Diazaquinomycins E–G,Novel Diaza-Anthracene Analogs from a Marine-Derived Streptomyces sp.

As part of our program to identify novel secondary metabolites that target drug-resistant ovarian cancers, a screening of our aquatic-derived actinomycete fraction library against a cisplatin-resistant ovarian cancer cell line (OVCAR5) led to the isolation of novel diaza-anthracene antibiotic diazaquinomycin E (DAQE; 1), the isomeric mixture of diazaquinomycin F (DAQF; 2) and diazaquinomycin G (DAQG; 3), and known analog diazaquinomycin A (DAQA; 4). The structures of DAQF and DAQG were solved through deconvolution of X-Ray diffraction data of their corresponding co-crystal. DAQE and DAQA exhibited moderate LC₅₀ values against OVCAR5 of 9.0 and 8.8 μM, respectively. At lethal concentrations of DAQA, evidence of DNA damage was observed via induction of apoptosis through cleaved-PARP. Herein, we will discuss the isolation, structure elucidation, and biological activity of these secondary metabolites.     

Colorimetric Analysis of <Emphasis Type="Italic">Hibiscus</Emphasis> Beverages and their Potential Antioxidant Properties

In food industry, roselle beverages and their subproducts could be functional ingredients since they are an excellent source of bioactive compounds with improved performance due to their important anthocyanins content. The aim of this study was to analyze anthocyanin content and antioxidant properties of aqueous infusions elaborated with color contrasting Hibiscus materials and design a mathematical model in order to predict color-composition relationship. Color measurements of beverages from roselle (Negra, Sudan and Rosa) were made by transmission spectrophotometry, anthocyanins quantification was determined by HPLC, and antioxidant potential was evaluated by in vitro methods (ABTS and FRAP assays). Beverages prepared with particle size minor of 250 μm presented until 4- and 2- times more anthocyanins content and antioxidant capacity respectively, in comparison to beverages prepared with powders with particle size major of 750 μm. Positive correlations among pigments composition and color parameters were found (p?<?0.05), showing that anthocyanins content, antioxidant capacity, C*_ab and h_ab values increased in relation with the smallest particle size of flours. Also, mathematical models were stablished to predict anthocyanin content (r?≥?0.97) and antioxidant capacity (r?≥?0.89) from color data; we propose equations for quick estimation of the antioxidant capacity in the Hibiscus beverages with high anthocyanin content. The obtained models could be an important tool to be used in food industry for pigment characterization or functional compounds with potential health benefits.     

Antihyperlipidemic Effect of Methanolic Extract from Opuntia joconostle Seeds in Mice Fed a Hypercholesterolemic Diet

The purpose of this study was to evaluate the hypolipidemic effect of a methanolic extract from Opuntia joconostle seeds fed to mice in a hypercholesterolemic diet. Acute toxicity of the methanolic extract was investigated by an established method. Phenolic composition and antioxidant activity were determined by high-performance liquid chromatography and DPPH, respectively. The total phenolic content of Opuntia joconostle seeds was 47.85?±?1.29 mg gallic acid equivalents/g dry weight. The main phenolic compounds were identified as quercetin, rutin, and cafeic acid. Percent inhibition of DPPH⁺ was 49.76?±?0.49 %. The oral LD₅₀ for the methanolic extract from the Opuntia joconostle seeds was >5,000 mg/kg BW. Mice fed a hypercholesterolemic diet for six days exhibited significantly (P?≤?0.001) higher plasma lipid levels than mice fed a normal diet. Remarkably, supplementation with methanolic extract from Opuntia joconostle at doses of 1, 2, and 5 g/kg body weight significantly (P?≤?0.001) prevented the increase in total cholesterol, low-density lipoprotein cholesterol, triglycerides level, and atherogenic index. Similar concentrations of the HDL cholesterol were observed in both treated and control groups. A significant dose-dependent reduction in lipid levels was noted for treated groups compared to the hypercholesterolemic group. We attribute this result to the seeds’ phenolic composition. This methanolic extract has potential to be included in short-term hypercholesterolemia treatment regimens as it exhibits hypolipidemic activity with no apparent toxic manifestations.     

Proteins and Carbohydrates from Red Seaweeds: Evidence for Beneficial Effects on Gut Function and Microbiota

Based on their composition, marine algae, and namely red seaweeds, are good potential functional foods. Intestinal mucosal barrier function refers to the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules. Here, we will first outline the component of seaweeds and will summarize the effects of these on the regulation of mucosal barrier function. Special attention will be paid to unique components of red seaweeds: proteins and derived peptides (e.g., phycobiliproteins, glycoproteins that contain “cellulose binding domains”, phycolectins and the related mycosporine-like amino acids) together with polysaccharides (e.g., floridean starch and sulfated galactans, such as carrageenans, agarans and “dl-hybrid”) and minerals. These compounds have been shown to exert prebiotic effects, to regulate intestinal epithelial cell, macrophage and lymphocyte proliferation and differentiation and to modulate the immune response. Molecular mechanisms of action of peptides and polysaccharides are starting to be elucidated, and evidence indicating the involvement of epidermal growth factor receptor (EGFR), insulin-like growth factor receptor (IGFR), Toll-like receptors (TLR) and signal transduction pathways mediated by protein kinase B (PKB or AKT), nuclear factor-κB (NF-κB) and mitogen activated protein kinases (MAPK) will also be summarized. The need for further research is clear, but in vivo experiments point to an overall antiinflammatory effect of these algae, indicating that they can reinforce membrane barrier function.     

Agronomic characterization of diploid hybrid families derived from crosses between haploids of the common potato and three wild Argentinian tuber-bearing species

Five diploid hybrid families derived from crosses between haploids of three Argentinian cultivars and three diploid wild species,Solanum gourlayi, S. chacoense andS. spegazzinii, were evaluated in a field experiment in Balcarce. All plants were androsterile and, thus, could not be screened for 2n pollen production. Data on agronomic tuber traits were statistically analyzed. Differences among families were non-significant for tuber number/plant, but were significant for tuber weight/plant and dry matter content (with values above 21.0% in two of them). The relative frequencies of tubers in the categories established for size, skin texture, and eye depth were family dependent, but they were familiy independent in the categories established for tuber shape and skin color. Great morphological variability was detected for all the traits studied, and plants with high yield and high dry matter content were identified. These families can be used as sources of germplasm in breeding and to explore heterotic responses in 2x × 4x crosses, given the capacity of some plants to produce 2n eggs, as found in a related investigation.     

Effects of Soybean Fortification on Protein Quality of Tortilla-Based Diets Produced from Regular and Quality Protein Maize

The physiological development of laboratory rats fed with a typical indigenous tortilla diet was studied for two generations. The experiment compared casein control diet and five different types of diets: (1) a diet of tortillas obtained from fresh masa (FM); (2) regular tortillas produced from enriched dry masa flour containing vitamins B₁, B₂, niacin, folic acid, and the microminerals iron and zinc (REDMF); (3) tortillas produced from enriched dry masa flour fortified with 6% defatted soybean meal (FEDMF); (4) tortillas produced from enriched quality protein maize flour (EQPM); and (5) and, tortillas produced from enriched quality protein maize flour fortified with 3% defatted soybean meal (FEQPM). The growth of rats fed FEDMF and FEQPM diets was significantly higher (P<0.05) in both generations than their counterparts fed EQPM, REDMF, or FM diet. Animals fed quality protein maize (QPM) tortilla had the highest protein digestibility, but the FEQPM and FEDMF diets had the highest biological value (BV), net protein utilization (NPU), and protein-digestibility-corrected EAA scores (PDCEAAS). The difference among treatments was more evident in the second-generation rats. The pregnancy rate, number of newborns/litter, litter weight, and newborn survival rate was also higher for rats fed FEDMF, EQPM, and FEQPM diets than their counterparts fed REDMF and FM.     

Antiradical Capacity and Induction of Apoptosis on HeLa Cells by a <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> Extract

Jamapa bean is a black Phaseolus vulgaris variety rich in condensed tannins, anthocyanins and flavonols with interesting biological activities. The objective of this work was to evaluate the antiradical capacity (ARC) of a Jamapa bean methanolic extract (BME) and some of the proanthocyanidin-rich fractions derived from it, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The effect of the BME on some proteins involved in apoptosis on HeLa cells was also evaluated. A strong correlation between proanthocyanidin concentration in BME and antiradical capacity was found, suggesting that these compounds contribute significantly to antiradical activity. BME was a better radical scavenger than butylated hydroxytoluene (45.6 and 33.9% ARC at 400 μM, respectively). Two proanthocyanidin-rich fractions obtained after a preliminary separation of the BME using Toyopearl (TP4 and TP6) exhibited a higher antiradical activity than the parent extract. The treatment of HeLa cells with 35 μg BME/ml/24 h increased the expression of Bax and Caspase-3, pro-apoptotic proteins (6.13 and 1.2 times for Caspase-3 and Bax, respectively). The mechanism of action of some proteins involved in apoptosis was also evaluated, and the results suggest that black Jamapa bean could be an important source of polyphenolic compounds with potential biological use as antioxidant and anticancer agents.     

Antioxidant and Antifungal Activity of <Emphasis Type="Italic">Verbena officinalis</Emphasis> L. Leaves

The scavenging activity against DPPH (1,1-diphenil-2-picrylhydrazyl) radical and the antifungal effect against chloroform, ethyl acetate and 50% methanolic extracts of Verbena officinalis leaves were investigated. The activity of different fractions of 50% methanolic extract and some isolated compounds were also investigated. The results suggest that 50% methanolic extract and caffeoyl derivatives could potentially be considered as excellent and readily available sources of natural antifungal and antioxidant compounds.     

Habitat configuration for an obligate shallow‐water delphinid: The Indo‐Pacific humpback dolphin,Sousa chinensis,in the Beibu Gulf (Gulf of Tonkin)

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