Acidic sites pigments

Acetyl-coenzyme A carboxylase (ACCase) carboxylates acetyl-coenzyme A to malonyl-coenzyme A which serves as an intermediate metabolite for several diverse pathways in plant metabolism including synthesis of fatty acids, flavonoids, pigments and waxes. Plants likely have more than one ACCase isoform -- one in the plastid for fatty acid synthesis and at least one non-plastidic form to provide malonyl-coenzyme A for the other pathways. In maize, the plastid-localized ACCase required for fatty acid synthesis has been identified as a target site for several herbicide families [1] and herbicide-tolerant maize mutants have been selected [2,3]. 

Use of dimethylaminoethyl (also rert-butylaminoethyl) methacrylate as a monomer permits the introduction of pendent amino groups which can serve as sites for secondary cross-linking, provide a way to make the copolymer acid-soluble, and provide anchoring sites for dyes and pigments. 

Vacuoles (70-78) are membrane-bound regions of the cell filled with cell sap. Vacuoles are surrounded by a tonoplast (vacuolar membranes) and are diverse with distinct functions. Most investigators believe that lysosomes and the plant vacuoles are the same. Vacuoles develop turgor pressure and maintain tissue rigidity. They are storage components for various metabolites such as reserve proteins in seeds and malic acid in crassulacean acid metabolism (CAM) plants. Vacuoles canremove toxic secondary products and are the sites of pigment deposition. 

The organic acid group of Naphthol AS pigment lakes is part of the diazo component a second site for salt formation can be provided by the coupling component. The plastics industry is the main user of such lakes. 

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