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941.
Ftima P. Machado Inês C. Rodrigues Luís Gales Jos A. Pereira Paulo M. Costa Tida Dethoup Sharad Mistry Artur M. S. Silva Vitor Vasconcelos Anake Kijjoa 《Marine drugs》2022,20(11)
An unreported isocoumarin, (3S,4R)-4-hydroxy-6-methoxymellein (2), an undescribed propylpyridinium anthraquinone (4), and an unreported C-glucosyl resorcinol derivative, acetyl carnemycin E (5c), were isolated, together with eight previously reported metabolites including p-hydroxybenzaldehyde (1), 1,3-dimethoxy-8-hydroxy-6-methylanthraquinone (3a), 1,3-dimethoxy-2,8-dihydroxy-6-methylanthraquinone (3b), emodin (3c), 5[(3E,5E)-nona-3,5-dien-1-yl]benzene (5a), carnemycin E (5b), tajixanthone hydrate (6a) and 15-acetyl tajixanthone hydrate (6b), from the ethyl acetate extract of the culture of a marine sponge-derived fungus, Aspergillus stellatus KUFA 2017. The structures of the undescribed compounds were elucidated by 1D and 2D NMR and high resolution mass spectral analyses. In the case of 2, the absolute configurations of the stereogenic carbons were determined by comparison of their calculated and experimental electronic circular dichroism (ECD) spectra. The absolute configurations of the stereogenic carbons in 6a and 6b were also determined, for the first time, by X-ray crystallographic analysis. Compounds 2, 3a, 3b, 4, 5a, 5b, 5c, 6a, and 6b were assayed for antibacterial activity against four reference strains, viz. two Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and two Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853), as well as three multidrug-resistant strains. However, only 5a exhibited significant antibacterial activity against both reference and multidrug-resistant strains. Compound 5a also showed antibiofilm activity against both reference strains of Gram-positive bacteria. 相似文献
942.
Mónica Costa Carlos Cardoso Cláudia Afonso Narcisa M. Bandarra José A. M. Prates 《Journal of animal physiology and animal nutrition》2021,105(6):1075-1102
The effects of dietary macroalgae, or seaweeds, on growth performance and meat quality of livestock animal species are here reviewed. Macroalgae are classified into Phaeophyceae (brown algae), Rhodophyceae (red algae) and Chlorophyceae (green algae). The most common macroalga genera used as livestock feedstuffs are: Ascophyllum, Laminaria and Undaria for brown algae; Ulva, Codium and Cladophora for green algae; and Pyropia, Chondrus and Palmaria for red algae. Macroalgae are rich in many nutrients, including bioactive compounds, such as soluble polysaccharides, with some species being good sources of n-3 and n-6 polyunsaturated fatty acids. To date, the incorporation of macroalgae in livestock animal diets was shown to improve growth and meat quality, depending on the alga species, dietary level and animal growth stage. Generally, Ascophyllum nodosum can increase average daily gain (ADG) in ruminant and pig mostly due to its prebiotic activity in animal's gut. A. nodosum also enhances marbling score, colour uniformity and redness, and can decrease saturated fatty acids in ruminant meats. Laminaria sp., mainly Laminaria digitata, increases ADG and feed efficiency, and improves the antioxidant potential of pork. Ulva sp., and its mixture with Codium sp., was shown to improve poultry growth at up to 10% feed. Therefore, seaweeds are promising sustainable alternatives to corn and soybean as feed ingredients, thus attenuating the current competition among food-feed-biofuel industries. In addition, macroalgae can hinder eutrophication and participate in bioremediation. However, some challenges need to be overcome, such as the development of large-scale and cost-effective algae production methods and the improvement of algae digestibility by monogastric animals. The dietary inclusion of Carbohydrate-Active enZymes (CAZymes) could allow for the degradation of recalcitrant macroalga cell walls, with an increase of nutrients bioavailability. Overall, the use of macroalgae as feedstuffs is a promising strategy for the development of a more sustainable livestock production. 相似文献
943.
Estevan Luiz da Silveira Eduardo Luis Cupertino Ballester Karine Andréa da Costa Elizabeth Weinhardt de Oliveira Scheffer André Martins Vaz‐dos‐Santos 《Ecology of Freshwater Fish》2018,27(4):1126-1139
Fish communities’ organisation is a challenging task due to global, local and temporal variations related to biotic and abiotic factors, highlighting anthropic activities. The Verde River Basin (VRB) was chosen as a model to the fish community study due to its complexity, presenting a longitudinal gradient of degradation. The ichthyofauna and abiotic factors were sampled during twelve months in four sites. Analyses employed rarefaction curves with Hill numbers estimators and canonical correspondence analysis. The endemic Apareiodon sp. (not described), Hypostomus albopunctatus, H. strigaticeps, Oligosarcus paranensis, Neoplecostomus yapo and Trichomycterus diabolus were associated with structurally complex and well‐preserved environments. In contrary, Astyanax aff. fasciatus, Corydoras ehrhardti, Geophagus brasiliensis, H. ancistroides and Phalloceros harpagos showed tolerance to impacted environments. The methods here employed allowed to identify and explain differences in the ichthyofauna structure, distinguishing the influence of spatial, temporal and human effects on the fish communities. 相似文献
944.
Survival of White Spot Syndrome Virus–Infected Litopenaeus vannamei Fed with Ethanol Extract of Uncaria Tomentosa 下载免费PDF全文
Osmar Tomazelli Júnior Fernanda Kuhn Paulo José Mendonça Padilha Luiz R. Mota Vicente Sergio Winckler da Costa Bruno Corrêa da Silva Delano Dias Schleder Cristiano Nunes Nesi Jacir Dal Magro Sílvia de Lamo‐Castellví 《Journal of the World Aquaculture Society》2018,49(1):165-174
With the present project, the phytochemical composition of Uncaria tomentosa cultivated in Chapecó (Brazil) was analyzed and then the potential of using this local plant extract to protect by oral feeding virus‐infected Litopenaeus vannamei shrimp was also investigated. For this study, five treatments were tested: uninfected shrimp fed with pelleted feed (TC), WSSV‐infected shrimp fed with pelleted feed (T1), infected shrimp fed with pelleted feed with 1% ethanol extract of U. tomentosa (EEUT) (T2), infected shrimp fed with pelleted feed with 2% EEUT (T3), and infected shrimp fed pelleted feed with 4% EEUT (T4). The chemical analysis of EEUT showed the presence of alkaloids, flavonoids, sterols, terpenes, coumarins, and tannins and also a high in vitro free radical‐scavenging activity as well as high total phenolic content. Shrimp fed with 2 and 4% EEUT (T3 and T4) showed a survival probability significantly higher than T1 and T2 treatments and no clinical symptoms of WSSV infection. Immunological assay also showed a positive phenoloxidase activity effect on shrimp fed with EEUT. 相似文献
945.
D. Lippi M.R. De Paolis E. Di Mattia S. Grego T. Pietrosanti I. Cacciari 《Biology and Fertility of Soils》2000,30(4):276-283
The effect of salinity on growth, starvation-survival and recovery from salt stress of a Rhizobium sp. strain isolated from nodules of Acacia tortilis from a soil of Senegal was studied. Growth parameters of C-limited continuous cultures, grown in the presence and the absence
of 342 mM NaCl, decreased in the saline medium and with increasing dilution rates. The survival capacity of starved cultures
depended on the previous growth conditions: culturability of cells grown with salt was inversely related to growth rate, while
culturability increased with increasing dilution rate for cultures grown without salt. Culturability of the cultures subjected
to the double stress of starvation and salinity was reduced and a high percentage of cells entered the viable but nonculturable
state. All the starved cultures were capable of regrowth when nutrients became available, thus showing that this strain can
withstand long periods of nutrient deprivation in soil while maintaining the capacity for an active metabolism and a potential
infectiousness toward an appropriate host.
Received: 14 December 1998 相似文献
946.
By F. Minvielle J. -L. Monvoisin J. Costa A. Frenot Y. Maeda 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》1999,116(5):363-377
In much animal production, commercial animals are crossbreds from closed lines or breeds under long-term directional selection. Therefore it is desirable to be able to predict heterosis gains over the generations as it is done for genetic progress under within-line selection. However, heterosis is the phenotypic expression of a complex phenomenon which may involve several types of genetic effects like dominance and epistasis. In animal breeding, basic quantitative genetics theory indicates that heterosis should be proportional to (squared) differences in gene frequency between populations (e.g. F alconer and M ac K ay 1996), and it has been found approximately correct, so it is commonly used for planning crosses. Under that type of heterosis, however, selection towards the same objective in two populations should bring gene frequencies closer, and therefore it should eventually decrease heterosis. On the other hand, reciprocal recurrent selection designed to increase genetic distance between lines should eventually achieve maximum heterosis (O llivier 1982). Some experiments reviewed by brun (1982) have already compared genetic progress under within-line and reciprocal recurrent selection, but they did not focus on comparing the trend of heterosis with generations between the two selection methods. Also, heterosis was monitored periodically in some selection experiments on poultry, and results were reviewed by F airfull (1990). They were somewhat contradictory, but they generally failed to relate genetic progress to loss of heterosis under within-line selection. Moreover, in commercial production, as purebreds and crossbreds are not contemporaries and are generally maintained under very different management systems, estimations of heterosis and of the evolution of crossbred advantage over the generations may be difficult to obtain. Using the Japanese quail as an experimental animal, the present work was initiated specifically to follow the changes in heterosis brought about by selection for a single heterotic trait, early egg production (M invielle et al. 1995). For that purpose, two selection methods expected to have opposite effects on heterosis, directional within-line (or individual) selection and reciprocal recurrent selection, were applied for 13 generations in four quail lines started from two different origins, and trends of heterosis in the selected character and in weight and egg traits were evaluated. 相似文献
947.
Thirty six horses from nine Brazilian states (Goiás, Minas Gerais, Pará, Maranh?o, Piauí, Paraíba, Pernambuco, Rio Grande do Norte, and Ceará) were examined for infections by small strongyles. The following species were identified: Cylicocyclus nassatus, C. insigne, C. brevicapsulatus, C. leptostomum, C. radiatus, C. ultrajectinus, C. ashworthi, Cylicostephanus goldi, C. calicatus, C. minutus, C. longibursatus, Petrovinema poculatum, Coronocyclus coronatus, C. labiatus, C. labratus, Cyathostomum catinatum, C. pateratum, C. alveatum, Parapoteriostomum euproctus, Cylicodontophorus bicoronatus, Poteriostomum ratzii, P. imparidentatum and Gyalocephalus capitatus. The most prevalent were C. longibursatus (100%), C. nassatus (97.22%) and C. catinatum (94.44%). They were also the most abundant species, comprising 31.84, 23.71 and 14.14%, respectively, of the Cyathostominae parasites found. Infections were found to include 2-17 species in a single horse, with variable associations. 相似文献
948.
Chadaporn Prompanya Tida Dethoup Lucinda J. Bessa Madalena M. M. Pinto Luís Gales Paulo M. Costa Artur M. S. Silva Anake Kijjoa 《Marine drugs》2014,12(10):5160-5173
Two new isocoumarin derivatives, including a new 5-hydroxy-8-methyl-2H, 6H-pyrano[3,4-g]chromen-2,6-dione (1) and 6,8-dihydroxy-3,7-dimethylisocoumarin (2b), a new chevalone derivative, named chevalone E (3), and a new natural product pyripyropene S (6) were isolated together with 6, 8-dihydroxy-3-methylisocoumarin (2a), reticulol (2c), p-hydroxybenzaldehyde, chevalone B, chevalone C, S14-95 (4), and pyripyropene E (5) from the ethyl acetate extract of the undescribed marine sponge-associated fungus Aspergillus similanensis KUFA 0013. The structures of the new compounds were established based on 1D and 2D NMR spectral analysis, and in the case of compound 3, X-ray analysis was used to confirm its structure and the absolute configuration of its stereogenic carbons. Compounds 1, 2a–c and 3–6 were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria, Candida albicans ATCC 10231, and multidrug-resistant isolates from the environment. Chevalone E (3) was found to show synergism with the antibiotic oxacillin against methicillin-resistant Staphylococcus aureus (MRSA). 相似文献
949.
The occurrence of intermixing, especially that resulting from genetically modified (GM) species, is increasingly becoming a problem in the delicate chain of feed and food quality control. Thus, a strategy is needed for precisely quantifying the presence of intermixing. An analytical assay based on real-time PCR has been developed; it can ascertain the extent of unexpected intermixing of GM soybean with maize meal. Three soybean-maize mix levels, with soybean intermix percentages of, respectively, 0.1, 0.5, and 1%, were prepared to simulate samples containing traces of soybean. As calibrator standards, ad hoc multiple-target pGEM-T plasmids containing soybean and maize reference genes in a 1:1 ratio were constructed. Four different maize endogenous genes, alcohol dehydrogenase 1 (adh1), high-mobility group protein a (hmga), invertase 1 (ivr1), and zein (zein), were assessed, each combined with the soybean endogenous lectin 1 (lect1) gene. Plasmids containing adh1-lect1 and zein-lect1 genes were found to be the most reliable calibration systems for this analysis, providing precise and accurate quantification results. Measuring the percentage of GM soybean intermixing makes it possible to calculate the actual transgenic component of the total sample. 相似文献
950.
Maria Vera Jesus Da Costa Yamunarani Ramegowda Venkategowda Ramegowda Nataraja N. Karaba Sheshshayee M. Sreeman Makarla Udayakumar 《水稻科学》2021,28(3):233-242
Simultaneous occurrence of drought and heat stress will have significant negative impact on rice yield, especially under upland conditions. The projected increase in global temperatures and reduced precipitation will increase the frequency of occurrence and intensity of these stresses, threatening rice production. Despite recognizing the importance of combined stress in rice, the knowledge generated in this area is very limited. Though complex, understanding combined stress tolerance of rice under water saving cultivation is more critical towards development of climate resilient rice cultivars. Here, we summarized the effects of combined stress on rice physiology with more emphasis on reproductive stage. Omics responses, phenotyping and physiology challenges and potential strategies for improving combined stress tolerance in rice are also discussed. 相似文献