Absorption of phytol from dietary chlorophyll in the rat

• Main Authors: James H. Baxter, Daniel Steinberg
• Format: Article
• Language: English
• Published: Elsevier 1967-11-01
• Series: Journal of Lipid Research
• Subjects: chlorophyll; U-14C-pheophytin a; spinach; availability of phytol; intestinal absorption; thoracic duct lymph
• Online Access: http://www.sciencedirect.com/science/article/pii/S0022227520388830

The fate of ingested chlorophyll—particularly of the phytol portion of the molecule—was studied. Uniformly 14C-labeled pheophytin a (the Mg-free derivative of chlorophyll a) was prepared from an extract of tobacco leaves grown in 14CO2, and was administered by stomach tube to rats in which the thoracic duct had been cannulated.Only about 2% of the administered radioactivity was absorbed in 24 hr, largely into the thoracic duct lymph. Moreover, only a fraction of this lymph radioactivity was derived from phytol (i.e., was found in phytol, phytenic acid, or phytanic acid). The results indicated that not more than 1-2% of chlorophyll phytol is available for absorption by the rat. Similarly, after the administration of whole spinach or spinach extract (not labeled) to rats, only about 1% of the total phytol content was absorbed into the intestinal lymph. Nearly all of the administered phytol was found in the feces and the contents of the colon, and was still largely in the form of pheophytin. The study also indicated that little of the nonphytol portion of the chlorophyll molecule is absorbed.