Unprecedented antioxidative cyclic ether from the red seaweed Kappaphycus alvarezii with anti-cyclooxygenase and lipoxidase activities

Abstract

An unprecedented non-isoprenoid oxocine carboxylate cyclic ether characterised as (3S, 4R, 5S, 6Z)-3-((R)-hexan-2′-yl)-3,4,5,8-tetrahydro- 4-methyl-2H-oxocin-5-yl acetate was isolated from the ethyl acetate– methanol extract of the red seaweed Kappaphycus alvarezii. The structure, as well as its relative stereochemistry, was proposed on the basis of extensive spectral data