Penicillin derivatives, penicillin G (1), penicillin V (2) and ampicillin (3), were modified with germanium-containing moieties and their structures were confirmed based on NMR spectroscopy and MALDI-TOF. Their antibacterial ability was tested. None of these exhibited activity stronger than the parent penicillins.

A cepham, cephalothin (4), was modified with germanium-containing moieties. Their structures were confirmed chiefly based on electrospray ionization mass spectrometry and NMR spectroscopy and their antibacterial properties were tested. None of these exhibited activity strong enough to be used as a medicine.

1 H and 13 C NMR spectra of minomycin were determined and a full assignment was carried out with the aid of HMQC, HMBC and other techniques. It was shown that the previous assignment for 13 C-NMR signals required some correction.