Biosynthesis and molecular actions of specialized 1,4-naphthoquinone natural products produced by horticultural plants

Abstract

The 1,4-naphthoquinones (1,4-NQs) are a diverse group of natural products found in every kingdom of life. Plants, including many horticultural species, collectively synthesize hundreds of specialized 1,4-NQs with ecological roles in plant–plant (allelopathy), plant–insect and plant–microbe interactions. Numerous horticultural plants producing 1,4-NQs have also served as sources of traditional medicines for hundreds of years. As a result, horticultural species have been at the forefront of many basic studies conducted to understand the metabolism and function of specialized plant 1,4-NQs. Several 1,4-NQ natural products derived from horticultural plants have also emerged as promising scaffolds for developing new drugs. In this review, the current understanding of the core metabolic pathways leading to plant 1,4-NQs is provided with additional emphasis on downstream natural products originating from horticultural species. An overview on the biochemical mechanisms of action, both from an ecological and pharmacological perspective, of 1,4-NQs derived from horticultural plants is also provided. In addition, future directions for improving basic knowledge about plant 1,4-NQ metabolism are discussed.

A Mild and Versatile Friedel–Crafts Methodology for the Diversity‐Oriented Synthesis of Redox‐Active 3‐Benzoylmenadiones with Tunable Redox Potentials

“…1,4‐Naphthoquinones (NQs) are redox‐active compounds widespread in all areas of life. They are synthesized in microorganisms and plants used in traditional medicine as secondary bioactive metabolites . They are well represented in numerous natural products with biological activities (e.g., antibiotic, anticancer, antiparasitic) and are generated in many vital metabolic processes .…”

“…They are synthesized in microorganisms and plants used in traditional medicine as secondary bioactive metabolites. [1] They are well represented in numerous natural productsw ith biological activities( e.g.,a ntibiotic, anticancer,antiparasitic) and are generated in many vital metabolic processes. [2] Structurally,t he NQ core, in its oxidized form (NQ ox ), is responsible for its redox properties owing to its ability to accept one or two electrons.…”

“…Variation of E 2 1/2 (V,second redox step) as af unctiono fE1 1/2 (V,first redox step). v = 200 mV s À1 ,reference electrode = KCl (3 m)/Ag/AgCl, working electrode = glassy carbon disk of 0.07cm 2 area,a uxiliary electrode = Pt wire.…”

Allosteric Regulation of Vitamin K2 Biosynthesis in a Human Pathogen

“…DHNA has also been shown to act as a virulence factor in the intracellular pathogen Listeria monocytogenes, where it promotes cytosolic survival, and may be a sensor of cytosolic stress [41]. In plants, phylloquinone biosynthesis enzymes share homology to those of classical bacterial MK biosynthetic enzymes and 1,4 naphthoquinones derived from DHNA act in roles mediating plant-plant, plant-insect and plant-microbe interactions [42].…”

Medicine is not health care, food is health care: plant metabolic engineering, diet and human health

“…DXS , 1‐deoxyxylulose‐5‐phosphate synthase; TAT , tyrosine aminotransferase; HPPD , 4‐hydroxyphenylpyruvate dioxygenase; GGDR , geranylgeranyl reductase; HPT ( vte2 ), homogentisate phytyl transferase; MPBQMT ( vte3 ), dimethyl‐pytylquinol methyl transferase; TC ( vte1 ), tocopherol cyclase; γ‐ TMT ( vte4 ), γ‐tocopherol C‐methyl transferase; HGGT , homogentisate geranylgeranyl transferase. Redrawn from Widhalm & Rhodes ().…”