Role Of Coumarins Research Articles

The role of coumarin, hespertin and liquritigenin against oral cancer novel drug target FAP protein

The role of coumarin, hespertin and liquritigenin against oral cancer novel drug target FAP protein

Изменение физико-химических и культуральных свойств бактерий Azospirillum baldaniorum Sp245 под влиянием некоторых синтетических кумаринов

Due to the small number of studies on the role of coumarins in associative symbiotic relationships, some aspects of the influence of synthetic coumarins on the physicochemical and cultural properties of Azospirillum baldaniorum Sp245 were studied for the first time. To reveal the role of hydroxylation in position 7 of the fused aromatic ring – 1-(2-oxo-2H-chromen-3-yl)butan-1,3-dione, comparative studies of the effect of the original and hydroxylated coumarins on the culture of a model strain of azospirilla were carried out. The survival of bacteria after the addition of coumarins was studied by counting CFU on an agar medium. The biofilm formation activity of the culture was assessed using crystal violet. The change in the surface of bacteria under the action of coumarins was studied by the electrical polarizability of bacterial cells on an ELUS electrooptical analyzer (EloSystemGbR, Germany). The yield and monosaccharide composition of extracellular glycopolymers were studied using gas-liquid chromatography.For the first time, an increase in the yield of EPS of bacteria during growth in the presence of 1-(7-hydroxy-2-oxo-2Hchromen-3-yl)butan-1,3-dione by 1.2 and 1.7 times for concentrations of 50 and 100 μM respectively was observed. It has been established for the first time that the hydroxylated substance has a higher antibacterial activity compared to the unsubstituted one. A decrease in the number of viable cells in planktonic culture and inhibition of biofilm growth were revealed. It has been shown by electro-optical analysis that the presence of coumarins in the cultivation medium in all concentrations studied leads to a change in the electrical polarizability of A. baldaniorum Sp245 cells. The use of electrooptical analysis of cell suspensions using monospecific antibodies obtained against lipopolysaccharides of this strain made it possible to reveal the absence of changes in carbohydrate antigenic determinants on the surface of bacterial cells. This is consistent with the data of the analysis of the composition of extracellular polysaccharides by GLC, during which no differences were found in the qualitative composition and ratio of monosaccharides. An increase in the yield of bacterial EPS during growth in the presence of 1-(7-hydroxy-2-oxo-2H-chromen-3-yl) butan-1,3-dione by 1.2 and 1.7 times for concentrations of 50 and 100 μM was shown. The results obtained allow us to consider the changes that have occurred as features of the adaptation of bacteria to the associative conditions of existence.

Does the exudation of coumarins from Fe-deficient, soil-grown Brassicaceae species play a significant role in plant Fe nutrition?

The availability of iron (Fe) is highly limited for plant uptake in calcareous soils. To overcome this challenge, plants have developed different strategies of Fe mobilization. Non-gramineous species employ a reduction-based strategy (strategy I), which is assisted by the release of Fe(III)-chelating and -reducing coumarins. In this study, the coumarin release by three strategy-I plant species of the Brassicaceae family, i.e. Brassica napus L., Raphanus sativus L. and Sinapis alba L., on calcareous soil was examined using the RHIZOtest approach. With this experimental setup, the plants were first grown hydroponically in a cylindrical growth unit for 12 days, which was then subsequently brought in contact with calcareous, Fe deficient soil for another 9 days. Root exudates were collected in both experimental phases. Total carbon (C) release, coumarin exudation rates, trace metal plant uptake as well as trace metal mobilization were determined in response to Fe deficiency after 3, 6 and 9 days of soil exposure. High total C exudation rates indicated a clear stress response upon Fe deficiency during the soil contact period. Six different coumarins were detected, with scopoletin being predominantly released by all three plant species during the hydroponic stage with zero Fe supply. The exudation rate of all detected coumarins was significantly lower during soil exposure and represented only a very small fraction of the total organic compounds released. Although the role of coumarins in Fe mobilization is very complex and still not completely understood, it seems that coumarins are less important in Fe mobilization by the three investigated plant species when grown on soil compared to phytosiderophore-releasing strategy-II plants. Our data further indicate that plants growing on a Fe-deficient soil release less coumarins than in an artificial nutrient solution setup with zero Fe supply, which highlights the importance of determining root exudation rates from soil-grown plants, since data from hydroponic studies are likely not representative for soil-grown plants.

Phytochemicals as inhibitors of bacterial cell division protein FtsZ: coumarins are promising candidates.

Naturally occurring phytochemicals with reported antibacterial activity were screened for their ability to inhibit the bacterial cell division protein Escherichia coli FtsZ. Among the representative compounds, coumarins inhibit the GTPase and polymerization activities of this protein effectively. Further screening with ten coumarin analogs we identified two promising candidates, scopoletin and daphnetin. The former is found to inhibit the GTPase activity of the protein in a noncompetitive manner. Docking of these coumarins with the modeled protein indicate that they bind to T7 loop, which is different from the GTP-binding site (active site), thereby supporting the experimental data. Lowest binding energy is obtained with scopoletin. 3D QSAR indicates the need for groups such as hydroxyl, diethyl, or dimethyl amino in the 7th carbon for enhanced activity. None of the coumarins exhibited cytotoxicity against NIH/3T3 and human embryonic kidney cell lines. The length of Bacillus subtilis increases in the presence of these compounds probably due to the lack of septum formation. Results of this study indicate the role of coumarins in halting the first step of bacterial cell division process.

Identification of coumarin-enriched Japanese green teas and their particular flavor using electronic nose

Conventionally, tea flavor is analyzed through the use of a combination of gas chromatography–mass spectrometry and human taste panel. These methods present time-consuming or inaccurate factor. In this work, a rapid, accurate and nondestructive approach was put forward to identify coumarin-enriched Japanese green teas and evaluate their particular flavor using electronic nose (E-nose) technique. The multivariable analyses including principal component analysis and cluster analysis were applied to distinguish the tea samples and evaluate the particular (coumarin-like) flavor of coumarin-enriched tea under different infusion conditions. A correct classification was achieved for the seven tea samples with different content of coumarin. The E-nose successfully characterized the drying temperature-dependently trend of coumarin content during the manufacture process of coumarin-enriched green tea. It also revealed that the comparatively low-infusion temperature and long-infusion time were favorable for the emission of coumarin-like flavor of the tea infusion. In addition, a comparatively newly developed “absolute value expression” (AVE) method was employed to divide the tea flavors into quality and express them numerically. Using AVE, the role of coumarin in the total flavor of coumarin-enriched green tea was elucidated. These results suggest that E-nose could be employed to identify the green teas with particular flavor and evaluate the tea flavor.

Coumarins inPrunus mahaleb and its herbivore, the small ermine mothYponomeuta mahalebellus

Larvae of the small ermine mothYponomeuta mahalebellus were reared on foliage ofPrunus mahaleb, a plant known to contain coumarins. Thin-layer chromatography and gas chromatography showed that coumarin, umbelliferone, and herniarin were present in leaves ofP. mahaleb and in pupae and adults ofY. mahalebellus. Overall concentrations of simple coumarins in the plant and insect were, respectively, 0.54% and 0.003-0.004% (dry weight). The possible role of coumarins in the chemical defense of both the plant and insect is discussed.

The role of coumarin as secondary plant substance in the food specificity of the cow pea aphid Aphis craccivora Koch

AbstractThe present work deals with the effect of three plant species of the family Leguminosae on the cow pea aphid. From the data obtained, it was clear that broad bean plant was highly acceptable as food and can support growth well, whereas clover and termis proved to be largely resistant for Aphis craccivora infestation and can not support growth well. Poor growth was related to a low rate of feeding which may have been due to the effect of nun‐nutrient feeding deterrents.Thus biochemical analysis of the broad bean and termis plants indicate the presence of coumarin in variable concentrations. The percentage of coumarin in termis was considerably higher than of broad bean. Accordingly bean plant with lower concentration of coumarin was found to be highly acceptable as host plant to the cow pea aphid, while termis with higher coumarin concentration proved to be highly resistant. Bean plant systemically treated with 100 ppm and 200 ppm coumarin and offered to the cow pea aphid as food, decreased significantly its natality and natality rate in comparison to the control (bean plant without treatment). Coumarin at higher dose (200 ppm.) acted as a detterent agent, where the resulting young died without reaching the second generation.ZusammenfassungZum Einfluß von Cumarin als sekundärer Pflanzeninhaltsstoff auf die Nahrungseignung für die Blattlaus Aphis craccivora KochDie Arbeit befaßt sich mit der Eignung von 3 Pflanzenarten aus der Fam. Leguminosae als Nahrung von A. craccivora. Es zeigte sich, daß die Bohne (Vicia faba) als Nahrung hoch geeignet war und ein gutes Wachstum der Population ermöglichte, während Klee (Trifolium alexandrinum) und Lupine (Termis lupinus) sich gegenüber der Laus als weitgehend resistent erwiesen und keine bzw. nur eine schwache Entwicklung der Population zuließen. Bei der Lupine nahmen die Läuse offensichtlich unter dem Einfluß einer Deterrent‐Substanz nur wenig Nahrung auf.Die biochemische Analyse von Bohne und Lupine ergab sehr unterschiedliche Mengen (bei Lupine sehr viel höher) an Cumarin. Wurden Bohnenpflanzen mit 100–200 ppm Cumarin behandelt und den Läusen als Nahrung vorgesetzt, ergab sich eine signifikante Abnahme der Nachkommenzahl im Vergleich zu unbehandelten Bohnen. Cumarin in der höheren Dosis (200 ppm) wirkte als ausgesprochenes Deterrent, unter dessen Einfluß die Nachkommen noch vor Erreichen der 2. Generation abstarben.

The Role of Coumarin in the Growth of Roots of Melilotus alba. Contributions from the Hull Botanical laboratory 365

1. Melilotic acid and o-coumaric acid inhibited cell elongation in the Avena coleoptile curvature test. Coumarin had no activity under the conditions employed. 2. All three compounds inhibited root growth of sweetclover and alfalfa seedlings. It is suggested that perhaps neither unsaturation nor lactone configuration is essential for their inhibitory activity. 3. The total length increment of roots of sweetclover and alfalfa seedlings grown on agar containing 5 p.p.m. of coumarin was about 55 and 40%, respectively, of the control. At a concentration of 50 p.p.m. of coumarin the increment of sweetclover roots was further decreased by only about 10%, whereas alfalfa roots placed on such agar did not grow at all. 4. The concentration of free and bound coumarin present in sweetclover roots was quantitatively determined. The average concentration of free coumarin was about 74 μgm/gm of fresh weight. Coumaric acid may account for 20% of this quantity. No longitudinal concentration gradient of coumarin was found in the roots of sweetclover seedlings. The possible role of coumarin as a natural growth inhibitor is discussed. 5. During the imbibition and subsequent periods of leaching of sweetclover seeds, coumarin was found in the leachate in quantities proportionate to the length of leaching time. During a leaching period of 24 hours, about 2 μgm. of coumarin were leached out per seed.