Characterization of alkaloids in bark extracts of Geissospermum vellosii by HPLC-UV-diode array-multistage high-resolution mass spectrometry.

A number of analytical studies, started in the sixties of the last century, concerning the stem bark of Geissospermum vellosii, have documented the presence of a number of indole alkaloids whose molecular identity was defined by NMR technique. The potential bioactivity of these compounds has inspired more recent analogous studies either devoted to structural elucidation of new alkaloid molecules or to the investigation of the role of some of them in cancer therapy. Anyway, a complete fingerprinting of the bark content is still lacking. In this paper, after a suitable extraction step, we obtain a chromatographic separation showing a number of components higher than the number of alkaloids so far described. Considering the great number of substances present in the stem bark, their identification is practically impossible to reveal by NMR techniques. As we presume that there are other stem bark unidentified alkaloids with important bioactivity, we propose to characterize their molecular structures by UV-Vis Diode Array spectrophotometry and High-Resolution Multistage Mass Spectrometry. The two adopted detection techniques were first tested on the already known Geissospermum vellosii molecules, and, after an inspection of their efficacy, were applied to the substances that have not yet been described. Herewith we propose the molecular structures of 10 substances that were never previously described, and in addition we provide experimental evidence of the presence of 6 already known substances which were never reported in the Geissospermum genus. A far more detailed description of the bark constituents is therefore provided.

Preparation and characterization of polymeric microparticles loaded with Moringa oleifera leaf extract for exuding wound treatment.

The aim of this study was to develop an innovative formulation, particularly useful for the treatment of exuding wounds. An extract from Moringa oleifera leaves (MOE), prepared by an eco-friendly method, was used as active ingredient. Its preliminary characterization showed that MOE is rich in quercetin-O-glucoside and quercetin-O-malonyl glucoside, responsible for the antioxidant, radical scavenging and antibacterial activities (toward Staphylococcus aureus, S. epidermidis, S. faecalis and S. pyogenes). Moreover, MOE showed the ability to stimulate keratinocytes growth. Thus, bioadhesive biocompatible polymeric microparticles loaded with such extract were developed and prepared in order to treat exuding wounds. The microparticles, obtained by spray drying, using chitosan as polymer, showed good swelling ability. This is useful to obtain the transition from microparticles to a continuous gel covering the wound, after deposition on it. This has the double function to protect the damage area and to promote the healing. The in vitro release study showed that the formed gel is able to release immediately MOE, in the first minutes after application, and to promote a sustained release within 24 h reaching an efficacious concentration against the most sensitive bacterial strains. These findings suggest that the developed microparticles represent an interesting tool for exuding wounds treatment.

Bioadhesive Polymeric Films Based on Red Onion Skins Extract for Wound Treatment: An Innovative and Eco-Friendly Formulation.

The onion non-edible outside layers represent a widely available waste material deriving from its processing and consumption. As onion is a vegetable showing many beneficial properties for human health, a study aiming to evaluate the use of extract deriving from the non-edible outside layers was planned. An eco-friendly extraction method was optimized using a hydroalcoholic solution as solvent. The obtained extract was deeply characterized by in vitro methods and then formulated in autoadhesive, biocompatible and pain-free hydrogel polymeric films. The extract, very soluble in water, showed antioxidant, radical scavenging, antibacterial and anti-inflammatory activities, suggesting a potential dermal application for wounds treatment. In vitro studies showed a sustained release of the extract from the hydrogel polymeric film suitable to reach concentrations necessary for both antibacterial and anti-inflammatory activities. Test performed on human keratinocytes showed that the formulation is safe suggesting that the projected formulation could be a valuable tool for wound treatment.

Formation of by-products during chemical interesterification of lipids. Detection and characterization of dialkyl ketones by non-aqueous reversed-phase liquid chromatography-high resolution mass spectrometry and gas chromatography-mass spectrometry.

A new class of foreign substances present in the unsaponifiable fraction of vegetable oils undergone to chemical interesterification was systematically investigated. Their chemical structure, corresponding to dialkyl ketones (DAK) molecules, was elucidated both by gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-high resolution mass spectrometry (LC-HRMS). An analytical protocol aimed to qualitative and quantitative detection of DAK molecules in vegetable oils of confectionery industry interest was developed. Being the range of concentration levels to be evaluated dependent on the technological task of interesterification process, the quantitation step was thoroughly examined. All the validation parameters were satisfactory and particularly the concentration determinations were made more reliable by the contemporary use of several quantitation standards. GC-MS and LC-HRMS analytical techniques exhibited comparable performances even if the second one shown better detection sensitivity.

Safety of Desmodium adscendens extract on hepatocytes and renal cells. Protective effect against oxidative stress.

AIM: The increased consumption of traditional medicinal plants has been driven by the notion that herbal products are safe and efficient. The purpose of this study was to evaluate the safety and the protective effect of a hydro alcoholic extract of Desmodium adscendens (DA) on liver (HEPG2) and kidney (LLC-PK1) cells. MATERIALS AND METHODS: A hydro alcoholic extract of DA was used. HEPG2 or LLC-PK1 cells were treated with different does of DA, and viability test (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium [MTS]), cytotoxicity assay lactate dehydrogenase (LDH release) and study of the cell morphology were used in order to determine effects of DA on these two cells. RESULTS: A viability test (MTS), a cytotoxicity assay LDH release and a study of the cell morphology revealed that pretreatment with 1 mg/ml or 10 mg/ml DA did not alter viability or LDH release in HEPG2 or LLC-PK1 cells. However, DA at the dose of 100 mg/ml significantly decreased cell viability, by about 40% (P < 0.05). Further, MTS studies revealed that DA 1 mg/ml or 10 mg/ml protected LLC-PK1 cells against a glucose-induced oxidative stress of 24 h (P < 0.05). CONCLUSION: Hence, the lowest concentrations of DA (1 mg/ml and 10 mg/ml) were safe for HEPG2 and LLC-PK1 and protective against an oxidative stress in LLC-PK1 cells. These data suggest that DA extracts used as a traditional herbal as food health supplements should be used at the lowest dosage.

Qualitative characterization of Desmodium adscendens constituents by high-performance liquid chromatography-diode array ultraviolet-electrospray ionization multistage mass spectrometry.

The many effects of the African medicinal herb Desmodium adscendens were studied in the 1980s and 1990s. In spite of this, a comprehensive analytical protocol for the quality control of its constituents (soyasaponins, alkaloids and flavonoids) has not yet been formulated and reported. This study deals with the optimization of extraction conditions from the plant and qualitative identification of the constituents by HPLC-diode array UV and multistage mass spectrometry. Plant constituents were extracted from leaves by liquid-liquid and solid matrix dispersion extraction. Separation was achieved via RP-C18 liquid chromatographywith UV and MS(n) detection and mass spectrometry analysis was conducted by electrospray ionization ion trap or orbitrap mass spectrometry. High resolution mass spectrometry (HRMS) was used for structural identification of active molecules relating to soyasaponins and alkaloids. The flavonoid fragmentations were preliminarily studied by HRMS in order to accurately characterize the more common neutral losses. However, the high number of isomeric species induced us to make recourse to a more extended chromatographic separation in order to enable useful tandem mass spectrometry and ultraviolet spectral interpretation to propose a reasonable chemical classification of these polyphenols. 35 compounds of this class were identified herein with respect to the five reported in literature in this way we made up a comprehensive protocol for the qualitative analysis of the high complexity content of this plant. This result paves the way for both reliable quality control of potential phytochemical medicaments and possible future systematic clinical studies.

Study of the photocatalytic transformation of synephrine: a biogenic amine relevant in anti-doping analysis.

The occurrence of some cases of positive results in anti-doping analysis of octopamine requires clarification as to whether its methylated derivative synephrine could be a metabolic precursor of octopamine itself. Synephrine is a natural phenylethylamine derivative present in some food supplements containing Citrus aurantium, permitted in sport regulations. A simulative laboratory study had been done using a photocatalytic process, to identify all possible main and secondary transformation products, in a clean matrix; these were then sought in biological samples obtained from three human volunteers and four rats treated with synephrine; the parent compound and its new potential metabolic products were investigated in human urine and rat plasma samples. The transformation of synephrine and octopamine and the formation of intermediate products were evaluated, adopting titanium dioxide as photocatalyst. Several products were formed and characterized using the HPLC-HRMS(n) technique. The main intermediates identified in these experimental conditions were compared with the major synephrine metabolites found in in vivo studies on rats and humans. Some more oxidized species, already formed in the photocatalytic process, were also found in urine and plasma samples of treated animals. These new findings could be of interest in further metabolism studies. The main photocatalytic pathway involving synephrine appears to be N-demethylation to give octopamine. On the contrary, we demonstrate the inconsistency of this reaction in both rat and human in vivo determinations, resulting in forensic importance.