Triproamide and pemukainalides, cyclic depsipeptides from the marine cyanobacterium Symploca hydnoides

• Published in: Journal of Natural Products
• Main Authors: Phyo, Ma Yadanar, Goh, Jun Xian, Tan, Lik Tong
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Peptides and proteins; Carbon; Molecules; Absolute configuration; Nuclear magnetic resonance spectroscopy; DML
• Online Access: http://hdl.handle.net/10497/23628; https://doi.org/10.1021/acs.jnatprod.1c00996

A new cyclic depsipeptide, triproamide (1), containing the rare 4-phenylvaline (dolaphenvaline, Dpv) and a β-amino acid, dolamethylleucine (Dml), originally found in dolastatin 16, was isolated from the polar VLC-derived fraction of the extracts prepared from the marine cyanobacterium Symploca hydnoides. Triproamide (1) was isolated along with the known molecule kulokainalide-1 (2), as well as its two new analogues, pemukainalides A (3) and B (4). Their planar structures were elucidated based on extensive NMR and mass spectrometric data. The absolute and relative configurations of the compounds were determined utilizing a combination of Marfey’s method, J-based configuration, and chiral-phase HPLC analyses. Kulokainalide-1 (2) and pemukainalide A (3) exhibited cytotoxicity against the MOLT-4 leukemia cell line with IC50 values of 5.9 and 5.6 μM, respectively. Accepted version