1 -Hydroxyindoles, 1 -hydroxytryptophans and 1-hydroxytryptamines

In this review, our recent developments in the chemistry of 1-hydroxyindoles, 1-hydroxytryptophans, and 1-hydroxytryptamines, attained between the beginning of 1999 and the end of May 2001, are summarized together with results obtained... 

Somei, M., Recent Advances in the Chemistry of 1-Hydroxyindoles, 1-Hydroxytryptophans, and 1-Hydroxytryptamines, 82, 101. 

Homolytic substitution of heteroaromatic compounds, 16, 123 Hydantoins, chemistry of, 38, 177 Hydrogen cyanide derivatives, synthesis of heterocycles from, 41, 1 Hydrogen exchange base-catalyzed, 16, 1 one-step (labeling) methods, 15, 137 Hydrogenated porphyrin derivatives hydroporphyrins, 43, 73 Hydroxamic acids, cyclic, 10, 199 1 -Hydroxyindoles, 1 -hydroxytryptophans, and 1-hydroxytryptamines,... 

Somei M (2006) A Frontier in indole chemistry 1-hydroxyindoles, 1-hydroxytryptamines, and 1-hydroxytryptophans. In Topics in heterocyclic chemistry. Springer, Berlin/Heidelberg, pp 77-111... 

Various acids promote the substitution reaction of 1-hydroxyindoles, 1-hy-droxytryptamines, and 1-hydroxytryptophans with nucleophiles. We have demonstrated that pKa of the organic acids has a remarkable effect on the reaction employing 1-hydroxy-Nb-methoxycarbonyltryptamine (52) as a substrate [33]. As can be seen from Table 5, neither propionic nor acetic acids have sufficient acidity for inducing the substitution reaction. They yield a slight quantity of dehydroxylated tryptamine (55) (entries 1-2). As the acidity increases, the yield of 5-hydroxytryptamine (104a), a product of nucleo-... 

As a result, we could open the door to a new frontier in indole chemistry. Various 1-hydroxyindoles (4a), l-hydroxytryptophans(la), 1-hydroxytryptamines (lb), and their derivatives have been given birth for the first time. As predicted, 1-hydroxytryptophan and 1-hydroxytryptamine derivatives are found to undergo previously unknown nucleophilic substitution reactions. In addition, we have been uncovering many interesting reactivities characteristic of 1-hydroxyindole structures. From the synthetic point of view, useful building blocks for indole alkaloids, hither to inaccessible by the well-known electrophilic reactions in indole chemistry, have now become readily available. Many biologically interesting compounds have been prepared as well. 

Taking a concentration of 5-hydroxytryptamine of 0-05 jug/ml in the blood and an excretion of 3-6 mg per day of 5-hydroxyindole acetic acid as a basis, Erspamer estimated that the amount of 5-hydroxytryptamine contained in the total blood volume is metabolized every 2-3 hr. Heissel " found that C-marked serotonin in the thrombocytes of eleven healthy subjects had a half-life of 5-6 days. Sjoerdsma et found a pool of 2800 mg 5-hydroxytryptamine with a half-life of 5 days in a patient with a metastasized carcinoid of the small intestine after intravenous injections of C-marked hydroxytryptophane. Zucker et found a half-life of 1-7-2-8... 

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