Amino acrylic acid

Other cyclic tetrapeptides have also been isolated by Japanese workers and AM toxins I, II, and III, isolated from Alternaria mail., are extremely toxic to certain plant species (9.10). These are constructed of L- i-hydroxyisovaleric acid, L-alanine, c-amino-acrylic acid and, in AM toxin I, L-6(-amino- -( .-methoxyphenyl)-valeric acid. The phenyl residue in AM toxin II is L-t(-amino-S-phenylvaleric acid, while in AM toxin III, it is L-ol-amino-( .-hydroxyphenyl)valeric acid (Figure 2), All the AM toxins produce leaf spot, or necrosis, in apple but as might he expected slight change in substitution (R-group) on the phenyl ring radically alters the specific activity of the molecule. Both AM toxin I and III induce interveinal necrosis in the "Indo" apple cultivar, which is also highly susceptible to A. mail. at concentrations as low as 0.1 pph within 18 h after treatment. In contrast, the resistant apple cultivar "Jonathan" is only affected by 1 ppm of AM toxin I and 10 ppm of AM toxin III. 

The initially formed rhodium/substrate (B) complex of the hydrogenation of Z-OC-(acyl-amino)acrylic acid in Figure 17.77 possesses structure C (Figure 17.78). The reaction starts with the reversible dissociation of two MeOH ligands from the central atom Rh(I). The two now... 

Fig. 17.78. Key intermediates in the enantioselective hydrogenations of the Z-configu-rated stereoiso meric a-(acyl-amino)acrylic acids in Fig.

Alkali treatment of proteins is becoming more common in the food industry and may result in several undesirable reactions. When cystine is treated with calcium hydroxide, it is transformed into amino-acrylic acid, hydrogen sulfide, free sulfur, and 2-methyl thia-zoIidine-2,4-dicarboxyIic acid as follows ... 

Amino-acrylic acid (dehydroalanine) is very reactive and can combine with the e-amino... 

Enamines can be deprotonated with n-BuLi or f-BuLi if some stabilizing groups are present at the nitrogen or on the alkene. Some examples are /3-amino acrylic acid derivatives 68 2987,988, which have also been employed as /S-acyl vinyl anion equivalents858. 

L-dopa Hydrogenation of a-amino acrylic acids Rh complex h... 

Irradiation of 2-[N-(pentafluorophenyI)amino]-3-phenylcyclopropenone promotes decarbonylation to give N-(pentafluorophenyl)phenylethynamine and 2-phenyl-3-[N-(pentafluorophenyl)amino]acrylic acid by a process for which there is no known precedent,and the photoextrusion of carbon monoxide from l,3-bis(ethylenedioxy)indan-2-one has been used as the first step in a new synthesis of 1,2-dioxobenzocyclobutene. This represents an unusual example of the decarbonylation of a five-membered cyclic ketone in the preparation of a highly strained and functionalised cyclobutane derivative. The photolysis of a-naphthaleneacetic acid in aqueous solution proceeds by decarboxylation and oxidation of the aromatic ring, and has been carried out at a variety of different wavelengths. The primary step occurs by pseudo-first order kinetics and the optimum photolysis rate has been observed using Ti02 as photocatalyst. Within the cavity of P-cyclodextrin, naproxene (129) has been photodecarboxylated to... 

COOH aUylsulfenlc acid amino acrylic acid... 

Our experiments with zwitterionic polymers are in a very prelimi-ntury sttige, and have concerned only a single polymer poly n-amino-acrylic acid). Suspensions of DPPC or DPPG are unaffected by this polymer at pH 7.4 or at pH 10. These experiments are continuing. 

Alliins are degraded to sulfenic acids and (X-amino acrylic acid (Fig. 190). oc-Aminoacrylic acid decomposes spontaneously to pyruvic acid and ammonia. 

Theoretically, the condensation of mono- and diiodotyrosine could yield four different compounds 3,3 -diiodothyronine, 3,3, 5 -triiodothyronine, 3,5,3 -triio-dothyronine, and thyroxine (see Fig. 8-4). The exact mechanism of the formation of these various iodinated derivatives is not clear, but it has been suggested that they are formed by the condensation of two molecules of iodotyrosines with loss of a side chain. In this reaction, the iodinated tyrosine is converted by the loss of two atoms of hydrogen to the quinoid form, which acts as a free radical and condenses with other molecules of iodinated tyrosine to yield a diphenyl ring. During such a reaction, an oxygen bridge is formed, and one of the side chains of tyrosine is split to yield an a-amino acrylic acid. The a-amino acrylic acid is further metabolized to yield ammonia and pyruvic acid. 

The increase in the extinction at this wavelength is related to the formation of a-amino-acrylic acid. The ultraviolet spectrum of a-aminoacrylic acid has been shown to have a maximum at 241 nm. This result could be explained if it is assumed that a nucleophilic attack (jS-elimination) of the alkoxide moiety (sugar residue) of Fraction B occurred to give a dehydro derivative (Fig. 4). The fact that glucose is released by alkaline treatment sug-... 

The formation of these compounds is based on the following reactions 1,2-elimination in the case of hydroxy amino acids and thio amino acids results in 2-amino-acrylic acid (dehydroalanine) or 2-aminocrotonic acid (dehydro-aminobutyric acid) ... 

Patchornik, A., and M. Sokolovsky Oxidative Cleavage of Dehydroalanine (a-Amino-Acrylic Acid) Peptides. Bull. Research Council of Israel, Proc. 30th Meeting of the Israel Chem. Soc. 11 A, 80 (1962). 

Acrylic acid, N-acetyl-a-amino Acrylic acid 0.49 1.41 661... 

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