Antioxidant Properties of the Manzamenones from the Tropical Marine Sponge Plakortis sp.

Abstract

A new manzamenone derivative (4) and four known manzamenones were isolated from the tropical marine sponge Plakortis sp. These compounds exhibited an improved inhibitory effect against the copper-induced low-density lipoprotein oxidation. To identify their structural properties for antioxidant effects, 43-O-methylmanzamenone A (2) has been exposed oxidative conditions such as hydrogen peroxide, mCPBA and primary alkyl amines to give various derivatives (6)-(9). The structures of the compounds were determined by spectroscopic analyses and comparison with literature values.