Other Indole Derivatives

Crystal stmcture data are available for an indole—trinitroben2ene complex (2) and for the lithium and sodium salts in the presence of polyamine Ligands (3). The crystal stmcture of indole itself is evidendy disordered (4). Table 1 gives the and C-nmr assignments in CDCl (5). C-nmr assignments have been tabulated for many other indole derivatives (6). 

At the present time we have not attempted to isolate a-thioisatin, the presumed intermediate in the synthesis of indigo. However, it is immediately apparent that if this intermediate could be isolated or intercepted in situ, then many possibilities would open up for the conversion of this compound directly into other indole derivatives. It is also apparent that it should be possible to carry out the reaction with substituted thioureas. We shall be exploring these possibilities. 

AM1241 (360) exhibited high affinity and selectivity for CB2 [it (CBi) = 280 nM, (CB2) = 3.4 nM]. (360) Dose dependently inhibited experimental neuropathic pain in a spinal nerve ligation-induced tactile and thermal hypersensitivity model [224]. Other indole derivatives bearing sulfonamide moieties on the side chain, such as compound (361), were disclosed [225]. Though 67 derivatives including pyridyl and other heteroaromatics instead of the indole core were listed, no specific biological data were shown. 

A number of other indole derivatives have also been observed to yield CL subsequent to oxidation. Among these is skatole (3-methylindole), which emits light after oxidation by 02 under strongly alkaline conditions [9],... 

Seven groups of these drugs can be separated based on their various chemical f structures (a) lysergic acid derivatives, of which lysergide (LSD) is the prototype (b) phenylethylamine derivatives, of which 3,4,5-trihydroxyphenylethylamine (mescaline) is the prototype (c) indolealkylamines, such as 4-phosphorodi-methyltryptamine (psilocybin) (d) other indolic derivatives, such as the harmine... 

In common with other indole derivatives, reserpine is susceptible to decomposition by light and oxidation, so it must be stabilized. Modifying the trimethoxyphenyl portion of the molecule gives other antihypertensive drugs with various potency and rapidity of action. 

A product has also been isolated from 2-meikyl indole (methylketole) as a pale yellow precipitate, resembling the other indole derivatives. Treatment of its aqueous suspension with hydrogen sulphide immediately gives black mercuric sulphide ... 

G. A. Russell, C. L. Myers, P. Bruni, F. A. Neugebauer, and R. Blankespoor, Semidiones. X. Semidione radical anions derived from indan-2.3-dione, coumaran-2.3-dione, thianaphthalenequi-none, isatin, and IV-hydroxy isatin. Nitroxide radicals derived from isatin, dioxindole, oxindole, and other indole derivatives, /. Am. Chem. Soc. 92, 2762-2768 (1970). 

The recently detected FADH2-dependent halogenases are substrate specific. Tryptophan 7-halogenase catalyzes the chlorination and bromination of d- and L-trypto-phan to 7-chloro- or 7-bromotryptophan, respectively1201. This enzyme also accepts a number of other indole derivatives such as tryptamine, indole-3-acetonitrile, 3-me-thylindole and 5-methylindole as substrates (Fig. 16.9-3a) 43L In addition to indoles, aminophenylpyrrole derivatives are also chlorinated by tryptophan 7-halogenase (Fig. 16.9-3b) 43L... 

Incapacitation produced by less likely candidates such as LSD and other indole derivatives, psychedelic phenethylamines, and potent opioids is theoretically possible, but it is unlikely that any of these compounds would be employed militarily. Covert use, which is logistically easier to accomplish and has fewer constraints, opens a broader spectrum of possibilities. This, however, is a concept that involves considerations that generally extend beyond the scope of chemical warfare. 

Circumstantial evidence for rigid control of the tryptophan synthesis is found in the relatively small pool sizes (1-10 /iim) of free tryptophan in all plant sources examined, an observation which is especially noteworthy in view of the accepted role of tryptophan as a precursor of indole acetic acid and other indole derivatives. Since repression of synthesis of key pathway enzymes apparently does not occur in the presence of high levels of tryptophan in tobacco, rice, carrot, and tomato cell cultures (Widholm, 1972b Chu and Widholm, 1972) control would most likely occur by end product feedback inhibition. 

Shaaban, M., Maskey, R.P., Wagner-Dobler, L, and Laatsch, H. (2002) Pharadne, a natural p-cyclophane and other indole derivatives from Cytophi a sp. strain AM13.1./. Nat. Prod., 65,1660-1663. 

Indol-3yl-acetic acid (lAA) also in dolylacetonitrile, indole aldehyde and other indole derivatives, some of which have still to he chemically characterised. 

Conversion of tryptophan or other indole derivatives into a nitro-samine by treatment with nitrous acid followed by diazotization with N-l-naphthylethylene diamine dihydrochloride has been recently studied by Goswami (752). The method seems to be sensitive and to follow Beer s law over of wide range of concentrations of tryptophan. Selective nitrosation of tryptophan is achieved at room temperature in 1 M HCl and diazotization at 10° C or below. Sodium chloride was found to interfere with the assay. The temperature must be controlled with care, since the diazotization reaction is exothermic and diazonium compounds are stable only at low temperatures. This fact would explain the optimum temperature of 10 or 6° C in the diazotization reaction. 

A sensitive spectrophotometric method for the determination of free or bound tryptophan has been proposed by Messineo and Musarra 258). The method utilizes the reaction of fructose with cysteine in sulfuric acid to give a green chromophore (A, max 415 nm), which upon the addition of tryptophan or other indole derivative forms a pink chromophore (A max 518 nm). Once the pink chromophore is formed, it is stable for more than 24 hours. The exact nature of the reactions involved is not known. The method offer advantages, since it does not require previous hydrolysis of the protein, and is simple and quite sensitive. 

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