Leila Zamani

ONE POT PREPARATIONS 1 - AMIDOALKYL - 2 - NAPHTHOLS DERIVATIVE CATALYZED BY NANO - Ti C l 4 .Si O 2 WITH ANTIMICROBIAL STUDIES OF SOME PRODUCTS

Nano - TiCl 4 ·SiO 2 has been introduced to be an extremely efficient cataly st for the preparation of 1 - amidoalkyl - 2 - naphthols from various aldehydes and amides under mild conditions. We synthesized this solid Lewis acid catalyst by the reaction of nano - SiO 2 and TiCl 4 . The processor was simple and environmentally benign with high to excellent yields. Our method has the advantages of high yields, simple methodology, and easy work - up. We studied the different properties of the catalyst by FT - IR (ATR), X - ray diffraction (XRD), scanning electron microscope (SEM), transmission electr on microscopy (TEM) and thermal gravimetric analysis (TGA) . It was stable at high temperature and also it was reusable for at least three times. The antimicrobial and antifungal activities of some of the synthetic compounds were determined by broth microd ilution methods as recommended by Clinical Laboratory Standard Institute. Further studies still needed to investigate the other biological activities of the compounds.

Conformational changes of 1-4-glucopyranosyl residues of a sulfated CC linked hexasaccharide

This work describes the structure of a fully sulfated maltotriose alpha-beta C-C linked dimer, where a central glycosidic bond was substituted by a non natural, hydrolase-resistant C-C bond. Such compound shows anti-metastatic properties being an inhibitor of the heparanase enzymatic activity and of P-selectin-mediated cell-cell interactions. NMR spectroscopy was applied to investigate the structure and conformational properties of this C-C linked hexasaccharide. The presence of sulfate substituents and the internal C-C bond drives the two internal rings in an unusual (1)C(4) chair conformation, while the external rings linked by glycosidic bonds retain the typical (4)C(1) conformation. The NMR results were confirmed by molecular mechanics calculations using structure corresponding di- and tetrasaccharides as models.