Malic acid is a tart-tasting organic dicarboxylic acid that plays a role in many sour or tart foods. Apples contain malic acid which contributes to the sourness of a green apple.

1-Methylhistamine dihydrochloride is a major metabolite of histamine by histamine N-methyltransferase in the pathway of histidine metabolism.?It has been used as a biomarker of histaminergic system activity in the brains of Alzheimer's disease patients as well as those with hypersomnia and other neurological conditions.

D-chiro-Inositol is an epimer of myo-inositol that is found in certain mammalian glycosylphosphatidylinositol protein anchors and inositol phosphoglycans possessing insulin-like bioactivity.