Essential oil composition and biological activity from Artemisia caerulescens subsp. densiflora (Viv.) Gamisans ex Kerguélen & Lambinon (Asteraceae), an endemic species in the habitat of La Maddalena Archipelago

The purpose of this study was to investigate the composition of the essential oil obtained from a population of Artemisia caerulescens subsp. densiflora growing in Razzoli, an island in the La Maddalena Archipelago (Sardinia, Italy). A. caerulescens sups. densiflora Viv. (Asteraceae), a wild herb, seldom studied in the Mediterranean, represents one of the many rare endemic species growing in North Sardinia. The essential oil composition was analysed by means of GC/MS analysis, which showed davana ethers as the major volatile components, accounting together for 17.5%, followed by (E)-nerolidol (4.5%), β-oplopenone (3.3%), cis-sabinene hydrate (5.2%) and terpinen-4-ol (4.7%). The oil was tested for antioxidant activity by means of DPPH test, inhibition of lipid oxidation test and hypochlorous acid test, which showed a quite interesting scavenger capacity. For the first time, we reported the cytotoxic activity of the essential oil of A. caerulescens subsp. densiflora, against three human tumour cell lines (A375, MDA-MB231 and HCT116), with IC₅₀ values in the range 5.20–7.61 μg/mL, which deserved further studies to support its use as chemopreventive agent. Finally, the antimicrobial activity of the essential oil, displayed on a panel of human pathogens, was very low.     

Efficiency and benchmarking with directional distances: a data-driven approach

In efficiency analysis the assessment of the performance of Decision-Making Units (DMUs) relays on the selection of the direction along which the distance from the efficient frontier is measured. Directional Distance Functions (DDFs) represent a flexible way to gauge the inefficiency of DMUs. Permitting the selection of a direction towards the efficient frontier is often useful in empirical applications. As a matter of fact, many papers in the literature have proposed specific DDFs suitable for different contexts of application. Nevertheless, the selection of a direction implies the choice of an efficiency target which is imposed to all the analysed DMUs. Moreover, there exist many situations in which there is no a priori economic or managerial rationale to impose a subjective efficiency target. In this paper we propose a data-driven approach to find out an ‘objective’ direction along which to gauge the inefficiency of each DMU. Our approach permits to take into account for the heterogeneity of DMUs and their diverse contexts that may influence their input and/or output mixes. Our method is also a data-driven technique for benchmarking each DMU. We describe how to implement our framework and illustrate its usefulness with simulated and real data sets.     

A rationalization of the solvent effect on the Diels-Alder reaction in ionic liquids using multiparameter linear solvation energy relationships

The Diels-Alder reaction between cyclopentadiene and three dienophiles (acrolein, methyl acrylate and acrylonitrile) having different hydrogen bond acceptor abilities has been carried out in several ionic liquids and molecular solvents in order to obtain information about the factors affecting reactivity and selectivity. The solvent effects on these reactions are examined using multiparameter linear solvation energy relationships. The collected data provide evidence that the solvent effects are a function of both the solvent and the solute. For a solvent effect to be seen, the solute must have a complimentary character; selectivities and rates are determined by the solvent hydrogen bond donation ability (alpha) in the reactions of acrolein and methyl acrylate, but not of acrylonitrile.     

On commuting polynomial automorphisms of {\mathbb{C}}^{k} , k ≥ 3

We characterize the polynomial automorphisms of ${\mathbb{C}}^3We characterize the polynomial automorphisms of , which commute with a regular automorphism. We use their meromorphic extension to and consider their dynamics on the hyperplane at infinity. We conjecture the additional hypothesis under which the same characterization is true in all dimensions. We give a partial answer to a question of S. Smale that in our context can be formulated as follows: can any polynomial automorphism of be the uniform limit on compact sets of polynomial automorphisms with trivial centralizer (i.e. )? Partially supported by Progetto MURST di Rilevante Interesse Nazionale Proprietà geometriche delle varietà reali e complesse. Supported by Istituto Nazionale Alta Matematica, “F. Severi”, Roma and G.N.S.A.G.A., Roma.     

Phytochemical analysis of non-volatile fraction of Artemisia caerulescens subsp. densiflora (Viv.) (Asteraceae), an endemic species of La Maddalena Archipelago (Sardinia – Italy)

Artemisia caerulescens subsp. densiflora Viv. is a rare endemic species from Corsica and Sardinia. We studied a sample collected from Razzoli, an island of the La Maddalena Archipelago. The polar secondary metabolites content of this species was investigated for the first time in this study showing the presence of sesquiterpenoids, flavonoids, caffeoylquinic acids and a coumarin, with the presence of several compounds already recognised in this genus. The metabolites composition was analysed in two different phenological stages, post blooming and flowering. During the blooming stage, the plant showed a molecular pattern mainly represented by sesquiterpenes and sterols with a minor amount of phenolics, while in flowering stage the molecular pattern was more rich in flavonoids and phenylpropanoids.     

New Cyclodextrin‐Bearing 8‐Hydroxyquinoline Ligands as Multifunctional Molecules

Recent investigations have rekindled interest in 8‐hydroxyquinolines as therapeutic agents for cancer, Alzheimer’s disease, and other neurodegenerative disorders. Three new β‐cyclodextrin conjugates of 8‐hydroxyquinolines and their copper(II) and zinc(II) complexes have been synthesized and characterized spectroscopically. In addition to improving aqueous solubility, due to the presence of the cyclodextrin moiety, the hybrid systems have interesting characteristics including antioxidant activity, and their copper(II) complexes are efficient superoxide dismutase (SOD) mimics. The ligands and their copper(II) complexes show low cytotoxicity, attributed to the presence of the cyclodextrin moiety. These compounds have potential as therapeutic agents in diseases related both to metal dyshomeostasis and oxidative stress.     

A dimensionally reduced finite mixture model for multilevel data

Recently, different mixture models have been proposed for multilevel data, generally requiring the local independence assumption. In this work, this assumption is relaxed by allowing each mixture component at the lower level of the hierarchical structure to be modeled according to a multivariate Gaussian distribution with a non-diagonal covariance matrix. For high-dimensional problems, this solution can lead to highly parameterized models. In this proposal, the trade-off between model parsimony and flexibility is governed by assuming a latent factor generative model.     

trans‐Di­chloro­tetrakis(4‐methylpyrimidine‐N1)­ruthenium(II)

The title compound, trans‐[Ru^IICl₂(N¹‐mepym)₄] (mepym is 4‐methylpyrimidine, C₅H₆N₂), obtained from the reaction of trans,cis,cis‐[Ru^IICl₂(N¹‐mepym)₂(SbPh₃)₂] (Ph is phenyl) with excess mepym in ethanol, has fourfold crystallographic symmetry and has the four pyrimidine bases coordinated through N¹ and arranged in a propeller‐like orientation. The Ru—N and Ru—Cl bond distances are 2.082 (2) and 2.400 (4) Å, respectively. The methyl group, and the N³ and Cl atoms are involved in intermolecular C—H?N and C—­H?Cl hydrogen‐bond interactions.     

Determination of the banned growth promoter moenomycin A in feed stuffs by liquid chromatography coupled to electrospray ion trap mass spectrometry

Flavomycin complex is an antibiotic banned in the European Union as an additive in feed stuffs. As a consequence, the monitoring programmes for official control within the Community require analysis of feeds for possible illegal use of flavomycin. A method for unambiguous identification and quantification of moenomycin A, the main pharmacologically active component of flamomycin complex, in several feeds by liquid chromatography coupled to electrospray ion trap mass spectrometry (LC/ESI‐MS/MS) is herein described for the first time. The method was developed to be used as a confirmative analytical tool for the network of Italian official control laboratories; both the singly and doubly charged molecular ions were observed as precursor ions, from which four product ions were selected for both quantitative analysis and unambiguous identification of moenomycin A. The method was in‐house validated for feeds in the concentration range 0.50–30.0 µg/g, according to the Regulation 882/2004/EC requirements. Mean recoveries ranging between 83.9–94.2% and relative standard deviations <23% account for method trueness and repeatability, respectively. Moreover, other analytical performance parameters, i.e. method specificity, ruggedness, the linearity of detector response, the limit of quantification (LOQ), the limit of detection (LOD), and measurement uncertainty were evaluated and reported. The ion trap LC/ESI‐MS/MS method is highly selective and reliable; high drug recovery, good reproducibility and an LOQ down to 0.10 µg/g guarantee its applicability for confirmatory purposes in the official control activity in Italy. Copyright © 2010 John Wiley & Sons, Ltd.