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 α-methyl substituent within the aminoacyl moiety and also exhibits Gram-positive antibacterial activity. We determined through an SAR experiment that the α-methyl is necessary for Staphylococcus activity of 1 and that it enhances Enterococcus activity.