Wf1 1899a, b and c, novel antifungal lipopeptides i. taxonomy, fermentation, isolation and physico-chemical properties

Echinocandin B1} is an antifungal lipopeptide antibiotic which is structurally characterized by a cyclic hexapeptide acylated with a long side chain. Other related lipopeptides from fungal origin are known as* aculeacins2), mulundocandin3) and pneumocandins4'5), which are produced by Aspergillus aculeatus, A. sydowi and Zalerion arboricola, respectively. These antibiotics have excellent anti-Candida activity attributed to selective inhibition of l ,3-/?-glucan synthesis. Furthermore, pneumocandins were reported to be active against Pneumocystis carinii6\ pathogen causing pneumonia in AIDS patients. They are, however, barely soluble in water. This insolubility is one of the reasons why they cannot be developed as a clinical use. In the course of our screening for new antifungal antibiotics, we found that a strain of Coleophoma empetri F-1 1899 produces water-soluble echinocandin analogs, WF1 1899A, B and C7) (Fig. 1). This paper describes taxonomic studies on the producing strain, fermentation, isolation and physico-chemical properties of these compounds.