Estrogenic and anticarcinogenic properties of kurarinone, a lavandulyl flavanone from the roots of Sophora flavescens
ABSTRACT Kurarinone, a lavandulyl flavanone, was isolated from a polyphenolic extract of the roots of Sophora flavescens using fractionation guided by estrogenic activity, which was determined by recombinant yeast and Ishikawa Var-I bioassays. Kurarinone showed weak estrogenic activity both in the yeast screen and in the Ishikawa Var-I assay with EC(50) values of 4.6 and 1.66 microM, respectively. Furthermore, kurarinone was found to have potent cytotoxic activity (IC(50) value = 22.2 microM) against human MCF-7/6 breast cancer cells in the sulforhodamine-B assay.
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- "In particular, prenylated flavonoids in higher plants protect them by exhibiting strong antibacterial and antifungal activities (Sohn et al., 2004). Many prenylated flavonoids have been identified as active components in medicinal plants with biological activities, such as anticancer, anti-androgen, anti-leishmania, and anti-nitric oxide production (De Naeyer et al., 2004; Ahmed-Belkacem et al., 2005; Han et al., 2006). Due to the beneficial effects for human health, prenylated flavonoids are of particular interest as lead compounds for producing new drugs and functional foods. "
ABSTRACT: Prenylated flavonoids are natural compounds that often represent the active components in various medicinal plants and exhibit beneficial effects on human health. Prenylated flavonoids are hybrid products composed of a flavonoid core mainly attached to either 5-carbon (dimethylallyl) or 10-carbon (geranyl) prenyl groups derived from isoprenoid (terpenoid) metabolism, and the prenyl groups are crucial for their biological activity. Prenylation reactions in vivo are crucial coupling processes of two major metabolic pathways, the shikimate-acetate and isoprenoid pathways, in which these reactions are also known as a rate-limiting step. However, none of the genes responsible for the prenylation of flavonoids has been identified despite more than 30 years of research in this field. We have isolated a prenyltransferase gene from Sophora flavescens, SfN8DT-1, responsible for the prenylation of the flavonoid naringenin at the 8-position, which is specific for flavanones and dimethylallyl diphosphate as substrates. Phylogenetic analysis shows that SfN8DT-1 has the same evolutionary origin as prenyltransferases for vitamin E and plastoquinone. The gene expression of SfN8DT-1 is strictly limited to the root bark where prenylated flavonoids are solely accumulated in planta. The ectopic expression of SfN8DT-1 in Arabidopsis thaliana resulted in the formation of prenylated apigenin, quercetin, and kaempferol, as well as 8-prenylnaringenin. SfN8DT-1 represents the first flavonoid-specific prenyltransferase identified in plants and paves the way for the identification and characterization of further genes responsible for the production of this large and important class of secondary metabolites.Plant physiology 04/2008; 146(3):1075-84. DOI:10.1104/pp.107.110544 · 7.39 Impact Factor
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ABSTRACT: 7,9,2′,4′-Tetrahydroxy-8-isopentenyl-5-methoxychalcone (THIPMC), isolated from the roots of Sophora flavescens Ait., was found to be active against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), either alone or in combination with ampicillin (AM) or gentamicin (GM), vis checkerboard assay. Minimum inhibitory concentrations ranged from 1 to 8 μg/mL for THIPMC, from 128 to 1024 μg/mL for AM, and from 128 to 512 μg/ mL for GM, respectively. The combinations of THIPMC plus AM or GM yielded a fractional inhibitory concentration index ranging from 0.188 to 0.375 μg/mL, thereby indicating a synergistic effect. These findings suggest that THIPMC alone or in combination with antibiotics against MRSA might be useful for controlling MRSA infections. However, VRE infection was only effectively treated by THIPMC alone.Journal of the Korean Society for Applied Biological Chemistry 53(3). DOI:10.3839/jksabc.2010.045 · 0.54 Impact Factor
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ABSTRACT: In this paper we present Myanmar character identification of handwriting between exhibits and specimen of Myanmar handwriting documents. This is also a method to identify the writer of Myanmar handwriting documents. Many methods have been reported for handwriting-based writer identification. Most such techniques assume that the written text is fixed. There are many methods for writer identification. In our method, we take the handwriting as an image containing some special individual character features, and writer identification is regarded as individual character identification. We apply the fast Fourier transform (FFT) method to extract features for one character. In individual character, there are character features mingled with noises. We use median filter algorithm to remove noises in this individual character features. All features were appropriately binarized so that binary feature vectors of constant lengths could be fanned. We also evaluate a weighted euclidean distance (WED) to compare training character features for fulfil identification task. The result of this paper will confirm whether the handwriting of the specimen is the true writer of the exhibit. The current application domain of the framework is writer identification and handwriting examination as frequently used in crime investigation and prosecution. The method is tested on 40 writers and proves to give interesting result. The identification correct rate is 97.5% in our experimentsInformation and Telecommunication Technologies, 2005. APSITT 2005 Proceedings. 6th Asia-Pacific Symposium on; 12/2005