• Biomolecules & Therapeutics
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• v.16 no.2
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• pp.106-112
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• 2008

The effects of harman and norharman on dopamine content and L-DOPA-induced cytotoxicity were investigated in PC12 cells. Harman and norharman decreased the intracellular dopamine content for 24 h. The $IC_{50}$ values of harman and norharman were 20.4 ${\mu}M$ and 95.8 ${\mu}M$, respectively. Tyrosine hydroxylase (TH) activity and TH mRNA levels were also decreased by 20 ${\mu}M$ harman and 100 ${\mu}M$ norharman. Under the same conditions, the intracellular cyclic AMP levels were decreased by harman and norharman. In addition, harman and norharman at concentrations higher than 80 ${\mu}M$ and 150 ${\mu}M$ caused cytotoxicity at 24 h in PC12 cells. Non-cytotoxic ranges of 10-30 ${\mu}M$ harman and 50-150 ${\mu}M$ norharman inhibited L-DOPA (20-50 ${\mu}M$)-induced increases of dopamine content at 24 h. Harman at 20-150 ${\mu}M$ and norharman at 100-300 ${\mu}M$ also enhanced LDOPA (20-100 ${\mu}M$)-induced cytotoxicity at 24 h. These results suggest that harman and norharman decrease dopamine content by reducing TH activity and aggravate L-DOPA-induced cytotoxicity in PC12 cells.

• Journal of Microbiology and Biotechnology
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• v.25 no.2
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• pp.174-177
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• 2015

A potent α-glucosidase inhibitor (compound I) was isolated from coffee brews by activity-based fractionation and identified as a β-carboline alkaloid norharman (9H-pyrido[3.4-b]indole) on the basis of mass spectroscopy and nuclear magnetic resonance spectra (¹H NMR, ¹³C NMR, and COSY). The norharman showed potent inhibition against α-glucosidase enzyme in a concentration-dependent manner, with an IC₅₀ value of 0.27 mM for maltase and 0.41 mM for sucrase. A Lineweaver-Burk plot revealed that norharman inhibited α-glucosidase enzyme uncompetitively, with a K_i value of 0.13 mM.

• Journal of Photoscience
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• v.12 no.3
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• pp.143-147
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• 2005

The simultaneous determination of harman, harmaline and norharman has been described using synchronous fluorescence technique. The method has been based on their natural fluorescence. It is difficult to analyze and determine their contents by conventional fluorescence method because of their similar molecular structures. The synchronous spectrum, maintaining a constant wavelength difference of ${\Delta}{\lambda}=185nm$ between the excitation and emission monochromators, was selected as optimum to perform the determination. The method was also performed in aqueous medium at pH 4.0 and in presence of sodium dodecyl sulfate (SDS), $1{\times}10^{-5}M$. Under the optimum conditions, each analyte has the linear determination range of $1{\times}10^{-7}M-\;1{\times}10^{-4}M$.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.85.2-85.2
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• 2003

In vivo aromatic ${\beta}$-carbolines, such as harman and norharman, may easily be formed by cyclization of indoleamines with e.g. aldehydes. Because of the structural similarity to MPTP, ${\beta}$-carbolines have been proposed as endogenous toxins. In this study, we have investigated the effects of harman and norharman on dopamine biosynthesis and L-DOPA-induced cytotoxicity in PC12 cells. Treatment of PC12 cells with harman and norharman showed 48.8% and 49.5% inhibition of dopamine content at a concentration of 20 ${\mu}$M and 100 ${\mu}$M for 48h. (omitted)

• Archives of Pharmacal Research
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• v.11 no.1
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• pp.52-55
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• 1988

From the ether soluble alkaloidal fraction of Panax ginseng, 4-methyl-5-thiazoleethanol, norharman and barman were isolated. 4-Methyl-5-thiazoleethanol was isolated for the first time from natural resources.

• Archives of Pharmacal Research
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• v.15 no.3
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• pp.220-223
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• 1992

The methanolic extract of Commelina communis (aerial part) showed antibacterial activity against a cariogenic bacterium, Streptococcus mutans OMZ 176. The active principles were identified to be $\beta$-carboline alkaloids, 1-carbomethoxy-$\beta$-carboline, norharman and harman, which were bactericidal in the minimal inhibitory concentration (MIC) of $100\;\mu{g/ml}$ against the strain.

• YAKHAK HOEJI
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• v.34 no.1
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• pp.34-39
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• 1990

The alkaloidal constituents of Commelina communis(Commelinaceae) were investigated. From the ether soluble alkaloidal fraction, three ${\beta}-carboline$ type alkaloids were isolated by chromatographic purification process. Their chemical structures were identified as $1-carbomethoxy-{\beta}-carboline$, norharman and harman from the physicochemical data, which were newly isolated from this plant.

• Archives of Pharmacal Research
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• v.8 no.4
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• pp.243-247
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• 1985

A new $\beta$-carboline alkaloid, 1-carbobutoxy-$\beta$-carboline as well as $N_{9}$ -formylharman, 1-carboethoxy-$\beta$-carboline, 1-carbomethoxy-$\beta$- carboline, perloyrine, harman and norharman were isolated from the rhizoma of Polygala tenuifolia Willdenow. The structures were elucidated on the basis of spectroscopic studies and chemical evidence.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.719-725
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• 2009

Heterocyclic aromatic amines (HCAs) are potent mutagens and possible human carcinogens that are formed during the heating of protein-rich foods. The effects of preheating treatment of beef patties using a microwave prior to frying at $220^{\circ}C$ for 10 min on each side on the reduction of HCAs (amino-carbolines and amino-imidazo-azaarenes) were evaluated. The amount of HCAs was then evaluated by solid-phase extraction and high pressure liquid chromatography (HPLC) analysis. The beef patties were treated by microwaving for various times (0, 1, 1.5, 2, or 3 min) before pan-frying. The results revealed the presence of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 3-amino-1,4-dimethyl-5H-pyrido-[4,3-b] indole (Trp-P-1), 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2), 9H-pyrido[3,4-b]indole (Norharman), 1-methyl-9H-pyrido[3,4-b]indole (Harman), 2-amino-9H-pyrido[2,3-b] indole ($A{\alpha}C$), 2-amino-3,8 dimethylimidazo[4,5-f]-quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP) in all samples. However, microwave pretreatment for 1 min inhibited the formation of these HCAs by up to 90% when compared to the control.

• YAKHAK HOEJI
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• v.30 no.1
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• pp.1-7
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• 1986

The alkaloid components in the root of Codonopsis lanceolata were studied. From the ether soluble alkaloid fraction, four $\beta$-carboline alkaloids were isolated in crystalline state by chromatographic purification process; comp. I mp $178^{\circ}$, isolated yield 4.5$\times$$10^{-5}%$, comp. II mp $166^{\circ}$, 6.0$\times$$10^{-5}%$, comp. III mp $164^{\circ}$, 1.8$\times$$10^{-4}%$ and comp. IV mp $197^{\circ}$, 3.5$\times$$10^{-5}%$. They were identified by spectral analysis and by total synthesis as being a new component $N_9$-formylharman, and already known components in other plant 1-carbomethoxy-$\beta$-carboline, perlolyrine and norharman.