Antioxidant Activity of Zyzzyanones and Makaluvamines from the Marine Sponge Zyzzya fuliginosa

Abstract

Antioxidant activities of zyzzyanones A-D (1–4) and makaluvamines C (8), E (5), G (6), H (9), and L (7) isolated from the marine sponge Zyzzya fuliginosa (Carter, 1879) were evaluated using 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) scavenging assay and AAPH (2,2′-azobis(2-amidinopropane) dihydrochloride) induced autoxidation of linoleic acid. Zyzzyanones A, B (1, 2; TE = 0.3), C, D (3, 4; TE = 0.24) and makaluvamines 5–7 (TE = 0.6) displayed moderate activities in the ABTS assay and in the autoxidation of linoleic acid (61–66 % inhibition at concentrations of 0.1 mM). Makaluvamines C (8) and H (9) were essentially inactive in the both assays. Structure-activity relationships showed that antioxidant activities of tested compounds depended on the presence of a phenolic function in molecules. Makaluvamines 5–7 possessing a p-hydroxystyryl moiety were more active than zyzzyanones 1–4 possessing a p-hydroxyphenyl fragment. The presence of a charged side chain in 1 and 2 slightly increases their ABTS scavenging activity in comparison with compounds 3 and 4. Structural variations in a pyrroloquinoline skeleton of 5–7 and in a dipyrroloquinone core of 1–4 have no effect on activities.