L-methionine (R)-sulfoxide (2S)-2-amino-4-[(R)-methylsulfinyl]butanoic acid 147.035400390625 147.19000244140625 15.994915008544921875 16.0 C 0 H 0 N 0 O 1 S 0 C 5 H 9 N 1 O 2 S 1 L-methionine (R)-S-oxide L-methionine (R)-sulfoxide M MOD:00720 MOD:01966 MOD_RES Methionine (R)-sulfoxide OBSOLETE because redundant and identical to MOD:00720. Remap to MOD:00720. PSI-MOD natural true