The biomimetic synthesis of balsaminone A and ellagic acid via oxidative dimerization

• Sharna-kay Daley and
• Nadale Downer-Riley

Beilstein J. Org. Chem. 2020, 16, 2026–2031, doi:10.3762/bjoc.16.169

• Sharna-kay Daley Nadale Downer-Riley Department of Chemistry, The University of the West Indies, Mona, Jamaica 10.3762/bjoc.16.169 Abstract The application of oxidative dimerization for the biomimetic synthesis of balsaminone A and ellagic acid is described. Balsaminone A is synthesized via the

• oxidative dimerization of 1,2,4-trimethoxynaphthalene under anhydrous conditions using CAN, PIDA in BF3·OEt2 or PIFA in BF3·OEt2 in 7–8% yields over 3 steps. Ellagic acid is synthesized from its biosynthetic precursor gallic acid, in 83% yield over 2 steps. Keywords: balsaminone A; biomimetic synthesis

• ; ellagic acid; oxidative dimerization; Introduction Over the last century, the formation of an aryl to aryl bond has garnered considerable synthetic attention due to the applications of biaryls as pharmaceutical agents, as well as chiral auxiliaries in asymmetric synthesis [1][2][3]. Methods such as the

Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• , production by a fungus and modification of the metabolites by plant enzymes is also possible. Further α-pyrone plant secondary metabolites are ellagitannins and ellagic acid (22) [27] (Figure 4). These metabolites are important constituents of different foods, e.g., berries, nuts, medicinal plants and

• antiestrogenic activities in a dose-dependent manner were shown for 23 and 24. Thus, the authors suggested further research to evaluate the possible role of ellagitannins and ellagic acid as dietary “pro-phytoestrogens” [32]. Even though many α-pyrones have been isolated from bacteria, only one dibenzo variant

• ellagitannin biosynthesis [73]. The ellagitannins can then be hydrolyzed to ellagic acid (22), and subsequently converted to urolithins (23–27). In microorganisms the PKS-derived origin was independently postulated for numerous compounds. The polyketide biosynthesis has much in common with fatty acid

Natural phenolic metabolites with anti-angiogenic properties – a review from the chemical point of view

• Qiu Sun,
• Jörg Heilmann and
• Burkhard König

Beilstein J. Org. Chem. 2015, 11, 249–264, doi:10.3762/bjoc.11.28

• , epigallocatechin-3-O-gallate, xanthohumol, (2S)-7,2’,4’-trihydroxy-5-methoxy-8-dimethylallylflavanone and genistein. Other compounds belong to the group of simple phenols (4-hydroxybenzyl alcohol), hydrolysable tannins (ellagic acid), stilbenoids (resveratrol) and diarylheptanoids (curcumin). In addition

• than curcumin. To date, the number of synthesized single enones and MACs have surpassed the 1000 mark. Ellagic acid Ellagic acid (7) is a naturally existing phenolic antioxidant widely found in numerous fruits and vegetables, such as raspberries (Rubus idaeus L., Rosaceae), strawberries (Fragaria spec

• . L., Rosaceae) and pomegranates (Punica granatum L., Lythraceae). It shows potent antioxidant effects by radical scavenging and the inhibition of lipid peroxidation [28][29]. Ellagic acid is also capable of interfering with some angiogenesis-dependent pathways. It exhibits anticarcinogenic activity