INTRODUCTION:
Azo compounds constitute one of the largest class of industrially synthesized organic compounds, potent in drug and cosmatics1 Azo dyes have been most widely used in dying textile fibers, biomedical studies, advanced applications in organic synthesis and high technology areas like lasers, liquid crystalline displays, electro-optical devices and ink jet printer2-4 as well as shows variety of interesting biological activities including antibacterial5-8 and pesticidal9 activities.
The azo dyes posses antiseptic and antiprotozoal properties and also promote wound healing. The cationic dyes are more active in acidic medium and preferably attack on Gram positive bacteria as compared to anionic dyes. Most common azo dyes used as antiseptics are scarlet red and diamazon10. The medicinal properties of azo compounds particularly synthesized from acetyl salicylic acid, thymol, aldimine and b-napthol etc have been frequently reported. However, paucity of information could be traced on the synthesis of azo compound containing Resorcinol moiety Hence, taking into consideration the possibility of antibacterial potential of azo compounds containing Resorcinol moiety, the present studies have been carried.
MATERIALS AND METHOD:
The chemicals used in the present studies are of synthetic grade, Merck company ltd. The products were characterized by 1HNMR and IR. The M.Ps.were determined by open capillary method and is uncorrected. The IR spectra were recorded on Perkin-Elmer spectrum-One FTIR instrument in the form of KBr pallet.1
HNMR spectra, were recorded in CDCl3 on a BRUKER AVANCE II 400 NMR spectrometer using TMS as an internal standard. The purity of compounds was checked by TLC. The crude products were recrystallized from 50% ethanol.
General procedure for synthesis of diazo compounds:(13- 14)
Substituted aromatic amines were mixed with
2.5ml conc. HCl and 2.5 ml (4N) cold solution of NaNO2 was added
with the stirring. The temperature of the reaction was maintained up to 0-5ºC.
Diazonium salt solution prepared above was added drop wise to the alkaline
solution of Resorcinol .the reaction mixture stirred for 10-20-miniutes
maintaining the temperature 5-10ºC. The colored products obtained is filtered
and washed with water dry the product and recrystallised from proper solvent.
Antimicrobial activity:-
The compounds 2a-h were screened for the presence of antimicrobial constituents against four micro organisms viz., Escherichia coli, Staphylococcus aureus, Pseudomonas aeroginosa and Salmonella typhi, by using disc diffusion method11. The compounds were dissolved in Ethanol to give 10 mg/1ml. solutions. Sterile discs were dipped in solutions, dried and placed on nutrient agar plates inoculated with the bacteria. The plates were incubated for 24 hrs and the zones of inhibition were measured using antibiotic zone reader (Hi-Media).
RESULT AND DISCUSSION:-
Spectroscopic study: - I.R. and 1HNMR Spectra Shows the expected signals which corresponds to various groups present in each compounds. The I.R. and 1HNMRspectaral data are shown in Table1. A total of, eight derivatives of resorcinol have been synthesized, purified and further used individually to analyzed its antimicrobial activity against four human pathogens viz: E. coli, S. aureas, S. typhi, and Pseudomonas species. The results revealed that, (table 2) there was miraculous inhibition of Pseudomonas species as compared to other pathogens. The derivative no. 2a, 2c, 2e, was found to be significant in inhibiting the Pseudomonas species with zone of inhibition (8), (6), and (6) mm. respectively. It was observed that, Pseudomonas species were not inhibited by derivative no.2b, 2d, 2f, 2g and 2h. S. aureus showed. Zone of inhibition with the diameter of (9) mm and (6) mm due to an activity of 2d and 2e; Compounds respectively. None of the compound showed inhibitory action against E. Coli. The compound 2e and 2d showed inhibitory action against S. typhi. With (6) mm and (8) mm. zone of inhibition respectively. It was observed that among all the compound studied the, 2a, 2c, 2d, and 2e showed antibacterial activity against test pathogens. Whereas, compound 2d, 2g, 2h and 2 did not showed any inhibitory effect on test pathogens. Compound 2e was found to be at par in inhibiting all the three pathogens. No report could be traced on the same line of action. The resistance shown by the test cultures against the inhibitory action of 2d, 2g, 2h as well as to the basic drug resoled. It might be due to the degradation potential of the cultures or may be due to the problem of permeability for the compound to reach up to the target organelle in the cell, whereas, the significant inhibitory action of 2a, 2c, 2d, and 2e may be due to the compatibility of these compounds to diffuse and to reach up to the target for cell destruction or may not have susceptibility to the degradetive enzymes responsible for its in activation. However, the optimization studies on the inhibiting compounds are needed for its systematic commercial exploitation.