Papain

Papain, a cysteine protease of the peptidase C1 family, is utilized in the food, pharmaceutical, textile, and cosmetic industries.

L-Cystine (Cystine Acid) is not considered one of the 20 amino acids, L-Cystine (Cystine Acid) is a sulfur-containing derivative obtained from oxidation of cysteine amino acid thiol side chains. It functions as an antioxidant and protects tissues against radiation and pollution, slowing the aging process. It also aids protein synthesis. L-Cystine (Cystine Acid) is abundant in many proteins of skeletal tissues and skin, and found in insulin and digestive enzymes chromotrypsinogen A, papain, and trypsinogen.

4'-O-Methylbavachalcone (O-Methylbroussochalcone B) is isolated from Psoralea corylifolia, inhibits severe acute respiratory syndrome coronavirus (SARS-CoV) papain-like protease (PLpro) activity (IC50: 10.1 μM).

Aureoquinone is a broad-spectrum proteinase (protease) inhibitor. It inhibits trypsin, papain, thermolysin, collagenase, and pronase, with IC50 values of 11.4 μg mL, 14.5 μg mL, 17.8 μg mL, 7.1 μg mL, and 8.7 μg mL, respectively.