Antibacterial Activity of Coumarine Derivatives Synthesized from 4-Chloro-chromen-2-one . The Comparison with Standard Drug AZIZ

This work reports the synthesis of some new derivatives from 4-Chloro-chromen-2-one and describe the results of antibacterial activity of purified compounds. Compounds 4-Butylaminochromen-2-one (1a) , 4-Butylamino-2-oxo-2H-chromene-3-sulfonyl chloride (2a) , 4-Butylamino2-oxo-2H-chromene-3-sulfonic acid (2-hydroxy-phenyl)-amide (3a), 4-Butylamino-5-ethyl-2-oxo7-(N’-phenyl-hydrazino)-2H-chromene-3-sulfonic acid (2-hydroxy-phenyl)-amide (4a) , have been synthesized and characterized using melting points , IR spectra , 1H-NMR and 13C-NMR spectra. The antibacterial activity of synthesized compounds and streptomycin at concentractions of 1mg/ ml, 3mg/ml and 5mg/ml , have been evaluated against three strains of bacterial culture; Staphylococcus aureus, E.coli and Klebsiella. The compounds show bacteriostatic and bactericidal activity.


INTRODUCTION
Starting from 4-Chloro-chromen-2-one (a); derivatives (1a,2a,3a,4a) are synthesized Coumarin derivatives are large group of heterocyclic with oxygen as heteroatom (Govori et  al 1996 ; Govori et al 2002 ; Stanovnik et al  1993).Coumarin is a chemical sompound (specifically , a benzo--pyrone) found in many plants (Lee et al 2002) notably in high concentration in the tonka bean ( Dipteryx odorata), vanilla grass (Anthoxanthum odoratum) , woodruff (Galium odoratum) , mullein (Verbascum spp), and sweet grass (Hierochloe odorata).Coumarine and their derivatives have shown varius biological activities.Their fame has come mainly from their antithrombic, antiinflammatory, vasodilatory , and antiviral activities.Other several coumarin derivatives have antimicrobial properties (Sanghyun ; et al 1996 ; Mohareb et al 2007; Nofal et al 2000), have urged us to synthesize some new coumarin derivatives and to investigate their antibacterial activity against staphylococcus aureus, E.coli and Klebsiella.The antibacterial activity of synthesized compounds is compared with antibacterial activity of streptomycin.
The identification of 2H-chromen-2-one derivatives (1a,2a,3a,4a) , is made by using melting point , infrared , 1 H NMR , 13 C NMR spectra and elemental analysis.Melting point was determinated on a Electrothermal apparatus (Fisher Scientific 2555) in a open capillary tube and are uncorrected.Infrared spectra were recorded in cm -1 for KBr pellts on a FT-IR Shimadzu 8400S spectrophotometer with resolution 4 cm -1 . 1 H NMR spectra were recorded on a Bruker UNITY plus-500 'NMR 1' spectrometer using DMSO-d 6 as the solvent and TMS as the internal references standard (  = 0,00 ppm).Chemical shifts are expressed in ṕpm.Mass spectra were taken on a LKB 9000 mass spectrometer.
Element analysze was performed on a Perikin-Elmer 240 BCHN analyzer.The purity of the compounds (synthesized) was routinely checked by TLC using Merck Kieselgel-60 (F-254) and benzene,toluene,glacial acetic acid (80:10:10)as mobile phase.The spots were exposed in iodine vapour for visualization.

After
filtration the product was recrystallized from ethanol .The recrystallizacion from ethanol gave a yellow product at 70% yield, melting.point;180o C. (Scheme 3 ).

Antibacterial activity
The purified synthesized compounds (1a,2a,3a,4a) was subjected to test in vitro its antibacterial activity against three bacterial cultures ; Staphylococcus aureus,E.Coli and Klebsiella.Antibacterial activity of compounds was investigated applying the Kirby-Bayer method 14 or disc method (d=5.5 mm max.capacity 10 µg)

CONCLUSION
From the results the followin conclusion were drawn:The study provides the first evidence that compounds (1a,2a,3a,4a) obviously inhibit the growth of Staphyllococcus auerus, E.coli and Klebsiella.
The compounds (1a,2a,3a,4a) compared with the antibacterial activity of Streptomycine in S.aureus , and Klebsiella.The chemical structures of synthesizen compounds were determined according to extensive NMR experiments and published data.

Table 3 : Antibacterial activity Klebsiella and the comparison with Streptomycine
OH ,0.5ml ClCH 2 CH 3, 0.2 ml Et 3 N and 0.2 ml HCl.The mixture was refluxed at 95 o C in water bath for ca. 2 h .The obtained red crystals are filtred and rinsed with CH 3 CN and dried at room temperature.Recrystallization from ethanol gave a