D-Tagatose a rare natural hexoketose is an isomer of d-galactose. D-Tagatose occurs naturally in Sterculia setigera gum and it is also found in small quantities in various foods such as sterilized and powdered cow's milk hot cocoa and a variety of cheeses yogurts and other dairy products.

H2S Donor 5a is a H2S donor that could mimic the slow and continuous H(2)S generation process.

L-Kynurenine is a key intermediate in the breakdown pathway of tryptophan. L-Kynurenine is a substrate of kynureninase KMO and KAT associated with the suppression of antitumor immune responses.