• Natural Product Sciences
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• 제25권1호
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• pp.76-80
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• 2019

Bioactivity-guided fractionation of MeOH extract of the dried fruits of Amomum tsao-ko led to isolation of nine compounds (1 - 9). Their structures were elucidated by spectroscopic methods including extensive 1D and 2D-NMR, as alpinetin (1), naringenin-5-O-methyl ether (2), naringenin (3), hesperetin (4), 2',4',6'-trihydroxy-4-methoxy chalcone (5), tsaokoin (6), boesenbergin B (7), 4-hydroxyboesenbergin B (8), and tsaokoarylone (9). Of these, compound 8 was isolated from a natural source for the first time, which was previously reported as a synthetic product. The isolated compounds (1 - 9) were tested for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Among them, three chalcone derivatives (compounds 5, 7, and 8) and a diarylheptanoid (compound 9) exhibited significant inhibitory activity on the NO production with $IC_{50}$ values ranging from 10.9 to $22.5{\mu}M$.

• Molecules and Cells
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• 제26권4호
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• pp.362-367
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• 2008

We identified a 1,134-bp putative type III polyketide synthase from the sequence analysis of Streptomyces peucetius ATCC 27952, named Sp-RppA, which is characterized as 1,3,6,8-tetrahydroxynaphthalene synthase and shares 33% identity with SCO1206 from S. coelicolor A3(2) and 32% identity with RppA from S. griseus. The 1,3,6,8-tetrahydroxynaphthalene synthase is known to catalyze the sequential decarboxylative condensation, intramolecular cyclization, and aromatization of an oligoketide derived from five units of malonyl-CoA to give 1,3,6,8-tetrahydroxynaphthalene, which spontaneously oxidizes to form 2,5,7-trihydroxy-1,4-naphthoquinone (flaviolin). In this study, we report the in vivo expression and in vitro synthesis of flaviolin from purified gene product (Sp-RppA).

• Archives of Pharmacal Research
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• 제29권6호
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• pp.479-483
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• 2006

Eight compounds were isolated from the fruiting bodies of Ganoderma applanatum, and were identified as 2-methoxyfatty acids (1), 5-dihydroergosterol (2), ergosterol peroxide (3) $3{\beta},7{\beta},20,23{\zeta}-tetrahydroxy-11,15-dioxolanosta-8-en-26-oic$ acid (4), $7{\beta},20,23{\zeta}-trihydroxy-3,11,15-trioxolanosta-8-en-26-oic$ acid (5), cerevisterol (6), $7{\beta},23{\zeta}-dihydroxy-3,11,15-trioxolanosta-8,20E(22)-dien-26-oic$ acid (7), and $7{\beta}-hydroxy-3,11,15,23-tetraoxolanosta-8,20E(22)-dien-26-oic$ acid methyl ester (8) by spectral analysis. All compounds were isolated for the first time from this fruiting bodies, and their effect on rat lens aldose reductase (RLAR) activity was tested. Among these eight compounds, ergosterol peroxide (3) was found to exhibit potent RLAR inhibition, its $IC_{50}$ value being $15.4\;{\mu}g/mL$.

• Archives of Pharmacal Research
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• 제28권5호
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• pp.534-540
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• 2005

Activity-guided fractionation of the CH$_2Cl_2$-soluble fraction of the roots of Sophora flavescens furnished five 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scaveng ers: trans-hexadecyl ferulic acid (1) cis-octadecyl ferulic acid (2), trans-hexadecyl sinapic acid (3), (-)-4-hydroxy-3-methoxy-(6aR,11aR)-8, 9-methylenedioxypterocarpan (4) and desmethylanhydroicaritin (8), along with nine known inactive compounds: (-)-maackiain (5), xanthohumol (6), formononetin (7), (2S)-2'-methoxykurarinone (9), (2S)-3${\beta}$,7,4'-trihydroxy-5-methoxy-8-(${\gamma},{\gamma}$- imethylallyl )-flavanone (10), (2S)-7,4'-dihydroxy-5-methoxy-8- (${\gamma},{\gamma}$-dimethylallyl ) -flavanone (11), umbelliferone (12), kuraridin (13), and trifolirhizin (14). Compounds 1-4 and 8 exhibited DPPH free radical scavenging effects at IC$_{50}$ values of 33.01 ${\pm}$ 0.20, 57.06 ${\pm}$ 0.16, 39.84 ${\pm}$ 0.36, 35.83 ${\pm}$ 0.47, and 18.11 ${\pm}$ 0.04${\mu}$M, respectively. L-Ascorbic acid, when used as a positive control, exhibited an IC$_{50}$ value of 7.39 ${\pm}$ 0.01 ${\mu}$M. Compounds 1-4 and 8 also appeared to exert significant scavenging effects on authentic ONOO-, with IC$_{50}$ values of 5.76 ${\pm}$ 1.19, 15.06 ${\pm}$ 1.64, 8.17 ${\pm}$ 4.97, 1.95 ${\pm}$ 0.29 and 4.06 ${\pm}$ 2.41 ${\mu}$M, respectively. Penicillamine (IC$_{50}$= 2.36 ${\pm}$ 0.79${\mu}$M) was used as a positive control. In addition, compounds 2,4,6,8, and 10 were isolated from this plant for the first time.

• Natural Product Sciences
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• 제14권4호
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• pp.233-238
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• 2008

The aerial parts of Epimedium koreanum Nakai have been used to stimulate hormone secretion in treating impotence. Ten flavonol glycosides, 3,4,5-trihydroxy-8-prenylflavone 7-O-[${\beta}$-D-glucopyranosyl($1{\rightarrow}2$)-${\beta}$-D-glucopyranoside] (1), hyperoside (2), icarisid II (3), 2"-O-Rhamnosylicarisid II (4), epimedin A (5), epimedin B (6), epimedin C (7), icariin (8), hexandraside E (9), and epimedoside A (10) were isolated from the an ethylacetate soluble extracts of the aerial parts of Epimedium koreanum Nakai through activity-monitord fractionation and isolation method. The structures of compounds 1 - 10 were elucidated by high resolution fast atom bombardment mass spectrometry and two dimentional nuclear magnetic resonance spectroscopy analysis. Compounds 1 and 4 showed potent antioxidant activity, with $IC_{50}$ values of 19.7 and 11.5 ${\mu}g$/mL and 88.2 and 90.5 ${\mu}M$, respectively.

• Korean Journal of Pharmacognosy
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• 제39권1호
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• pp.37-42
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• 2008

From the 70% EtOH extract from the roots of Paeonia lactiflora (Paeoniaceae), nine triterpenoids were isolated and identified as ${\beta}-amyrin$ (1), 24-methylenecycloartanol (2), betulinic acid (3), oleanolic acid (4), hederagenin (5), 30-norhederagenin (6), 30-norarjunolic acid (7), arjunolic acid (8), and $3{\beta},4{\beta},23-trihydroxy-24,30-dinorolean-12,20(29)-dien-28-oic$ acid (9) by spectroscopic methods. Among these compounds, 1, 2, 7, 8 and 9 were isolated for the first time from this plant.

• Natural Product Sciences
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• 제14권4호
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• pp.227-232
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• 2008

Phytochemical further investigation of the chloroform extract of the aerial parts of Crucianella maritima L. (Rubiaceae) growing in Egypt resulted in the isolation of a new anthraquinone; 3-formyl-1-hydroxy-2-methoxy anthraquinone (3) along with the four known compounds isolated for the first time from the genus Crucianella; alizarin-1-methyl ether (2), 1,4-dihydroxy-2-methoxy anthraquinone (5), 1, 3, 6-trihydroxy-2-methoxy anthraquinone (7) and the flavonol kaempferol (8), beside four known compounds previously isolated from the same plant. The structures of the isolated compounds were established based on different spectroscopic data including UV, IR, EIMS, 1D and 2D-NMR. Moreover, the antioxidant and antimicrobial activities of the isolated compounds were evaluated.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.3013-3016
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• 2013

Two new isoflavanones, (3R) 7,2',4'-trihydroxy-3'-methoxy-5-methoxycarbonyl-isoflavanone (1) and (3R) 7,2'-dihydroxy-3',4'-dimethoxy-5-methoxycarbonyl-isoflavanone (2), together with six known isoflavanones (3-8), were isolated from the stems of Cassia siamea. The structure of 1-8 was elucidated by spectroscopic methods including extensive 1D- and 2D-NMR techniques. Compounds 1, 2, 5-8 were evaluated for their anti-tobacco mosaic virus (Anti-TMV) activity. The results showed that compounds 1 and 6 showed potential anti-TMV activity with inhibition rates of 24.6% and 26.9%, respectively. Compounds 2, 5, 7, 8 also showed anti-TMV activity with inhibition rates in the range of 11.8-18.6%.

• Food Science and Biotechnology
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• 제16권1호
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• pp.116-122
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• 2007

Four compounds with antioxidant activity were isolated from the MeOH extract of peanut shells (pod) and identified as 5,7-dihydroxychromone (1), eriodictyol (2), 3',4',7-trihydroxyflavanone (3), and luteolin (4) by electron impact-mass spectrometry (EI-MS) and nuclear magnetic resonance (NMR) analyses. The relationship between antioxidant activity and chemical structure of the isolated compounds with their analogues [(-)-epicatechin, quercetin, taxifolin] was examined by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and using the 2-deoxy-D-ribose degradation system. The order of antioxidant activity on the basis of DPPH radical-scavenging was quercetin = (-)-epicatechin (6.0 molecules) > taxifolin (4,5 molecules) > 4 (luteolin; 4.0 molecules) > 2 (eriodictyol; 2.5 molecules) > 3 (3',4',7-trihydroxy-flavanone; 2.0 molecules) > 1 (5,7-dihydroxychromone; 0.5 molecules). On the other hand, using the 2-deoxy-D-ribose degradation system, the order of antioxidant activity was quercetin > 4 >> (-)-epicatechin ${\geq}\;2\;{\geq}$ taxifolin > 3 > 1. These compounds from peanut shells may provide defensive measures against oxidative stress and insects in the soil.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1459-1462
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• 2009

Two new flavone glycosides, giraldiin A and B, together with three known compounds, annulatin, myricetin 3-O-$\alpha$- L-rhamnopyranoside and gallic acid, were isolated from the ethanol extract of the root of Pteroxygonum giraldii Damm. et Diels. The structures of giraldiin A and B are designated as 3'-($\alpha$-L-arabinopyranosyloxy)-4',5,5',7- tetrahydroxy-3-methoxyflavone and 4'-($\beta$-D-glucopyranosyloxy)-5,5',7-trihydroxy-2',3-dimethoxyflavone, respectively, on the basis of detailed spectroscopic analyses. The free radical scavenging activity of giraldiin A was evaluated by decolouring spectrophotometry of pentamethine cyanine dye (Cy5) with $Fe^{2+}-H_2O_2$ Fenton radical generating system. The results indicated the hydroxyl free radical scavenging activity of giraldiin A (E$D_{50}$ = 23.7 nmol/mL) is higher than that of some known antioxidants such as rutin, puerarin, daidzein and 2,6-di-tertbutyl-4-methylphenol.