11. ON THE BIOSYNTHESIS OF CHLOROGENIC ACID

Leaf disks of Nicotiana tabacum var. Delcrest were supplied with a-Cl4labelled cinnamic, p-coumaric, and caffeic acids, p-coumaroyl-quinic acid, and the 1-glucose esters of cinnamic and p-coumaric acids. Considerable incorporation of radioactivity into chlorogenic acid occurred in 40 hours from all substrates except caffeic acid. In particular, p-coumaric acid was found to be a good precursor of c…