Ferula L. Plant Extracts and Dose-Dependent Activity of Natural Sesquiterpene Ferutinin: From Antioxidant Potential to Cytotoxic Effects

The employment studies of natural extracts in the prevention and treatment of several diseases highlighted the role of different species of genus Ferula L., belonging to the Apiaceae family, dicotyledonous plants present in many temperate zones of our planet. Ferula communis L. is the main source of sesquiterpene ferutinin, a bioactive compound studied both in vitro and in vivo, because of different effects, such as phytoestrogenic, antioxidant, anti-inflammatory, but also antiproliferative and cytotoxic activity, performed in a dose-dependent and cell-dependent way. The present review will focus on the molecular mechanisms involved in the different activities of Ferutinin, starting from its antioxidant potential at low doses until its ionophoric property and the subsequent mitochondrial dysfunction induced through administration of high doses, which represent the key point of its anticancer action. Furthermore, we will summarize the data acquired from some experimental studies on different cell types and on several diseases. The results obtained showed an important antioxidant and phytoestrogenic regulation with lack of typical side effects related to estrogenic therapy. The preferential cell death induction for tumor cell lines suggests that ferutinin may have anti-neoplastic properties, and may be used as an antiproliferative and cytotoxic agent in an estrogen dependent and independent manner. Nevertheless, more data are needed to clearly understand the effect of ferutinin in animals before using it as a phytoestrogen or anticancer drug.     

Hybrid E‐Tongue for the Evaluation of Sweetness and Bitterness of Soft Drinks Fortified with Epigallocatechin Gallate

A home‐made hybrid electronic tongue was set up, validated and applied to discriminate soft drinks fortified with plant extracts of green tea. The e‐tongue consists of a flow injection system equipped with two electrochemical and one optical sensors. Different formulations of soft drinks composed of glucose and epigallocatechin gallate were then discriminated by principal component analysis. Furthermore, two partial least squares regression models were developed to estimate the “sweetness” (r² of 0.992) and “bitterness” (r² of 0.993) of the model solutions and commercial soft drinks, before and after their fortification with epigallocatechin gallate.     

Nylon Nanofibrous Biosensors for Glucose Determination

Nanofibrous membranes have been produced by electrospinning to develop first generation glucose biosensors. The direct immobilization of glucose oxidase onto the polyamide nanofibrous surfaces by drop coating revealed a simple and efficient method for the development of sensitive, stable, and reproducible electrochemical biosensors. The biosensor showed a linear response over the range 1–9×10^?3 glucose (R²=0.9997) with a sensitivity of 1.11 μA/mM and a limit of detection of 2.5×10^?6 M (S/N=3). The uncertainty of repeatability was 2% (RSD%, n=30). After one month of storage, the signal decreased of 35%. The recovery of glucose, evaluated in real samples of honey, was 98% (RSD%=1%, n=3).     

Correlation between lactosylation and denaturation of major whey proteins: an investigation by liquid chromatography–electrospray ionization mass spectrometry

The Maillard-reaction-induced lactosylation of the major whey proteins, α-lactalbumin (α-La) and β-lactoglobulins (β-Lg) A and B, occurring upon heating at 70, 80 and 90 °C for 1 to 5 h in the presence of lactose excess, was studied by HPLC coupled to electrospray ionization single and tandem mass spectrometry (HPLC-ESI-MS, MS/MS). The presence of significant amounts of mono and bi-lactosylated forms of the three proteins and their increase with heating temperature and time were assessed from MS data. Evidences for a concomitant, significant denaturation, involving partial tertiary structure unfolding, were also obtained in the case of β-lactoglobulins. A subsequent ESI-MS and MS/MS investigation on the tryptic digests of heated protein solutions exhibiting high percentages of mono and bi-lactosylated forms provided information on lactosylation sites. In particular, the latter were identified both on tryptic and on aspecific peptides, whose unusual relevance (compared to similar studies) was found to be due mainly to heat-induced protein degradation, occurring before protein digestion with trypsin. Among lactosylation sites identified only on tryptic peptides, i.e., those reasonably related to intact protein lactosylation, two lysines residues were found for α-La, both located in accessible regions of its tertiary structure. In the case of β-Lg, besides three sites common to variants A and B (leucine 1, lysines 70, and 75), lysine 69 was found to be lactosylated only in variant B. Its proximity to a critical region of β-Lg tertiary structure suggests that the difference between the two variants could be ascribed to a different evolution of their conformation upon heating.     

Homoclinic bifurcations in radiating diffusion flames

We analyse the dynamics of a model describing a planar diffusion flame with radiative heat losses incorporating a single step kinetic using timestepping techniques for Lewis number equal to one. We construct the full bifurcation diagram with respect to the Damköhler number including the branches of oscillating solutions. Based on this analysis we found, for the first time, homoclinic bifurcations that mark the abrupt disappearance of the nonlinear oscillations near extinction as reported in experiments.     

On an assumption of geometric foundation of numbers

In line with the latest positions of Gottlob Frege, this article puts forward the hypothesis that the cognitive bases of mathematics are geometric in nature. Starting from the geometry axioms of the Elements of Euclid, we introduce a geometric theory of proportions along the lines of the one introduced by Grassmann in Ausdehnungslehre in 1844. Assuming as axioms, the cognitive contents of the theorems of Pappus and Desargues, through their configurations, in an Euclidean plane a natural field structure can be identified that reveals the purely geometric nature of complex numbers. Reasoning based on figures is becoming a growing interdisciplinary field in logic, philosophy and cognitive sciences, and is also of considerable interest in the field of education, moreover, recently, it has been emphasized that the mutual assistance that geometry and complex numbers give is poorly pointed out in teaching and that a unitary vision of geometrical aspects and calculation can be clarifying.     

Convergence analysis of a proximal Gauss-Newton method

An extension of the Gauss-Newton algorithm is proposed to find local minimizers of penalized nonlinear least squares problems, under generalized Lipschitz assumptions. Convergence results of local type are obtained, as well as an estimate of the radius of the convergence ball. Some applications for solving constrained nonlinear equations are discussed and the numerical performance of the method is assessed on some significant test problems.     

Comparative hydrodynamics of bacterial polymorphism

Most bacteria swim through fluids by rotating helical flagella which can take one of 12 distinct polymorphic shapes, the most common of which is the normal form used during forward swimming runs. To shed light on the prevalence of the normal form in locomotion, we gather all available experimental measurements of the various polymorphic forms and compute their intrinsic hydrodynamic efficiencies. The normal helical form is found to be the most efficient of the 12 polymorphic forms by a significant margin--a conclusion valid for both the peritrichous and polar flagellar families, and robust to a change in the effective flagellum diameter or length. Hence, although energetic costs of locomotion are small for bacteria, fluid mechanical forces may have played a significant role in the evolution of the flagellum.     

Screening of methylenedioxyamphetamine‐ and piperazine‐derived designer drugs in urine by LC–MS/MS using neutral loss and precursor ion scan

This study describes a method for the screening of methylenedioxyamphetamine‐ and piperazine‐derived compounds in urine by liquid chromatography‐tandem mass spectrometry. These substances, characterized by possessing common moieties, are screened using precursor ion and neutral loss scan mode and then quantified in multiple reaction monitoring acquisition mode. Based on the product‐ion spectra of different known molecules, chosen as ‘model’, characteristic neutral losses and product ions were selected: piperazines were detected in precursor ion scan of m/z 44 and neutral loss of 43 and 86 while amphetamines in precursor ion scan of m/z 133, 135 and 163. The applicability of the screening approach was studied in blank urine spiked with selected analytes and processed by solid‐phase extraction. Linearity, matrix effect, precision, accuracy, limits of detection and limits of quantification were evaluated both for the screening and the quantification methods. The ability of the screening method to provide semi‐quantitative data was demonstrated. This method appears to be a useful tool for the identification of designer drugs derived from piperazines or methylenedioxyamphetamines and can be potentially applied to other drug classes. Copyright © 2013 John Wiley & Sons, Ltd.