Fig. 2.

Metabolic fingerprinting by 1H-NMR. The distinct peak (ppm) fold change and direction of variation of metabolites were identified by 1H-NMR of 15 SP samples with ROS ≥ 60 and 15 with ROS < 20 RLU/s/10⁶ sperm. The metabolites have been exchanged in 3.23, 7.27, and 7.83 ppm with high (≥ 60 RLU/s/10⁶ sperm) and low (< 20 RLU/s/10⁶ sperm) ROS levels. This revealed upregulation of trimethylamine N-oxide and downregulation of tryptophan as well as tyrosine/tyrosol in SP samples with high ROS levels