Alternol is a monomeric compound extracted and purified from a mutant fungal strain of Taxus brevifolia bark. Alteronol is its oxide isomer. Recent studies have shown that both of them have potent and specific anti-tumor activity by interfering with multiple signal pathways in tumor cells, regulating the expressions of cell cycle-related proteins, and causing cell cycle arrest. Alternol specifically acts on xanthine oxidase, promotes the accumulation of reactive oxygen species in malignant cells, and activates intrinsic apoptotic pathway leading to cell death. Protein profiling studies discovered that alternol specifically binds to four enzymes which were involved in the mitochondrial tricarboxylic acid cycle, disrupting mitochondrial aerobic respiration and cellular energy metabolism, resulting in ATP reduction and xenograft tumor suppression in vivo. They also have shown the ability to inhibit tumor cell invasion and migration and to induce tumor cell differentiation. Most importantly, alternol has the property of selectively acting on tumor cells, no obvious effects on normal cells. Altogether, they possess potent anti-tumor effects at both cell culture models in vitro and xenograft models in vivo, representing a great research value and prospects as novel anti-cancer therapies.