Beta-lactam antibiotics functionalized with gem-bisphosphonates.

Acylation of amoxycillin and cephalexin with acids III, V and VII, and with isocyanate VIII furnished the corresponding beta-lactam antibiotics (X and XIII-XV, respectively). The antibacterial activity of these new antibiotic analogues against Helicobacter pylori was found to be identical with those of amoxycillin, Augmentin, erythromycin and ciprofloxacin.