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 1D 1 H-, 13 C-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 (EC 50 = 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.

Diversity of Polyhydroxynaphthoquinone Pigments in North Pacific Sea Urchins

“…Recently, we described the process of PHNQ isolation from St. pallidus shells. [20] Its CHCl 3 extract did not contain PHNQ pigments, and the AcOEt extract contained only two compoundsspinochrome E (1) and its aminated analogue spinamine E (2). Both S1 and S2 samples of St. pallidus collected near Chirpoy (south of the Kuril Islands chain) and Matua (centre of the Kuril Islands chain) had an identical composition of pigments ( Fig.…”

“…Recently, we described the process of PHNQ isolation from St . pallidus shells . Its CHCl 3 extract did not contain PHNQ pigments, and the AcOEt extract contained only two compounds – spinochrome E ( 1 ) and its aminated analogue spinamine E ( 2 ).…”

“…pallidus and M . nudus . Spinochrome D, 7,7′‐anhydroethylidene‐6,6′‐bis(2,3,7‐trihydroxy‐naphthazarin), and ethylidene‐3,3′‐bis(2,6,7‐trihydroxynaphthazarin) were isolated from Astropyga radiata …”

“…Spinochromes A, B, C, E and spinamine E were isolated from St. pallidus and M. nudus. [20] Spinochrome D, 7,7 0 -anhydroethylidene-6,6 0 -bis(2,3,7-trihydroxy-naphthazarin), and ethylidene-3,3 0 -bis(2,6,7-trihydroxynaphthazarin) were isolated from Astropyga radiata. [28] Animal Material Sea urchin samples S1 -S9 were collected by dredging (except sample S6, which was collected by hand) during the 47th scientific cruise of R/V Academic Oparin, in August 2015, the details of which are presented in Table 1.…”

Free Radical Scavenging Activity of Synthetic and Naturally Occurring Polyhydroxy-, Aminohydroxynaphthazarins and Related Compounds

“…Echinochrome (5) is used as a drug for the treatment of burns and traumas of eyes and heart stroke [5]. Along with echinochrome and spinochromes, some new unique natural hydroxylated aminonaphthazarins [(echinamines A (7) and B(8), spinamine E(9)] were isolated from the sea urchins Scaphechinus mirabilis [6], Strongylocentrotus pallidus, Mesocentrotus nudus [7]. The natural naphthazarin pigments revealed high antioxidant properties [8], as well as other types of biological activity [9].…”