An Ichip-Domesticated Sponge Bacterium Produces an N-Acyltyrosine Bearing an α-Methyl Substituent

The ichip (isolation chip) was employed for the first time in a marine sponge (Xestospongia muta), and a putatively new bacterial species, Alteromonas sp. RKMC-009, was isolated. Strain RKMC-009 produces a novel N-acyltyrosine (1) that is appended with a rare alpha-methyl substituent within the aminoacyl moiety and also exhibits Gram-positive antibacterial activity. We determined through an SAR experiment that the alpha-methyl is necessary for Staphylococcus activity of 1 and that it enhances Enterococcus activity.