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Lingyi Kong - One of the best experts on this subject based on the ideXlab platform.
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studies on the chemical constituents of psoralea corylifolia l
Journal of Asian Natural Products Research, 2007Co-Authors: B Ruan, Lingyi Kong, Yasuhiro Takaya, Masatake NiwaAbstract:A new isoflavone, corylinin (1), along with six known compounds, isoPsoralen (2), Psoralen (3), sophoracoumestan A (4), neobavaisoflavone (5), daidzin (6) and uracil (7), have been isolated from the dried fruits of Psoralea corylifolia L. The structure of 1 was established as 7,4′-dihydroxy-3′-[(E)-3,7-dimethyl-2,6-octadienyl]isoflavone on the basis of the spectroscopic methods. Structures of the known compounds were identified by comparison of the literature.
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preparative isolation and purification of Psoralen and isoPsoralen from psoralea corylifolia by high speed counter current chromatography
Journal of Chromatography A, 2004Co-Authors: Aifeng Li, Lingyi KongAbstract:Abstract Psoralen and isoPsoralen were separated from Psoralea corylifolia by high-speed counter-current chromatography (HSCCC). A two-phase solvent system composed of n-hexane–ethyl acetate–methanol–water (5:5:4.5:5.5, v/v) was used for HSCCC separation, and yielded, from 100 mg of crude extract, 39.6 mg of Psoralen and 50.8 mg of isoPsoralen each at over 99% purity as determined by high performance liquid chromatography (HPLC). The identification of Psoralen and isoPsoralen were performed with 1H NMR and 13C NMR.
Armand Guckert - One of the best experts on this subject based on the ideXlab platform.
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development of an enzyme immunoassay to detect and quantify Psoralen and bergapten in plants
Phytochemical Analysis, 1995Co-Authors: Frederic Bourgaud, F Dallacqua, V Bouque, S Marchal, G Innocenti, Armand GuckertAbstract:A competitive enzyme immunoassay has been developed in order to quantify furanocoumarins. 5-HydroxyPsoralen was modified and linked to bovine serum albumin to obtain an antigenic response. The rabbit serum that was collected was highly specific to 5-methoxyPsoralen and Psoralen but did not recognize angelicin (a Psoralen angular isomer), 8-methoxyPsoralen or 5,8-dimethoxyPsoralen, coumarin and related molecules. The detection limit was about 5 ng/mL for 5-methoxyPsoralen and 30 ng/mL for Psoralen. The test was applied to plants that contain furanocoumarins i.e. species of Psoralea. The correlation with a classical high-pressure liquid chromatographic method was satisfactory with both dry and fresh matter. With reference to the extraction method used with the plant material, the detection limit in the plant samples was about 15 μg/g for the dry matter and 20 μg/g for the fresh matter. This technique is a useful tool to detect and quantify Psoralen and 5-methoxyPsoralen in plant samples.
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A selective photobiological assay to detect and quantify Psoralen in Psoralea plants (Leguminosae)
Phytochemical Analysis, 1994Co-Authors: Frederic Bourgaud, J. Y. Grimal, Christophe Nguyen, G. Bitton, Armand GuckertAbstract:A simple and rapid bioassay involving the gram-positive bacterium Bacillus brevis was developed to detect and quantify furocoumarins (Psoralen and angelicin) in Psoralea plants (Leguminosae). Small paper discs, soaked with furocoumarin standards or the corresponding plant samples, are placed on B. brevis lawns in Petri dishes and irradiated for 24 h with UVA. The diameter of the growth inhibition zone around the discs is very well-correlated with the quantity of furocoumarin standard in the disc. Because Psoralen is more phototoxic than angelicin, its detection limit (5 × 10−8 g/disc) was lower than angelicin (5 × 10−7 g/disc). Consequently, it is possible to dilute a crude plant extract in order to reach a detectable Psoralen concentration whilst maintaining the angelicin concentration below its lower detection limit. In this condition, angelicin does not interfer with Psoralen detection, and the growth inhibition is entirely due to Psoralen. The bioassay was validated using a classical high pressure liquid chromatographic method and the correlation between the two techniques was satisfactory with plant samples. Therefore, the bioassay can be considered as a sensitive, simple, rapid and selective method to quantify Psoralen in Psoralea plants.
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Establishment of hairy root cultures of Psoralea species.
Plant Cell Reports, 1992Co-Authors: Christophe Nguyen-the, Paul Forlot, Frederic Bourgaud, Armand GuckertAbstract:Eight Psoralea species (Leguminosae) were inoculated with Agrobacterium rhizogenes, strains 8196 and 9402. Hairy roots were only induced by strain 9402. Attention was focussed on Psoralea lachnostachys. Transformed roots grew very rapidly in Gamborg B5 liquid medium with a doubling time of the culture of 38 hours. Whatever the culture conditions, the two furanocoumarins usually found in roots of Psoralea plants, Psoralen and angelicin, were not detected in cultured transformed and non transformed roots even when some chitosan was added to the medium. However, 669 μg.g−1 dry matter of Psoralen and 215 μg.g−1 dry matter of angelicin were found in roots from soil grown plants. A possible translocation of these compounds from the aerial parts to the roots is suggested.
Richard R Sinden - One of the best experts on this subject based on the ideXlab platform.
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Probing DNA structure with Psoralen in vitro.
Methods in Enzymology, 1992Co-Authors: David W Ussery, Robert W. Hoepfner, Richard R SindenAbstract:Publisher Summary This chapter presents the probing of DNA structure with Psoralen in vitro . Psoralens have been widely used as probes of DNA structure, RNA structure, and DNA–protein interaction. Bacterial and eukaryotic cells are permeable to Psoralens that can photobind to DNA inside cells. Psoralen binds preferentially to DNA in cells. The binding of Psoralens to DNA is sensitive to superhelical density, alternate DNA conformations, and protein association. Psoralens initially bind noncovalently to DNA by interacalation into the DNA double helix. The intercalative binding is sufficiently weak that relatively few Psoralens will bind DNA, resulting in little perturbation of the topology and structure of DNA. On irradiation with near-UV light (320-400 nm), an intercalated Psoralen can be photobound to an adjacent pyrimidine base, forming a monoadduct. When the adjacent base in the opposite strand is also a pyrimidine, interstrand crosslinks can form in a second photochemical reaction. Cross-links covalently bind the two strands of the double helix together. The number of Psoralens photobound to DNA can be carefully controlled by the incident exposure to UV light. Psoralens bind tightly to proteins and membranes, but the binding is not dependent on irradiation with 360 nm light.
Chengchao Zheng - One of the best experts on this subject based on the ideXlab platform.
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an efficient new method for extraction separation and purification of Psoralen and isoPsoralen from fructus psoraleae by supercritical fluid extraction and high speed counter current chromatography
Journal of Chromatography A, 2004Co-Authors: Xiao Wang, Yuqiang Wang, Jinpeng Yuan, Qinglei Sun, Jianhua Liu, Chengchao ZhengAbstract:Psoralen and isoPsoralen were extracted from Fructus Psoraleae (Psoralea corylitolia L.) by supercritical CO2. The effect of various parameters, i.e., pressure, temperature and sample particle size on yield was investigated with an analytical-scale supercritical fluid extraction (SFE) system to find the optimal conditions. The process was then scaled up by 50 times with a preparative SFE system under the optimized conditions of pressure (26 MPa), temperature (60 degrees C) and a sample particle size of 40-60 mesh. The yield of the preparative SFE was 9.1% and the combined yield of Psoralen and isoPsoralen was 2.5 mg/g of dry seeds. Psoralen and isoPsoralen in the extract were separated and purified by high-speed counter-current chromatography with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.7:1:0.8, v/v), and the fractions were analyzed by HPLC, MS, 1HNMR and 13C NMR. The structures of the products were further confirmed by comparison with authentic samples (National Institute of the Control of Pharmaceutical and Biological Products, Beijing, China).
Jeffrey D. Laskin - One of the best experts on this subject based on the ideXlab platform.
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Mechanism of action of Psoralens: isobologram analysis reveals that ultraviolet light potentiation of Psoralen action is not additive but synergistic.
Cancer chemotherapy and pharmacology, 1991Co-Authors: Edward J. Yurkow, Jeffrey D. LaskinAbstract:The combination of Psoralens and ultraviolet light (UVA, 320–400 nm), referred to as PUVA, inhibits proliferation of a variety of cell types. In the present studies, we used S-180 cells to investigate the mechanism underlying the antiproliferative actions of PUVA. We found that inhibition of growth of S-180 cells by PUVA was dependent on the concentration of Psoralen as well as the dose of UVA light. Neither the Psoralens nor UVA light by themselves inhibited cell growth. Several clinically important Psoralen analogs inhibited cell growth. The potent phototoxin 4,5′,8-trimethylPsoralen was the most active Psoralen analog tested, followed by 5-methoxyPsoralen and 8-methoxyPsoralen. The angular furocoumarin, 5-methylangelicin, was the least active inhibitor of growth. Multivariate (isobologram) analysis of the growth-inhibition curves revealed that combinations of Psoralens and UVA light were not simply additive but synergistic. Similar results were observed when inhibition of DNA synthesis was used as an endpoint for the biological effects of PUVA. These studies are the first to demonstrate that Psoralens and UVA light act synergistically. Our results suggest that the synergism between the Psoralens and UVA light may be an important property of PUVA that contributes to its therapeutic efficacy in proliferative diseases.
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Psoralen binding and inhibition of epidermal growth factor binding by Psoralen/ultraviolet light (PUVA) in human epithelial cells.
Biochemical pharmacology, 1991Co-Authors: Jeffrey D. Laskin, Edmund LeeAbstract:Abstract The Psoralen analogs 8-methoxyPsoralen (8-MOP) and 4,5′,8-trimethylPsoralen (TMP), in combination with ultraviolet light (UVA, 320–400 nm), are potent modulators of epidermal cell growth and differentiation and are commonly used in photochemotherapy of psoriasis and vitiligo. We have used KB cells, a human epithelial cell line, to examine the mechanism of action of these compounds. In KB cells, 8-MOP was found to bind to specific, saturable receptor sites. Binding of [ 3 H]-8-MOP to its receptor was inhibited by TMP as well as Psoralen. We found that binding of these analogs to the cells followed by UVA light treatment was associated with inhibition of epidermal growth factor (EGF) receptor binding. Inhibition of EGF binding was temperature dependent, occurred immediately following UVA light exposure, and appeared to be due to a decrease in the number of EGF receptors. In KB cells, 125 I-labeled EGF surface receptor binding is followed by its rapid internalization and degradation. We found that photoactivated Psoralens also inhibited internalization of 125 I-EGF, but had no apparent effect on EGF metabolism. These data indicate that the cell surface membrane may be an important target for the photoactivated Psoralens. In addition, since photoactivated Psoralens regulate cell proliferation, the interaction of these compounds with EGF receptor function may underlie their biological activity.
