90 research outputs found
Analysis of food supplement with unusual raspberry ketone content
In recent years food supplement market increased constantly, including slimming products and against obesity. The case of rasberry ketone (RK) is here reported. HPTLC and HPLC-DAD analyses on a marketed product containing raspberry juice evidenced an abnormal quantity of RK, not in accordance with the juice natural content. The reported data confirm the need of adequate controls on marketed food supplements and the necessity of a complete adherence between labelling and real constitution of the product. Practical Applications: Determining the natural origin and assuring the consumers' safety for raspberry-based food supplement
BIOGENIC AMINE CONTENT AND CHEMICAL AND PHYSICAL FEATURES OF ITALIAN FORMAGGIO DI FOSSA
Formaggio di Fossa is an Italian traditional cheese of the Montefeltro area (Emilia Romagna and Marche regions) characterized by a particular step of ripening that is carried out into pits (infossamento) borne in the sandstone. Since the XIV century, the inhabitants were used to set food, especially cereals and cheese, into pits to preserve them during winter and to protect them from invaders. The aim of the present work is to study physical and chemical features of this product with particular reference to the presence of the most important biogenic amines ( -Phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermine and spermidine), compared with a control cheese fully ripened in factory. Formaggio di Fossa showed higher values of Aw, pH, humidity, proteins, pH 4,6-soluble nitrogen (NCN) and water soluble nitrogen (NPN) and much lower amounts of fat. Much higher amounts of total biogenic amines were detected in Formaggio di Fossa than in control cheese, where their concentration was very low. Cadaverine, putrescine and tyramine were the most concentrated biogenic amines. Nevertheless, thyramine was present at levels suggested as compatible with GMPs. Histamine was detected at low amounts, far from potentially toxic levels
Studying ggdef domain in the act: Minimize conformational frustration to prevent artefacts
GGDEF-containing proteins respond to different environmental cues to finely modulate cyclic diguanylate (c-di-GMP) levels in time and space, making the allosteric control a distinctive trait of the corresponding proteins. The diguanylate cyclase mechanism is emblematic of this control: two GGDEF domains, each binding one GTP molecule, must dimerize to enter catalysis and yield c-di-GMP. The need for dimerization makes the GGDEF domain an ideal conformational switch in multidomain proteins. A re-evaluation of the kinetic profile of previously characterized GGDEF domains indicated that they are also able to convert GTP to GMP: this unexpected reactivity occurs when conformational issues hamper the cyclase activity. These results create new questions regarding the characterization and engineering of these proteins for in solution or structural studies
Phytochemical profile and biological activities of crude and purified Leonurus cardiaca extracts
Leonurus cardiaca L. (Lamiaceae) is a perennial herb distributed in Asia and Southeastern Europe and has been used in traditional medicine since antiquity for its role against cardiac and gynecological disorders. The polar extracts obtained from L. cardiaca aerial parts contain several compounds among which alkaloids, iridoids, labdane diterpenes, and phenylethanoid glycosides play a major role in conferring protection against the aforementioned diseases. On the other hand, the antioxidant activities and the enzyme inhibitory properties of these extracts have not yet been deeply studied. On the above, in the present study, crude and purified extracts were prepared from the aerial parts of L. cardiaca and have been chemically characterized by spectrophotometric assays and HPLC-DAD-MS analyses. Notably, the content of twelve secondary metabolites, namely phenolic acids (chlorogenic, caffeic, caffeoylmalic and trans-ferulic acids), flavonoids (rutin and quercetin), phenylethanoid glycosides (verbascoside and lavandulifolioside), guanidine pseudoalkaloids (leonurine), iridoids (harpagide), diterpenes (forskolin), and triterpenes (ursolic acid), has been determined. Furthermore, the extracts were tested for their antioxidant capabilities (phosphomolybdenum, DPPH, ABTS, FRAP, CUPRAC, and ferrous chelating assays) and enzyme inhibitory properties against cholinesterase, tyrosinase, amylase, and glucosidase. The purified extracts contained higher phytochemical content than the crude ones, with caffeoylmalic acid and verbascoside as the most abundant compounds. A linear correlation between total phenolics, radical scavenging activity, and reducing power of extracts has been found. Notably, quercetin, caffeic acid, lavandulifolioside, verbascoside, chlorogenic acid, rutin, and ursolic acid influenced the main variations in the bioactivities found in L. cardiaca extracts. Our findings provide further insights into the chemico-biological traits of L. cardiaca and a scientific basis for the development of nutraceuticals and food supplements
Isofuranodiene, a natural sesquiterpene isolated from wild celery (Smyrnium olusatrum L.), protects rats against acute ischemic stroke
The myrrh-like furanosesquiterpene isofuranodiene (IFD) is the main constituent of wild celery (Smyrnium olusatrum L., Apiaceae), an overlooked vegetable that was cultivated during the Roman Empire. In the present study, we investigated the protective effects of IFD pre-treatment against oxidative stress and inflammatory response in an animal model of ischemic stroke. IFD was isolated by the crystallization of Smyrnium olusatrum essential oil, and its structure and purity were confirmed by NMR and HPLC analyses. Acute pre-treatment of IFD (10 mg/kg i.p.) significantly reduced the levels of the inflammatory cytokines IL-1β and TNF-α, the expression of pNF-κB/NF-κB, and the lipid peroxidation indicator MDA. Finally, IFD boosted a faster recovery and better scores in grid-walking and modified neurological severity scores (mNSS) tests. Taken together, these findings indicate IFD as a promising lead compound for the discovery of new treatments of brain ischemia
Security gap analysis of some LDPC coded transmission schemes over the flat and fast fading Gaussian wire-tap channels
Utensile per la sterilizzazione della lancia vapore delle macchine da caffè
Utensile per la sterilizzazione della lancia vapore delle macchine da caffè, caratterizzato per il fatto di consistere sostanzialmente in un bicchiere con pareti isolate termicamente, che risulta chiuso in sommità da una membrana in gomma dotata di un foro centrale e che reca un condotto di sfiato eseguito in corrispondenza delle sue pareti laterali al di sotto dell’anzidetta membrana
Synthesis and solution studies by electrospray mass spectroscopy of new bis(imidazolyl)borate organotin(IV) complexes
New organotin(IV) derivatives containing the anionic dihydrobis(1-imidazolyl)borate [H2B(im)2]- have been synthesized from the reaction between SnRnX4-n (R = Me, Ph, nBu or Cy; n = 1-3) acceptors and [K{H2B(im)2}·(DMAC)] (DMAC = dimethylacetamide). Mono-nuclear complexes of the type {[H2B(im)2]RnSnCl4-n-1} have been obtained, which have been fully characterized by elemental analyses and FT-IR in the solid state and by NMR (1H and 119Sn) spectroscopy, conductivity measurements and electrospray ionization mass spectrometry (ESIMS) in solution. ESIMS spectra of a methanol solution of the complexes show the existence of hydrolysed species for mono- and di-organotin(IV) derivatives, while non-hydrolysed aggregates are detected for triorganotin(IV) derivative
- …