4-Methyl-benzenesulfonic Acid (2E)-[(5R)-2-Methyl-5-(1-methylethenyl)-2-cyclohexen-1-ylidene]hydrazide-d4 is an intermediate in synthesizing (+)-Limonene-d5 (L461742). It is present in blood oranges which show inhibition of angiogenesis in human colon cancer cells. Extracted from the oils of Mentha spicata it shows antimicrobial activity.