Kigamicins, Novel Antitumor Antibiotics

II. Structure Determination

Abstract

Kigamicin A (1), B (2), C (3), D (4) and E (5) are novel antitumor antibiotics. Their structures were determined by spectroscopic analyses including various NMR measurements. Kigamicins have a unique aglycone of fused octacyclic ring system containing seven of sixmembered rings and one oxazolidine. The aglycone links a sugar chain composed of one to four deoxysugars. These sugars were found to be amicetose and oleandrose.