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.
"Natural extracts of S. flavescens include a volatile flavonoid component (Kuroyanagi et al. 1999). Previous studies have shown that the major antimicrobial components of S. flavescens are kurarinone, kuraridin, and sophoraflavanone G (De Naeyer et al. 2004; Piao et al. 2006; Han et al. 2007), and antimicrobial activity is related to the quantities of these three major components (Chong et al. 2013). However, this chemical composition can be altered by environmental factors, particularly by temper- ature. "
[Show abstract][Hide abstract] ABSTRACT: Bioaerosols, such as bacterial and fungal cells and their spores, are components of indoor airborne particulate matter and have been associated with human health problems as well as various environmental issues. Natural antimicrobial products have been used in air filters for bioaerosol control. However, natural products may lose some function due to their sensitivity to environmental factors such as temperature and humidity. In this study, we investigated the effects of temperature on antimicrobial fiber filters coated with nanoparticles of a natural product, namely, Sophora flavescens extract. Inactivation efficiency decreased with increasing temperature and treatment time. A quantitative chemical analysis of the filters revealed that the quantities of antimicrobial compounds decreased noticeably, with a consequent decrease in antimicrobial activity. In addition, the S. flavescens nanoparticles on the filter fiber surface melted gradually as treatment time increased at temperatures >100°C. This change in nanoparticle morphology in turn affected the pressure and filtration efficiency of filters, both of which decreased with increasing temperature and treatment time. These results could provide a scientific basis for the improvement of indoor air-quality control using antimicrobial air filters coated with S. flavescens nanoparticles.Copyright 2014 American Association for Aerosol Research
"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. "
[Show abstract][Hide abstract] 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.
[Show abstract][Hide abstract] 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 experiments
Information and Telecommunication Technologies, 2005. APSITT 2005 Proceedings. 6th Asia-Pacific Symposium on; 12/2005
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