Chemistry of α-mangostin : studies on the semisynthesis of minor xanthones from Garcinia mangostana

\u3b1-Mangostin is the major prenylated xanthone from Garcinia mangostana and it has been used also in recent times as starting material for the semisynthetic preparation of various biologically active derivatives. Its structure is characterised by the presence of few functional groups amenable to chemical manipulations, but present in the molecule in multiple instances (three phenolic hydroxyl groups, two prenyl chains and two unsubstituted aromatic carbons). This study represents a first approach to the systematic investigation of the reactivity of \u3b1-mangostin and describes the semisynthesis of some minor xanthones isolated from G. mangostana

Sintesi chemoenzimatica di nucleosidi

A purine nucleoside phosphorylase from Aeromonas hydrophila was cloned, expressed in Escherichia coll and purified. The enzyme showed a good stability and a broad substrate specificity towards modified purine ribonucleosides. The enzyme was used for the synthesis of purine nucleosides structurally related to compds. of biol. interest via a "one pot, one enzyme" transglycosylation reaction using 7-Me guanosine iodide as the sugar donor and 6-substituted purines as acceptor

Chimica dei nuovi sapori : composti umami e kokumi

Umami \ue8 il caratteristico gusto impartito dalla presenza di glutammato monosodico (MSG) e 5'-ribonucleotidi, quali inosina 5'-monofosfato (IMP) e guanosina 5'-monofosfato (GMP). Questi composti sono naturalmente presenti in molti alimenti (in particolare carne, pesce e alcune verdure) e giocano un ruolo fondamentale nel conferire sapore ai cibi non solo per il loro peculiare gusto ben distinto dagli altri quattro, ma anche perch\ue8 esercitano una spiccata attivit\ue0 di esaltatori di sapore ("flavor enhancing activity"). Sono cio\ue8 in grado di aumentare l'appetibilit\ue0 del cibo anche se presenti in quantit\ue0 al di sotto della loro soglia di percezione. \uc8 stato inoltre scoperto che tra MSG e ribonucleotidi esiste un marcato fenomeno di "sinergismo", cio\ue8 un aumento pi\uf9 che additivo del tipico effetto di "flavor enhancement" che si verifica quando in un preparato alimentare sono presenti entrambi i tipi di composti.[1] Hanno il sapore umami tipico del glutammato monosodico e la capacit\ue0 di esaltare il "flavor" dei cibi a base salata anche alcune miscele peptidiche ottenute per idrolisi chimica e/o enzimatica di materie prime di origine vegetale ricche in proteine, quali grano, mais, soia, arachidi, girasole, ecc. (HVPs \u2013 Hydrolyzed Vegetable Proteins).[2] Al fine di individuare nuovi composti umami e di intraprendere uno studio SAR ("structure-activity relationships") di ribonucleotidi aventi "flavor enhancing activity", sono stati sintetizzati e sottoposti ad analisi sensoriale derivati dell'acido guanilico sostituiti in posizione 2 con catene alchiliche o aciliche.[3,4] Inoltre, nell\u2019ambito del progetto Velica ("Da antiche colture materiali e prodotti per il futuro" www.velica.org), abbiamo sviluppato procedure di idrolisi chimica ed enzimatica di materiale di scarto a elevato contenuto proteico quali i panelli derivanti dalla spremitura di semi oleaginosi, in particolare di lino e canapa.[5] In combinazione con il "flavor enhancement" proprio delle sostanze umami \ue8 stato recentemente evidenziato un altro effetto sensoriale, il kokumi. Le sostanze kokumi (per lo pi\uf9 \u3b3-glutammil derivati di amminoacidi o amminoacidi modificati) contribuiscono alla formazione del "flavor" generando in bocca le sensazioni di pienezza, rotondit\ue0, persistenza del sapore d\u2019impatto. In quest\u2019ambito \ue8 stata recentemente realizzata la sintesi chemoenzimatica di \u3b3-glutammil-S-alch(en)il cisteine e dei corrispondenti solfossidi presenti nell\u2019aglio e nella cipolla.[6] [1] Yamaguchi, S., Ninomiya, K., Food Rev. Int., 1998, 14, 123-138; [2] Maehashi, K., Matsuzaki, M., Yamamoto, Y., Udaka, S., Biosci. Biotechnol. Biochem., 1999, 555-559; [3] Cairoli, P., Pieraccini, S., Sironi, M., Morelli, C. F., Speranza, G., Manitto, P., J. Agric. Food. Chem., 2008, 56, 1043-1050; [4] Morelli, C. F., Manitto, P.4, Speranza, G., Flav. Fragr. Journal, 2011, 26, 279-281; [5] Bagnasco, L., Pappalardo, V., Meregaglia, A., Kaewmanee, T., Ubiali, D., Speranza, G., Cosulich, M. E., Food Res. Int. 2013, 50, 420-427; [6] Speranza, G., Morelli, C. F., J. Mol. Catal. B: Enz., 2012, 84, 65-71

Chimica dei nuovi sapori: composti umami e kokumi

Umami taste is imparted by monosodium L-glutamate (MSG) and disodium salts of 5’-ribonucleotides such as inosine 5’-monophosphate (IMP) and guanosine 5’-monophosphate (GMP). Peculiar characteristics of the umami substances are their ability to enhance the flavor of savory dishes and their mutual taste synergism. Kokumi, which is distinct from the five basic tastes and is typically represented by glutathione (GSH), refers to mouthfulness, thickness and increasing continuity of food taste perception

Enrichment of hemp oil with PUFAs by lipase-mediated reactions in a green low-water content medium

Hempseed oil is an exceptionally rich source of linoleic acid (18:2, n-6; LA) and alpha-linolenic acid (18:3, n-3; ALA), two essential polyunsaturated fatty acids (PUFAs) which represent about 70% of the total fatty acid (FA) content. These PUFAs are fundamental in human nutrition since they have a prominent role in the prevention and treatment of cardiovascular diseases, diabetes, rheumatoid arthritis and other inflammatory and autoimmune disorders. Due to nutritional benefits of consuming PUFA concentrates, the market of these products is rapidly growing. We have investigated the enrichment of hempseed oil with linoleic acid (LA) and alpha-linolenic acid (ALA) by lipase-catalyzed hydrolysis. The conventional hydrolytic biphasic system consisting of oil/isooctane/buffer was compared with a homogeneous medium based on oil and t-BuOH/water. The new system appeared to be superior to the classical one in terms of substrate/product solubility and biocatalyst stability. Seven commercial lipases were screened in the new reaction medium. The free fatty acid (FA) composition of the hydrolyzed oil was determined by GC analysis. Selectivity showed by lipase from Pseudomonas cepacia for saturated FAs was exploited to obtain acylglycerols enriched in LA and ALA. The enzymatic reaction was scaled up and the acylglycerol components were purified and analyzed by GC to assess FA composition. In the final product (yield: 29%) the amount of polyunsaturated FAs reached 82% (against 77% of the crude oil) whereas the content of saturated FAs was negligible

Management of cardiogenic shock in acute decompensated chronic heart failure: The ALTSHOCK phase II clinical trial

Management of acute decompensated heart failure patients presenting with cardiogenic shock (CS) is not straightforward, as few data are available from clinical trials. Stabilization before left ventricle assist device (LVAD) or heart transplantation (HTx) is strongly advocated, as patients undergoing LVAD implant or HTx in critical status have worse outcomes. This was a multicenter phase II study with a Simon 2-stage design, including 24 consecutive patients treated with low-moderate epinephrine doses, whose refractory CS prompted implantation of intra-aortic balloon pump (IABP) which was subsequently upgraded with peripheral venoarterial extracorporeal membrane oxygenation. At admission, patients had severe left ventricular dysfunction and overt CS, 7 patients could be managed only with inotropic therapy, and 16 patients were transitioned to IABP and 1 to IABP and venoarterial extracorporeal membrane oxygenation; the median duration of epinephrine therapy was 7\u202fdays (interquartile range 6-15), and the median dose was 0.08 \u3bcg/kg/min (interquartile range 0.05-0.1); 21 patients (87.5%) survived at 60\u202fdays (primary outcome); among them, 13 (61.9%) underwent LVAD implantation, 2 (9.5%) underwent HTx, and 6 (28.6%) improved on medical treatment, indicating that early and intensive treatment of CS in chronic advanced heart failure patients with low-dose epinephrine and timely short-term mechanical circulatory support leads to satisfactory outcomes

Effect of clinical signs, endocrinopathies, timing of surgery, hyperlipidemia, and hyperbilirubinemia on outcome in dogs with gallbladder mucocele

Gallbladder mucocele (GBM) is a common extra-hepatic biliary syndrome in dogs with death rates ranging from 7 to 45%. Therefore, the aim of this study was to identify the association of survival with variables that could be utilized to improve clinical decisions. A total of 1194 dogs with a gross and histopathological diagnosis of GBM were included from 41 veterinary referral hospitals in this retrospective study. Dogs with GBM that demonstrated abnormal clinical signs had significantly greater odds of death than subclinical dogs in a univariable analysis (OR, 4.2; 95% CI, 2.14–8.23; P < 0.001). The multivariable model indicated that categorical variables including owner recognition of jaundice (OR, 2.12; 95% CI, 1.19–3.77; P = 0.011), concurrent hyperadrenocorticism (OR 1.94; 95% CI, 1.08–3.47; P = 0.026), and Pomeranian breed (OR, 2.46; 95% CI 1.10–5.50; P = 0.029) were associated with increased odds of death, and vomiting was associated with decreased odds of death (OR, 0.48; 95% CI, 0.30–0.72; P = 0.001). Continuous variables in the multivariable model, total serum/plasma bilirubin concentration (OR, 1.03; 95% CI, 1.01–1.04; P < 0.001) and age (OR, 1.17; 95% CI, 1.08–1.26; P < 0.001), were associated with increased odds of death. The clinical utility of total serum/plasma bilirubin concentration as a biomarker to predict death was poor with a sensitivity of 0.61 (95% CI, 0.54–0.69) and a specificity of 0.63 (95% CI, 0.59–0.66). This study identified several prognostic variables in dogs with GBM including total serum/plasma bilirubin concentration, age, clinical signs, concurrent hyperadrenocorticism, and the Pomeranian breed. The presence of hypothyroidism or diabetes mellitus did not impact outcome in this study

Effect of clinical signs, endocrinopathies, timing of surgery, hyperlipidemia, and hyperbilirubinemia on outcome in dogs with gallbladder mucocele

Gallbladder mucocele (GBM) is a common extra-hepatic biliary syndrome in dogs with death rates ranging from 7 to 45%. Therefore, the aim of this study was to identify the association of survival with variables that could be utilized to improve clinical decisions. A total of 1194 dogs with a gross and histopathological diagnosis of GBM were included from 41 veterinary referral hospitals in this retrospective study. Dogs with GBM that demonstrated abnormal clinical signs had significantly greater odds of death than subclinical dogs in a univariable analysis (OR, 4.2; 95% CI, 2.14–8.23; P < 0.001). The multivariable model indicated that categorical variables including owner recognition of jaundice (OR, 2.12; 95% CI, 1.19–3.77; P = 0.011), concurrent hyperadrenocorticism (OR 1.94; 95% CI, 1.08–3.47; P = 0.026), and Pomeranian breed (OR, 2.46; 95% CI 1.10–5.50; P = 0.029) were associated with increased odds of death, and vomiting was associated with decreased odds of death (OR, 0.48; 95% CI, 0.30–0.72; P = 0.001). Continuous variables in the multivariable model, total serum/plasma bilirubin concentration (OR, 1.03; 95% CI, 1.01–1.04; P < 0.001) and age (OR, 1.17; 95% CI, 1.08–1.26; P < 0.001), were associated with increased odds of death. The clinical utility of total serum/plasma bilirubin concentration as a biomarker to predict death was poor with a sensitivity of 0.61 (95% CI, 0.54–0.69) and a specificity of 0.63 (95% CI, 0.59–0.66). This study identified several prognostic variables in dogs with GBM including total serum/plasma bilirubin concentration, age, clinical signs, concurrent hyperadrenocorticism, and the Pomeranian breed. The presence of hypothyroidism or diabetes mellitus did not impact outcome in this study