In this regard, we have attempted to detect the levels of lactate and lactyl-CoA at the intracellular and extracellular levels of breast cancer cells treated by DMSO and anticancer drug compositions enriched with free fatty acids and tripeptides . The use of anticancer drug composition CUDF is taken as one of the candidate drug models to see the difference in the detection of lactate and lactyl-CoA compared to the DMSO control. Extracellular metabolite profiling of MCF-7 breast cancer cells suggested surprising observations that lactate was not detected in DMSO control (Figure ). At the same time, CUDF-treated MCF-7 breast cancer cells previously reported for inducing cell death indicated the presence of lactate (m/z 89.0239, RT-1.483, mass-90.0131) in the LC-HRMS derived total ion chromatogram of extracellular conditioned medium (Figure ). The detailed MS and MS/MS spectra displayed clear evidence of lactate-specific negative ESI fragment ion spectra such as 89.0235 and 96.9594. Interestingly, LC-HRMS profiling of VTGE-purified intracellular metabolites did not show a detectable level of lactate and lactyl-CoA. At the same time, extracellular profiling showed the presence of lactate in the case of breast cancer cells under drug-induced stress and cell death (Figure ). But, we did not detect traces of lactyl-CoA in the case of both DMSO and CUDF-treated breast cancer cells.