Characterization of the geographical origin of Italian red wines based on traditional and nuclear magnetic resonance spectrometric determinations

Chemical characterization of Italian red wines from different geographical locations in the Apulia, region of southern Italy, have been performed by means of chromatographic, analyses routine analyses (density, alcohol content, acidity, dry extract and ash content), inductively coupled plasma-atomic emission spectrometric measurements and nuclear magnetic resonance (¹H NMR) spectrometric determinations. Multivariate statistical methods were applied separately to the analytical and NMR data. The results showed that Apulian red wines are divided in three groups according to their geographical origin.     

Conformational studies and solution structure of laulimalide and simplified analogues using NMR spectroscopy and molecular modelling

The solution structures of the potent microtubule-stabilizing anti-cancer agent laulimalide and simplified analogues were determined by a combination of high field ¹H NMR spectroscopic studies (J-based configuration analysis and NOESY) and constrained molecular dynamics simulations and discussed in relation to their antiproliferative activity.     

Study of interactions between Gallic Acid and Skin Surface using Infrared Spectroscopy

The transdermal transmission of model substance on the pigskin samples was investigated using the attenuated total reflection (ATR) technique of infrared (IR) spectroscopy. The collected vibrational spectroscopic data were evaluated by multidimensional statistical methods as principal component analysis (PCA), linear discriminant analysis (LDA) and partial least squares (PLS) regression which enable detection of individual substances in the skin, their identification and mutual differentiation. Gallic acid (GA), a natural phenolic anti-oxidant with many potential healing properties suitable e.g. for atopic dermatitis treatment, was used as an analyte. Effect of GA on the skin surface was examined for four different solvents namely ethanol (EtOH), methanol (MeOH), dimethyl sulfoxide (DMSO) and ultrahigh purity water (H₂O). Moreover, the effects of temperature related to GA solubility in H₂O were investigated. During the series of experiments, nonsystematic changes of untreated skin samples were observed; while systematic changes are evident after the skin treatment. The systematic effects correspond to structural changes of the skin constituents during substance penetration.     

Complexation of cadmium by the C-terminal hexapeptide Lys-Cys-Thr-Cys-Cys-Ala from mouse metallothionein: study by differential pulse polarography and circular dichroism spectroscopy with multivariate curve resolution analysis

The cadmium-binding properties of the C-terminal hexapeptide of mouse metallothionein I, Lys-Cys-Thr-Cys-Cys-Ala, were studied by circular dichroism spectroscopy (CD), differential pulse polarography (DPP) and ¹¹³Cd-nuclear magnetic resonance (NMR).

The structure of the multiple cadmium binding sites could not be determined by ¹¹³Cd-NMR because of the insolubility of the Cd–peptide samples at the high concentrations required for NMR. Therefore, alternative approaches were used: CD and DPP. The data were analyzed using a multivariate curve resolution (MCR) approach, based on factor analysis techniques, which allows the identification of the signal corresponding to different metal ions bound in different chemical environments. The CD study confirmed that the binding of Cd²⁺ induces important conformational changes in the structure of the peptidic complex, including the formation of a binuclear cluster. The DPP results obtained at various Cd²⁺-to-peptide concentration ratios and pH values, under conditions where electrode adsorption is low, if not negligible, indicated the formation of different Cd²⁺–peptide complexes, and a scheme for the electrochemical reduction of the complexed Cd²⁺ ions is proposed.

These results show that the application of MCR to complex data, such as those from DPP, allows to reach valuable information which is not possible to be obtained by univariate approaches.     

A study for quality evaluation of Taxilli Herba from different hosts based on fingerprint-activity relationship modeling and multivariate statistical analysis

In this study, a fingerprint-activity relationship modeling between chemical fingerprints and antirheumatic activity was established, and multivariate statistical analysis was used to evaluate the quality of Taxilli Herba (TH) from different hosts. Characteristic fingerprints of 20 batches of TH samples were generated by high-performance liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (HPLC-Triple TOF-MS/MS), and the similarity analysis was calculated based on thirteen common characteristic peaks by hierarchical clustering analysis (HCA). Subsequently, nine efficacy markers were discovered by combining fingerprints and antirheumatic activity through grey correlation analysis (GCA) and bivariate correlation analysis (BCA). Meanwhile, the content of 5 constituents in 9 markers was determined by high-performance liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (HPLC-QTRAP-MS/MS). The comprehensive quality of TH was assessed using multivariate statistical analysis, including principal components analysis (PCA) and technique for order preference by similarity to ideal solution (TOPSIS). The results showed that a high dose of TH extract could markedly ameliorate arthritis damage compared to other doses, with flavonoids playing an important role in the antirheumatic activity. The comprehensive quality of samples from Morus alba L. (SS) was superior to those from Liquidambar formosana Hance (FXS). The present study will demonstrate the markers associated with efficacy, and provide an applicable strategy for more comprehensive quality control and evaluation of TH.     

Synthesis,characterization, powder XRD and antimicrobial-antioxidant activity evaluation of trivalent transition metal macrocyclic complexes

The in vitro antimicrobial and antioxidant activities of metal complexes derived from 1,8-diaminonaphthalene and 5,5-dimethylcyclohexane-1,3-dione were evaluated. The complexes were synthesized by template method in the presence of trivalent metal salts, resulting in the formation of tetraaza macrocyclic complexes of the type [M (C₃₆H₃₆N₄) X] X₂, where M = Cr(III), Fe(III) and X = Cl^–, NO₃^–, CH₃COO^–. The synthesized complexes were characterized with the aid of elemental analyses, molar conductance measurements, magnetic susceptibility measurements, electronic, IR, mass and powder XRD studies. Based on various studies, a five-coordinated square pyramidal geometry was proposed for these complexes. The X-ray diffraction studies suggest a monoclinic crystal system for the complexes.