Isolation of Bafilomycin‐A1‐21‐O‐(α‐L‐rhamnopyranoside). Structural Determination by Chemical Correlation with Bafilomycin A1and LeucanicidinFrom cultures of an actinomycete strain, the known antifungal and insecticidal antibiotic leucanicidin (1) and a hitherto unknown antifungal antibiotic, bafilomycin‐A1‐21‐O‐(α‐L‐rhamnopyranoside) (2), were isolated. The latter is spectroscopically closely related to1and bafilomycin A1(3) and gave degradation products identical with compounds obtained by anal