The present invention relates to a novel compound and its use, particularly to the compound of 4-hydroxy-2,3-dimethoxy-6-methy-5(3,7,11-trimethyl-dodeca-2,6,10-trienyl)-cyclohex-2-enone separated from an Antrodia cinnamomea extract, and its application in inhibiting tumor cell growth. In the present invention, the aforementioned compound is first seen in Antrodia cinnamomea, which can be applied to inhibit growth of the breast, liver and prostate tumor cells, and at the same time as the pharmaceutical composition ingredient for inhibiting aforementioned tumor cells growth, or further its antioxidant activity can be used in preventing cardiovascular disease or added in healthy foods.本發明係關於一種新穎化合物及其用途,尤其係關於一種由牛樟芝萃取物中所分離出之4-羥基-2,3-二甲氧基-6-甲基-5(3,7,11-三甲基-2,6,10-十二碳三烯)-2-環己烯酮(4-hydroxy-2,3-dimethoxy-6-methy-5(3,7,11-trimethyl-dodeca-2,6,10-trienyl)-cyclohex-2-enone)及其於抑制腫瘤細胞生長之應用。本發明中,前述化合物係首見於牛樟芝中,其可應用於抑制乳癌、肝癌與攝護腺癌腫瘤細胞之生長,同時可作為抑制前述腫瘤細胞生長之醫藥組成物的成分,或進一步藉由其抗氧化活性應用於心血管疾病的預防或添加於健康飲食品當中。