• Natural Product Sciences
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• v.14 no.2
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• pp.143-146
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• 2008

Protein tyrosine phosphatase 1B (PTP1B) is emerging as a potential therapeutic target for the treatment of type-2 diabetes and obesity. To search for new types of PTP1B inhibitors, we have undertaken in vitro enzyme assay for some anthraquinones and stilbenes isolated from plants. Of the anthraquinones tested, physcion (1), 1-O-methylemodin (2), and emodin (3) showed high activities, with $IC_{50}$ values of 7.6, 7.0, and $3.8{\mu}g/mL$, respectively, while the anthraquinone glycosides, physcion-8-O-${\beta}$-D-glucopyranoside (4) and emodin-8- O-${\beta}$-D-glucopyranoside (5), were less active than their aglycones. All the stilbenens (6 - 15) slightly inhibited PTP1B activity at high concentration of $30{\mu}g/mL$. Our findings suggest that the hypoglycemic effect of anthraquinones may be associated with their PTP1B inhibitory activity.

• Natural Product Sciences
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• v.6 no.1
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• pp.40-43
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• 2000

The chemical investigation on the cell suspension culture of Morinda elliptica L. yielded eight anthraquinones, two of which, anthragallol-1,2-dimethyl ether (3) and purpurin-1-methyl ether (4), have not been isolated from the original plant. Other compounds isolated include nordamnacanthal (1), alizarin-1-methyl ether (2), rubiadin (5), soranjidiol (6), $lucidin-{\omega}-methyl$ ether (7), and morindone (8). The structures of anthraquinones were established based on spectral studies.

• Archives of Pharmacal Research
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• v.23 no.4
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• pp.283-287
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• 2000

A series of 2-(1-hydroxyiminoalkyl)-1,4-dimethoxy-9,10-anthraquinones (oximes) was synthesized and evaluated for cytotoxicity against L1210 cells and A549 cells. These oximes showed a greater cytotoxic activity compared to those of 2-(1-hyd roxyalkyl)-1,4-dimethoxy-9,10-anthraquinones as the hydroxyalkyl bioisosteres. The enhanced cytotoxiciy assumed to be due to the improved water solubility of the hydroxyimino group. Moreover, it was found that the cytotoxicity of the oximes decreased with elongation of alkyl groups at the side chain. All of the synthesized compounds showed higher cytotoxicity against L1210 cells than A549 cells.

• Natural Product Sciences
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• v.10 no.2
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• pp.63-68
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• 2004

From the extracts of Crucianella maritima L. (Rubiaceae), five new anthraquinones namely; 1-hydroxy-2-methyl-6-methoxy anthraquinone, 6-methoxy-2-methyl quinizarin, 6-methyl-anthragallol-2,3-dimethyl ether, 6-methyl-anthragallol-2-methyl ether, and 1-hydroxy-2-carbomethoxyanthraquinone were isolated and identified. In addition, deacetyl asperulosidic acid 6'-glucoside sodium salt, a new iridoid diglucoside, along with twelve known anthraquinones, three flavonols, three sterols, and one triterpene were also isolated and identified for the first time from this plant. Their chemical structures were established by physical, chemical and spectroscopic data, including UV, MS, ID- and 2D-NMR analyses. The antimicrobial, cytotoxic activities and a preliminary clinical trial of the crude extracts and some isolates are also presented. Chemotaxonomical aspects are briefly discussed.

• Korean Journal of Pharmacognosy
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• v.42 no.2
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• pp.144-148
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• 2011

Rhubarb (Rhei Rhizoma) has been used for the various clinical purposes such as purgative, stomach protective and pain relief for a long time. However, rhubarb in current market has a problem of quality control under which many of rhubarb fail to meet the standard specified in Korean Pharmacopoeia. This study was carried out to validate the method for the evaluation of the quality of five rhubarbs and Rumex species; Rheum palmatum, R. officinale, R. tanguticum, R. franzenbachii, R. undulatum, and Rumex species. The content of sennoside A with five anthraquinones (aloe-emodin, rhein, emodin, chrysophanol and physcion) in five rhubarbs and one Rumex has been performed by using HPLC quantitation analysis. In results, only four samples in Palmata sect. were qualified with sennoside A and those samples were R. officinale and R. tanguticum. Samples of R. palmatum did not meet the standard contents of sennoside A. The contents of anthraquinones in Palmata sect. were two times larger than those in Rhapontica sect. Moreover the content variations of anthraquinones were smaller than those of sennoside A. Thus, anthraquinones can be the key characterizing molecules to control quality of rhubarb.

• Korean Journal of Medicinal Crop Science
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• v.13 no.2
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• pp.80-84
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• 2005

Five known anthraquinones, physcion (1), I-O-methylemodin (2), emodin (3), $physcion-8-O-{\beta},-D-glucopyranoside$ (5), $emodin-8-O-{\beta},-D-glucopyranoside$ (6) and two known stilbenes, trans-resveratrol (4), $trans-resveratrol-3-O-{\beta},-D-glucopyranoside$ (7) were isolated from MeOH extract of Reynoutria sachalinensis (Polygonaceae). All structures were unambiguously established by 1D and 2D NMR and MS data and the compounds were evaluated for their cytotoxicity against L1210, HL-60, BI6F10 tumor cell lines in MTT assay. Among the compounds, trans-resveratrol (4) exhibited significant cytotoxic activity with $IC_{50}$ values of 9.2, 6.7 and $9.8\;{\mu}g/ml$, against the test cell lines respectively, but compounds 1-3 exhibited the moderate cytotoxic activity.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.12-21
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• 2018

Photorhabdus temperata (PT), a gram-negative bacterium, lives symbiotically within entomopathogenic nematodes. The insecticidal compounds derived from Photorhabdus are used as biopesticides in agriculture. However, the physiological properties are not well characterized. In the course of our screening for neuroprotective and anti-neuroinflammatory substances from natural products, the culture broth of PT showed considerable activities. By activity-guided purification, five anthraquinones, namely, 3-methoxychrysazine (1), 1,3-dimethoxy-8-hydroxy-9,10-anthraquinone (2), 1,3,8-trihydroxy-9,10-anthraquinone (3), 3,8-dihydroxy-1-methoxy-9,10-anthraquinone (4), and 1,3,4-trimethoxy-8-hydroxy-9,10-anthraquinone (5), were isolated from the ethyl acetate fraction of the PT culture broth. Among the isolated compounds, $75{\mu}M$ 3 significantly protected mouse hippocampal neuronal cells (HT22) against 5 mM glutamate-induced cell death via the inhibition of reactive oxygen species production, $Ca^{2+}$ influx, and lipid peroxidation. Additionally, 3 and 4 effectively suppressed the interferon-${\gamma}$-induced neuroinflammation of mouse-derived microglial cells (BV2) at 10 ng/ml, via the reduction of nitric oxide, interleukin-6, and tumor necrosis factor-${\alpha}$. Anthraquinones 3 and 4 derived from the PT culture broth are a potential starting point to discover neuroprotective and anti-neuroinflammatory drug leads. The novel compound 5 is reported for the first time in this study.

• Korean Journal of Oriental Medicine
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• v.13 no.3
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• pp.157-163
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• 2007

Objective: Polygonum multiflorum Thunberg (Polygonaceae) has been traditionally used as a tonic and the purgative in China and Korea. The genus Polygonum is a source of a wide range of phenolic compound, flavanoids, anthraquinones, stilbenes and tannins. In this study, three anthraquinones were isolated and quantitative determination of anthraquinones from P multiflorum has been developed for quality standardization. Methods : Three anthraquinone derivatives were isolated from a methanol extract of the radix of P. multiflorum by the chromatographic separation. Their structures were identified as emodin, physcion and ${\omega}$-hydroxyemodin on the basis of spectral data (MS, lH-NMR, 13C-NMR) and chemical analysis. HPLC analysis was performed to determine the contents of emodin, physcion, chrysophanol, rhein and ${\omega}$-hydroxyemodin in P. multiflorum from different specimens were collected from twenty Korean markets. Results: According to the results, the contents of emodin, physcion, chrysophanol, rhein and ${\omega}$-hydroxyemodin were 0.145%, 0.434%, 0.016%, 0.026%, 0.030% by HPLC, respectively. Conclusions : In these results, we have determined the contents of emodin, physcion, chrysophanol, rhein and ${\omega}$-hydroxyemodin in P. multiflorum, respectively. We hope that this study will contribute to the standardization and quality control of herbal medicine.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.398-403
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• 2020

Rhamnose is a naturally occurring deoxysugar present as a glycogenic component of plant and microbial natural products. A recombinant mutant Escherichia coli strain was developed by overexpressing genes involved in the TDP-ʟ-rhamnose biosynthesis pathway of different bacterial strains and Saccharothrix espanaensis rhamnosyl transferase to conjugate intrinsic cytosolic TDP-ʟ-rhamnose with anthraquinones supplemented exogenously. Among the five anthraquinones (alizarin, emodin, chrysazin, anthrarufin, and quinizarin) tested, quinizarin was biotransformed into a rhamoside derivative with the highest conversion ratio by whole cells of engineered E. coli. The quinizarin glycoside was identified by various chromatographic and spectroscopic analyses. The anti-proliferative property of the newly synthesized rhamnoside, quinizarin-4-O-α-ʟ-rhamnoside, was assayed in various cancer cells.

• Journal of the Korean Chemical Society
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• v.42 no.1
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• pp.64-68
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• 1998

Three anthraquinones, chrysophanol, physcion and 1-o-methyl-2-methoxychrysophanol which have $Na^+,K^+-ATPase$ and cyclic AMP phosphodiesterase lowering activities related to cardiotonic action were isolated from the Korean marine echiura, Urechis unicintus. Spectroscopic methods, including HMQC, HMBC and NOE studies, were used to establish the structures.