<jats:title>Abstract</jats:title><jats:p>The tunicate‐associated strain<jats:italic>Streptomyces</jats:italic>sp. JP90 produces the unprecedented metabolite cinnamoylphosphoramide (<jats:bold>1</jats:bold>) among several other compounds. Structure elucidation was accomplished by NMR spectroscopic studies and efficient total synthesis. The absolute configuration at phosphorus was determined by synthesis of both enantiomers of<jats:bold>1</jats:bold>performing a resolution of the corresponding diastereomeric phosphoramides of<jats:sc>L</jats:sc>‐phenylalanine ethyl ester. Unusual cinnamic acid derivative<jats:bold>1</jats:bold>represents the first bacterial organophosphoramide. As it matches the Schrader's formula for insecticidal organophosphates, its biological activity was investigated. A weak inhibition of acetylcholinesterase was observed in in vitro tests, and water‐soluble analogues of<jats:bold>1</jats:bold>were prepared. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)