Quinones

Biosynthesis of anthraquinones in cell cultures of Cinchona ‘Robusta’ proceeds via the methylerythritol 4-phosphate pathway

“…To a lesser extent, this substitution pattern has also been found in other genera of the Rubiaceae, such as Galium (Koyama et al, 1993) and Morinda (Leistner, 1973a). Normally this pattern is typical of AQs derived from acetyl-CoA via the polyketide pathway (Van den Berg and Labadie, 1989). However, the AQs in Cinchona are considered to be of the Rubia type.…”

“…There are two main biosynthetic pathways leading to AQs in higher plants: the polyketide pathway (Van den Berg and Labadie, 1989) and the chorismate/o-succinylbenzoic acid pathway (Leistner, 1985). In the polyketide pathway, AQs are biosynthesized from acetyl-CoA and malonyl-CoA via an octaketide chain.…”

9,10‐Anthraquinones and Other Biologically Active Compounds from the Genus Rubia

“…It has been established that the AQs originate from a variety of different precursors and pathways [14] [15]. There are two main biosynthetic pathways leading to AQs in higher plants: the polyketide pathway [16] and the chorismate/o-succinylbenzoic acid pathway [17], the latter occurs in the Rubiaceae.…”

Natural hydroxyanthraquinoid pigments as potent food grade colorants: an overview

“…2). HAQN pigments that are synthesized via this pathway only have one of the rings unsubstituted and at least one hydroxyl group in position R1 on the ring C. The rings A and B are derived from chorismate and -ketoglutarate via -succinylbenzoic acid (the HAQN biosynthesis branch at 1,4-dihydroxy-2-naphtoic acid), whereas ring C is formed from isopentenyl diphosphate either formed via the mevalonic acid pathway or the 2-C-methyl-D-erythritol 4-phosphate pathway 54,56,57 . The relevant colouring compounds are alizarin Figure 1.…”

“…There are at least two biosynthetic pathways leading to HAQN pigments. On one hand, the most important is the polyketide pathway (acetate-malonate pathway) that includes suitable folding and condensation of an octaketide chain derived from acetate (acetyl-CoA) and malonate (malonyl-CoA) units 3,32,54 . The resultant polycarbonyl compounds serve as substrates for various cyclases that produce aromatic compounds that represent typical fungal metabolites.…”