Alkaloids from Eucharis amazonica (Amaryllidaceae).

Jonquailine, a new pretazettine-type alkaloid isolated from Narcissus jonquilla quail, with activity against drug-resistant cancer

“…Jonquailine is closely related to 6- O -methylpretazettine isolated by Bastida and coworkers from Eucharis amazonica [39]. The configuration at C-3, C-4a and C-11 (our C-6a) of 6- O -methylpretazettine was assigned using ROESY correlations and coupling constants measured in the 1 H NMR spectrum.…”

“…Jonquailine ( 6 ): amorphous solid; R f 0.44, CHCl 3 / i -PrOH (95:5 v/v); UVλ max (log ε ) 287 (4.00), 240 (4.09) nm; CD ([θ] λ ): [θ] 242 + 18,588, [θ] 291 + 5163 (6- O -methylpretazettine [39] CD [θ] 244 − 4398, [θ] 299 + 4524; tazettine [40] CD MeOH ([θ] λ ):[θ] 207.2 + 194,500, [θ] 240.4 + 32,600, [θ] 289.2 − 3090; pretazettine [40] CD MeOH ([θ] λ ): [θ] 217.6 + 51,600, [θ] 233.7 0, [θ] 249.6 − 9830, [θ] 263.9 0, [θ] 291.0 + 13,130); IR ν max 1616, 1500, 1493, 1497 cm −1 ; 1 H and 13 C NMR, see Table 1; (+)-APCI MS m / z 346 [M + H] + , 314 [M − CH 3 OH] + ; (+)-HRESIMS m / z 713 [2 M + Na] + , 363 [M + NH 4 ] + and 346.1664 [M + H] + (calcd for C 19 H 24 NO 5 346.1654).…”

A New Amaryllidaceae Alkaloid from the Bulbs of Lycoris radiata

“…Amaryllidaceae alkaloids are produced almost by plants of galanthus genus 7 in Amaryllidaceae and are classified with three distinct scaffolds, lycorine (3)(4)(5)(6)(7)(8)(9)14), haemanthamine (1-2, 10, 15-18) and galanthamine (11)(12)(13) series, which are classified depending on the pattern of oxidative phenolic coupling. For the purpose of searching for bioactive alkaloids from natural resources, extensive phytochemical investigation of the bulbs extract of L. radiata had undertaken and finally resulted in the isolation of a new amaryllidaceae alkaloid (1), together with seventeen related alkaloids (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). The chemical structures of isolated 1-18 ( Fig.…”

“…The chemical structures of isolated 1-18 ( Fig. 1) were established by spectroscopic analyses as 6-hydroxytazettine (1), tazettine (2), lycorine (3), 2-O-acetyllycorine (4), homolycorine (5), 9-O-demethylhomolycorine (6), hippeastrine (7), O-methyllycorenine (8), 2-α-hydroxy-6-O-methyloduline (9), haemanthidine (10), galantamine (11), dihydrogalantamine (12), lycoramine N-oxide (13), lycosinineB (14), ismine (15), trisphaeridine (16), 3-epimacronine (17), and 6-O-methylpretazettine (18), [8][9][10][11][12][13][14][15][16][17][18] respectively. In the present paper, we describe briefly the isolation and identification of a new Amaryllidaceae alkaloid (1), as well as the inhibitory activities of isolated alkaloids (1-18) on acetylcholinesterase, in vitro assay.…”

“…The other purified components (2-18) were identified by direct comparison of their spectral data with those in the literatures. [8][9][10][11][12][13][14][15][16][17][18] All isolated Amaryllidaceae alkaloids (1-18) were evaluated for the inhibitory effect on acetylcholinesterse (EC 3.1.1.7. electric eel) using acetylcholine as substrate in vitro 20 and it was observed that galantamine (11) and ismine (15) exhibited a significant inhibitory effect on the acetylcholinesterase with IC 50 values of 27.9 and 109.7 µM, when other isolated compounds showed poor inhibitions (IC 50 > 300 µM) on acetylcholinesterse, in vitro assay. …”