J Nat Prod. 2017 Nov 7.
Urda C1, Fernández R1, Rodríguez J2, Pérez M1, Jiménez C2, Cuevas C1.
Author information :
1 = Medicinal Chemistry Department, PharmaMar S. A. , Pol. Ind. La Mina Norte, Avenida de los Reyes 1, 28770, Colmenar Viejo (Madrid), Spain.
2 = Departamento de Química, Facultade de Ciencias e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña , 15071 A Coruña, Spain.
Abstract
A new cyclodepsipeptide, daedophamide (1), has been isolated from a Daedalopelta sp. marine sponge collected from Alor Island (Indonesia). The planar structure of 1 was assigned on the basis of extensive 1D and 2D NMR spectroscopy and mass spectrometry. Daedophamide (1) contains 11 amino acid residues and an amide-linked 3-hydroxy-2,4,6,8-tetramethylnonanoic acid (Htemna). The amino acid constituents were identified as l-Leu, N-Me-l-Gln, d-Arg, d-Asp, d-allo-Thr, l-Pip, d-Ala, d-Ser, 3,4-dimethyl-Gln, O-MeThr, and 4-amino-7-guanidino-2,3-dihydroxyheptanoic acid (Agdha). The absolute configurations of eight of the amino acid residues in 1 were determined by application of the Marfey's method after acid-catalyzed hydrolysis, with the relative configurations of the remaining three amino acid residues and the Htemna unit being assigned by comparison of the NMR data with those reported for other similar peptides. Compound 1 displayed strong cytotoxic activity against a panel of four human tumor cell lines with GI50 values in the submicromolar range.