An unreported polyether macrocyclic lactone with antioxidative and anti-lipoxygenase activities from the Babylonidae gastropod mollusc Babylonia spirata

Abstract

A 16-member polyether macrocyclic lactone, with previously unreported framework was isolated as a result of the bioassay guided chromatographic fractionation of the ethyl acetate-methanol extract of the Babylonidae Babylonia spirata collected from the southwestern coast of Indian peninsular. The compound was characterized as 10, 14-dihydroxy-4-(1′-propyl-1′(Z)-hexen-1′-yl)-7, 12-dioxapentadecanolide based on extensive spectral data analysis. The antioxidant activities evaluated by in vitro free radical scavenging capacities reported that the studied compound possessed greater activity (IC50 0.058–0.065 × 10−2 M) than the commercial standards, butylated hydroxy anisole, butylated hydroxyl toluene and α-tocopherol (IC50 0.118–0.189 × 10−2 M). The compound was found to possess greater anti-inflammatory potentials as recognized by its lower IC50 value for the 5-lipoxygenase inhibition assay (0.073 × 10−2 M) than the non steroidal anti-inflammatory drugs aspirin (0.211 × 10−2 M) and ibuprofen (0.436 × 10−2 M). Structure-activity studies showed that bioactivities of the polyether macrocyclic lactone were directed by electronic and lipophilic descriptors. The lipophilic parameter of octanol-water partition coefficient (log Pow) of the studied compound recorded a value as low as 2.76 when judged against commercial antioxidant α-tocopherol (log Pow 9.98), and was recognized as a primary physico-chemical descriptor dictating the antioxidant characteristics of the isolated polyether macrocyclic lactone, whereas the electronic parameters appeared to contribute towards its anti-inflammatory activity. This is the first report of the occurrence of macrocyclic lactone featuring a dioxapentadecanolide framework possessing potential antioxidative and anti-inflammatory activities, and therefore, anticipated as a potential naturally-derived antioxidative and anti-inflammatory constituent in functional food and pharmaceutical applications.