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Abstract: The enzymatic synthesis of esters is well documented in the literature. A number of parameters have been revised to optimize the operating conditions, in view of a more industrial approach. The experimental conditions presented here are now superior to those of literature and the yields of esters show 78% of fructose laurate. Analytical methods have been perfected and rapid methods (based on different TLC conditions depending on the desired information), accurate methods (based on HPLC) and several purification methods were developed. [Copyright &y& Elsevier]

Abstract: The large ring cyclodextrins (with more than 8 glucose units) existence was first described in the 1950s. Because of their hard purification and low yield, these molecules were little studied until recently. Since large ring cyclodextrins have unique structures compared to α-, β- and γ-cyclodextrin, they could offer new opportunities for specific host-guest complex and thus enlarge the area of cyclodextrin applications. This paper gives a literature survey regarding the synthesis, the purification and the applications of cyclodextrins containing more than eight glucose units. [Copyright &y& Elsevier]

In our work, we have prepared a catalyst based on montmorillonite which is obtained by the purification of Algerian clay (region of M'zila Mostaghanem). The montmorillonite was pillared by the chromium and chromium-aluminum with different ratios Cr/clay and Cr/Al. The materials prepared have been characterized by fluorescence-X (FX), X ray diffraction (XRD), physisorption of nitrogen at 77K and FTIR spectroscopy. The chromium pillared montmorillonite (MMP-Cr) show the basal spacing approximately of 16 Å and a specific surface area of 124 m²/g. However, pillared montmorillonite with chromium-aluminum (MMP-Cr-Al) give a better basal spacing ranging from 17 to 18 Å and specific surface area of 152 m²/g. The best conversion of alcohol (99%) is obtained in the presence of MMP-Cr-Al system. the MMP-Cr catalyst led to 60% of converted alcohol. [ABSTRACT FROM AUTHOR]