L. Phan, Ma Zhenkun
2002
Citations
0
Influential Citations
0
Citations
Journal
Journal name not available for this finding
Abstract
Macrolide antibiotics are widely prescribed for the treatment of upper and lower respiratory tract infections. Erythromycin is the first member of this class and has been in clinical used for over four decades. To overcome some of the drawbacks of erythromycin, including acid instability [2], gastro intestinal (GI) irritation [2], and poor pharmacokinetic properties, second-generation macrolides such as clarithromycin [3] and azithromycin [4] were developed. Clarithromycin addresses the acid instability by methylating the 6-hydroxyl group and thus preventing the 6,9-ketal formation, while azithromycin addresses the problem by transforming the 9-ketone into a ring-expanded analog via Beckman rearrangement of the corresponding 9-oxime. Other drugs such as roxithromycin [5] and dirithromycin [6] solve the acid instability by converting the 9-keto group of erythromycin into 9-oxime and 9-amino derivatives respectively.