Molecular basis for redox control by the human cystine glutamate antiporter system xc Nature Communications Kokumi! If you want a whole picture on umami, there's the core concept of glutamate, then a second level of umami boosting from ribonucleotides like IMP. There's a third layer that's not Glutathione an overview ScienceDirect Topics Glutathione Gsh Antioxidant Plants Animals Fungi Stock Illustration 1320541694 Shutterstock