pteridine/spinacia oleracea

A number of pteridine derivatives stimulate photosynthetic phosphorylation in spinach chloroplasts. In general, tetrahydro or dihydro compounds are highly active, as is one aromatic, naturally occurring compound, biopterin. The physiological characteristics of this photosynthetic phosphorylation are

The photoreduction and interaction with the photosynthetic "reaction center" of 2-amino,4-hydroxy-6-substituted pteridine indicates that these low-potential ( approximately -0.7 v), naturally occurring compounds play a primary role in photosynthetic electron transport. These unconjugated pteridines,

A number of pteridines were examined for activity in promoting photophosphorylation in broken spinach chloroplasts and in stimulating cytochrome c photooxidation in sonicated chloroplasts. Correlation was found between activities for the 2 reactions. Photophosphorylation promoted by pteridines was

1. An enzyme from the leaves of spinach beet (Beta vulgaris L.) that catalyses the hydroxylation of p-coumaric acid to caffeic acid in the presence of ascorbate has been purified about 1000-fold on a protein basis. 2. It is activated by high concentrations of ammonium sulphate and sodium chloride.

Folate is an important vitamin mainly ingested from vegetables, and folate deficiency causes various health problems. Recently, several studies demonstrated folate biofortification in plants or food crops by metabolic engineering through genetic modifications. However, the production and sales of