A kind of Serratieae is plain (Serranticin), with antitumor/antioxidant activity; The present invention also provides the preparation method of the Serratieae element, including the following steps: 1. carry out solution urea Serratieae (Serratia ureilytica as carbon/nitrogen source with cuttlefish gartilage powder (SPP), shrimp head powder (SHP), crab shell (CSP) powder) TKU013 fermentation; 2. fermented supernatant fluid is extracted with ethyl acetate; And 3. with silica gel column chromatography separate the acetic acid ethyl ester extract obtain Serratieae element; The present invention also provides the purposes of the Serratieae element as antitumor/antioxidant, the Serratieae element of 200 mcg/ml of concentration is to diphenylpicrylhydrazine (α, α-diphenyl- β-picrylhydrazyl) clearance rate of (DPPH) reaches 98%, and the benefits of tool cell poisoning fruit, to the ED50 of human breast gland cancer (Human breast adenocarcinoma) MCF-7 and human colon's gland cancer (Human colon adenocarcinoma) WiDrRespectively 14.7 micrograms (μ g)/milliliter (mL) and 6.52 mcg/mls.一種沙雷氏菌素(Serranticin),其具有抗腫瘤/抗氧化活性;本發明也提供該沙雷氏菌素之製備方法,包括下列步驟:1.以烏賊軟骨粉(SPP)、蝦頭粉(SHP)、蟹殼(CSP)粉當作碳/氮源進行解脲沙雷氏菌(Serratia ureilytica)TKU013之發酵;2.用乙酸乙酯萃取發酵上清液;及3.以矽膠管柱層析術分離該乙酸乙酯萃取物得到沙雷氏菌素;本發明也提供該沙雷氏菌素作為抗腫瘤/抗氧化劑的用途,濃度200微克/毫升的沙雷氏菌素對二苯基苦基肼(α,α-diphenyl-β-picrylhydrazyl)(DPPH)的清除率達到98%,且具細胞毒殺之效果,對人類乳房腺癌(Human breast adenocarcinoma)MCF-7及人類結腸腺癌(Human colon adenocarcinoma)WiDr的ED50分別為14.7微克(μg)/毫升(mL)及6.52微克/毫升。