Purification of a Low Molecular Weight Fucoidan for SPECT Molecular Imaging of Myocardial Infarction

Fucoidans constitute a large family of sulfated polysaccharides with several biochemical properties. A commercial fucoidan from brown algae, containing low molecular weight polysaccharidic species constituted of l-fucose, uronic acids and sulfate groups, was simply treated here with calcium acetate solution. This treatment led to a purified fraction with a yield of 45%. The physicochemical characterizations of the purified fucoidan using colorimetric assay, MALLS, dRI, FT-IR, NMR, exhibited molecular weight distributions and chemical profiles similar for both fucoidans whereas the sulfate and l-fucose contents increased by 16% and 71%, respectively. The biodistribution study in rat of both compounds labeled with ^99mTc evidenced a predominant renal elimination of the purified fucoidan, but the crude fucoidan was mainly retained in liver and spleen. In rat myocardial ischemia-reperfusion, we then demonstrated the better efficiency of the purified fucoidan. This purified sulfated polysaccharide appears promising for the development of molecular imaging in acute coronary syndrome.     

A miniaturized method for fast,simple, and sensitive pesticide analysis in soils

Journal of Soils and Sediments - Organochlorine pesticides (OCPs) like lindane and DDT have been used extensively after World War II until the 1990s. Still, residues of these pesticides can be...     

Investigating Wild Berries as a Dietary Approach to Reducing the Formation of Advanced Glycation Endproducts: Chemical Correlates of In Vitro Antiglycation Activity

Evidence supports the health promoting benefits of berries, particularly with regard to the prevention and management of chronic diseases such cardio- and cerebrovascular disease, diabetes and Alzheimer’s disease. Two related pathophysiological features common to many of these conditions are oxidative stress and the accumulation of advanced glycation endproducts (AGEs). Whereas antioxidant properties are well-established in several species of berries and are believed central to their protective mechanisms, few studies have investigated the effects of berries on AGE formation. Here, employing a series of complementary in vitro assays, we evaluated a collection of wild berry extracts for 1) inhibitory effects on fluorescent-AGE and Nε- (carboxymethyl)lysine-albumin adduct formation, 2) radical scavenging activity and 3) total phenolic and anthocyanin content. All samples reduced AGE formation in a concentration-dependent manner that correlated positively with each extract’s total phenolic content and, to a lesser degree, total anthocyanin content. Inhibition of AGE formation was similarly related to radical scavenging activities. Adding antiglycation activity to the list of established functional properties ascribed to berries and their phenolic metabolites, our data provide further insight into the active compounds and protective mechanisms through which berry consumption may aid in the prevention and treatment of chronic diseases associated with AGE accumulation and toxicity. As widely available, safe and nutritious foods, berries represent a promising dietary intervention worthy of further investigation.     

trans-C18:1 isomers in cheeses enriched in unsaturated fatty acids and manufactured with different milk fat globule sizes

Increasing the knowledge on dietary fat composition, mainly the minor components, will improve the nutritional value of foods and their labeling. In this study, we examined the trans-octadecenoic acid (C18:1) composition of Emmental cheeses enriched in unsaturated fatty acids (FA) and manufactured with milks produced by cows selected to produce small and large fat globules. The FA composition of the milks was not significantly ( P > 0.05) different from the FA composition of the corresponding Emmental cheeses. Increasing the unsaturated FA content of the cheeses using dietary manipulations lead to an increase in the trans-C18:1 and changed their isomeric profiles. In milk fat produced with the linseed-enriched diet, the trans-10 C18:1 concentration was greater than trans-11 C18:1 (vaccenic acid), which is classically the major trans-C18:1 in milk fat. The content in trans-C18:1 and more particularly in trans-10 C18:1 was negatively correlated with the size of fat globules ( r (2) = 0. 82 and 0.87, respectively) and related to milk fat depression. The trans-C18:1 content was negatively correlated with the saturated FA (slope = -0.35; r (2) = 0.81) and positively correlated with the unsaturated (slope = 0.29; r (2) = 0.85) and monounsaturated (slope = 0.32; r (2) = 0.81) FA. Focusing on the health-related considerations of fat in food products, further nutritional studies are needed to elucidate the role of trans-C18:1 isomers.     

Characterization of metabolites of fungicidal cymoxanil in a sensitive strain of Botrytis cinerea

The metabolism of cymoxanil [1-(2-cyano-2-methoxyiminoacetyl)-3-ethyl urea] by a very sensitive strain of Botrytis cinerea toward this fungicide was studied by using [2-(14)C]-cymoxanil. Labeled cymoxanil was added either in a culture of this strain or in its enzymatic extract. The main metabolites, detected in biological samples, were isolated and identified by mass and NMR spectrometry. Their identification allowed us to show that this strain quickly metabolized cymoxanil according to at least three enzymatic pathways: (i) cyclization leading, after hydrolysis, to ethyl parabanic acid, (ii) reduction giving demethoxylated cymoxanil, and (iii) hydrolysis and reduction followed by acetylation leading to N-acetylcyanoglycine. In a cell-free extract of the same strain, only the first and the second enzymatic reactions, quoted above, occurred. Biological tests showed that, among all the metabolites, only N-acetylcyanoglycine is fungitoxic toward this sensitive strain.     

Phenolic compounds contribute to dark bran pigmentation in hard white wheat

Unacceptably dark bran color has prevented the white-kernelled variety Argent from meeting grain color marketing standards for hard white wheats (Triticum aestivum L.). The objective of this research was to identify phenolic compounds that negatively affect bran color in white wheat using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and vanillin-HCl and NaOH staining methods. In mature bran, FT-ICR-MS detected derivatives of the flavonol quercetin in varieties Argent and RL4137 (red-kernelled wheat) but not in W98616, a white wheat variety with acceptable grain color. Derivatives of the isoflavone formononetin were more abundant in W98616 relative to RL4137 and Argent. Vanillin-HCl staining indicated that RL4137 sequestered high levels of proanthocyanidin (PA) throughout its entire seed coat, whereas white wheats sequestered PAs as discrete speckles. Argent possessed abundant speckles over its entire seed coat, whereas speckles were almost undetectable in W98616. In mature kernels, flavonoids throughout the seed coat of RL4137 reacted with NaOH, but only the speckles appeared to react in white wheats. W98616 consistently had lighter grain than Argent before and after NaOH treatment. Free and bound phenolic differences in bran samples confirmed that the darker seed coat color of Argent, relative to W98616, was likely due to higher total phenolic acid content. Although isoflavones accumulated in Argent and RL4137, it appears that the majority of the flux through the flavonoid pathway ultimately accumulates quercetin derivatives and PAs. In W98616, PAs accumulate, but it appears that flavonoid biosynthesis ultimately accumulates isoflavones. Argent, compared to W98616, generally accumulated higher levels of total phenolics (flavonols, stilbenes, and PAs) within its darker pigmented bran.     

Irradiance-induced plasticity in the hydraulic properties of saplings of different temperate broad-leaved forest tree species

We assessed the irradiance-related plasticity of hydraulic architecture in saplings of Betula pendula Roth., a pioneer species; Acer pseudoplatanus L., Fraxinus excelsior L. and Quercus robur L., which are post-pioneer light-requiring species; and Quercus petraea Matt. Liebl. and Fagus sylvatica L. Plants were grown in pots in 36%, 16% and 4% of full sunlight. Hydraulic conductance was measured with a high-pressure flow-meter in entire, in situ root systems and in excised shoots. Leaf-specific whole-plant conductance (LSC) increased with irradiance, due, in part, to an effect of irradiance on plant size. In addition, there was a size-independent effect of irradiance on LSC due, in part, to an increase in root hydraulic conductance paralleled by an increase in root biomass scaled to leaf area. Changes in shoot conductivity also contributed to the size-independent plasticity of LSC. Vulnerability to cavitation measured in current-year twigs was much larger in shade-grown plants. Betula pendula had the highest whole-plant, root and shoot conductances and also the greatest vulnerability to cavitation. The other species were similar in LSC, but showed some variation in root conductance scaled to biomass, with Q. robur, Q. petraea and F. sylvatica having the lowest root conductance and susceptibility to cavitation. All species showed a similar irradiance-related plasticity in LSC.     

Induction of hypericins in Hypericum perforatum in response to chromium

Seedlings of Hypericum perforatum were grown with 0.01 and 0.1 mM of chromium added to the nutrient media. A treatment with 0.01 mM Cr(VI) for seven days resulted in an increased production of protopseudohypericin (+135%), hypericin (+38%) and pseudohypericin (+5%). Treatment with 0.1 mM Cr(VI) for two days also caused an increase of protopseudohypericin (+167%), hypericin (25%) and pseudohypericin (+5%). The greatest effect of chromium treatment was observed at a concentration of 0.1 mM for seven days: protopseudohypericin increased +404% and pseudohypericin to +379%. Hypericin was not affected by this treatment.     

Biomass, size, and trophic status of top predators in the Pacific Ocean

Fisheries have removed at least 50 million tons of tuna and other top-level predators from the Pacific Ocean pelagic ecosystem since 1950, leading to concerns about a catastrophic reduction in population biomass and the collapse of oceanic food chains. We analyzed all available data from Pacific tuna fisheries for 1950-2004 to provide comprehensive estimates of fishery impacts on population biomass and size structure. Current biomass ranges among species from 36 to 91% of the biomass predicted in the absence of fishing, a level consistent with or higher than standard fisheries management targets. Fish larger than 175 centimeters fork length have decreased from 5% to approximately 1% of the total population. The trophic level of the catch has decreased slightly, but there is no detectable decrease in the trophic level of the population. These results indicate substantial, though not catastrophic, impacts of fisheries on these top-level predators and minor impacts on the ecosystem in the Pacific Ocean.     

Elemental compositions of comet 81P/Wild 2 samples collected by Stardust

We measured the elemental compositions of material from 23 particles in aerogel and from residue in seven craters in aluminum foil that was collected during passage of the Stardust spacecraft through the coma of comet 81P/Wild 2. These particles are chemically heterogeneous at the largest size scale analyzed ( approximately 180 ng). The mean elemental composition of this Wild 2 material is consistent with the CI meteorite composition, which is thought to represent the bulk composition of the solar system, for the elements Mg, Si, Mn, Fe, and Ni to 35%, and for Ca and Ti to 60%. The elements Cu, Zn, and Ga appear enriched in this Wild 2 material, which suggests that the CI meteorites may not represent the solar system composition for these moderately volatile minor elements.