<jats:title>Abstract</jats:title><jats:p>Two new cycloheptapeptides, tunicyclins F and G, were isolated from the roots of <jats:italic>Psammosilene tunicoides.</jats:italic> Their chemical structures were elucidated by extensive analysis of 1D‐ and 2D‐NMR, as well as HR‐ESI‐MS data. Tunicyclin G contains an unusual <jats:italic>α</jats:italic>,<jats:italic>β</jats:italic>‐dehydrotryptophan (Δ<jats:sup><jats:italic>Z</jats:italic></jats:sup>‐Trp) residue, which mainly occurs in the cyclic peptides from marine sponge and bacteria.