2-METHYL-6-PHYTYLQUINOL AND 2,3-DIMETHYL-5-PHYTYLQUINOL AS PRECURSORS OF TOCOPHEROL SYNTHESIS IN SPINACH CHLOROPLASTS

Article abstract of DOI:10.1016/S0031-9422(00)81963-9

The incorporation of from SAM- into precursors indicates the following sequence of tocopherol synthesis in spinach: 2-methyl-6-phytylquinol (6-phytyltoluquinol) (1a) -> 2,3-dimethyl-5-phytylquinol (phytylplastoquinol) (2a) -> γ-tocopherol (5a) -> α-tocopherol (6). 1a is a particularly preferred to 2-methyl-5-phytylquinol (1b) and 2-methyl-3-phytylquinol (1c). 1a only forms 2a. 2a is converted to 6 via 5a and, to a lesser extent, 2,5-dimethyl-6-phytylquinol (2b) to 6 via β-tocopherol (5b).Trimethylphytylquinol (3) is not an intermediate in the formation of 6.All reactions are independent of light. - Key Word Index - Spinacia oleracea; Chenopodiaceae; tocopherol biosynthesis; 2-methyl-6-phytylquinol; 2,3-dimethyl-phytylquinol; phytylquinol synthesis.