SYNTHESIS, PHOTOCHEMICAL PROBE AND ANTIMICROBIAL EFFECTS OF NOVEL NORFLOXACIN ANALOGUES

Abstract

The emerging resistance to antimicrobial drugs demands the synthesis of new remedies for microbial infections. Attempts have been made to prepare
new compounds by modifications in the quinolone structure. An important method for the synthesis of new quinolones is using Vilsmeier approach,
but has its own limitations. In an effort to synthesize norfloxacin analogues, only 7‐bromo‐6‐N‐benzyl piperazinyl‐4‐oxoquinoline‐3‐carboxylic acid
was isolated using Vilsmeier approach at high temperature. On the other hand, N,N'‐bis‐(4‐fluoro‐3‐nitrophenyl)oxalamide and
N,N'­bis‐(3‐chloro‐4‐fluorophenyl)malonamide were obtained under reverse Vilsmeier approach. Structures of the products have been established
from their elemental analysis and spectral measurements. Correlation results showed that lipophilicity, molecular mass and electronic factors might
influence the activity. The synthesized compounds were evaluated for their antimicrobial effects including: Gram +ve bacteria: Bacillus Subtilis and
Staphylacoccus Aureus; Gram ‐ve bacteria Escherichia Coli and Klebsiella Pneumonia and Fungi: Candida Albicans and Aspergillus Funigates compared
with standard drugs, like Nalidixic acid and Nystatin. These compounds were also studied for their potential use in the inhibition of vitiligo.