Challenging Structure Elucidation of Lumnitzeralactone, an Ellagic Acid Derivative from the Mangrove .

The previously undescribed natural product lumnitzeralactone (), which represents a derivative of ellagic acid, was isolated from the anti-bacterial extract of the Indonesian mangrove species Willd. The structure of lumnitzeralactone (), a proton-deficient and highly challenging condensed aromatic ring system, was unambiguously elucidated by extensive spectroscopic analyses involving high-resolution mass spectrometry (HRMS), 1D H and C nuclear magnetic resonance spectroscopy (NMR), and 2D NMR (including 1,1-ADEQUATE and 1,n-ADEQUATE). Determination of the structure was supported by computer-assisted structure elucidation (CASE system applying ACD-SE), density functional theory (DFT) calculations, and a two-step chemical synthesis.

Influence of β-Carotene and Lycopene on Oxidation of Ethyl Linoleate in One- and Disperse-Phased Model Systems.

The induction period (IP) of ethyl linoleate stressed at 60 °C was monitored via the formation of hydroperoxides. The addition of lycopene (1% w/w) increased the IP from 7.0 to 10.