Isolation and Structure Elucidation of New Cytotoxic Macrolides Halosmysins B and C from the Fungus Halosphaeriaceae sp. Associated with a Marine Alga.

ABSTRACT: Two new cytotoxic metabolites, halosmysins B and C, have been isolated from the fungus Halosphaeriaceae sp. OUPS-135D-4 separated from the marine alga Sargassum thunbergii. These chemical structures have been elucidated by 1D and 2D NMR, and HRFABMS spectral analyses. The new compounds had the same 14-membered macrodiolide skeleton as halosmysin A, which was isolated from this fungal strain previously. As the unique structural feature, a diketopiperazine derivative and a sugar are conjugated to the 14-membered ring of halosmysins B and C, respectively. The absolute stereostructures of them were elucidated by the chemical derivatization such as a hydrolysis, the comparison with the known compounds (6R,11R,12R,14R)-colletodiol and halosmysin A, and a

SUBMITTER: Yamada T 

PROVIDER: S-EPMC9030429 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature