Verbena littoralis

Li, Y. et al., Littorachalcone, a new enhancer of NGF-mediated neurite outgrowth, from Verbena littoralis, Chem. Pharm. Bull, 51, 872, 2003. 

Dihydrochalcone-dihydrochalcone Littorachalcone C30H26Og Verbena littoralis Verbenaceae 270... 

Li, Y.-S. et al., Verbenachalcone, a novel dimeric dihydrochalcone with potentiating activity on nerve growth factor-action from Verbena littoralis, J. Nat. Prod., 64, 806, 2001. 

Synthesis of verbenachalcone, isolated from Verbena littoralis H.B.K., was accomplished using the diaryl ether 11, a one-electron oxidation product of the corresponding phenol 10 [10]. 

Tanabe T, Doi F, Ogamino T, Nishiyama S (2004) A total synthesis of verbenachalctme, a bioactive diaryl ether from Verbena littoralis. Tetrahedron Lett 45 3477-3480... 

Crotaramin and crotin, which are pyranodihydrochalcones isolated from Crotalaria ramosissima, exhibited weak inhibition of maturation of Plasmodium falciparum (NF-54) parasites [64]. Dimeric dihydrochalcones verbenachalcone and littorachalcone were isolated from the aerial parts of Verbena littoralis. These compounds were reported to act as enhancers of nerve growth factor (NGF)-mediated neurite outgrowth and axonal branching in rat pheochromocytoma PC12D cells [184, 185] (Fig. 61.12). 

MacMillan et al. reported total synthesis of iridoids, brasoside (71), and littoralisone (72), in 13 steps in 13% overall yield [102]. Both these iridoids were isolated earlier from Verbena littoralis, and littoralisone (72) was demonstrated to be the active agent for increased NGF-induced neurite outgrowth in PC12D cells [103]. They synthesized the iridolactone aglucone (73) using (-) citronellol (74) as starting material via the intermediate, formyl enal (74a). Proline-catalyzed intramolecular Michael addition of the formyl enal was the key step of their synthesis (Scheme 97.4). 

Nerve growth factor (NGF) is one of the neurotrophic factors for neurodegenerative disorders. Verbena littoralis (Verbenaceae) was useful for treatment of dementia. To find out the bioactive chemicals, Li et al. isolated some iridoids from this plant... 

CalsamigUa S, Busquet M, Cardozo PW, Castillejos L, Ferret A (2007) Invited review essential oils as modifiers of rumen microbieil fermentation. J Dairy Sci 90 2580-2595 Castro-Gamboa I, Castro O (2004) Iridoids from the aerieil parts of Verbena littoralis (Verbenaceae). Phytochemistry 65 2369—2372... 

In 2005, Mangion and MacMillan reported on the smart synthesis of two closely related natural compounds littora-lisone isolated from Verbena littoralis and brasoside (Scheme 11.25). ° These two syntheses were crucial for the expansion of organocatalysis because they highlighted the extraordinary potential of several organocatalytic methodologies. The key point for the synthesis of these molecules was the development of an intramolecular Michael addition. Using L-proline as catalyst, the substrate reacted under kinetic catalyst control to furnish the desired... 

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