QUINOLONES FROM A BACTERIUM AND TYROSINE METABOLITES FROM ITS HOST SPONGE, SUBEREA-CREBA FROM THE CORAL-SEA

A marine bacterium, identified as a pseudomonad, isolated from Suberea creba Bergquist, 1995 (Porifera, Dictyoceratida, Verongida, Aplysinel lidae) collected along the eastern coast of New Caledonia, gave in cul ture phenazine-alpha-carboxamide, 2-n-heptylquinol-4-one, 2-n-nonylqui nol-4-one, 2-n-(1 'E-nonenyl)quinol-4-one, 3-nheptyl-3-hydroxyquinolin -2,4-dione, a N-oxide-2-n-heptylquinoline derivative, and a benzyldike topiperazine. None of these products could be detected, at the HPLC-UV sensitivity level, in the sponge extracts, which contained instead ()-aerothionin, homoaerothionin, (+)-aeroplysinin-1, dibromo-, bromochl oro-, and dichloroverongiaquinol. 2-n-Heptylquinol-4-one, (+)-aeroplys inin-1, and dibromoverongiaquinol showed strong antibacterial activity in vitro. The latter also proved promising for mariculture, rivaling chloramphenicol as an antibacterial agent in cultures of Pecten maximu s larvae, while being nontoxic according to the Artemia salina test.