Prenylation and methylation reactions in phylloquinone (vitamin K1) synthesis in Capsicum annuum plastids.

The biosynthesis of phylloquinone (vitamin K1) was examined using Capsicum fruit chloroplasts and chromoplasts (apparently phylloquinone free). In both cases, the synthesis of phylloquinone from α-naphthoquinone, dihydro-α-naphthoquinone, 1,4-dihydroxy-2-naphthoic acid (as precursors of the ring moiety) and (S)-adenosyl-L-methionine was achieved. In the presence of phytylpyrophosphate, the biosynthesis of phylloquinone in both organelles is particularly enhanced when 1,4-dihydroxy-2-naphthoic acid is used.