title: New Aminonaphthoquinone from the Sea Urchins Strongylocentrotus pallidus and Mesocentrotus nudus.
abstract: The aminonaphthoquinone, spinamine E (5), was isolated for the first time from the sea urchins Strongylocentrotus pallidus (Sars G.O., 1872) and Mesocentrotus nudus (A. Agassiz, 1864). The structure of 5 was elucidated as 2-amino-3,5,6,7,8-pentahydroxy-1,4-naphthoquinone using ID 1H-, 13C- and 2D NMR procedures, and HR-ESI mass-spectrometric data of 5 and its trimethyl ether. Spinamine E, as well as two other aminonaphthoquinones of sea urchins, echinamines A (2) and B (3), along with their hydroxylated analogues, spinochrome E (4) and echinochrome A (1), were tested for their ability to scavenge the stable DPPH radical and to inhibit lipid peroxidation. All investigated naphthoquinones obtained from the sea urchins showed a high antiradical activity, which was up to 1.5 times higher than that of α-tocopherol. Echinamine B showed the highest scavenging effect (EC50 = 6.5-10(-6) M); this effect decreases in the series 3>5>1>2>4>α-tocopherol. In a lipid peroxidation inhibition testing model, echinamine B and spinamine E showed the highest inhibitory effect. The stability of compounds 1-5 in weakly alkaline solutions was evaluated.
authors.forename: Elena A
authors.initials: EA
authors.lastname: Vasileva
authors.forename: Natalia P
authors.initials: NP
authors.lastname: Mishchenko
authors.forename: Pavel A
authors.initials: PA
authors.lastname: Zadorozhny
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Fedoreyev
mesh_terms: D000818:Animals; D015227:Lipid Peroxidation; D015394:Molecular Structure; D009285:Naphthoquinones / Q000737:chemistry*; D012617:Sea Urchins / Q000737:chemistry*; D047269:Strongylocentrotus / Q000737:chemistry*
chemical_list: D009285:Naphthoquinones