KMID : 0380219990320050451
|
|
Journal of Biochemistry and Molecular Biology 1999 Volume.32 No. 5 p.451 ~ p.455
|
|
Biosynthesis and Metabolism of Vitamin C in Suspension Cultures of Scutellaria baicalensis
|
|
Ahn Young-Ock
Kwon Suk-Yoon Lee Haeng-Soon Park Il-Hyun Kwak Sang-Soo
|
|
Abstract
|
|
|
The concentrations of L-ascorbic acid (AsA, ascorbate, vitamin C) and its biosynthetic and metabolically-related enzymes such as L-galactono-1,4-lactone dehydrogenase (GLDase), ascorbate peroxidase (APX), and ascorbate oxidase (ASO) were investigated in suspension cultures of Scutellaria baicalensis. Cells growing from 4 days after subculture (DAS) to 9 DAS and from 16 DAS to 19 DAS showed a diauxic growth, and then growth rapidly decreased with further culturing. The AsA content slowly increased to 19 DAS, reached a maximum at 21 DAS (ca 120¥ìg/g dry cell wt), and then rapidly decreased with further culturing. GLDase and ASO activity were well correlated with the cell growth curve, showing a maximum at 19 DAS, whereas APX activity showed a good correlation with the changes in AsA content, showing a maximum at 21 DAS. The total ascorbate contents (reduced form, AsA, and oxidized form, dehydroascorbate, DHA) were markedly enhanced at 10 DAS when L-galactose and L-galactono-1,4-lactone (25 mM) were added to SH medium supplemented with 20 g/l sucrose at 9 DAS, by 5.5 and 6.8 times, respectively. DHA composed more than 90% of the total ascorbate contents in suspension cultures of S. baicalensis, even though the ratio of reduced to oxidized form slightly varied with cell growth stage. The results indicate that L-galactose and L-galactono-1,4-lactone are effective precursors of AsA in cell cultures of S. baicalensis, and that in vitro cultured cells provide suitable biomaterials for the study of biosynthesis and metabolism of AsA.
|
|
KEYWORD
|
|
Ascorbic acid (vitamin C), Biosynthesis, L-Galactose, Scutellaria baicalensis, Suspension culture
|
|
FullTexts / Linksout information
|
|
|
|
Listed journal information
|
|
|
|