A novel antimicrobial agent labeled JS-1, being a member of isoquinoline alkaloids, of molecular formula C10H9NO4 was isolated from the culture broth of Streptomyces sp. 8812. In this study, we present the structure based on physicochemical and spectroscopic NMR investigations and on quantum chemical structure modeling. The structure of a molecule suggests the biosynthetic path starting from 3'-hydroxy tyrosine. The synthesis was undertaken and it resulted in NMR data that fully agree with the presented analysis.