Differential scanning calorimetry evidence of the enhancement of beta-sitosterol absorption across biological membranes mediated by beta-cyclodextrins

beta-Sitosterol is a plant sterol that has received much attention because of its effectiveness in reducing the absorption of dietary cholesterol, as well as in offering protection from cardiovascular diseases and cancer development. Thus, the knowledge of the interaction of beta-sitosterol with biological membranes can help in understanding its mechanism of action. In the present paper, the differential scanning calorimetry technique has been used to study the interaction of beta-sitosterol with a biomembrane model constituted by dimyristoylphosphatidylcholine multilamellar vesicles. Furthermore, kinetic experiments have been carried out to follow the uptake of beta-sitosterol by biomembranes and the effect of beta-cyclodextrins on such a process. Our results indicate that opportune concentrations of beta-cyclodextrins improve the uptake of beta-sitosterol by phospholipid membranes.     

How heating affects extra virgin olive oil quality indexes and chemical composition

Two monovarietal extra virgin olive oils from Arbequina and Picual cultivars were subjected to heating at 180 degrees C for 36 h. Oxidation progress was monitored by measuring oil quality changes (peroxide value and conjugated dienes and trienes), fatty acid composition, and minor compound content. Tocopherols and polyphenols were the most affected by the thermal treatment and showed the highest degradation rate although their behavior was different for each cultivar. Alpha-tocopherol loss was more important in Arbequina oil whereas, total phenol content loss was greater in Picual oil. The later showed an important decrease in hydroxytyrosol (3,4-DHPEA) and its secoiridoid derivatives (3,4-DHPEA-EDA and 3,4-DHPEA-EA), while lignans decrease was lesser. For Arbequina oil these compounds remained stable, and a lowering tendency was observed for tyrosol (p-HPEA) and its derivatives (p-HPEA-EDA and p-HPEA-EA). In general, flavone content showed a decrease during heating, being higher for Arbequina oil. On the other hand, oleic acid, sterols, squalene, and triterpenic alcohols (erythrodiol and uvaol) and acids (oleanolic and maslinic) were quite constant, exhibiting a high stability against oxidation. From these results, we can conclude that despite the heating conditions, VOO maintained most of its minor compounds and, therefore, most of its nutritional properties.     

Recycling of the #5 polymer

Polypropylene (PP) is a widely used plastic with consumer applications ranging from food packaging to automotive parts, including car battery casings. To differentiate it from other recyclable plastics, it is designated as #5. Here, the factors contributing to PP recycling rates are briefly reviewed. Considerations include collection and separation efficiency, processing chemistry, and market dynamics for the products derived from recyclates.     

Megastigmane and phenolic components from Laurus nobilis L. leaves and their inhibitory effects on nitric oxide production

Laurus nobilis L. leaves are widely used in cooking and in folk medicine. Five new megastigmane glucosides (2-4, 7, and 9) named laurosides A-E and a new phenolic glucoside 12 were isolated from the methanolic extract of L. nobilis L. leaves, along with 10 known components: megastigmane (5), megastigmane glucosides (1, 6, 8, 10, and 11), aromatic compounds (13 and 14), and flavonoids (15 and 16). The structures and relative stereochemistry have been elucidated by one- and two-dimensional nuclear magnetic resonance experiments ((1)H and (13)C NMR, DEPT, correlation spectroscopy, heteronuclear multiple quantum correlation, heteronuclear multiple bond correlation, and nuclear Overhauser enhancement spectroscopy) and by chemical derivatization. The effect of isolated compounds on nitric oxide production in lipopolysaccharide-activated murine macrophages were examined.     

Biochemical performance of degraded soil recovered by lake-dredged materials (LDM) as pedotechnomaterials

Purpose

The increasing need for disposal of lake-dredged material (LDM) as a consequence of intensified natural and/or anthropogenically mediated erosion processes has lead the scientific community to find new strategies for its reuse. The aim of this study is to investigate the effect of LDM use on the biochemical and functional performance of a degraded soil affected by erosion and entisolization processes.

Materials and methods

As a paradigmatic case study, a hydrographic basin located in Sardinia (Italy) was investigated. Severe soil degradation processes affect this area and have resulted in intensive sheet and rill water erosion. In contrast, an increase in sedimentation has been recorded on the bottom of an artificial lake. A degraded soil, collected in this area, were treated by co-utilization of LDM, other mineral matrices (a zeolitized tuff), organic amendment (a commercial manure), and mineral fertilizer (urea, triple superphosphate, and potassium sulfate) for the growth of a pasture grass under controlled (pot) conditions. The evolution of nine different model proto-horizons (MPH) was monitored through a series of biochemical parameters and techniques (total/extracellular enzymatic activity, isoelectric focusing, and gas chromatography) to assess the potential of LDM in soil biochemical recovery.

Results and discussion

On the whole, treatments containing LDM resulted in good recovery of degraded soils, as shown by a general enhancement in biochemical functionality. Application of LDM increased the more stable fraction of organic matter and its active biochemical fraction, showing the highest stable humic carbon content and humic activity. Such outcomes seem to represent a long-term beneficial effect on soil functionality.

Conclusions

This study demonstrates that LDM could be a useful pedotechnomaterial (PTM) for improving the biochemical functionality of extremely degraded soils. Additionally, the use of LDM as a PTM has the ecological advantage of recycling what is often considered as a “waste material.” From a socioeconomic point of view, the reuse of LDM in pedotechnique could represent a new low-cost alternative to the complex and expensive management and disposal of this material.

     

Seasonal effects on microorganisms in the rhizosphere of two tropical plants in a polyculture agroforestry system in Central Amazonia,Brazil

Rhizosphere and bulk soil samples were taken from two perennial plant species (the palm Bactris gasipaes and the dicot Theobroma grandiflorum) growing in an experimental polyculture agroforestry system in Central Amazonia in the wet and the dry season. In the dry season, the soil water potential in the rhizosphere and the bulk soil was below pF 4.2. Microbial biomass and basal respiration were lower in the dry season than in the wet season. However, the lower metabolic quotient in the dry season indicated a higher metabolic efficiency. While the number of oligotrophic microorganisms was not affected by the season, the number of eutrophic microorganisms in the rhizosphere was lower in the dry season than in the wet season. The substrate utilisation pattern of the bacterial community was also affected by the season. Despite marked differences in root morphology there were no significant differences in any of the microbiological parameters between the two plant species. It is concluded that during the dry season, a large portion of the microbial biomass dies off or enters a dormant stage resulting in a change in community composition.     

Herbal drug quality and phytochemical composition of Hypericum perforatum L. affected by ash yellows phytoplasma infection

Qualitative/quantitative phytochemical variations were observed in dried flowering tops of cultivated Hypericum perforatum L. cv. Zorzi infected by phytoplasmas of the "ash yellows" class, identified by direct and nested polymerase chain reaction (PCR); this is the first report of ribosomial group 16SrVII phytoplasmas in St. John's Wort. Methanolic extracts of healthy and infected plants were separated by reversed phase high-performance liquid chromatography to quantify naphthodianthrones and flavonoids, while essential oils were analyzed by means of gas chromatography (GC)-GC/MS. The affected plants exhibited decreased amounts of rutin (1.96 +/- 0.23 vs 4.96 +/- 0.02 mg/g), hyperoside (2.38 +/- 0.21 vs 3.04 +/- 0.05 mg/g), isoquercitrin (1.47 +/- 0.04 vs 3.50 +/- 0.08 mg/g), amentoflavone (0.12 +/- 0.01 vs 0.39 +/- 0.02 mg/g), and pseudohypericin (1.41 +/- 0.23 vs 2.29 +/- 0.07 mg/g), whereas the chlorogenic acid content was doubled (1.56 +/- 0.11 vs 0.77 +/- 0.02 mg/g). Hypericin, quercitrin, and quercetin contents were not severely affected. The essential oil yield was drastically reduced in infected material (0.11 vs 0.75% in healthy material) and revealed an increased abundance of sesquiterpenes (beta-caryophyllene, delta-elemene, and germacrene D, in particular) and a matching decrease in monoterpene hydrocarbons and aliphatics. The consequences that the phytopathological condition of cultivated H. perforatum plants has on the commercial quality, market value, and therapeutic efficacy are outlined.