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Edible and non-edible lipid feedstocks A B S T R A C TThis study reports the synthesis, physicochemical characterization by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and solid-state MAS NMR ( 1 H, 23 Na, 29 Si and 119 Sn MAS NMR) of a metallo-stannosilicate and its application as a heterogeneous catalyst for biodiesel production via ethanolysis and methanolysis routes using edible, non-edible an waste oils as feedstocks. XRD characterization of the metallo-stannosilicate has revealed a typical structure of mixed octahedral-pentahedral-tetrahedral material with an orthorhombic unit cell (a = 14.522 Ǻ, b = 12.469 Ǻ, and c = 10.654 Ǻ). 119 Sn single-pulse MAS NMR results presented two resonance lines, at δ 1 = -683.8 ppm and δ 2 = -690.9 ppm, which were assigned to the tin octahedrally coordinated in the metallo-stannosilicate structure. Heterogenous catalytic studies in the transesterification of refined edible, non-edible, and waste oils have resulted in high yields of FAMEs and FAEEs (fatty acid methyl and ethyl esters), nevertheless the highest FAMES (98.2%) and FAEEs (96.6%) yields were obtained for non-edible microalgae oil extracted from the genetically modified heterotrophic algal strain Prototheca moriformis. Catalytic studies also using non-edible macaw palm oil (Acrocomia aculeata) with a high content of free fatty acids (FFAs) demonstrated that the catalyst could simultaneously perform esterification and transesterification reactions. These findings indicate the potential application of this novel metallo-stannosilicate in the production of renewable and environmentally clean biofuels, like biodiesel, using different sources of lipids feedstocks, notably those that do not compete with food production.⁎ Corresponding author at: Rua Cristóvão Colombo 2265, São José do Rio Preto, SP,

Gadolinium-based contrast agents (CAs) were synthesized using faujasite zeolite (NaX) and zeolite beta (BEA) and their performances in vitro and in vivo were compared to the widely used commercial CA, gadoteric acid (Gd-DOTA). Magnetic resonance imaging (MRI) relaxometry studies (considering longitudinal [T 1 ] and transverse [T 2 ] relaxation times) were performed using Gd-DOTA and the zeolitic materials loaded with Gd 3+ . The Gd-loaded NaX, which presented large pores and cavities (7.35 and 11.24 Å, respectively), exhibited relaxivity values of around 52 mM −1 s −1 , while BEA, which presented smaller pore and cavity diameters (5.95 and 6.68 Å, respectively) showed lower relaxivity values of~4.8 mM −1 s −1 . The effect of the Gdloaded NaX as MRI CA was tested in vivo in Sprague-Dawley rats, employing a 7 T scanner, with comparison to Gd-DOTA MRI angiography. The relaxivity measurements showed that the Gd-loaded NaX (50 mM −1 s −1 ) provided better image contrast than Gd-DOTA (5.1 mM −1 s −1 ). Clearance studies of the CAs using urine and blood showed that both Gd-loaded NaX and Gd-DOTA were eliminated from the body after 2 days, demonstrating the potential of Gd-loaded NaX for use as an MRI CA.

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