (3a), characterized as the corresponding methyl esters 2b and 3b. The crude methylated sponge extract also yielded the new norsesterterpene cyclic peroxide sigmosceptrellin E methyl ester (4). Relative stereochemistry about C2, C3, and C6 was assigned by established empirical rules and absolute stereochemistry by the advanced Mosher procedure. A plausible biosynthetic pathway has been proposed that rationalizes key transformations in the biosynthesis of all known norterpene cyclic peroxides and related norterpene ketones, dienes and sigmosceptrins.

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As a consequence of the transfer of the type species Conglomeromonas largomobilis subsp. largomobilis to the genus Azospirillum, the name of the genus Conglomeromonas must be changed in accordance with Rule 37a(1) of the International Code of Nomenclature of Bacteria. Consequently, it is proposed that the subspecies Conglomeromonas largomobilis subsp, parooensis be transferred to the genus Skermanella gen, nov. as the type species Skermanella parooensis gen, nov., sp, nov. This taxon belongs to an isolated subline of descent in the Azospirillum branch of the alpha-Proteobacteria. The spelling of the specific epithet of Azospirillum largomobile is corrected to Azospirillum largimobile.

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Microorganisms that hydrolyse the ester linkages between phenolic acids and polysaccharides in plant cell walls are potential sources of enzymes for the degradation of lignocellulosic waste. An anaerobic, mesophilic, spore-forming, xylanolytic bacterium with high hydroxy cinnamic acid esterase activity was isolated from the gut of the grass-eating termite Tumilitermes pastinator. The bacterium was motile and rod-shaped, stained gram-positive, had an eight-layered cell envelope, and.formed endospores. Phylogenetic analysis based on 16S rRNA indicated that the bacterium is closely related to Clostridium xylanolyticum and is grouped with polysaccharolytic strains of clostridia. A wide range of carbohydrates were fermented, and growth was stimulated by either xylan or cellobiose as substrates. The bacterium hydrolysed and then hydrogenated the hydroxy cinnamic acids (ferulic and p-coumaric acids), which are esterified to arabinoxylan in plant cell walls. Three cytoplasmic enzymes with hydroxy cinnamic acid esterase activity were identified using non-denaturing gel electrophoresis. This bacterium possesses an unusual multilayered cell envelope in which both leaflets of the cytoplasmic membrane, the peptidoglycan layer and the S layer are clearly discernible. The fate of all these components was easily followed throughout the endospore formation process. The peptidoglycan component persisted during the entire morphogenesis. It was seen to enter the septum and to pass with the engulfing membranes to surround the prespore. It eventually expanded to form the cortex, verification for the peptidoglycan origin of the cortex. Sporogenic vesicles, which are derived from the cell wall peptidoglycan, were associated with the engulfment process. Spore coat fragments appeared early, in stage II, though spore coat formation was not complete until after cortex formation.

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Two species of Deretrema (Zoogonidae) are reported from labrid fishes from the Great Barrier Reef. D. nahaense Yamaguti, 1942 is recorded from the gall-bladders of the labrids Thalassoma hardwicke (Bennett), T. jansenii (Bleeker), T. lunare (Linnaeus) and T. lutescens (Lay & Bennett). This species is recognised, despite having been formerly synonymised with D. pacificum Yamaguti, 1942. In addition to morphological distinction, D. nahaense appears to have strict host-specificity for the genus Thalassoma. D. woolcockae n.sp. is described from the gall-bladder of Hemigymnus fasciatus (Bloch). The new species is close to D. acutum Pritchard, 1963 and D. plotosi Yamaguti, 1940, but differs slightly in the distribution of the vitelline follicles, the sucker-ratio and the position of the cirrus-sac. In addition, this species also appears to have a distinct host-specificity, being restricted to one labrid species.