RF-3192C and other polyketides from the marine endophytic ASSB4: structure assignment and bioactivity investigation.

Chemical investigation of the methanolic extract of endophytic SB4, isolated from the marine alga , afforded the pentacyclic polyketide, RF-3192C (), the dimeric coumarin orlandin (), fonsecin B (), TMC-256A1 (), cyclo-(Leu-Ala) (), and cerebroside A ().The chemical structure of RF-3192C () is assigned herein for the first time using 1D/2D NMR and HRESI-MS. Additionally, the revision of the NMR assignments of orlandin () was reported herein as well. Investigation of the antimicrobial activities of isolated compounds revealed the high activity of RF-3192C () against and , and moderate activity against yeast. Moreover, an in vitro cytotoxic activity against liver (HEPG2), cervical (HELA), lung (A549), prostate (PC3), and breast (MCF7) cancer cell lines of the isolated compounds was evaluated. The isolation and taxonomical characterization of the producing fungus was reported as well.