Sea bamboo (Isis hippuris) is one of the octocorallia classes that has unique biological activity and is beneficial for pharmaceutical development. Evaluation of bioactive compounds from sea bamboo collected from Sulawesi (Celebes) waters has been previously reported but lacks information. Gas chromatography and mass spectrometry (GC-MS) are one of the instruments used to evaluate bioactive compounds. This study aims to evaluate bioactive compounds from extracts of sea bamboo from Sulawesi by GC-MS, analyze their antioxidant properties using the DPPH method, and predict their activity computationally using PASS. Samples of sea bamboo were collected from Kabonga Besar Coast, Palu Bay, Central Sulawesi, Indonesia. Samples were extracted by maceration method using methanol: dichloromethane solvent (1:1). GC-MS evaluation identified six alkaloid-derived compounds, namely tetramethyldiaminoethane, dimethylisopropanolamine, 2,4-dimethylpyrrole, 1-(carboxymethyl)pyridinium chloride, pyridine, 3,4-dimethyl-, and N-nitroso-2-methylthiazolidine. The Celebes sea bamboo extracts have potent antioxidant activity. Tetramethyldiaminoethane and dimethylisopropanolamine compounds are predicted to have antioxidant abilities closely related to their role as NADPH-oxidase inhibitors.