Several 5-substituted nb-methoxycarbonyl-L- and -D-tryptophan derivatives were synthesized from proline by a new route involving electrochemical oxidation, as well as by the known procedures.Removal of the Nb-methoxycarbonyl group was accomplished by treatment with Me3SiI in refluxing chloroform, then alkaline hydrolysis of the methyl esters afforded 5-substituted L- and D-tryptophans with high optical purities.Keywords - L-tryptophan 5-substituted; D-tryptophan 5-substituted; anodic oxidation; N-methoxycarbonyl group deprotection; Fischer indole synthesis; iodotrimethylsilane
One-Electron Redox Potentials of Phenols. Hydroxy- and Aminophenols and Related Compounds of Biological Interest
The rate constants for reversible electron transfer between a series of substituted phenolate ions and anilines and various substituted phenoxyl or anilino radicals in aqueous solution were measured by observing the formation or depletion of the radicals involved.Nonequilibrium concentrations of the radicals were produced in the presence of the corresponding phenols or anilines by using the pulse radiolysis technique.The relaxation of the system to equilibrium was monitored by optical detection methods.From the equilibrium constants for one-electron transfer, the one-electron redox potentials (E2) for 38 phenolic or anilino type compounds were determined, many of which are natural products.The redox potentials are strongly influenced by electron-donating or -withdrawing substituents at the aromatic system.
Steenken, S.,Neta, P.
p. 3661 - 3667
(2007/10/02)
5-HYDROXYTRYPTOPHAN AND SOLUBLE PIGMENT FORMATION IN CLAVICEPS SP. PRL 1980
5-Hydroxytryptophan (156 mg/l) was identified in 15-day-old cultures of Claviceps sp.PRL 1980. DL-Tryptophan and 5-hydroxytryptophan were incorporated into the brown pigment in cultures of the same fungus, 6percent and 24percent, respectively.Key Word Index - Claviceps sp.PRL 1980; Clavicipitaceae; ergot; 5-hydroxytryptophan; pigment; biosynthesis.
Cho, Sung-Hwan,Anderson, John A.
p. 1975 - 1976
(2007/10/02)
α-Alkyl(or aryl)thio-5-hydroxytryptophan derivative and the preparation process thereof
As a novel compound, an α-alkyl(or aryl)thio-5-hydroxytryptophan derivative and the preparation process thereof are disclosed. Said novel compound is readily convertible to 5-hydroxytryptophan having a versatile utilization.
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(2008/06/13)
Preparation of 5 hydroxytryptophan by microbiologic hydroxylation of L tryptophan
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Daum,Kieslich
p. 167 - 168
(2007/10/04)
Indoles for comparison with Amanita toxins. VI. Hydroxylation of tryptophan and tryptophyl peptides