Activation of Vegetable Oils by Reaction with Maleic Anhydride as a Renewable Source in Chemical Processes: New Experimental and Computational NMR Evidence.

Vegetable oils are bio-based and sustainable starting materials that can be used to develop chemicals for industrial processes. In this study, the functionalization of three vegetable oils (grape, hemp, and linseed) with maleic anhydride was carried out either by conventional heating or microwave activation to obtain products that, after further reactions, can enhance the water dispersion of oils for industrial applications. To identify the most abundant derivatives formed, trans-3-octene, methyl oleate, and ethyl linoleate were reacted as reference systems. A detailed NMR study, supported by computational evidence, allowed for the identification of the species formed in the reaction of trans-3-octene with maleic anhydride. The signals in the 1H NMR spectra of the alkenyl succinic anhydride (ASA) moieties bound to the organic chains were clearly identified. The reactions achieved by conventional heating were carried out for 5 h at 200 °C, resulting in similar or lower amounts of ASA units/g of oil with respect to the reactions performed by microwave activation, which, however, induced a higher viscosity of the samples.

HT-SuMD: making molecular dynamics simulations suitable for fragment-based screening. A comparative study with NMR.

Fragment-based lead discovery (FBLD) is one of the most efficient methods to develop new drugs. We present here a new computational protocol called High-Throughput Supervised Molecular Dynamics (HT-SuMD), which makes it possible to automatically screen up to thousands of fragments, representing therefore a new valuable resource to prioritise fragments in FBLD campaigns. The protocol was applied to Bcl-XL, an oncological protein target involved in the regulation of apoptosis through protein-protein interactions. Initially, HT-SuMD performances were validated against a robust NMR-based screening, using the same set of 100 fragments. These independent results showed a remarkable agreement between the two methods. Then, a virtual screening on a larger library of additional 300 fragments was carried out and the best hits were validated by NMR. Remarkably, all the in silico selected fragments were confirmed as Bcl-XL binders. This represents, to date, the largest computational fragments screening entirely based on MD.

Limited genotypic and geographic variability of 16-O-methylated diterpene content in Coffea arabica green beans.

The acknowledged marker of Robusta coffee, 16-O-methylcafestol (16-OMC), can be quantified by NMR as a mixture with 16-O-methylkahweol (16-OMK), which accounts for approximately 10% of the mixture. In the present study, we detected and quantified 16-O-methylated diterpenes (16-OMD) in 248 samples of green Coffea arabica beans by NMR. We did not observe any differences between genotypes introgressed by chromosomal fragments of Robusta and non-introgressed genotypes. Environmental effects suggesting a possible protective role of 16-OMD for adaptation, as well as genotypic effects that support a high heritability of this trait were observed. Altogether, our data confirmed the presence of 16-OMD in green Arabica at a level approximately 1.5% that of a typical Robusta, endorsing the validity of 16-OMD as a marker for the presence of Robusta.

Antiadhesive Activity and Metabolomics Analysis of Rat Urine after Cranberry (Vaccinium macrocarpon Aiton) Administration.

Cranberry (Vaccinium macrocarpon Aiton) is used to treat noncomplicated urinary tract infections (UTIs). A-type procyanidins (PAC-A) are considered the active constituents able to inhibit bacterial adhesion to the urinary epithelium. However, the role of PAC-A in UTIs is debated, because of their poor bioavailability, extensive metabolism, limited knowledge about urinary excretion, and contradictory clinical trials. The effects of 35-day cranberry supplementation (11 mg/kg PAC-A, 4 mg/kg PAC-B) were studied in healthy rats using a ultra performance liquid chromatography-mass spectrometry (UPLC-MS)-based metabolomics approach. Microbial PAC metabolites, such as valeric acid and valerolactone derivatives, were related to cranberry consumption. An increased urinary excretion of glucuronidated metabolites was also observed. In a further experiment, urine samples were collected at 2, 4, 8, and 24 h after cranberry intake and their antiadhesive properties were tested against uropathogenic Escherichia coli. The 8 h samples showed the highest activity. Changes in urinary composition were studied by ultra performance liquid chromatography-time-of-flight (UPLC-QTOF), observing the presence of PAC metabolites. The PAC-A2 levels were measured in all collected samples, and the highest amounts, on the order of ng/mL, were found in the samples collected after 4 h. Results indicate that the antiadhesive activity against uropathogenic bacteria observed after cranberry consumption is ascribable to PAC-A metabolites rather than to a direct PAC-A effect, as the measured PAC-A levels in urine was lower than those reported as active in the literature.

New findings on the in vivo antioxidant activity of Curcuma longa extract by an integrated (1)H NMR and HPLC-MS metabolomic approach.

Curcuminoids possess powerful antioxidant activity as demonstrated in many chemical in vitro tests and in several in vivo trials. Nevertheless, the mechanism of this activity is not completely elucidated and studies on the in vivo antioxidant effects are still needed. Metabolomics may be used as an attractive approach for such studies and in this paper, we describe the effects of oral administration of a Curcuma longa L. extract (150 mg/kg of total curcuminoids) to 12 healthy rats with particular attention to urinary markers of oxidative stress. The experiment was carried out over 33 days and changes in the 24-h urine samples metabolome were evaluated by (1)H NMR and HPLC-MS. Both techniques produced similar representations for the collected samples confirming our previous study. Modifications of the urinary metabolome lead to the observation of different variables proving the complementarity of (1)H NMR and HPLC-MS for metabolomic purposes. The urinary levels of allantoin, m-tyrosine, 8-hydroxy-2'-deoxyguanosine, and nitrotyrosine were decreased in the treated group thus supporting an in vivo antioxidant effect of the oral administration of Curcuma extract to healthy rats. On the other hand, urinary TMAO levels were higher in the treated compared to the control group suggesting a role of curcumin supplementation on microbiota or on TMAO urinary excretion. Furthermore, the urinary levels of the sulphur containing compounds taurine and cystine were also changed suggesting a role for such constituents in the biochemical pathways involved in Curcuma extract bioactivity and indicating the need for further investigation on the complex role of antioxidant curcumin effects.

Preliminary Characterization of Monofloral Coffea spp. Honey: Correlation between Potential Biomarkers and Pollen Content.

To determine the botanical origin of Coffea honey, a new method using proton nuclear magnetic resonance ((1)H NMR) is proposed. Integration of the aromatic region of the NMR spectrum of Coffea honey diluted in deuterated water allowed us to simultaneously quantify caffeine, theobromine, and trigonelline, as well as other compounds. The amounts of the three markers listed are significantly higher than those previously reported for Citrus spp. honey: caffeine ranged from 15 to 98 mg/kg, theobromine from 25 to 160 mg/kg, and trigonelline from 23 to 86 mg/kg. The concurrent presence of these three substances is proposed as an indicator of the botanical origin of Coffea honey. Excellent correlation was found between these markers and the relative amounts of Coffea pollen measured in the same samples.

Rapid authentication of coffee blends and quantification of 16-O-methylcafestol in roasted coffee beans by nuclear magnetic resonance.

Roasted coffee is subject to commercial frauds, because the high-quality Coffea arabica species, described as "100% Arabica" or "Highland coffee", is often mixed with the less expensive Coffea canephora var. Robusta. The quantification of 16-O-methylcafestol (16-OMC) is useful to monitor the authenticity of the products as well as the Robusta content in blends. The German standard method DIN 10779 is used in the determination of 16-OMC in roasted coffee beans to detect C. canephora in blends, but it is laborious and time-consuming. Here, we introduce a new method that provides a quantitative determination of esterified 16-OMC directly in coffee extracts by means of high-resolution proton nuclear magnetic resonance spectroscopy. Limit of detection and limit of quantitation were 5 and 20 mg/kg, respectively, which are adequate to detect the presence of Robusta at percentages lower than 0.9%. The proposed method is much faster, more sensitive, and much more reproducible than the DIN standard method.

Changes in urinary metabolic profile after oral administration of curcuma extract in rats.

The diffusion of phytochemicals in health promoting products is growing, but studies related to their effects on healthy subjects are still lacking despite the large consumption of natural products as nutraceuticals or food supplements. In many cases, research supports the in vitro antioxidant activity of phytochemicals, but the health claims attributed to the final marketed nutraceutical products have dubious scientific foundation. Also, studies focussed on the definition of their biological targets and mechanisms of action can be useful to assess their efficacy and safety. In this study, the effect of oral administration of 80mg/kg of Curcuma longa Linn. extract to 12 healthy rats over 25 days was evaluated by monitoring the changes of urinary composition. 24-h urine was collected during the animal experiment and the composition was analyzed by (1)H NMR and HPLC-MS. The two datasets were studied individually through a metabolomic approach and the multivariate analysis revealed significant differences between the control and the treated group. Curcumin levels were also measured in 24-h urine samples by HPLC-MS. Both the (1)H NMR and the HPLC-MS dataset showed that the administration of 80mg/kg of Curcuma longa extract to healthy animals induces changes in urinary composition. Decreased allantoin urinary levels can be considered a partial demonstration of the in vivo effect of curcumin on oxidative stress in a healthy animal model.

DJ-1 is a copper chaperone acting on SOD1 activation.

Lack of oxidative stress control is a common and often prime feature observed in many neurodegenerative diseases. Both DJ-1 and SOD1, proteins involved in familial Parkinson disease and amyotrophic lateral sclerosis, respectively, play a protective role against oxidative stress. Impaired activity and modified expression of both proteins have been observed in different neurodegenerative diseases. A potential cooperative action of DJ-1 and SOD1 in the same oxidative stress response pathway may be suggested based on a copper-mediated interaction between the two proteins reported here. To investigate the mechanisms underlying the antioxidative function of DJ-1 in relation to SOD1 activity, we investigated the ability of DJ-1 to bind copper ions. We structurally characterized a novel copper binding site involving Cys-106, and we investigated, using different techniques, the kinetics of DJ-1 binding to copper ions. The copper transfer between the two proteins was also examined using both fluorescence spectroscopy and specific biochemical assays for SOD1 activity. The structural and functional analysis of the novel DJ-1 copper binding site led us to identify a putative role for DJ-1 as a copper chaperone. Alteration of the coordination geometry of the copper ion in DJ-1 may be correlated to the physiological role of the protein, to a potential failure in metal transfer to SOD1, and to successive implications in neurodegenerative etiopathogenesis.

Green coffee oil analysis by high-resolution nuclear magnetic resonance spectroscopy.

In this work, we show how an extensive and fast quantification of the main components in green coffee oil can be achieved by NMR, with minimal sample manipulation and use of organic solvents. The approach is based on the integration of characteristic NMR signals, selected because of their similar relaxation properties and because they fall in similar spectral regions, which minimizes offset effects. Quantification of glycerides, together with their fatty acid components (oleic, linoleic, linolenic and saturated) and minor species (caffeine, cafestol, kahweol and 16-O-methylcafestol), is achieved in less than 1h making use of (1)H and (13)C spectroscopy. The compositional data obtained are in reasonable agreement with classical chromatographic analyses.

Characterization of markers of botanical origin and other compounds extracted from unifloral honeys.

The possibility of tracing the botanical and geographical origin of products such as honey has become more important because of market globalization. As a consequence, numerous analytical methods have been applied to the determination of honey authenticity. The scope of the present work is to chromatographically purify and characterize 23 compounds from organic extracts of unifloral (chestnut, linden, orange, acacia, eucalyptus, honeydew) and polyfloral honeys. Of these compounds, 17 were identified as specific markers and were used for botanical discrimination in a previous study based on multivariate statistical analysis of proton nuclear magnetic resonance ((1)H NMR) data. Together with the botanical markers, 6 other substances were isolated and characterized using NMR and mass spectrometry. These phytochemicals belong to several classes, that is, terpenes, organic acids, flavonoids, and others. For the first time, a diacylglyceryl ether and 5 other compounds present in different types of honey were identified and characterized.

NMR quantification of trace components in complex matrices by band-selective excitation with adiabatic pulses.

The use of band-selective excitation with adiabatic pulses to rapidly obtain NMR spectra of trace components in the presence of strong signals is described, along with qualitative and quantitative examples from food matrices like olive oil and honey.

New furan side tetracyclic allopsoralen derivatives: synthesis and photobiological evaluation.

Novel tetracyclic allopsoralen derivatives characterized by the condensation of a fourth cyclohexenylic (5-7) or benzenic (8-10) ring at the furan side and a methoxy (5 and 8), a hydroxy (6 and 9), or a dimethylaminopropoxy (7 and 10) side chain in the 10 position of the chromophore were prepared. Compounds 7 and 10 showed a strong photoantiproliferative activity, up to 3 orders of magnitude higher than that of the photochemotherapeutic drug 8-methoxypsoralen (8-MOP). The investigation into the mechanism of action demonstrated for 10 the capacity to intercalate between DNA base pairs in the ground state, to give rise to a covalent photoaddition upon UVA irradiation, and to inhibit polymerase chain reaction (PCR) in a sequence-specific manner. Conversely, compound 7 showed a limited capacity to form an intercalative complex and the lack of ability to photoadd to the macromolecule, thus revealing a novel and unusual behavior for an allopsoralen derivative.