Reaction between hydroxycinnamic acids and anthocyanin-pyruvic acid adducts yielding new portisins     

Oliveira J  de Freitas V  Silva AM  Mateus N 《Journal of agricultural and food chemistry》2007,55(15):6349-6356

Three new anthocyanin-derived pigments were found to occur in a 2-year-old Port red wine. Their structures were elucidated through LC/DAD-MS and NMR analysis and were found to correspond to a pyranoanthocyanin moiety linked to substituted cinnamyl substituents. The structures of these compounds are very similar to the one already reported for portisins, with a phenolic moiety replacing the catechin moiety. The newly formed anthocyanin-derived compounds display a bathochromic shift of the lambdamax ( approximately 540 nm) when compared with their anthocyanin-pyruvic acid adduct precursor (lambdamax = 511 nm), which may be due to the extended conjugation of the pi electrons in the structures of those pigments. Studies performed in model solutions helped to clarify the formation mechanism of these pigments that can result from the nucleophilic attack of the olefinic double bond of a hydroxycinnamic acid to the eletrophilic C-10 position of the anthocyanin-pyruvic acid adduct, followed by the loss of a formic acid molecule and decarboxylation. The chromatic characterization of these malvidin-3-glucoside-derived compounds revealed a higher resistance to discoloration against the nucleophilic attack by water and bisulfite when compared to malvidin-3-glucoside that is almost converted into its colorless hemiacetal form. However, the resistance to discoloration of these new pigments is not as high as the one reported for catechin-derived portisins. This could be explained by the presence of a smaller group (hydroxycinnamyl group), which does not protect so efficiently the chromophore against nucleophilic attack at the C-2 position. The occurrence of these pigments in red wine highlights new chemical pathways involving anthocyanin-pyruvic acid derivatives as precursors for the formation of new pigments in subsequent stages of wine aging that may contribute to its color evolution.  相似文献   

Inhibition of photophosphorylation and electron transport chain in thylakoids by lasiodiplodin, a natural product from Botryosphaeria rhodina     

Veiga TA  Silva SC  Francisco AC  Filho ER  Vieira PC  Fernandes JB  Silva MF  Müller MW  Lotina-Hennsen B 《Journal of agricultural and food chemistry》2007,55(10):4217-4221

Four natural products were isolated from the fungus Botryosphaeria rhodina, and their effects on photosynthesis were tested. Only lasiodiplodin (1) inhibited ATP synthesis and electron flow from water to methylviologen; therefore, it acts as a Hill reaction inhibitor in freshly lysed spinach thylakoids. Photosystem I and II and partial reactions as well as ATPase were measured in the presence of 1. Three new different sites of 1 interaction and inhibition were found: one at CF1, the second in the water-splitting enzyme, and the third at the electron-transfer path between P680 and QA; these targets are different from that of the synthetic herbicides present. Electron transport chain inhibition by 1 was corroborated by fluorescence induction kinetics studies.  相似文献   

Bioactive Compounds and Antioxidant Capacity of Strawberry Jams     

Da Silva Pinto M  Lajolo FM  Genovese MI 《Plant foods for human nutrition (Dordrecht, Netherlands)》2007,62(3):127-131

Strawberries represent the main source of ellagic acid derivatives in the Brazilian diet. They are also good sources of flavonoids, mainly anthocyanins, and phenolic acids, to which many beneficial effects have been attributed. However, as the fruit is not available all the year, the objective of this work was to determine whether the jams could also represent a good source of bioactive compounds. In the current study, five different commercially available strawberry jams were characterized in relation to flavonoids, total phenolics, free and total ellagic acid contents, and antioxidant capacity. Anthocyanins were detected only in two jams at very low content. Kaempferol glycosides were the main flavonoids present (from 0.38 to 1.05 mg/100 g fresh weight, FW), while quercetin glycosides were present in the range 0.14–1.20 mg/100 g FW. Free and total ellagic acid content ranged from 0.4 to 2.9 mg/100 g FW, and from 17.0 to 29.5 mg/100 g FW, respectively. Total phenolics varied from 58 to 136 mg/100 g FW, and the antioxidant capacity from 0.55 to 0.76 μmol BHT (Butylhydroxytoluene) equivalents/g FW. Overall, results indicated that jams can also represent a good source of antioxidant compounds, although compared to the fruit important losses seem to occur.  相似文献   

Kinetics of energy source utilization in Boophilus microplus (Canestrini, 1887) (Acari: Ixodidae) embryonic development     

Campos E  Moraes J  Façanha AR  Moreira E  Valle D  Abreu L  Manso PP  Nascimento A  Pelajo-Machado M  Lenzi H  Masuda A  Vaz Ida S  Logullo C 《Veterinary parasitology》2006,138(3-4):349-357

The present work evaluates the kinetics of utilization of the main potential energy sources throughout the embryonic developmental stages of Boophilus microplus. The embryonic development of this arthropod is completed in 21 days. Cellularization of the blastoderm occurs on the 6th day and is rapidly followed by germ band extension and segmentation, whose first signs are visible on the 7th day. Cellularization is typically a maternal-driven process, carried out by molecular determinants deposited in the oocyte during oogenesis. On the other hand, segmentation is of zygotic nature, being the consequence of the synthesis of various components by the growing embryo. The enhancement in total B. microplus RNA was observed after cellularization, corroborating the replacement of maternal-driven processes by embryonic zygotic expression. An abrupt increase in oxygen consumption was observed from cellularization until the 8th day of development. The reduction in dry weight at the same period and the susceptibility of oxygen consumption to KCN suggest that the respiration process is activated during early embryonic development. A marked decrease in total lipid content occurred between the 5th and 7th days of development, suggesting this is the main energy source for cellularization. A major reduction in carbohydrate content occurred later, between the 7th and 9th days, and it could be assigned to the morphological segmentation of the embryo. Although the total amount of proteins remains unchanged from oviposition to hatching, a 15% reduction in vitellin (VT) content was observed before cellularization, up to the 4th day after egglaying. This observation was correlated to the synthesis of new proteins needed to support early embryo development. Additional 20% of VT was consumed thereafter, mainly at the end of embryogenesis, and in this case VT is probably used as energy source to the older embryo. Altogether, these data indicate different energy sources for maternal and zygotic driven processes.  相似文献   

Virulence-associated gene profiling of Streptococcus suis isolates by PCR   总被引：11，自引：0，他引：11  

Silva LM  Baums CG  Rehm T  Wisselink HJ  Goethe R  Valentin-Weigand P 《Veterinary microbiology》2006,115(1-3):117-127

Definition of virulent Streptococcus suis strains is controversial. One successful approach for identification of virulent European strains is differentiation of capsular serotypes (or the corresponding cps types) and subsequent detection of virulence-associated factors, namely the extracellular factor (EF, epf), the muramidase-released protein (MRP, mrp) and the hemolysin suilysin (SLY, sly). In this work we present a novel multiplex PCR (MP-PCR) and an mrp variant PCR for identification and characterization of virulent S. suis strains. These new methods were used to identify association of disease with particular profiles of virulence-associated genes. The MP-PCR allowed identification of S. suis through detection of the housekeeping gene gdh, differentiation of four cps types (1, 2, 7 and 9), and detection of epf, mrp, sly and arcA (arginine deiminase from S. suis). Furthermore, this study describes the first PCR assay for differentiation of at least six mrp variants. Expression of the corresponding size variants of MRP was shown for four of the six mrp variants, but was undetectable for the two larger mrp variants in the particular strains investigated. The results of this study suggest that cps7 strains are associated with pneumonia and that variation of mrp is very pronounced among these strains. Gene profiles of invasive, pneumonia and carrier S. suis isolates by combination of PCR assays allowed differentiation of 24 different genotypes among cps1, 2, 7 and 9 strains. Forty-five percent of the invasive S. suis diseases investigated in this study were caused by only two of these genotypes, namely cps2/mrp+/epf+/sly+ and cps9/mrp(*)/epf-/sly+. Thus, this study demonstrates for the first time a uniform profile of the particular virulence-associated genes for the vast majority of the investigated invasive cps9 strains.  相似文献   

Antinociceptive activity of the pyranocoumarin seselin in mice   总被引：1，自引：0，他引：1  

Lima V  Silva CB  Mafezoli J  Bezerra MM  Moraes MO  Mourão GS  Silva JN  Oliveira MC 《Fitoterapia》2006,77(7-8):574-578

Seselin an angular pyranocoumarin at dose of 0.5, 4.5 or 40.5 mg/kg inhibited the writhing response induced by acetic acid in a significant and dose-dependent manner, by 19.5%, 26.2% and 41.4%, respectively. Using the same doses, seselin elicited a significant inhibition of formalin response during the second phase (inflammatory), by 90.3%, 97.8% and 95.3%, respectively. Besides, a significant reduction of licking time was observed during the first phase (neurogenic) at the highest doses of seselin, by 34.4% and 66.9%, respectively. On the contrary, in the hot plate test no effect was observed after seselin treatment. In conclusion, seselin was able to inhibit inflammatory hyperalgesia, suggesting that this natural product possesses both important peripheral anti-inflammatory and antinociceptive properties.  相似文献   

Scion-rootstock interaction affects the physiology and fruit quality of sweet cherry     

Gonçalves B  Moutinho-Pereira J  Santos A  Silva AP  Bacelar E  Correia C  Rosa E 《Tree physiology》2006,26(1):93-104

Water relations, leaf gas exchange, chlorophyll a fluorescence, light canopy transmittance, leaf photosynthetic pigments and metabolites and fruit quality indices of cherry cultivars 'Burlat', 'Summit' and 'Van' growing on five rootstocks with differing size-controlling potentials that decrease in the order: Prunus avium L. > CAB 11E > Maxma 14 > Gisela 5 > Edabriz, were studied during 2002 and 2003. Rootstock genotype affected all physiological parameters. Cherry cultivars grafted on invigorating rootstocks had higher values of midday stem water potential (Psi(MD)), net CO(2) assimilation rate (A), stomatal conductance (g(s)), intercellular CO(2) concentration (C(i)) and maximum photochemical efficiency of photosystem II (PSII) (F(v)/F(m)) than cultivars grafted on dwarfing rootstocks. The Psi(MD) was positively correlated with A, g(s) and C(i). Moreover, A was positively correlated with g(s), and the slopes of the linear regression increased from invigorating to dwarfing rootstocks, indicating a stronger regulation of photosynthesis by stomatal aperture in trees on dwarfing Edabriz and Gisela 5. The effect of rootstock genotype was also statistically significant for leaf photosynthetic pigments, whereas metabolite concentrations and fruit physicochemical characteristics were more dependent on cultivar genotype. Among cultivars, 'Burlat' leaves had the lowest concentrations of photosynthetic pigments, but were richest in total soluble sugars, starch and total phenols. Compared with the other cultivars, 'Summit' had heavier fruits, independent of the rootstock. 'Burlat' cherries were less firm and had lower concentrations of soluble sugars and a lower titratable acidity than 'Van' cherries. Nevertheless, 'Van' cherries had lower lightness, chroma and hue angle, representing redder and darker cherries, compared with 'Summit' fruits. In general, Psi(MD) was positively correlated with fruit mass and A was negatively correlated with lightness and chroma. These results demonstrate that: (1) water relations and photosynthesis of sweet cherry tree are mainly influenced by the rootstock genotype; (2) different physicochemical characteristics observed in cherries of the three cultivars suggest that regulation of fruit quality was mainly dependent on the cultivar genotype, although the different size-controlling rootstocks also had a significant effect.  相似文献   

Acute cattle intoxication from Nerium oleander pods     

Soto-Blanco B  Fontenele-Neto JD  Silva DM  Reis PF  Nóbrega JE 《Tropical animal health and production》2006,38(6):451-454

Seven outbreaks of acute intoxication from oleander (Nerium oleander) in cattle were reported in Northeast of Brazil. A total of 92 cattle were poisoned by oleander in 7 different herds; 57 animals died (67% of affected cattle). All cases reported here occurred during dry season. Two of the outbreaks resulted from offering oleander triturated and mixed with fodder. In the other cases, accidental ingestion of residual parts of oleander derived from pruning or cutting plants on grazing land were responsible. Clinical signs were diverse; the most common were locomotion disturbances, diarrhoea, depression and sudden death. Postmortem findings varied from no significant lesions to widespread haemorrhage. The presence of oleander leaves in the rumen was noted in all cases. The lack of information about the toxicity of oleanders was the main cause for the accident, which prompt us to stimulate wide divulgation of the common toxic plants.  相似文献   

Expression of terminal differentiation proteins defines stages of mouse mammary gland development     

Mikaelian I  Hovick M  Silva KA  Burzenski LM  Shultz LD  Ackert-Bicknell CL  Cox GA  Sundberg JP 《Veterinary pathology》2006,43(1):36-49

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Differential diagnosis of dog hookworms based on PCR-RFLP from the ITS region of their rDNA     

e Silva LM  Miranda RR  Santos HA  Rabelo EM 《Veterinary parasitology》2006,140(3-4):373-377

Species of Ancylostoma infecting dogs and sometimes humans are sympatric in many parts of the world. The establishment of a specific molecular diagnostic tool is important, not only to refine information for epidemiological studies, but also to evaluate the efficacy of vaccine programmes and assist in the development of specific drug treatments. The ITS region from 20 specimens of A. braziliense, collected from three separate geographical areas of Brazil, and from 10 specimens of A. caninum, collected from the same area in Brazil were sequenced and analyzed. Alignment of sequences showed that this gene is highly conserved. The intraspecific polymorphism for both species was less then 1%, whereas the interspecific polymorphism was 6.2, 7.3 and 9.4% between A. ceylanicum and A. braziliense; A. caninum and A. ceylanicum and A. ceylanicum and A. braziliense, respectively. Among the three species it was 12.3%. This revealed the ITS region as highly conserved and consequently a good molecular marker for diagnostic studies. In this work, four restriction enzymes were used in a PCR-RFLP using the ITS region of rDNA, to establish a differential diagnosis which discriminates between three Ancylostoma species, A. braziliense, A. caninum and A. ceylanicum. The best pattern was given by the HinfI enzyme, which produced different fragment sizes for each of the three species. Furthermore, the diagnostic tool differentiates DNA extracted directly from faeces of Ancylostoma-infected dogs.  相似文献