Ornithine derivatives

Ornithine-Derived Alkaloids. Ornithine (23) undergoes biological decarboxylation reductively to generate either putrescine [110-60-1] (36), or its biological equivalent, and subsequent oxidation and cyclization gives rise to the pyrroline [6724-81-2], (37), C H N. 

Alkaloids derived from L-ornithine, L-lysine, and L-trypthophan occur in the Legume plant family (Fabaceae Juss.) (Table 9). This plant family is the third largest botanical family, with 650 genera and 18000 species in the humid tropics, sub-tropics, temperate and sub-arctic zones around the Globe". L-ornithine-derived alkaloids such as senecionine are present in the genus Crota Crotalaria L.). 

L-ornithine-derived Solanaceae Atropa belladonna (—) -hyoscy amine... 

L-ornithine Ornithine-derived alkaloids True alkaloids Pyrrolidine alkaloids Tropane alkaloids Pyrrolizidine alkaloids... 

An alternative approach to the preparation of N -protected lysine, e.g. A -(benzyloxy-carbonyl) lysine (11), and ornithine derivatives is based on selective N -deprotection of A ,A -bis(benzyloxycarbonyl)lysine (8) (or the respective ornithine derivative) which proceeds via the corresponding acid chloride 9 and A-carboxyanhydride 10 (Scheme... 

The W -Trt groups are somewhat more stable than the A/ -Trt derivatives. In fact, cleavage of Trt-Lys-OH or Trt-Om-OH with 1% trifluoroacetic acid in dichloromethane occurs within 3 minutes at 0 °C, while for the corresponding A/ -derivatives 2 hours at room temperature are required for deprotection with 5% trifluoroacetic acid in dichloromethane. This differentiated acid lability is exploited for the synthesis of A/ -triarylmethyl-protected lysine and ornithine derivatives that are readily obtained by selective N -deprotection of a,co-bis-pro-tected diamino acids via treatment with mild acids.The subsequent N -protection, e.g. with the Fmoc group, is then carried out by standard procedures under Schotten-Baumann conditions. ... 

Zieve, L., Lyftogt, C., Raphael, D. Ammonia toxicity comparative protective effect of various arginine and ornithine derivatives, aspartate, benzoate, and carbamyl glutamate. Metab. Brain Dis. 1986 1 25-35... 

Fig. 4a. Pathways of hydroxamic acid syntheses of siderophores containing Ns-hydroxyornithine building blocks, a) Starts with e-nitro-L-norvaline. Schemes b) and c) start with ornithine derivatives protected at N5 with CBZ (benzyloxycarbonyl) and Tos (toluenesulfonate), BZL (benzyl), respectively Fig. 4b. Scheme of the synthesis of aerobactin. Protected g-hydroxynorleucine 1 (P = BOC,P = CH3) is transformed into the protected hydroxamic acid 2. Deprotection of the a-NH2 grqup enables alkylation of the o-substituted hydroxamate to give compound 3...

Various groups of arthropods have been shown to produce alkaloids that incorporate amino acid-derived building blocks. Examples include the incorporation of serine-derived ethanolamine or ornithine-derived putrescine into polyacetate-derived structures in ladybird beetles, as described in the preceding sections. 

The reaction postulated for the formation of omithinoalanine from ornithine (derived from the hydrolysis of the guanido group of arginine) and dehydroalanine is shown in Figure 14. 

The ornithine derived from arginine is in a separate pool from ornithine en route to arginine. 

L-ornithine-derived alkaloids Solanaceae Atropa belladonna ()-hyoscyamine ()-hyoscine Cuscohygrine... 

The poor fluorescence of the cysteine, lysine, and ornithine derivatives may be a drawback of the technique. Cysteine yields weakly fluorescent properties due to its sulfydryl group (Cooper and Turnell, 1982). However, these sulfydryl groups can be blocked with iodoacetic acid, lodoacetamine, or acrylonitrile, with the result that fluorescent isoindoles can then be formed with OPA (Cooper and Turnell, 1982). Cysteine may also be oxidized to cysteic acid, which forms a highly fluorescent product with OPA. Following the oxidation of cysteine, however, it may be difficult to obtain high reproducibility with the OPA derivatization of amino acids, because the conditions for these two reac-... 

Simple examples of alkaloids that contain a nicotinic acid residue as a partial structure include nicotine and anabasine. These alkaloids also possess a pyrrolidine and a piperidine ring in their partial structure, respectively, in addition to the pyridine ring derived from nicotinic acid.The origins of the aliphatic portions of these alkaloids are ornithine and lysine, respectively. In this volume, these particular alkaloids are described in the sections on ornithine-derived and lysine-derived alkaloids, respectively. 

Lee, B.H., G.J. Gerfen, and M.J. Miller Constituents of Microbial Iron Chelators. Alternate Syntheses of 6-N-Hydroxy-a-ornithine Derivatives and Applications to the Synthesis of Rhodotorulic Acid. J. Organ. Chem. (USA) 49, 2418 (1984). 

The so-called ureide plants use allantoin and allantoic acid as a nitrogen store from which ammonia may be liberated by further degradation (E 2.2), In the liver of lungfish a glycine-allantoin cycle (Fig. 182) causes the formation of urea (cf. the formation of urea via L-ornithine derivatives, D 19). 

Leete, E. Alkaloids derived from ornithine, lysine and nicotinic acid. In Encyclopedia of Plant Physiology, New Series, Vol. 8, Secondary Plant Products (E. A. Bell, B. V. Charlwood, eds.), pp. 65-91. Springer, Berlin-Heidelberg-New York 1980 Liebisch, H. W., Schiitte, H. R. Ornithine-derived alkaloids. In Biochemistry of Alkaloids (K. Mothes, H. R. Schiitte, M. Luckner, eds.) Deutscher Verlag der Wissenschaften, Berlin 1985... 

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