• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.114-114
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• 2001

Tetrahydropapaveroline (THP), a dopamine-derived 6, 7-dihydroxy-1-(3' ,4'-dihydroxybenzyl)-1,2,3,4-tetrahydroisoquinoline, has been suspected as a possible dopaminergic neurotoxin to elicit Parkinsonism. Autooxidation or enzymatic oxidation of THP and subsequent generation of reactive oxygen species (ROS) may contribute to the degeneration of dopaminergic neurons induced by this isoquinoline alkaloid.(omitted)

• Analytical Science and Technology
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• v.30 no.6
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• pp.379-389
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• 2017

In this study, we set up an analytical method that can be used for rapid and accurate determination of representative isoquinoline alkaloids in medicinal plants using UPLC-ESI-Q-TOF MS (ultra pressure liquid chromatography-electrospray ionization-quadrupole-time-of-flight mass spectrometry). The compounds were eluted on a C18 column with 0.1 % formic acid and acetonitrile, and separated with good resolution within 13 min. Each of the separated components was characterized by precursor ions (generated by ESI-Q-TOF) and fragment ions (produced by collision-induced dissociation, CID), which were used as a reliable database. We also performed method validation: analytes showed excellent linearity ($R^2$, 0.9971-0.9996), LOD (5-25 ng/mL), LOQ (17-82 ng/mL), accuracy (91.6-97.4 %) as well as intra- and inter-day precisions (RSD, 1.8-3.2 %). In the analysis of Chelidonium majus L., magnoflorine, coptisine, sanguinarine, berberine and palmatine were detected by matching retention times and characteristic fragment ion patterns of reference standards. We also confirmed that, among the quantified components, coptisine was present in the highest quantity. Furthermore, alkaloid profiling was carried out by analyzing the fragment ion patterns corresponding to peaks of unknown components. In this manner, protopine, chelidonine, stylopine, dihydroberberine, canadine, and nitidine were tentatively identified. We also proposed the molecular structure of the fragment ions that appear in the mass spectrum. Therefore, we concluded that our suggested method for the determination of major isoquinoline alkaloids by UPLC-Q-TOF can be useful not only for quality control, but also for rapid and accurate investigation of phytochemical constituents of medicinal plants.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.423-426
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• 2005

Two isoquinolines and one quinolone were isolated from the stem bark of Pellodendron amurense Rupr. (Rutaceae). Two isoquinolines were elucidated as thalifoline (2) and pharmacological active berberine (3) has been blocking the release of $Ca^{2+}$ from internal stores. One quinolone was identified as N-methylatanine (1). This is the first report on the isolation of N-methylatanine (1) and thalifoline (2) from this plant.

• Archives of Pharmacal Research
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• v.19 no.4
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• pp.258-260
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• 1996

Palmatine, an protoberberine isoquinoline alkaloid, has been found to inhibit dopamine biosynthesis by reducing tyrosine hydroxylase (TH) activity in PC12 cells (Lee and Kim, 1996). We have therefore investigated the effects of palmatine on bovine adrenal TH. Palmatine showed a mild inhibition on bovine adrenal TH (36.4% inhibition at concentration of $200\muM$). Bovine adrenal TH was inhibited competitively by palmatine with a substrate L-tyrosine. The Ki value was found to be 0.67 mM. This result suggests that the inhibition of TH activity by palmatine may be partially involved in the reduction of dopamine biosynthesis in PC12 cells.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.510-512
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• 1997

The effects of noscapine a phthalide isoquinoline alkaloid, on dopamine biosynthesis and tyrosine hydroxylase (TH) activity in PC12 cells were investigated. Noscapine showed 74.6% inhibition on dopamine content in PC12 cells at a concentration of $20{\mu}M.$ $IC_{50}$ of noscapine was $6.8{\mu}M.$ TH activity was inhibited by the treatment of noscapine in PC12 cells (20.9% inhibition at 20 .mu.M). Therefore, the inhibition of TH activity by noscapine might be involved in at least one component of the reduction of dopamine biosynthesis in PC12 cells.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.350-353
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• 2001

Porcine pneumonia is caused by Pasturella multiocida and Actinobacillus pleuropneumoniae. To identify a potent drug for antipneumonia therapy, several herbal compounds showing antibacterial effects were screened, and it was found that a methanol extract of Coptidis rhizoma root stem exhibited activity against both pneumonia-causing bacteria. Using an activity-guided fragmentation procedure, an isoquinoline alkaloid was isolated which would be responsible for the antibacterial activities against P. multocida and A. pleuropneumoniae.

• YAKHAK HOEJI
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• v.42 no.2
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• pp.170-174
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• 1998

The effects of bulbocapnine, an aporphine isoquinoline alkaloid, on dopamine content in PC12 cells were investigated. Bulbocapnine decreased the dopamine content dose-dependentl y (39.2% inhibition at 2O${\mu}$M for 24 hr). The $IC_{50}$ value of bulbocapnine was 22.7${\mu}$M. Dopamine content was lowered at 6 hr after exposure to bulbocapnine. And then, the decreased dopamine level was almost maintained at 36 hr and recovered to the control level at about 60 hr. Tyrosine hydroxylase, the rate limiting enzyme in the catecholamine blosynthetic pathway, was also inhibited at 20${\mu}$M of bulbocapnine by 23.1% relative to control. We, therefore, hypothesized that the inhibition of tyrosine hydroxylase by bulbocapnine with a single treatment might be partially contributed to the decrease in dopamine content in PC12 cells.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1224-1227
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• 2005

Here we report the cytotoxic activity of three known compounds isolated for the first time from Corydalis pallida (Papaveraceae). An isoquinoline alkaloid, berberine, exhibited cytototoxic activity against two human cancer cell lines, HT-1080 (human fibrosarcoma) and SNU-638 (human stomach adenocarcinoma), with $IC_{50}$ values of 3.2 and 3.4 $\mu$g/mL, respectively. N­trans-feruloyltyramine and N-trans-feruloylmethoxytyramine were also isolated from this plant but were inactive.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.139.1-139.1
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• 2003

The effects of liriodenine, an aporphine isoquinoline alkaloid, on dopamine biosynthesis and L-DOPA-induced neurotoxicity in PC12 cells were investigated. Treatment of PC12 cells with liriodenine at 10 $\mu\textrm{M}$ showed 33.6％ inhibition of dopamine content decreased at 3 h and reached a minimal level at 12 h after the exposure to liriodenine at 10 $\mu\textrm{M}$. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.79.3-80
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• 2003

The effects of anonaine, an aporphine isoquinoline alkaloid, on dopamine biosynthesis and L-DOPA-induced neurotoxicity in PC12 cells were investigated. Treatment of PC12 cells with 0.05 ${\mu}$M anonaine showed a significant inhibition of dopamine content. The IC$\sub$50/ value of anonaine was 0.05 ${\mu}$M. Under the same conditions, 0.05 ${\mu}$M anonaine also inhibited tyrosine hydroxylase (TH) activity at 24 h (62.0% inhibition of the control level). TH mRNA levels were also decreased by the treatment with anonaine. (omitted)