New Macrocyclolipopeptides and Steroids from Mariana Trench-Derived Fungus Cladosporium sp.

Two unusual 13-membered macrocyclolipopeptides, cladosporiums A (1) and B (2), and four new steroids, cladosporisteroids D-G (3-6), were isolated from the Mariana Trench-derived fungus Cladosporium sp. RCDB004. Cladosporiums A (1) and B (2) possess an unprecedented macrocyclic skeleton formed by the condensation reaction of fatty acids and an alanine. The planar structures of isolated compounds were established by NMR and HRESIMS, with the stereochemical configurations further corroborated through X-ray crystallography. Notably, cocrystals of 1 were successfully obtained through the crystalline mate method.