Daffodil

Lycorine (69) was recognized as a potent emetic and a moderately toxic base from the time of its initial isolation from Narcissus pseudonarcissus E. (in about 1877) (48). Since that time its isolation from many other AmaryUidaceae, for example, Lpcom radiate Herb., has served to estabUsh it as the most cosmopohtan alkaloid of the family. TypicaUy, as much as 1% of the dry weight of daffodil bulbs may consist of lycorine (69), which has been reported to... 

In 1956, the alkaloid Methylpseudolycorine (101) isolated from the King Alfred daffodil (Narcissus pseudonarcissus L.) was oxidized to the pale yellow chloride with selenium dioxide (Scheme 36). Conversion into the betaine was accomplished by aqueous ammonia to give yellow prisms of the trihydrate of Criasbetaine (100) (56JA4145, 56JA4151). The UV absorption... 

Clearly, the control of gene expression at the transcriptional level is a key regulatory mechanism controlling carotenogenesis in vivo. However, post-transcriptional regulation of carotenoid biosynthesis enzymes has been found in chromoplasts of the daffodil. The enzymes phytoene synthase (PSY) and phytoene desaturase (PDS) are inactive in the soluble fraction of the plastid, but are active when membrane-bound (Al-Babili et al, 1996 Schledz et al, 1996). The presence of inactive proteins indicates that a post-translational regulation mechanism is present and is linked to the redox state of the membrane-bound electron acceptors. In addition, substrate specificity of the P- and e-lycopene cyclases may control the proportions of the p, P and P, e carotenoids in plants (Cunningham et al, 1996). 

Rice Psy cDNA from daffodil CaMV 35S Phytoene accumulation in endosperm Burkhardt et al., 1997... 

The formation of P-carotene in rice endosperm, where carotenoids are normally absent, was achieved by the simultaneous transfer of three genes Psy from daffodil, crti from Erwinia herbicola and crtL-B from daffodil (Ye et al,... 

POTRYKUS I (1997) Transgenic rice Oryza sativa) endosperm expressing daffodil Narcissuspseudonarcissus) phytoene synthase accumulates phytoene, a key intermediate of provitamin A biosynthesis , Plant J, 11, 1071-78. 

In rice endosperm that accumulated phytoene by virtue of daffodil Psy transgenesis, Burkhart et al. reported the failure of daffodil Pds over-expression in rice endosperm to condition accumulation of -carotene, even though an increase in PDS antigen was detected. ... 

The availability of precursor IPP may ultimately be most influential over accumulation of carotenoid metabolites. While over-expression of DXS and DXR in color complementation systems leads to hyperaccumulation of carotenoids (discussed in Section 5.3.3.3), over-expression of plant Dxs genes has not always been effective. Over-expression of DXS resulted in increased carotenoid accumulation in transgenic tomato and Arabidopsis, but over-expression of daffodil DXS in rice endosperm did not increase pigment accumulation. ... 

Over-expression and anti-sense constructs of LCYB have been tested in rice and tomato. In Golden Rice, daffodil LCYB was over-expressed but found to be unnecessary for accumulation of carotenes. Only PSY and CRTI are needed to accumulate carotenes and xanthophylls in the endosperm. 

Beyer, R, Weiss, G., and Kleinig, H., Solubilization and reconstitution of the membrane-bound carotenogenic enzymes from daffodil chromoplasts, Eur. J. Biochem. 153, 341, 1985. 

I am walking in Hyde Park and here in London, April is being surprisingly kind. I am jet-lagged, but the London sun on the daffodils and forsythia in Hyde Park seems to sweep away the mental fog. No matter that a chain of mix-ups has preceded my arrival... 

Source Naturally occurs in cranberries, ligonberries (1,360 ppm), peppermint leaves (20-200 ppb), tea leaves, cassia bark, carob, blessed thistle, purple foxglove, jasmine, hyacinth, apples, tobacco leaves, daffodils, autumn crocus, prunes, anise seeds, ripe cloves, and wild black cherry tree bark (Duke, 1992 quoted, Verschueren, 1983). 

Daffodil bulbs require well-drained soil and a sunny planting location. They should be planted in holes that are 3-6 inches deep and there should be 2-4 inches between bulbs. The bulb should be placed in the hole, pointed side up, root side down. Once the bulb is planted, water the area thoroughly. 

Rashes, itchy skin bulbs of daffodils, hyacinths, tulips variable response. Allergens located on outer cells of plant... 

Several inhibitors of AChE have been developed for use in treating Alzheimer s disease, which requires that the drugs readily enter the CNS. These inhibitors are structurally unrelated and vary in their mechanism of inhibition, although all are reversible inhibitors. Tacrine (Cognex) is a monoamine acridine. Donepezil (Aricept) is a piperidine derivative that is a relatively specific inhibitor of AChE in the brain, with little effect on pseudo-ChE in the periphery. Galanthamine (Reminyl) is a tertiary alkaloid and phenanthrene derivative extracted from daffodil bulbs that is a reversible competitive inhibitor of AChE it also acts on nicotinic receptors. 

Extracted from the bulbs of the daffodil, Narcissus pseudonarcissus Patient/Family Education... 

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