Figure 3

The Smirnoff-Wheeler AsA biosynthetic pathway.Plants synthesize AsA from glucose via phosphorylated hexose intermediates. 1. hexokinase (E.C. 2.7.1.1), 2. phosphoglucose isomerase (E.C. 5.3.1.9), 3. phosphomannose isomerase (E.C. 5.3.1.8), 4. phosphomannose mutase (E.C. 5.4.2.8), 5. GDP-mannose pyrophosphorylase (E.C. 2.7.7.22), 6. GDP-mannose-3,5-epimerase (E.C. 5.1.3.18), 7. GDP-L-galactose pyrophosphatase, 8.L-galactose-1-phosphate phosphatase, 9.L-galactose dehydrogenase, 10.L-galactono-1,4-lactone dehydrogenase (E.C. 1.3.2.3). Glc,D-glucose; Fru,D-fructose; Man,D-mannose;L-Gal,L-galactose;L-GalL,L-galactono-1,4-lactone. Where no E.C. numbers are listed they have yet to be assigned.