LAUSR

Abstract Two non-sulfated steroidal glycosides, cistoindosides A-B were isolated from organic extract of the marine ‘old woman octopus’ Cistopus indicus (family Octopodidae). Their structures were characterized as 3β-acteoxy-23β-hydroxy-cholesta-9-ene-β-D-xylopyranoside (cistoindoside A) and 22,23-epoxy-3β-hydroxy-cholesta-5-ene-β-D-4'-O-acetoxy-xylopyranoside (cistoindoside B). Cistoindoside B, glycosylated with β-D-4'-O-acetoxy-xylopyranoside in conjunction with epoxy moieties displayed superior anti-inflammatory properties as acknowledged by its promising 5-lipoxygenase attenuation potential (IC50 2.11 µM) than the 5-lipoxygenase inhibitor drug zileuton (IC50 3.76 µM). The anti-inflammatory properties were corroborated by the promising antioxidant activities (IC50 ∼ 1.0–1.5 mM) of these steroid glycosides. Sizeably greater electronic properties, balanced hydrophobic-lipophilic properties (log POW ∼ 4.0) and comparatively lower steric factors were directly proportional to their bioactivities. Molecular simulation studies in the active sites of 5-lipoxygenase displaying lesser binding energies and inhibition constant (Ki) of cistoindoside B could be correlated with anti-inflammatory properties. Cistoindosides could be projected for their utilization as potential bioactive leads in functional food and pharmaceutical applications. Graphical Abstract