%0 Journal Article
%T Synthesis and Antimicrobial Activity of Carbohydrate Based Schiff Bases: Importance of Sugar Moiety
%A Helmoz R. Appelt
%A Julieta S. Oliveira
%A Roberto C. V. Santos
%A Oscar E. D. Rodrigues
%A Maura Z. Santos
%A Elisiane F. Heck
%A L¨ªria C. Rosa
%J International Journal of Carbohydrate Chemistry
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/320892
%X A series of D-glucosamine derivatives were synthesized (2¨C4) and evaluated for their antimicrobial activity. Some of the compounds investigated have shown significant antimicrobial activity against Gram-positive and Gram-negative bacterial strains as well as a few fungal strains. The results suggest that the presence of sugar moiety is necessary to biological activity. 1. Introduction Carbohydrates are the most abundant class of biomolecules, making up 75% of the biomass on Earth [1]. Carbohydrates are used to store energy but also perform other important functions to life [2]. Recently, carbohydrates and their derivatives have emerged as an important tool for stereoselective synthesis and as a chiral pool for the design of chiral ligands. They are used as chiral building blocks, precursors for drug synthesis and chiral catalysts in asymmetric catalysis [3¨C8]. Despite the importance of carbohydrates in biological events, the pace of development of carbohydrate based therapeutics has been relatively slow. This is mainly due to practical synthetic and analytical difficulty. Recent advances in the field, however, have demonstrated that many of these problems can be circumvented and evidence the importance of carbohydrates as bioactive substances, with regard to antibacterial, antiviral, antineoplastic, antiprotozoal, and antifungal activity among others, related recently in literature [9, 10]. On the other hand, imines or Schiff bases are easily generated by condensation of carbonyl groups and primary amines. In carbohydrate chemistry, a large number of imines have been reported, both by reaction of sugar aldehydes with amines and by reaction of aminosugars with aldehydes [11¨C16]. Schiff bases and their metal complexes have several applications as catalysts in oxygenations, hydrolysis, and other reactions, antimicrobial and antiviral activities, among other applications [15¨C17]. Preparation of 4-anisaldehyde and cinnamaldehyde glucosamine imines and their acetylated derivatives is usually used as a convenient strategy for selective protecting of the amino group of the aminosugar [11, 18, 19]. Recent studies have shown that Schiff bases derived from glucosamine have antifungal [20] and antibacterial activity [21]. On the other hand, aldehydes present in essential oils may also have action against different microorganisms. Cinnamaldehyde, the main component of Cinnamomum zeylanicum essential oil, specie of Lauraceae family, has several activities such as antioxidant, antibacterial, and antifungal [22]. This field has been explored by our research group and
%U http://www.hindawi.com/journals/ijcc/2013/320892/