L-Gulonolactone (also known as reduced ascorbic acid RAA) is the substrate of the enzyme L-gulono-14-lactone oxidoreductase (EC 1.1.3.8) which catalyzes the last step of the biosynthesis of L-ascorbic acid (vitamin C) in plants and animals.

Phenylpyruvic acid is a keto-acid that is an intermediate or catabolic byproduct of phenylalanine metabolism. It has a slight honey-like odor. Levels of phenylpyruvate are normally very low in blood or urine. High levels of phenylpyruvic acid can be found in the urine of individuals with phenylketonuria (PKU) an inborn error of metabolism.

Vinyl Cinnamate is a nartural product from Cinnamomum cassia Presl.