Mycoleptodiscins A and B, Cytotoxic Alkaloids from the Endophytic Fungus Mycoleptodiscus sp. F0194
journal contributionposted on 26.04.2013, 00:00 by Humberto E. Ortega, Paul R. Graupner, Yumi Asai, Karen TenDyke, Dayong Qiu, Young Yongchun Shen, Nivia Rios, A. Elizabeth Arnold, Phyllis D. Coley, Thomas A. Kursar, William H. Gerwick, Luis Cubilla-Rios
Two novel reddish-orange alkaloids, mycoleptodiscin A (1) and mycoleptodiscin B (2), were isolated from liquid cultures of the endophytic fungus Mycoleptodiscus sp. that had been isolated from Desmotes incomparabilis in Panama. Elucidation of their structures was accomplished using 1D and 2D NMR spectroscopy in combination with IR spectroscopic and MS data. These compounds are indole-terpenes with a new skeleton uncommon in nature. Mycoleptodiscin B (2) was active in inhibiting the growth of cancer cell lines with IC50 values in the range 0.60–0.78 μM.