Staphylococcus cohnii mediated production of perillic acid from limonene and synthesis of its amide derivatives for the induction of apoptosis in TNBC Cells.

Perillic acid (PA), an oxygenated monoterpenoid derived from limonene, has attracted significant attention owing to its wide range of biological activities, especially its promising anticancer properties. However, its limited availability and inefficient chemical synthesis routes restrict its broader therapeutic exploration. In the present study, perillic acid was produced through microbial biotransformation of R-(+)-limonene using Staphylococcus cohnii IIIMB2707, which showed the highest oxidation efficiency among eleven screened microbial strains. Under simplified and scalable operating conditions (pH 7.0, 28 °C, 48 h), the strain achieved a conversion yield of 77.91%, demonstrating an efficient, scalable biocatalytic process for perillic acid production. The product was isolated and structurally confirmed by GC-MS, NMR, and LC-MS analysis. To enhance the anticancer potential of PA, a series of novel piperazine-based amide derivatives C1-C8 were synthesized and characterized using NMR and HRMS techniques. Cytotoxicity evaluation revealed compound C-1 as the most potent derivative, exhibiting selective activity against MDA-MB-231, triple-negative breast cancer cells (TNBC), with a selectivity index (SI) of 6.24, indicating favorable selectivity toward cancer cells. Mechanistic investigations demonstrated that C-1 induces apoptosis through a reactive oxygen species (ROS)-mediated intrinsic mitochondrial pathway. Overall, this study establishes Staphylococcus cohnii IIIMB2707 as a new microbial biocatalyst for efficient perillic acid production and identifies C-1 as a promising hit for further mechanistic elucidation.