Calleryanin

Scalable total synthesis of natural vanillin-derived glucoside omega-esters.[Pubmed:36179617]

Carbohydr Res. 2022 Dec;522:108683.

The first total synthesis of vanilloloside, Calleryanin, and a series of naturally occurring omega-esters of vanilloloside was realized through direct glycosylation of vanillin-based aglycones or late-stage derivatization of vanilloloside. All aglycones and their fragments were synthesized from vanillin as the sole aromatic precursor. Subsequently, these intermediates were used to construct various vanillin-derived glucoside omega-esters using a mild acidic deacetylation as the key synthetic step, providing the final products in the total yields of 10-50% and general purity of >95%. Additionally, the first operationally simple and sustainable synthesis of litseafoloside B was realized on large scale, avoiding the use of toxic solvents and reagents, providing an attractive alternative to isolation of this and other similar compounds from plant sources.

Bio-guided isolation of cholinesterase inhibitors from the bulbs of Crinum x powellii.[Pubmed:16317657]

Phytother Res. 2005 Nov;19(11):984-7.

In a search for potential acetylcholinesterase (AChE) inhibitors, the ethanol extract of the bulbs of Crinum x powellii (Amaryllidaceae) was found to demonstrate a marked inhibition of this enzyme. Using a bio-guided isolation strategy, linoleic acid ethyl ester has been identified as the compound responsible for this inhibition. Three other molecules - the alkaloid hippadine, the glycosylated benzyl alcohol derivative Calleryanin and 4'-hydroxy-7-methoxyflavan - were also isolated and characterized for the first time from Crinum x powellii. The structures of these compounds were elucidated by spectrometric methods including EI, D/CI mass spectrometry, (1)H, (13)C and 2D NMR experiments. Linoleic acid was also found to inhibit AChE.