The Role of Allium subhirsutum L. in the Attenuation of Dermal Wounds by Modulating Oxidative Stress and Inflammation in Wistar Albino Rats

In our study, Allium subhirsutum L. (AS) was investigated to assess its phenolic profile and bioactive molecules including flavonoids and organosulfur compounds. The antioxidant potential of AS and wound healing activity were addressed using skin wound healing and oxidative stress and inflammation marker estimation in rat models. Phytochemical and antiradical activities of AS extract (ASE) and oil (ASO) were studied. The rats were randomly assigned to four groups: group I served as a control and was treated with simple ointment base, group II was treated with ASE ointment, group III was treated with ASO ointment and group IV (reference group; Ref) was treated with a reference drug “Cytolcentella^® cream”. Phytochemical screening showed that total phenols (215 ± 3.5 mg GAE/g) and flavonoids (172.4 ± 3.1 mg QE/g) were higher in the ASO than the ASE group. The results of the antioxidant properties showed that ASO exhibited the highest DPPH free radical scavenging potential (IC50 = 0.136 ± 0.07 mg/mL), FRAP test (IC50 = 0.013 ± 0.006 mg/mL), ABTS test (IC50 = 0.52 ± 0.03 mg/mL) and total antioxidant capacity (IC50 = 0.34 ± 0.06 mg/mL). In the wound healing study, topical application of ASO performed the fastest wound-repairing process estimated by a chromatic study, percentage wound closure, fibrinogen level and oxidative damage status, as compared to ASE, the Cytolcentella reference drug and the untreated rats. The use of AS extract and oil were also associated with the attenuation of oxidative stress damage in the wound-healing treated rats. Overall, the results provided that AS, particularly ASO, has a potential medicinal value to act as effective skin wound healing agent.     

Purification and characterization of an alkaline protease prot 1 frombotrytis cinerea

Alkaline thiol protease named Prot 1 was isolated from a culture filtrate ofBotrytis cinerea. The enzyme was purified by ammonium sulfate fractionation, gel filtration, and ion-exchange chromatography. Thus, the enzyme was purified to homogeneity with specific activity of 30-fold higher than that of the crude broth. The purified alkaline protease has an apparent molecular mass of 43 kDa under denaturing conditions as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The native molecular mass (45 kDa), determined by gel filtration, indicated that the alkaline protease has a monomeric form. The purified protease was biochemically characterized. The enzyme is active at alkaline pH and has a suitable and high thermostability. The optimal pH and temperature for activity were 9.0–10.0 and 60°C, respectively. This protease was stable between pH 5.0 and 12.0. The enzyme retained 85% of its activity by treatment at 50°C over 120 min; it maintained 50% of activity after 60 min of heating at 60°C. Furthermore, the protease retained almost complete activity after 4 wk storage at 25°C. The activity was significantly affected by thiol protease inhibitors, suggesting that the enzyme belongs to the alkaline thiol protease family. With the aim on industrial applications, we focused on studying the stability of the protease in several conditions. Prot 1 activity was not affected by ionic strength and different detergent additives, and, thus, the protease shows remarkable properties as a biodetergent catalyst.     

Stochastic nuclear outages semidefinite relaxations

This paper deals with stochastic scheduling of nuclear power plant outages. Focusing on the main constraints of the problem, we propose a stochastic formulation with a discrete distribution for random variables, that leads to a mixed 0/1 quadratically constrained quadratic program. Then we investigate semidefinite relaxations for solving this hard problem. Numerical results on several instances of the problem show the efficiency of this approach, i.e., the gap between the optimal solution and the continuous relaxation is on average equal to 53.35 % whereas the semidefinite relaxation yields an average gap of 2.76 %. A feasible solution is then obtained with a randomized rounding procedure.     

Alkyne versus allene activation in platinum- and gold-catalyzed cycloisomerization of hydroxylated 1,5-allenynes

Chemo- and stereoselective transformations of 3-hydroxy-1,5-allenynes 1 into a variety of new and potentially useful cyclic compounds have been achieved. Substrates bearing a silyl group at the alkyne moiety undergo purely thermal or Lewis acid catalyzed Alder-ene type transformations into 2-methylene-3-vinylcyclopent-3-enol derivatives 2. When heated in the presence of a catalytic amount of PtCl(2) or PtCl(4), these incipient cyclopentenols could be further transformed into 3-vinylcyclopent-2-enones 3. On the other hand, alkyl-substituted 3-hydroxy-1,5-allenynes proved to be stable under refluxing conditions. Nevertheless, PtCl(2) and PtCl(4) could selectively activate the alkyne moiety of these substrates toward intramolecular nucleophilic attack of the internal allene double bond to yield unprecedented 6-methylenebicyclo[3.1.0]hexan-3-one derivatives 4. With gold-based catalysts, provided that the reaction is carried out in dichloromethane, both Au(I) and Au(III) complexes selectively activate the allene fragment of the substrates toward intramolecular nucleophilic attack of the hydroxyl group to yield 2-ethynyl-3,6-dihydro-2H-pyrans 5. Compounds of type 4 can also be formed with Au(I) and Au(III) complexes if the reaction is carried out in toluene. The reactivity of these new compounds has been partially investigated, and polycyclic ketones were obtained after oxidation under mild conditions or gold-catalyzed cycloisomerization.     

On probabilistic constraints induced by rectangular sets and multivariate normal distributions

In this paper, we consider optimization problems under probabilistic constraints which are defined by two-sided inequalities for the underlying normally distributed random vector. As a main step for an algorithmic solution of such problems, we prove a derivative formula for (normal) probabilities of rectangles as functions of their lower or upper bounds. This formula allows to reduce the calculus of such derivatives to the calculus of (normal) probabilities of rectangles themselves thus generalizing a similar well-known statement for multivariate normal distribution functions. As an application, we consider a problem from water reservoir management. One of the outcomes of the problem solution is that the (still frequently encountered) use of simple individual probabilistic constraints can completely fail. By contrast, the (more difficult) use of joint probabilistic constraints, which heavily depends on the derivative formula mentioned before, yields very reasonable and robust solutions over the whole time horizon considered.     

Antimicrobial Agents Act Differently on Staphyloccocus aureus and Ralstonia eutropha Flavohemoglobins

Flavohemoglobins (FlavoHb) play a key role in bacterial resistance to nitrosative stress and NO signaling modulation. In this study, we cloned, expressed, and characterized the flavoHb from the opportunistic pathogen, Staphylococcus aureus. The higher amino-acid sequence homology is shared with that from Saccharomyces cerevisiae which was therefore used to build a model structure by homology modeling. Interestingly, the high sequence homology with S. cerevisiae did not correlate with the enzymatic and kinetic properties which are much similar to those of Escherichia coli. In vitro and aerobically, we showed that S. aureus and Ralstonia eutropha flavoHbs accept cytochrome c and oxygen as substrates. Based on this feature, we investigated the preferences for both substrates depending on miconazole or econazole addition and found that the inhibitor chemical composition is determinant.