Norharman products

Rodgman also discussed the already identified and other possible theoretical relationships (Figure XVII.F-5) between tryptophan XX and 9//-pyrido[3,4-( ]indole (norharman) II its methyl homolog l-methyl-9//-pyrido[3,4-fc]indole (harman) III and other substituted norharmans VI, R = C2H5, CH3CH=CH, and -C4H9, the tryptophan pyrolysis products 3-amino-1,4-dimethyl-5/7-pyrido-[4,3-( Jindole (Trp-P-1) IV and 3-amino-l-methyl-5//-pyrido[4,3-( ] indole (Trp-P-2) V the alkyl- and dialkyl-indoles indole-... 

Wakeham (4103) noted the reported presence of 97/-pyrido[3,4-/>]indole (norharman) and l-methyl-9//-pyrido[3,4-b]indole (barman) in cigarette smoke and discussed their formation from a reaction product of tryptophan and an aldehyde. As noted by Rodgman (3253a), the structure of the aldehyde reacting with tryptophan ultimately dictates the structure of alkylated norharmans found (see Table XVII.F-6) in CSC. 

Detection of comutagenic compounds, harman and norharman, in pyrolysis products of proteins and food by gas chromatography-mass spectrometry Proc. 37th Ann. Mtg., Japan Cancer Assoc. (1978) 21. 

The comutagenic action of Norharman upon aryl hydrocarbon hydroxylase activity is shown to be cytochrome P-448 dependent by immunochemical analysis. The hydroxylated products of Norharman and Harman may play an important role in their comutagenic action by fluidizing the microsomal or nuclear membranes. 

The confusion on the mechanism of the comutagenesis and mutagenesis of these pyrolysis products, especially pertaining to the enhancement and inhibition effects of Harman and Norharman,centers around the problem of the lack of certain fixed variables in the experimentation, particularly, the availability of the purified enzymes involved in the metabolic activation, which constitute the cytochrome P-450 mixed function oxidase system. We, therefore, undertake this problem to elucidate the mechanism of microsomal metabolism of these oyrolysis products with the purified mixed function oxidase(MFO) system. 

Microsomal Metabolism of Norharman Crude 3-MC microsomes metabolized norharman in vitro, as shown in Figure 4. The major metabolites of norharman were eluted at earlier retention times than the parent compound. They could be some hydroxylated products as they showed more polar potential in the reverse-phase chromatography. 

The alternative explanation must involve the MFO system. The possible mechanism for the inhibitory effect or enhancement effect of Norharman upon covalent DNA binding and mutagenicity must be the results of the net balancing of substrate inhibition and membrane fluidization of the microsomal membrane or of the lipid vesicles in the reconstituted MFO system. A schematic pathway of the metabolism of these tryptophan pyrolysis products is postulated as shown in Figure 8. 

Feeding early precursors as secologanin, tryptophan and tryptamine did not improve the alkaloid production in our cell suspension cultures. Tryptophan even proved to be highly toxic to the cells. Tryptophan was converted in the presence of the cells, among others into norharman. This blue fluorescent product was also found to be formed from tryptophan dissolved in medium without cells upon sterilization (34,35). 

HCAs are primarily found in the crust of cooked meat and fish with minor amounts left in the inner parts of fried meat [28]. In the few studies where co-mutagens harman and norharman have been analyzed, these p-carbolines have been found in the highest range [15,67]. Usually, PhIP is the most abundant HCA, detected in amounts of up to almost 500 ng/g. PhIP seems to form more easily in chicken (up to 40 ng/g) than in beef, pork, fish, or offal products during cooking, while the amount of, for example, MelQx is generally lower in cooked chicken than in cooked beef and pork... 

Human P450 lAl activates aminomethyl-phenylnorharman, a fusion product of norharman [260], but not as weU as P450 1A2. P450 lAl... 

Leonard and Elderfield have also carried out degradation experiments with alstonine and its tetrahydride. On fusion with potassium hydroxide at 300-350° in nitrogen, alstonine furnishes harman (p. 490) and indefinite basic and acidic fractions. Tetrahydroalstonine on like treatment produces harman, norharman, and three unidentified bases, each of which fluoresces blue in alcoholic hydrochloric acid Base A, m.p. 171-5 to 172-5°, forms a picrate, m.p. > 267° is probably a substituted -carboline. Base B, CieH e or 18 2) gives a picrate, m.p. 261° (dec.). Base C, isolated as the picrate, m.p. 203-5-205-5°. From the acid products of the fusion indole-2-carboxylic acid was isolated. 

Methylthiazolidine-4-carboxylic acid, a condensation product of cysteine and acetaldehyde, occurs even in human blood as a consequence of ethanol consumption. Serine and threonine analogously produce C-2 substituted (2J S,4S)-oxazolidine-4-carboxylic acids (2-124). Heterocyclic products, C-2 substituted (2J S,4S)-pyrimidine-4-carboxylic acids, are also produced in the reaction of aldehydes with asparagine (2-125). Phenylalanine yields C-1 substituted (lJ S,3S)-tetrahydroisoquinoline-3-carboxylic acids (2-126) and analogous products arise from tyrosine. Tryptophan reacts with aldehydes under the formation of 9H-pyrido[3,4-b]indole (also known as -carboline or norharmane) derivatives, (lJ S,3S)-l,2,3,4-tetrahydro-fi-carboline-3-carboxylic acids (2-127, R = H or alkyl or residues of other aldehydes and sugars), the reaction of tryptamine yields the corresponding (lRS)-l,2,3,4-tetrahydro-P-carbolines. 

Decarboxylation and oxidation products of 1,2,3,4-tetrahydro-P-carbohne-3-carboxylic acids derived from formaldehyde, 9H-pyrido(3,4-fo]indole (norharmane, 2-127), and acetaldehyde, 1-methyl-9//-pyrido[3,4-fo]indole (harmane, 2-127), were identified in a number of foods at levels up to 700 mg/kg, although more typically their concentrations in smoked, cooked and fermented foods range from a few mg/kg to 1-2 orders of magnitude less. Typical norharmane and harmane findings in pan-fried, minced meat, beef patties or ground beef prepared at temperatures of 175-230 °C and... 

The roasted root contains a steam-distillable fraction (aroma), which is composed of pyra-zines, benzothiazoles, aldehydes, aromatic hydrocarbons, furans, phenols, organic acids, and others, totaling 3 3 identifiedcompounds, among which acetophenone is a characteristic component of roasted chicory not previously reported as a component of aroma of any heated food products such as coffee. Other constituents of the roasted root include 2-acetylpyrrole, furfural, phenylacetaldehyde, phenylacetic acid, and vanillin. Small amounts oftwo indole alkaloids ((3-carbolines), barman and norharman, have also been isolated from the roasted root. ... 

---