Marmesin plays a central role in the biosynthesis of furocoumarins in the plant ruta graveolens, more commonly known as rue. It acts as the natural intermediate in the formation of the furan ring that leads to a 4’,5’-dihydro furocoumarin-derivative. This substance can then be transformed into psoralen and other furocoumarins present in rue. Upon feeding the herb a dose of marmesin, radioactivity became strongly incorporated into psoralen and thus the plant itself.[2]
Synthesis of marmesin has been successfully conducted in the laboratory on multiple occasions. One way of doing so is by a strategy based on the palladium-catalyzed intramolecular coupling reaction. This reaction would construct the dihydropyran ring and synthesize the compound from the intermediate (-)-peucedanol. The key step in the overall synthesis uses catalytic asymmetric epoxidation of an enone.[6]
^Caporale, G.; Dall’Acqua, F.; Capozzi, A.; Marciani, S.; Crocco, R. Studies on the biosynthesis of some furocoumarins present in Ruta graveolens. Zeitschrift für Naturforschung B 1971, 26, 1256-1259.
^Ando, T.; Nagumo, M.; Ninomiya, M.; Tanaka, K.; Linhardt, R. J.; Koketsu, M. Synthesis of coumarin derivatives and their cytoprotective effects on t-BHP-induced oxidative damage in HepG2 cells. Bioorg. Med. Chem. Lett. 2018, 28, 2422-2425.
^Kommera, R.; Bhimapaka, C. R. A simple and efficient approach for the preparation of dihydroxanthyletin, xanthyletin, decursinol and marmesin. Synthetic Communications 2020, 50, 3204-3211.
^Anonymous Dictionary of natural products; Chapman & Hall: London, 1994.
^Nemoto, T.; Ohshima, T.; Shibasaki, M. Enantioselective total syntheses of novel PKC activator (+)-decursin and its derivatives using catalytic asymmetric epoxidation of an enone. Tetrahedron Lett. 2000, 41, 9569-9574.
