Six new lamellarin sulfates (<b>1</b>-<b>6</b>) were isolated from the methanolic extract of the Pacific tunicate <i>Didemnum ternerratum</i>, collected from the Kingdom of Tonga. Mass spectrometric molecular networking through the GNPS platform was used to target the isolation of <b>1</b>-<b>6</b>. Planar structures were elucidated through a combination of NMR and MS experiments. Through comparison of experimental and calculated ECD spectra, the absolute configurations of atropisomers <b>2</b>-<b>5</b> were determined, with their energetic barriers to racemization also determined computationally. The cytotoxicity of the compounds was tested against the human colon carcinoma cell line HCT-116, where lamellarin D-8-sulfate (<b>5</b>) exhibited moderate activity with an IC<sub>50</sub> of 9.7 μM.