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


D. K.. Salunkhe


B. Singh


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.