• Microbiology and Biotechnology Letters
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• v.21 no.2
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• pp.139-143
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• 1993

Three isoflavonoids having tyrosinase-inhibiting activity were isolated from the culture filtrate of Streptomyces sp. 20747. Their structures were determined by UV, EI-MS, 1H-NMR, 13C-NMR to be daidzein, daidzein 7-rhamnoside, and genistein 7-rhamnoside, which were competitive with substrate and had IC50 value of 14, 19, and 16 ng/ml, respectively to mushroom tyrosinase and did not inhibit melanin production of Streptomyces bikiniensis. Soybean meal as well as peptone were found to be a good nitrogen source for tyrosinase-inhibiting isoflavonoids production, susgesting that soybean meal is not the origin of tyrosinase inhibiting isoflavonoids formation in Streptomyces sp. 20747 strain.

• Advances in Traditional Medicine
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• v.6 no.2
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• pp.69-78
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• 2006

The isoflavonoids comprise a group of phyto-oestrogens that have useful biological activities including oestrogenic, antioxidant and anticancer. As dietary components for humans, they are bioavailable from leguminous vegetables (such as genistein from soybean), and have been well-documented to have numerous health benefits. A wide range of epidemiological studies in humans and limited studies in animals have identified isoflavonoids as potential chemopreventive agents against hormone-dependent cancers. Therefore, an attempt has been made through this review to summarise the information in the mechanisms aspect of isoflavonoid phyto-oestrogens in inhibiting cancer in vitro and in vivo in the models of human cancers.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.444-449
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• 1997

Five flavonoids were isolated from the heartwoods of Maackia fauriei. On the basis of spectroscopic evidences, the structure of these compounds were established as (-)maa ckiain(3-hydroxy-8,9-methylenedioxypterocarpan), ononin(4'-methoxyisoflavone- 7-O-${\beta}$-D-glucoside), wistin(4',6-dimethoxyisoflavone-7-O-${\beta}$-D-glucoside), daidzin(4'-hydroxyisoflavone-7-O-${\beta}$-D-glucoside) and 2'-methoxy-4'- hydroxyisoflavone-6-O-${\beta}$-D-glucoside. In these compounds, 2'-methoxy-4'-hydroxyisoflavone-6-O-${\beta}$-D-glucoside was for the first time isolated from the plant source.

• Journal of the Korean Wood Science and Technology
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• v.31 no.3
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• pp.70-76
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• 2003

Five isoflavonoids, biochanin A-7-O-β-D-xylopyranosyl-(1⟶6)-β-D-gluco- pyranoside (1), (-)-maackiain (2), calycosin (3), trifolirhizin (4) and genistein (5), were tested for antifungal activity against nine fungi. These compounds were isolated from the wood (compound 1 and 2) and from the bark (compound 3, 4 and 5) of S. japonica. According to the results of antifungal activity test, (-)-maackiain was evaluated as the best antifungal compound among the isolated compounds. In this regard, it could be mentioned that high antifungal activity of S. japonica wood extracts was originated from (-)-maackiain.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.351-355
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• 1999

In order to find anti-dementia drugs from natural products, prolyl endopeptidase inhibitors were purified from Puerariae Flos by consecutive solvent partition, followed by silica gel, Sephadex LH-20, and HPLC. Four isoflavonoid inhibitors were isolated and identified as tectorigenin, genistein, 5,7-dihydroxy-4',6-dimethoxyisoflavone, and 5-hydroxy-6,7,4'-trimethoxyisoflavone by means of instrumental analyses including $^{1}H-$, $^{13}C-$, $^{2}D-NMR$ and MS and $IC_{50}$ values against PEP were 5.30 ppm$(17.7\;{\mu}M)$, 10.39 ppm$(38.5\;{\mu}M)$, 13.92 ppm$(44.3\;{\mu}M)$, and 20.61 ppm$(62.8\;{\mu}M)$, respectively. Some previous mistakes in $^{13}C-NMR$ assignment were revised by careful investigation of HMBC and HMQC data.

• Journal of Life Science
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• v.21 no.11
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• pp.1549-1557
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• 2011

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can selectively induce apoptosis in many types of transformed cells; however, some human hepatocellular carcinoma cells are particularly resistant to the effects of TRAIL. Although genistein, a natural isoflavonoid phytoestrogen, has been shown to have pro-apoptotic activity against human cancer cell lines, little is known about the mechanism of genistein in terms of TRAIL-induced apoptosis. In the present study, it was investigated whether or not combined treatment with genistein and TRAIL synergistically induced apoptosis in Hep3B hepatocarcinoma cells. Results indicate that treatment with TRAIL in combination with nontoxic concentrations of genistein sensitized TRAIL-resistant Hep3B cells to TRAIL-induced apoptosis, which was associated with mitochondrial dysfunction. Further, the inhibition of p38 mitogen-activated protein kinase (MAPK) activation markedly decreased genistein and TRAIL-induced cell viability and apoptosis by enhanced truncation of Bid, increase of pro-apoptotic Bax, decrease of anti-apoptotic Bcl-2, and release of cytochrome c from mitochondria to cytoplasm. Activation of caspases and degradation of poly (ADP-ribose) polymerase induced by the combined treatment was also markedly increased by the inhibition of p38 MAPK, through the mitochondrial amplification step. In conclusion, our data suggest that genistein sensitizes TRAIL-induced-apoptosis via p38 MAPK-dependent pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1201-1207
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• 2011

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been proposed as a potent tool to trigger apoptosis in cancer therapy. However, as many types of cancer cells remain resistant towards TRAIL-induced cytotoxicity, several combined therapy approaches aimed to sensitize cells to TRAIL have been developed. Genistein, a natural isoflavonoid phytoestrogen, has been shown to have anticancer activity by inducing cell cycle arrest at G2M phase as well as apoptosis in various cancer cell lines. In the present study, we showed that treatment with TRAIL in combination with subtoxic concentrations of genistein sensitized U937 human leukemia cells to TRAIL-mediated apoptosis. Combined treatment with genistein and TRAIL effectively activated caspases through Bid truncation (tBid) and down-regulation of cellular caspase-8 (FLICE)-like inhibitory proteinL ($cFLIP_L$). However, the apoptotic effects of co-treatment with genistein and TRAIL were significantly inhibited by specific caspase inhibitors, which demonstrates the important role of caspases in apoptosis induced by genistein and TRAIL. Overall, our results indicate that genistein can potentiate TRAIL-induced apoptosis through down-regulation of $cFLIP_L$ and up-regulation of pro-apoptotic tBid proteins.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.326-332
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• 2010

Daidzein, a natural isoflavonoid phytoestrogen, structurally resembles estradiol (E2) and possesses estrogenic activity. This study was designed to test the hypothesis that daidzein may mimic the effects of E2 on ovine follicle development by regulation of the mRNA expression of bone morphogenetic protein receptor genes and thereby influence the reproductive system. Granulosa cells were cultured in serum-free McCoy's 5A medium with and without supplementation of daidzein. Results showed that daidzein (10-100 ng/ml) significantly increased the proliferation of ovine granulosa cells (p<0.05), but inhibited the growth of granulosa cells at a dose of 1,000 ng/ml (p<0.01). Daidzein inhibited progesterone production in a dose dependent manner; however, it did not affect estradiol production by granulosa cells. We also investigated the effects of daidzein on BMPRII, BMPRIB and ALK-5 mRNA expression in ovine granulosa cells by quantitative real-time PCR. Treatment of granulosa cells with daidzein increased significantly expression of these genes at 10-100 ng/ml. Thus, these data suggested that a low concentration of daidzein (10-100 ng/ml) had a direct stimulatory effect on ovine granulosa cells while a high concentration was toxic.

• YAKHAK HOEJI
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• v.50 no.1
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• pp.15-20
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• 2006

Puerarin and daidzin have been isolated from Puerariae thunbergiana Benth. Structures were determined by spectroscopic methods. Compounds showed weak antimicrobial activity against S. mutans, S. epidermidis, S. aureus, and C. albicans (MIC, $800{\mu}g/ml$). However, these compounds were not antioxidative. Puerariae thunbergiana Benth. extracts against microorganisms were evaluated in terms of the minimum inhibitory concentrations (MIC). In general, C. albicans was stronger antimicrobial activity than the other microorganisms. The antioxidative activity of was observed in the etyl acetate extract ($IC_{50},\;119.87{\pm}0.16\;{\mu}g/ml$). The DPPH radical scavenging effect ($IC_{50},\;1,673.3{\pm}0.54\;{\mu}M$) of the puerarin was comparable with that of synthetic antioxidant, BHA $(IC_{50},\;88.39{\pm}1.1){\times}10^{3}{\mu}M$. These results suggest that puerarin and daidzin have a potential antimicrobial activity.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.643-647
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• 2004

Natural antimicrobial substance from peanut (Arachis hypogaea) shells was isolated and structurally elucidated. Peanut shells were extracted with methanol (MeOH) and concentrated in vacuo, MeOH extract was solvent-fractionated with ethyl acetate (EtOAc) and various buffer to obtain EtOAc acidic, neutral, and phenolic fractions. EtOAc neutral fraction, which showed antimicrobial activity, was purified through silica gel adsorption column, Sephadex LH-20 column, ODS column, and high performance liquid chromatographies, and its active substance was isolated and identified as pratensein (3',5,7-trihydroxy-4'-methoxyisoflavone) by spectroscopic methods of proton-nuclear magnetic resonance, mass spectrometry, and nuclear overhauser enhancement spectroscopy.