Leucojum aestivum

O. elwesii Hook., Haemanthus puniceus L., Leucojum aestivum L. var. pulcheUum Salisb., L. vernum L., Pancratium maritimum L., Sprekelia formosissima Herb., Stembergia lutea (L.) Ker-Gawl., and Vallotta speciosa L Herb. 

In feeding experiments in Leucojum aestivum L. it has been observed that [3, 5 -3H2 14C-0-methyl]O-methylnorbelladine (343) is a good precursor of 147 which retains the same 3H/14C ratio of the fed precursor. As expected lycorine showed ca. 50% 3H loss. 

Sanguinine (272), reported previously as a constituent of Leucojum aesti-vum sub. was obtained from Leucojum aestivum sub. pulchelum (54). The structures of the representative alkaloids isolated are shown in Fig. 17. 

Although norbelladine was shown not to be a precursor of galanthamine (101) in King Alfred daffodils, an incorporation of this compound with labels as shown (103), comparable to that for lycorine (104), has been obtained for galanthamine in Leucojum aestivum As expected, the lycorine showed loss of half its tritium. On the other hand, no loss of tritium was apparent in the galanthamine. The latter result suggested that in the biosynthesis of galanthamine conversion of (105) to narwedine (100) was either not reversible or, if so, enzy-mically controlled. 

Three new alkaloids of the galantharaine group have been isolated. The structure of 0-deraethyllycoramine (5) from Lycoris radiata was apparent from its formation from the reaction of lycoramine with pyridine hydrochloride at 190°C. Leucojum aestivum contains leucotamine (9), which was converted with diazomethane into a second new alkaloid of this species, 0-methylleucotamine (10) the... 

Although norbelladine (85) was shown not to be a precursor of galanthamine (70) in Narcissus pseudonarcissus cv. King Alfred, an incorporation of this labelled compound has been obtained in Leucojum aestivum (128). 

The search for new sources of galanthamine continues, and Galanthus nivalis, G. woronowi, Eucharis subedentata Leucojum aestivum, and Vallota speciosa have been investigated this year. 

Ivanov I, Georgiev V, Georgiev M, Ilieva M, Pavlov A. Galanthamine and related alkaloids production by Leucojum aestivum L. shoot culture using a temporary immersion technology. Appl Biochem Biotechnol 2011 163(2) 268-77. 

Schumann A, Berkov S, Claus D, Gerth A, Bastida J, Codina C. Production of galanthamine by Leucojum aestivum shoots grown in different bioreactor systems. Appl Biochem Biotechnol 2012 167(7) 19O7—20. 

Galanthamine para- ortho Narcissus pseudonarcissus Leucojum aestivum Galanthus niveali Galanthus elewesii Pancratium maritimum acetylcholinesterase inhibitor, treatment for Alzheimer s disease [4,8-10]... 

Narciclasine para- para Narcissus spp. Leucojum aestivum Lycoris radiata, Pancratium maritimum Hymenocallis expansa cytotoxic [3,4]... 

El Tahehy, A., et al.. Kinetic study of the rearrangement of deuterium-labeled 4 -0-methylnorbelladine in Leucojum aestivum shoot cultures by mass spectrometry. Influence of precursor feeding on amaryllidaceae alkaloid accmnulation. J. Nat. Prod, 2011.74(11) p. 2356-61. 

In daffodil plants, galanthamine is biosynthesized from compounds 19-21, but not from norbelladine (5) [which is a good precursor of haemanthamine (14) and lycorine (8) in the same plants] (Fig. 33.6). These experiments suggest a definite order of methylation of norbelladine (5) during the biosynthesis of galathamine. In feeding experiments with the plant Leucojum aestivum, [2,4- H2 C-0-methyl]0-methylnorbelladine (13) is a precursor of galanthamine (18) that retains the same ratio as in the precursor. There... 

G. latifolius Wor. Leucojum aestivum L. Sternbergia colchiciflora Pancratium maritimum L. ... 

Stanilova MI, Molle ED, Yanev SG (2010) Galanthamine production by Leucojum aestivum cultures in vitro. In Cordell GA (ed) The alkaloids, vol 68. Elsevier Scientific Publishing,... 

Berkov S, Codina C, Viladomat F, Bastida J (2008) N-Alkylated galanthamine derivatives potent acetylcholinesterase inhibitors from Leucojum aestivum. Bioorg Med Chem Lett 18 2263... 

Fuganti C (1969) Biosynthesis of galanthamine feeding experiments in Leucojum aestivum (Amaryllidaceae). La Chimica e I Industria 51 1254... 

---