Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Food Sciences

Committee Chair(s)

D. K. Salunkhe, Bharat Singh


D. K. Salunkhe


Bharat Singh


C. A. Ernstrom


G. H. Richardson


The incorporation of 3- C-,B-hydroxy-, B-methylglutaric acid (HMG) vii into carotenoids of excised etiolated maize shoots, crude cell free extracts and soluble extracts (20, 000 x g) of maize was investigated. HMG was effectively incorporated into carotenoids of excised shoots, crude extracts and soluble extracts. The excised shoots, crude extracts and soluble extracts incorporated 2- 14 C-mevalonic acid (MVA) into carotenoids as well. The results indicated the presence of HMG-CoA reductase in the plant as well as an HMG activating enzyme. The soluble extract showed a pH optimum of 7. 0 for incorporation of HMG into carotenoids. Endogenous metabolites such as MVA in the soluble enzyme preparation decreased the amount of 3- 14 C-HMG incorporated into carotenoids. The conversion of HMG to MVA may be a regulatory site in carotenoid biosynthesis in the plant. Telone (a mixture of cis-1, 3-dichloropropene, trans-I, 3-dichloropropene and other halogenated hydrocarbons), 3-chloroallyl alcohol, viii 3-chloropropionic acid, 3-hydroxypropionic acid, 3-chloro-1-propanol and 14 malonic acid significantly reduced the amount of 3- C-HMG incorporated into carotenoids of maize. Activity of lipoxidase from tomato extracts was significantly inhibited by Telone, cis-1, 3-dichloropropene, trans-1, 3-dichloropropene, 3-chloroallyl alcohol, 3-chloropropionic acid, 3-hydroxy-propionic acid, 3-chloro-1-propanol and malonic acid.