Loline alkaloids lolines

Analysis of fractions for loline alkaloids. Loline alkaloids present in the various fractions were determined by the quantitative capillary gas chromatographic method of Yates al. (7). Prior to GC analysis, 50-/iL or 100-/iL aliquots of each fraction to be analyzed were diluted to 0.98 mL with MeOH, and phenyl morpholine was added as an internal standard (200 /ig in 20 /iL MeOH) l-pL injections were used. 

An intermediate 5-hydroxy-5,6-dihydro-2/7-pyrrolo[l,2- ][l,2]oxazin-7(4a//)-one 142 has been described in the total synthesis of (—)-loline, a pyrrolizidine alkaloid extracted from rye grass Lolium cuneatum. The key step of the synthesis was an intramolecular cycloaddition of acylnitrosodienes (obtained by in situ oxidation of the corresponding hydroxamic acids 143). This reaction generated predominantly the rro/o-stereoisomer that was further cleaved at the N-O bond with Na(Hg) and further elaborated in several steps to reach the target compound (Scheme 19) <2001J(P 1)1831 >. 

Tong DW et al, Seasonal change of loline alkaloids in endophyte-infected meadow fescue, Agric Sci China 5 793-797, 2006. 

Spiering MJ et al. Gene clusters for insecticidal loline alkaloids in the grass-endophytic fungus Neotyphodium uncinatum, Genetics 169 1403—1414, 2005. 

The simple necine bases loline (18), norloline (19), and lolinine (20) have been identified previously from Lolium cuneatum Nevski.7 Further investigations on the seeds of this plant by Russian workers have established the presence of four new alkaloids. N-Formylnorloline (21),8 JV-methyl-loline (22), JV-acetylnorloline (23), and AT-formyl-loline (24)9 have been identified. In addition, a novel dimeric pyrrolizidine alkaloid, lolidine, containing chlorine, was isolated in trace amounts (7 mg from 10 kg of seeds). The structure (25) has been suggested for lolidine on the basis of spectral data.10... 

The bases (46) and (47), derived from the loline group of alkaloids, have been used as stimulants of plant growth.40... 

The structure (25) has been deduced for both loline, an alkaloid of Lolium cuneatum Nevski, ° and festucine, a constituent of Festuca arundinacea Schreb. The identity of loline and festucine has now been confirmed by direct comparison. 

Blankenship JD, Spiering MJ, Wilkinson UH, Fannin FF, Bush LP, Schardl CL. Production of loline alkaloids by the grass endophyte, Neotyphodium uncinatum, in defined media. Phytochemistry 58 395-401, 2001. 

TePaske MR, Powell RG, Clement SL. Analyses of selected endophyte-infected grasses for the presence of loline-type and ergot-type alkaloids. J Agric Food Chem 41 2299-2303, 1993. 

Wilkinson HH, Siegel MR, Blankenship JD, Mallory AC, Bush LP, Schardl CL. Contribution of fungal loline alkaloids to protection from aphids in a grass-endophyte mutualism. Mol Plant-Microbe Int 13 1027-1033, 2000. 

Riedell WE, Kieckhefer RE, Petroski RJ, Powell RG. Naturally occurring and synthetic loline alkaloid derivatives insect feeding behavior modification and toxicity. J Entomol Sci 26 122-129, 1991. 

Strickland et al. (1991, 1994) studied the effects of ergot and loline alkaloids of E+ fescue on prolactin release by isolated and perfused rat pituitary cells. The ergot alkaloids had prolactin-lowering effects and mimicked dopamine action. The use of a D2 dopamine receptor antagonist (domperidone) blocked the effect of the ergot alkaloids and prevented their prolactin-lowering effect. Domperidone... 

Grass species Endophyte species Ergot alkaloids Lolines Peramine Lolitrems... 

Petroski RJ, Dombos DL Jr, Powell RG. Germination and growth inhibition of annual ryegrass (Lolium multiflorum L.) and Alfalfa (Medicago sativa) by loline alkaloids and synthetic N-acylloline derivatives. J Agric Food Chem 38 1716-1718, 1990. 

A number of closely related naturally occurring pyrrolizidine cyclic ethers have been identified.74 Four of these, loline (=festucine75) (119), norloline (120), lolinine (121), and decorticasine (122), have had their structures and relative configurations established by chemical methods. In addition, the relative stereochemistry of loline has been defined by an X-ray crystal structure determination of its dihydrochloride.76 The absolute configurations for all these alkaloid bases have now been established by the X-ray technique of anomalous dispersion using the same dihydrochloride of loline (119).7 7... 

VII. The ether bridge in loline was established by treating the alkaloid... 

Details of the synthesis of the ring system of the loline alkaloids [as in loline (33)] have now been provided ( f. Vol. 10, p. 50). The authors speculate on the close biogenetic... 

Petrosld, R.J. etaL 1989. Isolation, semisyn-thesis and nmr studies of loline alkaloids JournalofNaturalProducts810-817. 

Loline ( = festucine 34), norloline (35), lolinine (36), and decorticasine (37) form a quartet of closely related alkaloids whose structures and relative configurations have been established by interconversions, particularly with loline, for which the relative configuration expressed in (34) has been established by A"-ray crystal structure determination of its dihydrochloride. The absolute configurations for these bases implied in the structures [(34)—(37)] have now been established by the X-ray technique of anomalous dispersion, using the dihydrochloride of loline. 

This synthetic strategy has been extended by the same authors to the synthesis of the ring system of the loline alkaloids. Seven simple loline alkaloids [e.g. loline (9)] and one dimeric species have been identified (see these Reports, Vol. 8, Ch. 3). The ketone (10) was converted into the amine (11) in analogous fashion to the formation of (7) from cyclohept-4-enone (see Scheme 3). Treatment of the amine (11) with bromine led to transannular cyclization and formation of the 3-aza-9-oxabrendane system (13) in good yield (85%), as shown in Scheme 4. The... 

Decinine, Decodine see Lythraceae alkaloids. Decorticasine see lolines. 

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