Synthesis of 3-Deoxyclarithromycin through Biotransformation of Clarithromycin by Aspergillus niger and its Antibacterial Activity

Biotransformation of clarithromycin (1), by the plant pathogen aspergillus niger atcc 10549, produced one main metabolite identified as 3-deoxyclarithromycin (2). testing the antibacterial activity against staphylococcus aureus and escherichia coli showed that compound 2 has a moderate activity against the tested bacteria. this result provides further evidence that the presence of oxygen at position 3 in clarithromycin enhances the antibacterial activity. the structure of compound 2 was elucidated by different nmr techniques. 2d-nmr (cosy, hmbc and hmqc) experiments allowed full assignments of the proton and carbon chemical shifts.