Identification and enhancement of antioxidant P1-peptide isolated from Ganoderma lucidum hydrolysate

Ganoderma lucidum is an edible fungus which typically used in functional food products because of the potential enhancement of health. Many hydrolysates from G. lucidum exhibit various biological functions. Using LC-MS/MS, the peptide sequence was predicted based on the de novo sequencing algorithm and P1-peptide (VDLPTCKGF) was identified. The peptide was modified by shortening C-terminal residue one at a time until three residues remained, and chemically synthesized all modified peptides by SPPS. Seven-synthetic peptides were purified and molecularly evaluated by HPLC and LC-MS. The antioxidant capacity of these peptides was evaluated, while also the intracellular-ROS was detected to validate the antioxidant activity. This study showed that 3 of 7 synthetic peptides had in vitro antioxidant activity and suppressed intracellular-ROS. Among all modified peptides, VDLPTC exhibited the highest antioxidant capacity and revealed intracellular-ROS suppression. This evidence reflects their radical-scavenging activities and provides the rationale for the development of novel functional food ingredients.