488-06-2Relevant articles and documents
E/Z-Thesinine-O-4′-α-rhamnoside, pyrrolizidine conjugates produced by grasses (Poaceae)
Koulman, Albert,Seeliger, Claudine,Edwards, Patrick J.B.,Fraser, Karl,Simpson, Wayne,Johnson, Linda,Cao, Mingshu,Rasmussen, Susanne,Lane, Geoffrey A.
, p. 1927 - 1932 (2008)
Based on direct infusion mass spectrometry we identified a novel alkaloid as a major component of perennial ryegrass (Lolium perenne). Initial mass spectral data suggested it to be a pyrrolizidine conjugate. As this class of alkaloids has not been described before from grasses, we isolated it to elucidate its structure. The isolated alkaloid proved to be a mixture of two stereoisomers. The structures of the two compounds as determined by 1D and 2D NMR spectroscopy, were E-thesinine-O-4′-α-rhamnoside (1) and Z-thesinine-O-4′-α-rhamnoside (2). These identifications were supported by the characterisation by GC-MS and optical rotation of (+)-isoretronecanol as the necine base released on alkaline hydrolysis of these alkaloids. 1 and 2 together with the aglycone and a hexoside were also detected in tall fescue (Festuca arundinacea). This is the first report of pyrrolizidine alkaloids produced by grasses (Poaceae).
Pyrrolizidine alkaloids from Liparis nervosa with antitumor activity by modulation of autophagy and apoptosis
Chen, Lin,Huang, Shuai,Li, Chun Ying,Gao, Feng,Zhou, Xian Li
, p. 147 - 155 (2018)
Seven pyrrolizidine alkaloids, nervosine X–XV and nervosine VII N-oxide, together with a reaction product, namely chloride-(N-chloromethyl nervosine VII), were isolated from Liparis nervosa. Their structures were elucidated by extensive spectroscopic analyses. Most of these compounds were investigated for their cytotoxicity in vitro against HCT116 human cancer cell line, and the results showed that chloride-(N-chloromethyl nervosine VII) induced tumor cell death in a dose-dependent manner. Furthermore, the mechanisms underlying its cytotoxicity were investigated, including apoptosis and autophagy. Apoptosis in HCT116 cells was associated with up-regulation of caspase-3 and -9 expressions by activation of the mitochondrial pathway. The autophagy inducing effect was associated with the regulation of autophagic markers, including LC3-II, p62, and Beclin 1. Mechanistic studies showed that JNK, ERK1/2, and p38 MAPKs signaling cascades play an important role in chloride-(N-chloromethyl nervosine VII) induced autophagy and apoptosis.
Stereodivergent Synthesis of 1-Hydroxymethylpyrrolizidine Alkaloids
Appayee, Chandrakumar,Sarkale, Abhijeet M.
, (2020/06/05)
A first stereodivergent strategy for the asymmetric synthesis of all stereoisomers of 1-hydroxymethylpyrrolizidine alkaloids is developed using an asymmetric self-Mannich reaction as a key step. An anti-selective self-Mannich reaction of methyl 4-oxobutanoate with the PMP-amine catalyzed by a chiral secondary amine is successfully optimized for the asymmetric synthesis of (+)-isoretronecanol and (-)-isoretronecanol. A syn-selective self-Mannich reaction catalyzed by proline is utilized for the asymmetric synthesis of the diastereomer, (+)-laburnine, and its enantiomer, (-)-trachelanthamidine.
Organocatalytic asymmetric mannich cyclization of hydroxylactams with acetals: Total syntheses of ( )-epilupinine, ( )-tashiromine, and ( )-trachelanthamidine
Koley, Dipankar,Krishna, Yarkali,Srinivas, Kyatham,Khan, Afsar Ali,Kant, Ruchir
, p. 13196 - 13200 (2015/02/19)
An asymmetric, organocatalytic, one-pot Mannich cyclization between a hydroxylactam and acetal is described to provide fused, bicyclic alkaloids bearing a bridgehead N atom. Both aliphatic and aromatic substrates were used in this transformation to furnish chiral pyrrolizidinone, indolizidinone, and quinolizidinone derivatives in up to 89% yield and 97% ee. The total syntheses of (-)-epilupinine, (-)-tashiromine, and (-)-trachelanthamidine also achieved to demonstrate the generality of the process.
The stereoselective addition of titanium(IV) enolates of 1,3-oxazolidin-2-one and 1,3-thiazolidine-2-thione to cyclic N-acyliminium ion. The total synthesis of (+)-isoretronecanol
Pereira, Elaine,De Fátima Alves, Concei??o,B?ckelmann, Maria Alice,Pilli, Ronaldo A.
, p. 2691 - 2693 (2007/10/03)
(+)-Isoretronecanol (1) has been prepared in four steps and 36% overall yield via the diastereoselective addition of the titanium(IV) enolate derived from N-4-chlorobutyryl-1,3-thiazolidine-2-thione (3) to N-Boc-2- methoxypyrrolidine (5), which afforded 2-substituted pyrrolidine 7 in 84% yield (8:1 diastereoisomeric ratio), followed by reductive recovery of the chiral auxiliary and cyclization.
Syntheses from chiral heterocyclic β-amino esters. A new versatile access to pyrrolizidine and quinolizidine alkaloids
Ledoux, Stéphane,Marchalant, Elisabeth,Célérier, Jean-Pierre,Lhommet, Gérard
, p. 5397 - 5399 (2007/10/03)
Chiral heterocyclic β-amino esters can be easily transformed into bicyclic alkaloids after a diastereoselective alkylation followed by specific chemical transformations.
Synthesis of Optically Active Pyrrolizidine Bases
Robins, David J.,Sakdarat, Santi
, p. 909 - 913 (2007/10/02)
Regiospecific 1,3-dipolar cycloaddition of ethyl propiolate to the NO-diformyl derivative (1) of natural (-)-4-hydroxy-L-proline followed by stereospecific hydrogenation gave ethyl (+)-6α-hydroxy-β-pyrrolizidine-1α-carboxylate (4).Confirmation of the abso
