COX Inhibitory and Cytotoxic Naphthoketal-Bearing Polyketides from Sparticola junci
Katherine Yasmin M. Garcia, Mark Tristan J. Quimque, Gian Primahana, Andreas Ratzenböck, Mark Joseph B. Cano, Jeremiah Francis A. Llaguno, Hans‐Martin Dahse, Chayanard Phukhamsakda, Frank Surup, Marc Stadler, Allan Patrick G. Macabeo
Abstract
Axenic fermentation on solid rice of the saprobic fungus Sparticola junci afforded two new highly oxidized naphthalenoid polyketide derivatives, sparticatechol A (1) and sparticolin H (2) along with sparticolin A (3). The structures of 1 and 2 were elucidated on the basis of their NMR and HR-ESIMS spectroscopic data. Assignment of absolute configurations was performed using electronic circular dichroism (ECD) experiments and Time-Dependent Density Functional Theory (TDDFT) calculations. Compounds 1–3 were evaluated for COX inhibitory, antiproliferative, cytotoxic and antimicrobial activities. Compounds 1 and 2 exhibited strong inhibitory activities against COX-1 and COX-2. Molecular docking analysis of 1 conferred favorable binding against COX-2. Sparticolin H (2) and A (3) showed a moderate antiproliferative effect against myelogenous leukemia K-562 cells and weak cytotoxicity against HeLa and mouse fibroblast cells.