Purity ~90% by HPLC. Bafilomycin A1 is a member of a potent family of macrocyclic lactones with a broad spectrum of biological activity including activity against bacteria, yeast, fungi, nematodes, insects and antitumor cell lines. Bafilomycin A1 is an inhibitor of vacuolar-type ATPase. Related to: Bafilomycin B1, Bafilomycin C1, Concanamycin A Solubility: Freely soluble in DMSO; may react with methanol or ethanol, so these solvents are not recommended for stock solutions; very poorly soluble in water; maximum solubility in plain water is estimated to be about 5-10uM; buffers, serum, or other additives may increase or decrease the aqueous solubility.