Crop Yield and Essential Oil Composition of Two Thymus vulgaris Chemotypes along Three Years of Organic Cultivation in a Hilly Area of Central Italy

Thymus vulgaris L. is one of the most commonly used medicinal and aromatic plants (MAPs), owing to a range of therapeutic properties of its essential oil. Plant growth, biomass yield, essential oil content and composition are influenced by chemotype, environmental conditions, cultivation techniques and vegetative development. Since in MAPs cultivation special attention is paid on high quality of raw material, the adoption of sustainable agriculture methods is of pivotal importance. Therefore, we evaluated the agronomic and qualitative performances of two Thymus vulgaris L. chemotypes, organically cultivated under the Mediterranean climate of hilly lands of central Italy for three consecutive years (2017–2019). Along the trial, total above-ground dry biomass significantly increased from the 1st to 3rd year after planting and large variations in the main biological, biometric and productive traits were observed between the two chemotypes. The ‘thymol’ chemotype EO obviously showed thymol as the major constituent (51.26–49.87%) followed by γ-terpinene and p-cymene. The ‘linalool’ chemotype EO showed high percentages of oxygenated monoterpenes (about 90%) with linalool (75%), linalyl acetate (8.15%) and b-caryophyllene (3.2%) as main constituents. This study highlighted that T. vulgaris can be successfully organically grown in the hilly lands of Tuscany, with interesting biomass and essential oil yields, even though the plants were in the initial years of crop establishment (start in 2017). The introduction of this species into organic cultivation systems could contribute to obtain high-quality raw material, as well as to enhance crop rotation diversification, which is of pivotal importance in the management of organic farms.     

Electronic Circular Dichroism Spectra of DNA Quadruple Helices Studied by Molecular Dynamics Simulations and Excitonic Calculations including Charge Transfer States

We here investigate the Electronic Circular Dichroism (ECD) Spectra of two representative Guanine-rich sequences folded in a Quadruple helix (GQ), by using a recently developed fragment diabatisation based excitonic model (FrDEx). FrDEx can include charge transfer (CT) excited states and consider the effect of the surrounding monomers on the local excitations (LEs). When applied to different structures generated by molecular dynamics simulations on a fragment of the human telomeric sequence (Tel21/22), FrDEx provides spectra fully consistent with the experimental one and in good agreement with that provided by quantum mechanical (QM) method used for its parametrization, i.e., TD-M05-2X. We show that the ECD spectrum is moderately sensitive to the conformation adopted by the bases of the loops and more significantly to the thermal fluctuations of the Guanine tetrads. In particular, we show how changes in the overlap of the tetrads modulate the intensity of the ECD signal. We illustrate how this correlates with changes in the character of the excitonic states at the bottom of the La and Lb bands, with larger LE and CT involvement of bases that are more closely stacked. As an additional test, we utilised FrDEx to compute the ECD spectrum of the monomeric and dimeric forms of a GQ forming sequence {"type":"entrez-nucleotide","attrs":{"text":"T30695","term_id":"612793"}}T30695 (5′TGGGTGGGTGGGTGGG3′), i.e., a system containing up to 24 Guanine bases, and demonstrated the satisfactory reproduction of the experimental and QM reference results. This study provides new insights on the effects modulating the ECD spectra of GQs and, more generally, further validates FrDEx as an effective tool to predict and assign the spectra of closely stacked multichromophore systems.     

CB1 Cannabinoid Receptor Signaling and Biased Signaling

The CB1 cannabinoid receptor is a G-protein coupled receptor highly expressed throughout the central nervous system that is a promising target for the treatment of various disorders, including anxiety, pain, and neurodegeneration. Despite the wide therapeutic potential of CB1, the development of drug candidates is hindered by adverse effects, rapid tolerance development, and abuse potential. Ligands that produce biased signaling—the preferential activation of a signaling transducer in detriment of another—have been proposed as a strategy to dissociate therapeutic and adverse effects for a variety of G-protein coupled receptors. However, biased signaling at the CB1 receptor is poorly understood due to a lack of strongly biased agonists. Here, we review studies that have investigated the biased signaling profile of classical cannabinoid agonists and allosteric ligands, searching for a potential therapeutic advantage of CB1 biased signaling in different pathological states. Agonist and antagonist bound structures of CB1 and proposed mechanisms of action of biased allosteric modulators are used to discuss a putative molecular mechanism for CB1 receptor activation and biased signaling. Current studies suggest that allosteric binding sites on CB1 can be explored to yield biased ligands that favor or hinder conformational changes important for biased signaling.     

Chemical Composition,Antioxidant, Antimicrobial and Cytotoxic/Cytoprotective Activity of Non-Polar Extracts of Grape (Vitis labrusca cv. Bordeaux) and Blackberry (Rubus fruticosus) Seeds

The aim of this study was to compare the influence of the extraction method, chemical composition, antimicrobial effects, antioxidant activity, and cytotoxicity on human cells of the non-polar extracts of grape (Vitis labrusca) and blackberry (Rubus fruticosus) seeds. The Soxhlet (Sox), Bligh–Dyer (BD), and ultrasound (US) methods were used for extractions. For blackberry non-polar seed extract, extraction via the BD method showed the highest mean values of total phenolic content (TPC), expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (102.37 mg GAE/100 mL), and higher antioxidant activity in relation to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (11.50 mg AAE/100 mL), if compared with the Sox and US extractions. Similar results were obtained for the non-polar grape seed extracts, where BD extraction obtained the highest values for TPC (28.61 mg GAE/100 mL) and DPPH (35.36 mg AAE/100 mL). The type of extraction method had an impact on the composition of fatty acids. Only the non-polar blackberry and grape seed extracts obtained via the Sox method showed some in vitro inhibitory effect against Escherichia coli (IAL 2064) and Staphylococcus aureus (ATCC 13565). Regardless of the extraction method used, the non-polar blackberry and grape seed extracts did not decrease the cell viability (IC₅₀ >1000 µg/mL) of cancer and normal cell lines, thus indicating the relative safety of the extracts. All the seed extracts decreased the generation of reactive oxygen species in the cell lines. Blackberry and grape seed lipid fractions can be utilized as antioxidants, and the extraction methods used cause significant changes in relation to their bioactivity and chemical composition.     

A liquid chromatographic method optimization for the assessment of low and high molar mass carbonyl compounds in wines

Carbonyl compounds (CC) play an important role in beverage aroma since they may affect flavor of wines, brandies, and beers, among others. For this reason, it is necessary to identify and quantify CC through adequate analytical techniques. This study is a proposal of both developing and optimization of a new analytical methodology that allows investigate C₁–C₈ CC in wines simultaneously by quantifying even those ones that are predominantly present in the adduct form hydroxylalkylsulfonic acids (HASA). The HASA dissociation is undertaken by specific alkaline media (pH 11). The developed methodology employed the LC with UV/VIS detection (λ = 365 nm) technique under gradient elution in the way to reach both free‐CC and bound‐CC quantification. Results showed that binary gradient system using eluent A (MeOH/ACN/H₂O 74.5:0.5:25% v/v/v) and eluent B (MeOH) reached the best separation condition of both lower and higher molecular mass CC. This proposed method allowed simultaneous quantification of formaldehyde, acetaldehyde, propanone, furfuraldehyde, butyraldehyde, benzaldehyde, hexanaldehyde, 2‐ethyl‐hexanaldehyde, E‐pent‐2‐en‐1‐al, and cyclohexanone – all of them were found in white wine (Moscato Canelli) and red wine (Shiraz) produced in the São Francisco Valley, in the Northeastern Region of Brazil – although this optimized method may probably be suitable for quantification of propionaldehyde, isobutyraldehyde, heptanaldehyde, octanaldehyde, benzaldehyde, and E‐hex‐2‐en‐1‐al as well. We could not prove if this method is also able to determine the latter CC group since we have not found these substances present in detectable levels in our real samples considered in this study.     

Organic-Inorganic Hybrid Materials with the Ability to Bind Metal Ions: Calorimetric Properties and Thermostability

Organic-inorganic hybrid materials with excellent heavy metal ions chelating properties were synthesized by covalent bonding of multifunctional polymers of polyamidoamine (PAA) type onto silica. Two series of polyamidoamine-silica hybrid materials differing in the PAA chemical structure were prepared and their thermal properties were investigated. Differential Scanning Calorimetry was used to study the effects of chain immobilization and ion chelation on the glass-transition temperature (Tg) of the polymers. The Tg of PAA-hybrid materials was elevated with respect to ungrafted PAAs. Complex formation with metal ions such as Cu⁺⁺ or Co⁺⁺ caused total suppression of Tg for both linear polymers as well as the corresponding hybrid materials. Finally, the silica particles slightly influenced the decomposition temperatures of linear polymers increasing their thermal stability.     

Diffusion of Organic Vapors in Materials for Gas Sensing Application

Mass-variation measurements were carried out on carbon black (CB)-poly(vinyl chloride) (PVC) composite film with 40% by weight of di(2-ethylhexyl)-phthalate (DOP), cast on resonant piezo-layer (RPL) elements of lead zirconat titanate (PZT). Even if anomalous diffusion is predicted by fitting the data with M_t/M_∞=kt^α, the fractional uptake M_t/M_∞ is linear with the square root of the time up to M_t/M_∞=0.6, suggesting Fickian behavour. The anomalous values of α are probably due to experimental time lag. A dependence of the diffusion on the morphology of the material and the penetrant shape and flexibility has been found.     

Blends Based on Polystyrene and Statistical Aromatic Copolycarbonates

The compatibility of polystyrene (PS) with aromatic copolycarbonates containing bisphenol A (BPA) and tetramethyl bisphenol A (TMBPA) was investigated. The simple prevision scheme developed by Sonja Krause was employed to evaluate the effect of the copolymer molecular structure on the miscibility with polystyrene. These prevision data were used to select copolycarbonates of potential interest. Statistical copolycarbonates (CPC) containing different BPA/TMBPA molar ratios were synthesised by polycondensation reaction between a mixture of the two monomers and phosgene. PS/polycarbonates blends, prepared by casting from chloroform solution, were studied with differential scanning calorimetry and optical microscopy to evaluate the components compatibility, which increases with the TMBPA copolymer content.