Achillea moschata Wulfen: From Ethnobotany to Phytochemistry,Morphology, and Biological Activity

A multidisciplinary investigation on Achillea moschata Wulfen (Asteraceae) is outlined herein. This work, part of the European Interreg Italy–Switzerland B-ICE project, originated from an ethnobotanical survey performed in Chiesa in Valmalenco (Sondrio, Lombardy, Northern Italy) in 2019–2021 which highlighted this species’ relevance of use in folk medicine to treat gastrointestinal diseases. In addition, this contribution included analyses of the: (a) phytochemical profile of the aqueous and methanolic extracts of the dried flower heads using LC-MS/MS; (b) morpho-anatomy and histochemistry of the vegetative and reproductive organs through Light, Fluorescence, and Scanning Electron Microscopy; (c) biological activity of the aqueous extract concerning the antioxidant and anti-inflammatory potential through cell-based in vitro models. A total of 31 compounds (5 phenolic acids, 13 flavonols, and 13 flavones) were detected, 28 of which included in both extracts. Covering and secreting trichomes were observed: the biseriate 10-celled glandular trichomes prevailing on the inflorescences represented the main sites of synthesis of the polyphenols and flavonoids detected in the extracts, along with volatile terpenoids. Finally, significant antioxidant and anti-inflammatory activities of the aqueous extract were documented, even at very low concentrations; for the first time, the in vitro tests allowed us to formulate hypotheses about the mechanism of action. This work brings an element of novelty due to the faithful reproduction of the traditional aqueous preparation and the combination of phytochemical and micromorphological research approaches.     

Flexible Structures Based on a Short Pitch Cholesteric Liquid Crystals

We report on the realization and characterization of electro-responsive and pressure sensitive polydimethylsiloxane (PDMS) conductive photonic structures combined with the reconfigurable properties of short pitch cholesteric liquid crystals (aligned in Grandjean configuration). By combining ion-implantation process and surface chemistry functionalization, we have overcome the insulating properties of PDMS and induced long range organization of cholesteric liquid crystals, thus controlling both diffraction and selective Bragg reflection of light by means of external perturbations (electric field, pressure). We have characterized our devices in terms of morphological, optical and electro-optical properties.     

Anion effects on the recognition of ion pairs by calix[4]arene-based heteroditopic receptors

A novel heteroditopic receptor (5) based on a rigid calix[4]arene cavity bearing at the upper rim four arylsulfonamido binding sites has been synthesized. The binding abilities of this new host have been investigated in apolar solvents toward a series of tetramethylammonium salts (tosylate, chloride, acetate, trifluoroacetate, and picrate) and compared with those of monotopic and heteroditopic calix[4]arene-bis(crown-3)-based receptors 1 and 2 in order to evaluate the role of the anion on ion-pair recognition. While monotopic host 1 shows an efficiency order toward the different salts that increases when the anion is less interactive (Hofmeister trend), an opposite role of the counteranion on the recognition process was observed with host 5 (anti-Hofmeister trend). A more complex behavior is experienced by host 2, which shows a high and leveled efficiency for all the anions tested. The results obtained were explained on the basis of the different types of ion pairs present in the recognition process. Further information on the role of the anion were obtained by the "dual host" strategy utilizing the tri-n-butylthioureido derivative of tren 7, which forms a stable complex with chloride anion. The very high efficiency shown by these heteroditopic hosts opens new routes in supramolecular projects and is a very interesting tool in the molecular recognition of ion-pairs and its applications.     

Pharmacological and Therapeutic Potential of Myristicin: A Literature Review

Natural products have been used by humanity for many centuries to treat various illnesses and with the advancement of technology, it became possible to isolate the substances responsible for the beneficial effects of these products, as well as to understand their mechanisms. In this context, myristicin, a substance of natural origin, has shown several promising activities in a large number of in vitro and in vivo studies carried out. This molecule is found in plants such as nutmeg, parsley, carrots, peppers, and several species endemic to the Asian continent. The purpose of this review article is to discuss data published in the last 10 years at Pubmed, Lilacs and Scielo databases, reporting beneficial effects, toxicity and promising data of myristicin for its future use in medicine. From 94 articles found in the literature, 68 were included. Exclusion criteria took into account articles whose tested extracts did not have myristicin as one of the major compounds.     

Metadynamics study of a β-hairpin stability in mixed solvents

Understanding the molecular mechanisms that allow some organisms to survive in extremely harsh conditions is an important achievement that might disclose a wide range of applications and that is constantly drawing the attention of many research fields. The high adaptability of these living creatures is related to the presence in their tissues of a high concentration of osmoprotectants, small organic, highly soluble molecules. Despite osmoprotectants having been known for a long time, a full disclosure of the machinery behind their activity is still lacking. Here we describe a computational approach that, taking advantage of the recently developed metadynamics technique, allows one to fully describe the free energy surface of a small β-hairpin peptide and how it is affected by an osmoprotectant, glycine betaine (GB) and for comparison by urea, a common denaturant. Simulations led to relevant thermodynamic information, including how the free energy difference of denaturation is affected by the two cosolvents; unlike urea, GB caused a considerable increase of the folded basin stability, which transposes into a higher melting temperature. NMR experiments confirmed the picture derived from the theoretical study. Further molecular dynamics simulations of selected conformations allowed investigation into deeper detail the role of GB in folded state protection. Simulations of the protein in GB solutions clearly showed an excess of osmoprotectant in the solvent bulk, rather than in the protein domain, confirming the exclusion from the protein surface, but also highlighted interesting features on its interactions, opening to new scenarios besides the classic "indirect mechanism" hypothesis.     

Preparation and physical properties of novel nonionic surfactants and their grafting copolymers with linear low density polyethylene (LLDPE)

Three nonionic surfactants, S1, S2, and S3 and their acrylates, AS1, AS2, and AS3, were synthesized with poly(ethylene oxide) and diols such as glycol, 1,6‐hexanediol, and 1,10‐decanediol as the main starting materials. Their chemical structures were characterized by means of Fourier transform infrared (FTIR) spectroscopy and ¹H NMR. The surface activity and surface tension (γ) of S1, S2, and S3 were evaluated by a drop weight method. The surface tension was found to decrease with the length of the lipophilic spacer in the molecular chains (γ_S1 < γ_S2 < γ_S3). AS1, AS2, and AS3 were adopted as functionalizing monomers and grafted onto linear low density polyethylene (LLDPE) with a melt reactive extrusion procedure. The graft degrees of LLDPE were determined by FTIR. Three grafted LLDPE samples with grafting degrees of 1.16% (AS1), 0.82% (AS2), and 0.71% (AS3) were prepared. Thermal and rheological properties of grafted LLDPE samples were studied with differential scanning calorimetry and a rotational rheometer. Crystallization rates of grafted LLDPE were faster than that of plain LLDPE at a given crystallization temperature because graft chains could act as nucleating agents. The isothermal crystallization behavior of grafted LLDPE was in accordance with the Avrami model only in the first stage, and deviated from the model with an increase in the crystallization time. Shear thinning at high shear rates and shear thickening at low shear rates were observed for the grafted LLDPE. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 314–322, 2005     

Il problema di Cauchy-Dirichlet per una classe di sistemi parabolici a coefficienti misurabili

Riassunto Si dimostrano teoremi di esistenza, di unicità e di regolarizzazione per la soluzione del problema di Cauchy-Dirichlet per una classe di sistemi parabolici a coefficienti misurabili.

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Summary We show that the Cauchy-Dirichlet problem for a class of parabolic systems with measurable coefficients admits a unique solution. We show, also, regularity's properties for the solution.

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Lavoro eseguito nell'ambito del gruppo G.N.A.F.A. del C.N.R.     

Bilateral evolution problems of non-variational type: Existence,uniqueness, Hölder-regularity and approximation of solutions

We study bilateral problems for a second order parabolic operator with principal part not of divergence form. We prove existence, uniqueness, Holder-continuity and approximation results for both strong and generalized solutions.     

Glass transition temperatures of some linear polymers containing phenyl side groups

The glass transition temperatures of a number of poly(vinyl phenyl ketones), poly-(vinyl benzoates), and poly(phenyl acrylates) have been measured by a refractometric method. The effects exerted on T_g by the nature and position of the ring substituents and by the different groups binding the pendant phenyl rings to the polyvinyl chain are discussed. The importance of knowledge of the side-group motions in the glassy state for the interpretation of glass temperature data is emphasized.