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International @ CDFA+GSC; International audience; IntroductionThe use of renewable resources in the elaboration of various industrial materials and chemicals has been recently revitalized because of environmental concerns. Nowadays, vegetable oils constitute one of the most important classes of renewable resources. They can be extracted from the soybean or rapeseed press cakes. They are already a part of some polymeric material formulations but can also be used as polymer plasticizers To substitute paraffinic oil that are used at present as plasticizers for EPDM, modified vegetables oils were prepared as a new bio plasticizer. Efficient oxirane ring opening of fatty epoxides was performed to synthesis various poly ester and ether-ester. Some physico-chemical characterization of the synthetized modified oils were reported [ref]CC. In this paper, we wish to present our contribution in the synthesis of this bioplasticizers together with some characterizations in EPDM formulation. Results and discussionWe prepared a range of products via successive ring oxirane opening reaction. The ether-ester modified vegetable oils were prepared in two steps from epoxide derivatives. Initially, the ring opening of the epoxide with an alcohol was carried out to yield the hydroxyl-ether intermediate which was esterified in the presence of an anhydride. The polyester derivatives were prepared from the fatty epoxide via opening reaction with a series of acids then esterification of the resulting alcohol with anhydride. The reaction was performed in solvent free conditions and the influence of the catalysts (homogeneous or heterogeneous) in these reactions was evaluated. With this approach ether-ester and poly esters were prepared. Homogeneous (strong acid, Lewis acid [1, 2]) or heterogeneous catalysts (Amberlyst 15 [3]) were compared in solvent free conditions and with an excess of alcohol. With this approach fatty ether-esters were prepared. Among the evaluated catalysts, Amberlyst 15 and BF3.OEt2 exhibited significant activities for the two steps. Optimisations of the reaction conditions were performed in order to achieve complete conversion. The products were characterized by NMR, GC, GPC and TGA. Thermal stability plays a key role for EPDM plasticization (figure 1). Their properties as EPDM bioplasticizer are compared to non-modified oil and fatty polyester. Cyrille GraphFig. 2: Rheology analysis of modified and non modified oil.Some vegetable oils derivatives may be good candidates to substitute paraffinic oils usually added as plasticizer . The influence of the chemical modifications on the properties will be described.ConclusionThis two-step ring opening approach allowed to prepare a range of potential bioplasticizers for EPDM starting from vegetable oils. This is an interesting method to add new functions on fatty acid esters and to have low polarity with different functions. References1.Soi, H.S., et al., Monomers of polyhydroxy compounds and manufacturing methods therefor, CN1962601A, 2007.2.Hwang, H.-S. and Erhan, S.Z., Industrial Crops and Products, 2006. 23, 3: 311-317.3.Cramail, H., et al., Manufacture of polyols having ester groups from vegetable oils for manufacture of polyurethanes, FR2950051A1, 2011.

Introduction: Cobalamin (Cbl) deficiency affects the peripheral nervous system (PNS) morphologically and functionally. We investigated whether the octapeptide repeat (OR) region of prion protein (PrP C) (which is claimed to have myelinotrophic properties) is involved in the pathogenesis of rat Cbldeficient (Cbl-D) polyneuropathy. Methods: We intracerebroventricularly administered antibodies (Abs) against the OR region (OR-Abs) to Cbl-D rats to prevent myelin damage and maximum nerve conduction velocity (MNCV) abnormalities, and PrPCs to normal rats to reproduce PNS Cbl-D-like lesions. We measured nerve PrP c levels and MNCV. Results: The OR-Abs normalized myelin ultrastructure, MNCV values, and tumor necrosis factor (TNF)-α levels in the sciatic and tibial nerves of Cbl-D rats. PrP c levels increased in Cbl-D nerves. The nerves of the PrPC-treated rats showed typical Cbl-D lesions, significantly decreased MNCV values, and significantly increased TNF-α levels. Conclusions: OR-Abs prevent the myelin damage caused by increased OR regions, and excess TNF-α is involved in the pathogenesis of Cbl-D polyneuropathy. © 2011 Wiley Periodicals, Inc.

International @ CDFA+GSC:CPI:LDJ; International audience; IntroductionThe use of renewable resources in the elaboration of various industrial materials and chemical has been recently revitalized because of environmental concerns. Nowadays, vegetable oils constitute one of the most important classes of renewable resources. To substitute the phthalate derivatives that are used at present as plasticizers for PVC, modified vegetables oils were prepared as a new bio plasticizer [1]. Efficient oxirane ring opening of fatty epoxides was performed to synthesis various diesters. Modified oils were characterized. In this paper, we wish to present catalyzed ring opening reaction and effects of esters groups on the PVC plasticisation.Results and discussionWe prepared a range of products via successive ring oxirane opening reaction with a series of acids then esterification of the resulting alcohol with anhydride. The reaction was performed in solvent free conditions and the influence of the catalysts (homogeneous or heterogeneous) in these reactions was evaluated. With this approach symmetric and dissymmetric esters were prepared [2-3].Among the evaluated catalysts, NBu4Cl, TiO2 and Nb2O5 exhibited significant activities for both reactions. Optimisations of the reaction conditions were performed in order to achieve complete conversion. The reaction has been perfomed on G scale. The products were characterized by NMR, GC and TGA and their properties as a bioplasticizer for PVC were evaluated.Fig. 1: Viscoelastic profile of plastisol with modified oils(AcMeSBO : acetylated methyl soyate, BzMeSBO : methyl soyate with benzoate,Ac/CyclohMeSBO : methyl soyate with acetate and cyclohexanoate)Plastisols were prepared by mixing PVC and the fatty ester derivatives (PVC/plasticizers: 2/1 in mass?). The angular frequency used is 6.3 rd/s. The storage modulus G’ was recorded as function of temperature (fig. 1). The temperatures of gelation were almost the same as the standard plasticizer (DINP). Some modified vegetable oils may be good candidates to substitute the phthalate derivative usually added as plasticizer. The influence of the chemical modifications on the properties will be described.ConclusionThis two-step ring opening approach allowed to prepare a range of potential bioplasticizers for PVC starting from vegetable oils. is an interesting method to add new functions on fatty acid esters and it can be applied to the synthesis of PVC bio plasticizers.References[1] R. Stringer, I. Labunska, D. Santillo, J. Siddorn, A. Stephenson, Environ Sci Pollut Res 2000 7,1, 27-36.[2] G. Fogassy, C. Pinel, G. Gelbard, Cat. Commun. 2009 10, 557-560[3]G. Fogassy, P. Ke, F. Figueras, P. Cassagnau, S. Rouzeau, V. Courault, G. Gelbard, C. Pinel, Appl. Catal. A, 2011 393, 1–8

We have recently demonstrated that the myelinolytic lesions in the spinal cord (SC) of rats made deficient in vitamin B(12) (cobalamin) (Cbl) through total gastrectomy (TG) are tumor necrosis factor-alpha (TNF-alpha)-mediated. We investigate whether or not permanent Cbl deficiency, induced in the rat either through TG or by chronic feeding of a Cbl-deficient diet, might modify the levels of three physiological neurotrophic factors-epidermal growth factor (EGF), vasoactive intestinal peptide (VIP), and somatostatin (SS)-in the cerebrospinal fluid (CSF) of these rats. We also investigated the ability of the central nervous system (CNS) in these Cbl-deficient rats to synthesize EGF mRNA and of the SC to take up labeled Cbl in vivo. Cbl-deficient rats, however the vitamin deficiency is induced, show a selective decrease in EGF CSF levels and an absence of EGF mRNA in neurons and glia in various CNS areas. In contrast, radiolabeled Cbl is almost exclusively taken up by the SC white matter, but to a much higher degree in totally gastrectomized (TGX) rats. Chronic administration of Cbl to TGX rats restores to normal both the EGF CSF level and EGF mRNA expression in the various CNS areas examined. This in vivo study presents the first evidence that the neurotrophic action of Cbl in the CNS of TGX rats is mediated by stimulation of the EGF synthesis in the CNS itself. It thus appears that Cbl inversely regulates the expression of EGF and TNF-alpha genes in the CNS of TGX rats.

Repeated intracerebroventricular (i.c.v.)microinjection of tumor necrosis factor-alpha (TNF-alpha) into normal rats causes intramyelin and interstitial edema in the white matter of the spinal cord (SC). This response is identical to that observed in the SC white matter of rats made cobalamin (Cbl) deficient by total gastrectomy (TG). Immunoblot analysis showed that: 1) the level of the biologically active form of the TNF-alpha protein (17 kDa) is higher in the SC of totally gastrectomized (TGX) rats 2 months after TG, i.e., at the postoperative time when edema is observed; 2) SC levels of TNF-alpha protein (17 kDa) in 2-mo-TGX-, Cbl-treated rats are reduced to control. Repeated i.c.v. microinjections of anti-TNF-alpha antibodies, transforming growth factor-beta1 (TGF-beta1) or interleukin-6 (IL-6) into TGX rats, begun shortly after TG, substantially reduced both intramyelin and interstitial edema in the SC white matter. This study provides the first evidence that the hallmark myelin damage of Cbl-deficient central neuropathy, which is a pure myelinolytic disease, is not caused directly by the withdrawal of the vitamin itself, but reflects enhanced production of the biologically active form of TNF-alpha by SC cells. This study thus supports the view that TGF-beta1 and IL-6 may act as neuroprotective agents in Cbl deficiency central neuropathy.

Proc. non ancora ricevuti

We investigated immunoreactivity for p75 neurotrophin receptor (NTR)in the spinal cord white matter and septum of rats made cobalamin-deficient (Cbl-D) by means of total gastrectomy or a Cbl-D diet. Cbl deficiency down-regulates p75NTR-immunoreactive cell levels in spinal cord white matter and septum with different time courses. On the whole, the spinal cord white matter seems to be more affected in terms of p75NTR-immunoreactive cells, most of which are astrocytes. The p75NTR-immunoreactive cell levels in the spinal cord white matter and septum normalized in rats treated with Cbl (scheme b) and killed 4 months after total gastrectomy. However, Western blot analysis of p75NTR in the spinal cords of Cbl-D rats shows increased p75NTR protein levels, which are resistant to Cbl replacement. These findings demonstrate that a neurotrophic vitamin (Cbl) positively regulates the levels of a neurotrophic receptor (p75NTR) (at least in terms of immunohistochemistry) in rat central nervous system, although the underlying mechanism(s) are still unknown.

Severe permanent cobalamin (Cbl) deficiency was induced in rats either by total gastrectomy (TG) or through prolonged dietary Cbl deprivation. This paper deals with an ultrastructural investigation of different parts of the central nervous system (CNS) of rats made Cbl-deficient through one of these of two procedures. In both totally gastrectomized (TGX) rats and in rats chronically fed a Cbl-deficient diet, we observed intramyelin edema, with splitting of the lamellae, and interstitial edema affecting the white matter, mainly in the spinal cord (SC). These lesions were also present in the subcortical white matter, although to a lesser degree. In both TGX-rats and in rats chronically fed a Cbl-deficient diet the pyramidal tract and the optic nerve were completely spared. Vascular lesions were never observed. Intramyelin edema and interstitial edema of the white matter account for the patchy myelopathic spongy vacuolation, which is the histological hallmark of human subacute combined degeneration and has been previously seen in SC white matter of TGX-rats. Macro- and micro-glial cells in the white matter were activated, at least as seen ultrastructurally. Interestingly enough, there were activated glial cells even in the gray matter, in which neurons showed absolutely no alterations. Chronic subcutaneous Cbl administration of TGX-rats partially repaired the CNS damage. However, the amelioration produced by this treatment was greater when Cbl was given shortly after TG than when given three and four months after TG, i.e. when the lesions have already been formed.