(S)-Sabutoclax ((S)-BI-97C1), an optically pure derivative of apogossypol, serves as a pan-active inhibitor of the antiapoptotic B-cell lymphoma/leukemia-2 (Bcl-2) family proteins. It effectively blocks the binding of BH3 peptides to key proteins in the family, including Bcl-XL, Bcl-2, Mcl-1, and Bfl-1, displaying inhibitory concentration (IC50) values of 0.31, 0.32, 0.20, and 0.62 μM, respectively. Furthermore, (S)-Sabutoclax demonstrates potent efficacy in inhibiting the growth of various cancer cell lines, such as those from human prostate cancer, lung cancer, and lymphoma, with half-maximal effective concentration (EC50) values of 0.13, 0.56, and 0.049 μM, respectively. This compound is utilized in research focusing on apoptosis-based cancer therapies [1].