Polyphenols contents,heavy metals analysis and in vitro antibacterial activity of extracts from Cladanthus arabicus and Bubonium imbricatum of Moroccan Origin

Abstract

Aim of this study was to evaluate polyphenols and major and trace elements of Cladanthus arabicus and Bubonium imbricatum, along with their in vitro antibacterial activity against six multidrug resistant Enterobacteriaceae (Escherichia coli S33/16, E. coli S34/16, Proteus mirabilis S32/16, Klebsiella pneumoniae S12/16, Enterobacter cloacae S5/16, and Salmonella sp S12/14). UV spectrophotometry, ultra-high-performance liquid chromatography coupled to mass spectrometry and inductively coupled plasma mass spectrometry were used to evaluate total polyphenol content, quali-quantitative profile of single polyphenols and inorganic elements of the extract. The antibacterial activity was investigated by standard methods. Twelve polyphenols were identified in both plants and these were more concentrated in B. imbricatum than C. arabicus extracts. High levels of minerals, essential trace elements and tolerable levels of heavy metals (Cd, As and Pb) were found. Furthermore, the extracts showed also a strong in vitro antibacterial activity, particularly versus E. coli S33/16 (MIC, 0.125?mg ml^?1).     

Self-adaptive methods for mixed quasi-variational inequalities

It is well known that the variational inequalities involving the nonlinear term φ are equivalent to the fixed-point problems and the resolvent equations. In this paper, we use these alternative equivalent formulations to suggest and analyze some new self-adaptive iterative methods for solving mixed quasi-variational inequalities. Our results can be viewed as significant extensions of the previously known results for mixed quasi-variational inequalities. An example is given to illustrate the efficiency of the proposed method.     

A self-adaptive method for solving general mixed variational inequalities

The general mixed variational inequality containing a nonlinear term φ is a useful and an important generalization of variational inequalities. The projection method cannot be applied to solve this problem due to the presence of the nonlinear term. To overcome this disadvantage, Noor [M.A. Noor, Pseudomonotone general mixed variational inequalities, Appl. Math. Comput. 141 (2003) 529-540] used the resolvent equations technique to suggest and analyze an iterative method for solving general mixed variational inequalities. In this paper, we present a new self-adaptive iterative method which can be viewed as a refinement and improvement of the method of Noor. Global convergence of the new method is proved under the same assumptions as Noor's method. Some preliminary computational results are given.     

Hypersurfaces compactes d'un fibré vectoriel riemannien à courbure moyenne prescriteCompact hypersurfaces of a Riemannian vector bundle with prescribed mean curvature

Let M be a compact Riemannian manifold, E a Riemannian vector bundle on M and Σ the sphere subbundle of E. We look for embeddings of Σ into E admitting prescribed mean curvatures of various types. To cite this article: P. Cherrier, A. Hanani, C. R. Acad. Sci. Paris, Ser. I 335 (2002) 525–528.     

Global solutions and self-similar solutions of semilinear wave equation

We prove existence, uniqueness and regularity results for the global solutions of the semilinear wave equations. In particular, we show existence of regular self-similar solutions. Also, we build some finite-energy asymptotically self-similar solutions. Received: 20 September 1999; in final form: 10 May 2000 / Published online: 25 June 2001     

Reversible photomagnetic properties of the molecular compound [{Cu(bipy)2}2{Mo(CN)8}]·9H2O·CH3OH

The optical and photomagnetic properties of [{Cu^II(bipy)₂}₂{Mo^IV(CN)₈}]·9H₂O·CH₃OH (1) have been reinvestigated. A comparison between spectra in solution and in the solid state revealed the presence of an intervalence band (or Metal–Metal Charge Transfer, hereafter noted MMCT) at 570 nm. The photomagnetic properties have been performed in a Superconducting QUantum Interference Device at 10 K with irradiation in the range of the MMCT: 488 nm, 520 nm and 647 nm at 10 K. An important increase of the magnetic signal has been measured after 1 h of irradiation at 488 nm, whereas a weaker increase has been obtained for the irradiation at 520 nm in the same conditions. Moreover, after an excitation at 488 nm, an irradiation at 647 nm has induced a decrease of the magnetic moment, which corresponds to a partial deexcitation. The complete characterization of the photoproduct has been realised after an irradiation of 4 h at 488 nm. The photomagnetic properties have shown an increase of the paramagnetism of 1 at low temperature. After a thermal heating at 300 K, the material goes back to its initial state before irradiation. It is the first time that a fully reversible photomagnetic behaviour for the compound [{Cu^II(bipy)₂}₂{Mo^IV(CN)₈}]·9H₂O·CH₃OH has been described. The observed properties have been discussed in terms of an electron transfer mechanism Mo → Cu.     

A regiodivergent synthesis of ring a C-prenylflavones

Capitalizing on the use of orthogonal protecting groups and the development of a modified Robinson flavone synthesis that avoids harsh acidic conditions, a regioselective synthesis of 6- and 8-prenylflavones from the same prenylated disilylated phloracetophenone (9) has been developed, targeting cannflavin B (1d), the COX-inhibiting principle of marijuana, and its unnatural isomer isocannflavin B (1e) as model compounds.     

Dynamic near three-to-one internal resonance in composite stiffened panels

Nonlinear dynamic of composite stiffened panels to parametric and three-to-one internal resonances is investigated. The ordinary differential equation of two mode shapes is established by using Galerkin method and the condition of three-to-one internal resonance between the first mode (1,3) and the second mode (3,1) is examined near the principal resonance 2:1 of the first mode. Then, the nonlinear behavior of the two buckling mode shapes is analyzed using a perturbation analysis. We show the existence of jump phenomena for the two modes indicating a complex dynamic of the structure near the three-to-one internal resonance for the HM Graphite/epoxy materials.