title: Triterpenoids with acetylcholinesterase inhibition from Chuquiraga erinacea D. Don. subsp. erinacea (Asteraceae).
abstract: A bioactivity-guided approach was taken to identify the acetylcholinesterase (AChE) inhibitory agents in the ethanolic extract of Chuquiraga erinacea D. Don. subsp. erinacea leaves using a bioautographic method. This permitted the isolation of the pentacyclic triterpenes calenduladiol (1), faradiol (2), heliantriol B2 (3), lupeol (4), and a mixture of alpha-and beta-amyrin ( 5A and 5B) as active constituents. Pseudotaraxasterol (6) and taraxasterol (7) were also isolated from this extract and showed no activity at the same analytical conditions. Compound 1 showed the highest AChE inhibitory activity with 31.2 % of inhibition at 0.5 mM. Looking forward to improve the water solubility of the active compounds, the sodium sulfate ester of 1 was prepared by reaction with the (CH3)3N.SO3 complex. The semisynthetic derivative disodium calenduladiol disulfate (8) elicited higher AChE inhibition than 1 with 94.1 % of inhibition at 0.5 mM (IC (50) = 0.190 +/- 0.003 mM). Compounds 1, 2, 3, 5, 6, and 7 are reported here for the first time in C. erinacea. This is the first report of AChE inhibition from calenduladiol (1) as well as from a sulfate derived from a natural product.
authors.affiliation: INQUISUR-CONICET, Departamento de Química, Universidad Nacional del Sur, Bahía Blanca, Argentina.
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Gurovic
authors.forename: María Julia
authors.initials: MJ
authors.lastname: Castro
authors.forename: Victoria
authors.initials: V
authors.lastname: Richmond
authors.forename: María Belén
authors.initials: MB
authors.lastname: Faraoni
authors.forename: Marta S
authors.initials: MS
authors.lastname: Maier
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Murray
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D002800:Cholinesterase Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D015394:Molecular Structure; D014315:Triterpenes / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D002800:Cholinesterase Inhibitors; D014315:Triterpenes