In the case of compound 7, we initially hypothesized that incorporating deuterium into the THA core would enhance its metabolic stability . However, the results indicate that the t1/2 and CLint values of compound 7 are nearly identical to THA. Similarly, the formation of 7-OH-THA from compound 7 occurred at comparable levels to THA (Table ). A detailed HRMS spectral analysis further revealed the presence of deuterated 7-OH-THA, confirming that deuterium-labeled metabolites were formed.