%0 Journal Article
%T Hybrid Polyketides from a Hydractinia-Associated Cladosporium sphaerospermum SW67 and Their Putative Biosynthetic Origin
%J Marine Drugs | An Open Access Journal from MDPI
%D 2019
%R https://doi.org/10.3390/md17110606
%X Five hybrid polyketides (1a, 1b, and 2¨C4) containing tetramic acid core including a new hybrid polyketide, cladosin L (1), were isolated from the marine fungus Cladosporium sphaerospermum SW67, which was isolated from the marine hydroid polyp of Hydractinia echinata. The hybrid polyketides were isolated as a pair of interconverting geometric isomers. The structure of 1 was determined based on 1D and 2D NMR spectroscopic and HR-ESIMS analyses. Its absolute configuration was established by quantum chemical electronic circular dichroism (ECD) calculations and modified Mosher¡¯s method. Tetramic acid-containing compounds are reported to be derived from a hybrid PKS-NRPS, which was also proved by analyzing our 13C-labeling data. We investigated whether compounds 1¨C4 could prevent cell damage induced by cisplatin, a platinum-based anticancer drug, in LLC-PK1 cells. Co-treatment with 2 and 3 ameliorated the damage of LLC-PK1 cells induced by 25 ¦ÌM of cisplatin. In particular, the effect of compound 2 at 100 ¦ÌM (cell viability, 90.68 ¡À 0.81%) was similar to the recovered cell viability of 88.23 ¡À 0.25% with 500 ¦ÌM N-acetylcysteine (NAC), a positive control. View Full-Tex
%U https://www.mdpi.com/1660-3397/17/11/606