Giorgio Antonio Mario Pintore

Separation of brompheniramine enantiomers by capillary electrophoresis and study of chiral recognition mechanisms of cyclodextrins using NMR-spectroscopy, UV spectrometry, electrospray ionization mass spectrometry and X-ray crystallography.

Opposite migration order was observed for the enantiomers of brompheniramine [N-[3-(4-bromphenyl)-3-(2-pyridyl)propyl]-N,N-dimethylamine] (BrPh) in capillary electrophoresis (CE) when native beta-cyclodextrin (beta-CD) and heptakis(2,3,6-tri-O-methyl)-beta-CD (TM-beta-CD) were used as chiral selectors. NMR spectrometry was applied in order to obtain information about the stoichiometry, binding constants and structure of the selector-selectand complexes in solution. The data were further confirmed by UV spectrometry and electrospray ionization mass spectrometry. The structure of the complexes in the solid state was determined using X-ray crystallography performed on the co-crystals precipitated from the 1:1 aqueous solution of selector and selectand. This multiple approach allowed an elucidation of the most likely structural reason for a different affinity (binding strength) of BrPh enantiomers towards beta-CD and TM-beta-CD. However, the question about a force responsible for the opposite affinity pattern of BrPh enantiomers towards these CDs could not be answered definitely.

Mechanistic study of opposite migration order of dimethindene enantiomers in capillary electrophoresis in the presence of native β-cyclodextrin and heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin

The possible mechanisms of the opposite affinity pattern of the enantiomers of dimethindene [(R,S)-N,N-dimethyl-3[1(2-pyridyl)ethyl]indene-2-ethylamine] (DIM) towards native beta-cyclodextrin (beta-CD) and heptakis(2,3,6-tri-O-methyl-)-beta-CD (TM-beta-CD) were studied using capillary electrophoresis (CE), NMR spectrometry, electrospray ionization mass spectrometry (ESI-MS) and X-ray crystallography. NMR spectrometry allowed to estimate the stoichiometry of the complex and to determine the binding constants. As found using ESI-MS, together with more abundant 1:1 complex, a complex with 1:2 stoichiometry may also be present in a rather small amount in a solution of DIM and beta-CD. One-dimensional ROESY experiments indicated that the geometry of the complexes of DIM with native beta-CD depends on the ratio of the components in the solution. In the 1:1 solution of DIM and beta-CD the complex may be formed by inclusion of the indene moiety of DIM into the cavity of beta-CD on the primary side and into the cavity of TM-beta-CD into the secondary side. The most likely structural reason for lower affinity of the enantiomers of DIM towards the cavity of TM-beta-CD compared to native beta-CD could be elucidated. The indene moiety does not enter the cavity of TM-beta-CD as deeply as the cavity of beta-CD. This may be the most likely explanation of significantly higher affinity constants of DIM enantiomers towards the latter CD compared to the former one. The marked difference between the structure of the complexes may also be responsible for the opposite affinity pattern of the DIM enantiomers towards beta-CD and TM-beta-CD.

An Hydroalcoholic Chamomile Extract Modulates Inflammatory and Immune Response in HT29 Cells and Isolated Rat Colon

Inflammatory bowel diseases (IBDs) are chronic disorders characterized by disruption and ulceration of the colonic mucosa or of any part of the digestive tract (Crohns disease). Antioxidant/anti‐inflammatory herbal extract supplementation could represent an innovative approach to contrast IBDs. Clinical trials demonstrated the efficacy of natural formulas, containing chamomile, in patients with gastrointestinal disorders. This is consistent, albeit in part, with the antioxidant and anti‐inflammatory properties of chamomile. The aim of the present study was to explore the possible protective role of a chamomile extract, on human colorectal adenocarcinoma HT29 cell, and rat colon specimens treated with lipopolysaccharide (LPS) to induce an inflammatory stimulus, a well established model of acute ulcerative colitis. In this context, the activities of different biomarkers of inflammation and lipid peroxidation such as ROS, myeloperoxidase (MPO), serotonin (5‐HT), prostaglandin (PG)E2, 8‐iso‐prostaglandin (8‐iso‐PG)F2α, NF‐kB, tumor necrosis factor (TNF)α and interleukin (IL)‐6 were assessed. We found that chamomile extract was as effective as sulfasalazine (2 mg/ml) in reducing the production of MPO, 5‐HT, IL‐6, NF‐kB, TNFα, PGE2 and 8‐iso‐PGF2α, after inflammatory stimulus. The observed modulatory effects support a rationale use of chamomile supplementation as a promising pharmacological tool for the prevention and management of ulcerative colitis in humans. Copyright

'Moringa oleifera: study of phenolics and glucosinolates by mass spectrometry' †

Moringa oleifera is a medicinal plant and an excellent dietary source of micronutrients (vitamins and minerals) and health-promoting phytochemicals (phenolic compounds, glucosinolates and isothiocyanates). Glucosinolates and isothiocyanates are known to possess anti-carcinogenic and antioxidant effects and have attracted great interest from both toxicological and pharmacological points of view, as they are able to induce phase 2 detoxification enzymes and to inhibit phase 1 activation enzymes. Phenolic compounds possess antioxidant properties and may exert a preventative effect in regards to the development of chronic degenerative diseases. The aim of this work was to assess the profile and the level of bioactive compounds in all parts of M. oleifera seedlings, by using different MS approaches. First, flow injection electrospray ionization mass spectrometry (FI-ESI-MS) fingerprinting techniques and chemometrics (PCA) were used to achieve the characterization of the different plants organs in terms of profile of phenolic compounds and glucosinolates. Second, LC-MS and LC-MS/MS qualitative and quantitative methods were used for the identification and/or determination of phenolics and glucosinolates in M. oleifera.

Variability of chemical composition and antioxidant activity of essential oils between Myrtus communis var. Leucocarpa DC and var. Melanocarpa DC

Essential oils (EOs) from several individuals of Myrtus communis L. (M. communis) growing in different habitats in Sardinia have been studied. The analyses were focused on four groups of samples, namely cultivated and wild M. communis var. melanocarpa DC, characterized by red/purple berries, and cultivated and wild M. communis var. leucocarpa DC, characterized by white berries. Qualitative and quantitative analyses demonstrated different EO fingerprints among the studied samples: cultivated and wild leucocarpa variety differs mainly from the melanocarpa variety by a high amount of myrtenyl acetate (>200 mg/mL and 0.4 mg/mL in leucocarpa and melanocarpa varieties respectively). Conversely, the wild group is characterized by a higher amount, compared with the cultivated species, of linalool (about 110 mg/mL and 20 mg/mL respectively), linalyl acetate (about 24 mg/mL and about 6 mg/mL respectively) whereas EOs of the cultivated plants were rich in pinocarveol-cis compared with wild plants (about 2 mg/mL and about 0.5 mg/mL respectively). Principal component analysis applied to the chromatographic data confirm a differentiation and classification of EOs from the four groups of M. communis plants. Finally, antioxidant activity of the studied EOs shows differences between the various categories of samples.

Genetic and metabolite diversity of Sardinian populations of Helichrysum italicum

Background Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia. Methods H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA. Key results The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity. Conclusions The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.

Essential Oil Composition of Hypericum perforatum L. var. angustifolium DC Growing Wild in Sardinia (Italy)

Abstract The oil from inforescences of Hypericum perforatum var. angustifolium growing wild and harvested in Sardinia (Italy) was analyzed by GC and GC/MS. The major compounds in the oil were 2-methyloctane (21.1%), germacrene D (17.6%) and α-pinene (15.8%).

Antimicrobial Activity against Beneficial Microorganisms and Chemical Composition of Essential Oil of Mentha suaveolens ssp. insularis Grown in Sardinia

UNLABELLED The aim of this work was to determine the chemical constituents and in vitro antimicrobial activity of the essential oil (EO) of the aerial parts of Mentha sueveolens spp. insularis grown in Sardinia (Italy) against probiotic and starter microorganisms. The gas chromatography-mass spectrometry (GC-MS) analysis allowed to identified 34 compounds, most of oxygenated monoterpene compounds (82.5%) and among them, pulegone was found as major compound (46.5%). The agar diffusion test carried out employing the EO of Mentha suaveolens spp. insularis showed a low antibacterial activity, in particular no action was noticed for probiotic bacteria belonging to lactic acid bacteria groups, whereas almost all yeasts strains tested were inhibited. The automated microtitter dilution assay showed a clear effect at increasing concentration of EO on the specific growth rate (μ) and extension of the lag phase (λ) only for S. xylosus SA23 among bacteria and for Saccharomyces cerevisiae, Tetrapisispora phaffii CBS 4417, Metschnikowia pulcherrima, and Candida zemplinina among yeasts. Results obtained in this work allow us to broaden the knowledge on the effect of EOs on probiotic and food-related microorganisms. PRACTICAL APPLICATION Mentha suaveolens spp. insularis may be used in combination with probiotic bacteria into the food matrix or encapsulated in coating and edible films for food preservation.

Chemical and biological study on the essential oil of Artemisiacaerulescens L. ssp. densiflora (Viv.)

Artemisia caerulescens L. ssp. densiflora (Viv.) is a wild shrub that grows in the archipelago of La Maddalena, Sardinia, Italy. The antifungal activity of the volatile oil of this sub-species has not been evaluated earlier. This study aimed to identify the main components of the essential oil of A. caerulescens L. ssp. densiflora and to investigate its antifungal activity. Identification of the different components of the essential oil obtained by hydrodistillation from A. caerulescens L. ssp. densiflora was done by both techniques: GC-MS and NMR analyses (1H, 13C, HSQC-NMR). Antifungal activity was evaluated by agar disc diffusion technique against environmental isolates of fungal strains: two yeasts (Rhodotorula spp., Candida spp.), three moulds (Aspergillus spp., Alternaria spp., Fusarium spp.) and a mixture of moulds. GC-MS analysis of the essential oil yielded 42 compounds, out of which, 26 compounds were identified. The main compound was identified as terpinen-4-ol (22%) followed by p-cymene (7.6%) and α-terpineol (3.02%). The significant inhibition spectrum of the essential oil of A. caerulescens L. ssp. densiflora can be considered as an alternative to common disinfectants.

Volatiles, color characteristics and other physico-chemical parameters of commercial Moroccan honeys.

Seven commercial Moroccan honeys were considered for chemical characterisation. Volatile fraction, total polyphenols content, antioxidant and antiradical activities were evaluated by employing different analytical methodologies. Several physical parameters such as refractive index, pH, water content, solids content and colour were measured. Volatile fraction revealed an abundant presence of cis- and trans-linalool oxide in the seven studied samples. The presence of high levels of compounds related to the Maillard reaction, like furfural and hydroxymethylfurfural, could be the result of thermal treatments used to liquefy commercial honeys or of long storage times. The CIE L*a*b*Cab*hab° chromatic coordinates confirmed the advanced stage of the Maillard reaction, showing L* values lower than the common values found for honey of similar typologies.