Hamacanthins A and B, New Antifungal Bis Indole Alkaloids from the Deep-Water Marine Sponge, Hamacantha Sp.

Abstract

Hamacanthin A [1] and hamacanthin B [2] are two bioactive dihydropyrazinonediylbis(indole) alkaloids isolated from a new species of deep-water marine sponge, Hamacantha sp. The hamacanthins are growth inhibitors of Candida albicans and Cryptococcus neoformans. Isolation and structure elucidation of 1 and 2 by nmr spectroscopy are described.

Antimicrobial Activity and Cytotoxicity of Bis(indole) Alkaloids from the Sponge Spongosorites sp.

“…1). Compounds 1-9 were identified as deoxytopsentin (1), 6) bromodeoxytopsentin (2), 7,12) bromotopsentin (3), 6) 4,5-dihydro-6Љ-deoxybromotopsentin (4), 6) hamacanthin A (5), 8) trans-4,5-dihydrohamacanthin A (6), 7) hamacanthin B (7), 8) 6Љ-debromohamacanthin A (8), 14) and 6Љ-debromohamacanthin B (9).…”

“…Currently, however, we cannot fully explain the mode of action of antimicrobial activity of these bis(indole) alkaloids. For bis(indole) alkaloids containing either an imidazole-or pyrazinone-derived spacer unit, only the pharmacologic activity 8,[10][11][12][13][14] has been investigated so far, and little is known about their molecular mechanism of action.…”

“…1), topsentin class (1-4) and hamacanthin class (5)(6)(7)(8)(9), were obtained during a previous study. 16) Samples were stored in a freezer at Ϫ80°C until needed.…”

“…Since topsentin, a bis(indolyl)imidazole, and its analogues were isolated from the sponge Topsentia genitrix (ϭSpongosorites genitrix), 6) metabolites containing the bis(indole) moiety have been found with various carbon skeletons and functionalities. [7][8][9][10][11][12][13] These compounds exhibit a wide spectrum of pharmacologic activities such as cytotoxic, [10][11][12]14) antitumor, 13) antiviral, 13) antimicrobial, 8,11,14) and antiinflammatory activities as well as binding to the a1-adrenergic receptor 15) that make bis(indole) alkaloids attractive targets for biomedical and synthetic studies.…”

3,6-Bis(5’-bromo-3’-indolyl)-1,4-dimethypiperazine-2,5-dione

“…Isolated from the marine sponge series Dragmacidin, Hexadella, and Spongosorites, unique bisindolylpiperazine alkaloids have received significant attention in recent years for their antiviral, cytotoxic, and anti-inflammatory properties [1][2][3][4][5][6][7][8][9][10]. The dragmacidin series of alkaloids each contain a central piperazine ring with indole units attached at the 2-and 5-positions.…”