A new N-acetylsulfanilylation series of uridine have been synthesized in good yield using direct acylation method and afforded the 5'-O-N-acetylsulfanilyluridine. In order to obtain newer products, the 5'-O-N-acetylsulfanilyluridine derivative was further transformed to a series of 2',3'-di-Oacyl derivatives containing a wide variety of functionalities in a single molecular framework. The chemical structures of the newly synthesized compounds were confirmed on the basis of their FTIR, 1 H-NMR spectroscopy, physicochemical properties and elemental analysis. All the synthesized uridine derivatives were tested for their in vitro antibacterial activity against six human pathogenic bacterial strains and for comparison standard antibiotic Ampicillin was also determined. The study revealed that the selectively acylated derivatives 5'-O-N-acetylsulfanilyl-2',3'-di-O-lauroyluridine and 5'-O-N-acetylsulfanilyl-2',3'-di-O-pivaloyluridine showed highest inhibition against Staphylococcus aureus and Bacillus cereus, respectively. We also observed that the introduction of hexanoyl, decanoyl, lauroyl, myristoyl and pivaloyl groups, the antibacterial functionality of the compound uridine increases. Another noteworthy observation was that the uridine derivatives * Corresponding author. S. M. A. Kawsar et al. 233were found comparatively more effective against Gram-positive microorganisms than those of Gram-negative microorganisms. In addition, the test chemicals were also tested for cytotoxicity by brine shrimp lethality bioassay and compounds showed different rate mortality with different concentrations.

Uridine is a natural nucleoside precursor of uridine monophosphate in organisms and thus is considered to be safe and is used in a wide range of clinical settings. The farreaching effects of pharmacological uridine have long been neglected. Here, we report a novel series of uridine esters were designed and synthesized by direct method with microbial efficacy. The structures of the prepared compounds have been characterized using various physico-chemical methods including C, H elemental analysis, melting point determination, IR and 1 H-NMR spectroscopy. The synthesized uridine derivatives were subjected to in-vitro antibacterial screening using agar disc diffusion method on some clinically isolated Gram-positive and Gram-negative bacterial strains. Also, antifungal functionality test was performed against a number of plant pathogenic fungi. The compounds showed varied antibacterial and antifungal activities. In addition, cytotoxic activity showed different rate mortality with different concentrations. In conclusion, it may useful for antibacterial and antifungal active agents after investigating their further analysis to develop safer and more potent drugs in the future.

ABSTRACT.This study was carried out to regioselective myristoylation of methyl α-Dglucopyranoside (1) using the direct acylation method gave the corresponding methyl 6-Omyristoyl-α-D-glucopyranoside (2) in fair yield. A number of 2,3,4-tri-O-acyl derivatives (3-15) of this 6-O-substitution product using a wide variety of acylating agents were also prepared in order to obtain newer derivatives of synthetic and biological importance. The reaction conditions are reasonably simple and yields were very good. The structures of the title compounds (2-15) were established by using analytical, physicochemical techniques and spectroscopic data (IR and 1 H-NMR). All the synthesized compounds were employed as test chemicals for in vitro antimicrobial functionality test against Gram-positive Bacillus subtilis, Staphylococcus aureus, Gram-negative Escherichia coli, Pseudomonas aeruginosa bacteria and plant pathogenic fungi Aspergillus niger and Candida albicans. For comparative studies, antimicrobial activity of standard antibiotics, Ampicillin and Nystatin were also carried out against these microorganisms. The study revealed that the tested samples exhibited moderate to good antibacterial and antifungal activities. It was also observed that the test substances were more effective against fungal phytopathogens than those of the human bacterial strains. Encouragingly, a number of tested chemicals showed nearest antibacterial and antifungal activities with the standard antibiotics employed.

Methyl α-D-glucopyranoside was easily prepared by the treatment of D-glucose with anhydrous methyl alcohol in presence of hydrogen chloride at freezing temperature in good yield. Then N-acetylsulfanilylation of methyl α-D-glucopyranoside has been carried out by the direct method and afforded the 6-O-N-acetylsulfanilyl derivative in an excellent yield. In order to obtain newer products, the 6-O-N-acetylsulfanilyl derivative was further transformed to a series of 2,3,4-tri-O-acyl derivatives containing a wide variety of functionalities in a single molecular framework. The chemical structures of the newly synthesized compounds were elucidated by Fourier Transform Infrared spectroscopy (FTIR), 1 H-NMR (Proton nuclear magnetic resonance) spectroscopy elemental and physicochemical properties analysis. All the newly synthesized D-glucose derivatives were tested for their in vitro antibacterial activity against some human pathogenic bacterial strains. The study revealed that a good number of acylated products exhibited promising antibacterial activities. It is expected that the acylated derivatives of D-glucose may be considered as a potential source for developing new and better antibacterial agents against a number of pathogenic organism.

A novel series of benzenesulfonyl derivatives of methyl α-D-glucopyranoside (1) were synthesized by reacting benzenesulfonyl chloride in pyridine followed by direct acylation method to yield 6-O-benzenesulfonyl derivative (2). In order to obtain newer products for antibacterial evaluation studies, the 6-O-benzenesulfonyl derivative was further transformed to a series of 2,3,4-tri-O-acyl derivatives (3-11) containing a wide variety of functionalities in a single molecular framework. All the synthesized compounds have been confirmed by IR,1H NMR and elemental analysis. These newly synthesized compounds were screened forin vitroantibacterial activity against some human pathogenic bacterial strains. The study revealed that the acylated products exhibit moderate to good antibacterial activities. It was interesting to observe that the selected compounds were more sensitive against Gram-Ve bacteria than that of the Gram-+Ve bacterial strains.