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PubMed1991

Skin necrosis following prolonged administration of coumarin in a patient with inherited protein S deficiency.

Depression of the vitamin K-dependent modulators of coagulation during the initial phase of oral anticoagulant therapy may lead to a transient hypercoagulable state and skin necrosis. We report a case of skin necrosis associated with inherited protein S deficiency following prolonged coumarin therapy. As a result of a stasis ulceration causing a rise in c4b binding protein and concurrent treatment with topical sulfonamide, we hypothesize that a precipitous decrease in free protein S led to skin necrosis. Progression of the necrosis was halted with unactivated prothrombin complex concentrate. This case confirms the rare association between coumarin induced skin necrosis and protein S deficiency and emphasizes potential drug interactions.

Adult↗
PubMed1988

Constituents of Justicia pectoralis Jacq. 2. Gas chromatography/mass spectrometry of simple coumarins, 3-phenylpropionic acids and their hydroxy and methoxy derivatives.

The analysis of extracts from the South American plant Justicia pectoralis Jacq. permitted the identification, among other compounds, of coumarin, dihydrocoumarin, umbelliferone and 3-(2-hydroxyphenyl)propionic acid by gas chromatography/mass spectrometry (GC/MS); the acids and phenolic compounds were derivatized with diazomethane. GC/MS of simple coumarins, phenylpropionic acids and their hydroxylated isomers was performed after derivatization through methylation and trimethylsilylation; these results may be useful for the identification and quantification of these compounds in other biological materials.

Coumarins↗
PubMed2005

Bleaching of Serratia marcescens by some coumarins: a spectrophotometric study.

Recently, we reported that umbelliprenin inhibits the red pigment production in Serratia marcescens . In this current investigation the bleaching effect of the umbelliprenin was further studied using the spectrophotometric method, and its IC 50 was calculated. Also in this study the effect of the other coumarins extracted from Ferula persica roots were evaluated for depigmentation of Serratia marcescens . None of these compounds appeared to have a bleaching effect against a test strain at certain concentrations. Comparing the structures of the different coumarins showed that the linear sesquiterpene part of the umbelliprenin structure may be essential for the bleaching effect of S. marcescens .

Anti-Bacterial Agents↗
PubMed1976

Coumarins XIV: high-resolution mass spectra of 3',4'-disubstituted 3',4'-dihydroseselins.

High-resolution mass spectra of 14 3',4'-disubstituted 3',4'-dihydroseselins were examined. The nature of the substituents determinines the mode of fragmentation. Compounds having one or two acyloxy substituents fragment mainly by a pathway leading to the stable coumarinopyrilium ion. Coumarins with alkoxy or hydroxy substituents proceed by way of fission of the chroman ring, accompanied by the loss of two ring carbon atoms. Several generalizations are formulated which will aid in the interpretation of the mass spectra of this class of coumarins from a structural standpoint.

Chemical Phenomena↗
PubMed2003

Recent progress in the development of coumarin derivatives as potent anti-HIV agents.

Numerous plant-derived compounds have been evaluated for inhibitory effects against HIV replication, and some coumarins have been found to inhibit different stages in the HIV replication cycle. This review article describes recent progress in the discovery, structure modification, and structure-activity relationship studies of potent anti-HIV coumarin derivatives. A dicamphanoyl-khellactone (DCK) analog, which was discovered and developed in our laboratory, and calanolide A are currently in preclinical studies and clinical trials, respectively.

Anti-HIV Agents↗
PubMedDate not supplied

HPLC comparison of supercritical fluid extraction and solvent extraction of coumarins from the peel of Citrus maxima fruit.

The efficiency of carbon dioxide supercritical fluid extraction (SFE) of the biologically active compounds imperatorin, meranzin and meranzin hydrate from the fruit peel of Citrus maxima Merr. has been compared with that of solvent extraction with acetone. Under the best SFE conditions tested for the three coumarins, which involved extraction at 50 degrees C and 27.6 MPa, the extractive efficiencies were 84, 76 and 18% for imperatorin, meranzin and meranzin hydrate, respectively. The presence of modifiers significantly affected the extraction efficiency: the highest extraction efficiency of the three coumarins was obtained with ethanol as modifier.

Chromatography, High Pressure Liquid↗
PubMed2004

Effects of betaine, coumarin and flavonoids on mucin release from cultured hamster tracheal surface epithelial cells.

Betaine, coumarin, hesperidin and kaempferol are the components derived from Lycium chinense, Angelicae decursiva, Poncirus trifoliata and Polygonatum odoratum, respectively. These plants have been used for the treatment of respiratory diseases in oriental medicine and their respective components were reported to have various biological effects. In this study, we investigated whether these natural products affect mucin release from cultured hamster tracheal surface epithelial cells and compared the possible activities of these agents with the inhibitory action on mucin release by poly-L-lysine and the stimulatory action by adenosine triphosphate. Confluent primary hamster tracheal surface epithelial cells were metabolically radiolabeled using (3)H-glucosamine for 24 h and treated for 30 min in the presence of varying concentrations of each agent to assess the effects on (3)H-mucin release. The results were as follows: (i) Coumarin and kaempferol did not affect mucin release significantly; (ii) Betaine and hesperidin increased mucin release at the highest concentration; (iii) Poly-L-lysine inhibited and adenosine triphosphate increased mucin release. We conclude that betaine and hesperidin can increase mucin release by direct acting on airway mucin-secreting cells and suggest these agents be further studied for the possible use as mild expectorants during the treatment of chronic airway diseases.

Animals↗
PubMed1976

Coumarin-7-hydroxylase activity in microsomes from needle biopsies of normal and diseased human liver.

The specific activity of coumarin-7-hydroxylase was measured in liver microsomes from normal subjects and patients with liver disease. Liver specimens were obtained by needle biopsy and the microsomal fraction was separated by differential centrifugation. Its freedom from mitochondria was demonstrated by the absence of succinic dehydrogenase, a marker enzyme for mitochondria. Liver from healthy subjects showed variation in the specific activity of coumarin-7-hydroxylase from 0.16 to 0.65 nmol-mg-1-min-1, which is probably due to genetic factors. Patients with cirrhosis of the liver, chronic fatty hepatitis (chronic alcoholic hepatitis) and chronic active hepatitis showed a significantly lower mean hydroxylase activity. There was no significant difference in the mean level of hydroxylase between patients with subacute viral hepatitis or chronic persistent hepatitis and the normal controls.

Acute Disease↗
PubMed1976

Decrease of normotest/thrombotest discrepancy in non-contacted coumarin plasma after glass or ellagic acid activation.

Activation of coumarin plasmas in glass tubes for 60 min resulted in a clear shortening of Thrombotest clotting times. Normotest clotting times were shortened too but to a much lesser extent. As a consequence the Normotest (NT)/Thrombotest (TT) discrepancy which was quite large at 0 time, became progressively smaller. This phenomenon was observed both in undiluted and 6:10 diluted plasma. After ellagic acid activation a similar phenomenon was noted even though a less pronounced shortening of Thrombotest was noted. These data suggest that Thrombotest is very sensitive to contact phase and to factor VII activation and not to any coumarin-induced inhibitors.

Blood Coagulation Tests↗
PubMed1975

The K-test (trypsin clotting time) in coumarin treated patients and in congenital deficiencies and abnormalities of the prothrombin complex.

The behavior of K-test (Trypsin clotting time) has been studied in 38 patients on long-term coumarin therapy and in 19 patients with congenital coagulation disorders of the prothrombin complex. All coumarin treated patients showed a clear prolongation of the test. The results obtained were compared with the standard prothrombin time, the Hepato-Quick-test (P-P test) and the Factor II + X test values, observed in the same patients. A good correlation was observed in each instance. The highest correlation was observed between K-test and the Factor II + X test (r=+0,78;t=7,80;p less than 0.001). All congenital coagulation disorders of the prothrombin complex yielded a prolonged K-test value but for Factor VII deficiency. In three patients with this latter condition a perfectly normal value was obtained. The K-test together with the prothrombin time may be useful in the differential diagnosis of factor VII deficiency from factor X deficiency and from the factor X Friuli abnormality.

Blood Coagulation Disorders↗
PubMed1976

The effect of coumarin on the liver weight of thermally injured rats.

Coumarin (a benzo-pyrone) has been shown to significantly increase liver weights 2 days after its injection. It is believed that coumarin belongs to a group of reticulo-endothelial system stimulants which increase the numbers of phagocytosing sites by increasing the number of phagocytic cells.

Animals↗
PubMed2006

Monoamine oxidase inhibitory coumarins from the aerial parts of Dictamnus albus.

The methanol extract from the aerial parts of Dictamnus albus was active in inhibiting monoamine oxidase (MAO) from the mouse brain. Activity-guided fractionation led to the isolation of four known coumarins, 7-(6'R-hydroxy-3', 7'-dimethyl-2'E, 7'-octadienyloxy) coumarin (1), auraptene (2), umbelliferone (3), and xanthotoxin (4), as active compounds along with an inactive alkaloid, skimmianine (5). Compounds 1 and 2 inhibited MAO activity in a concentration-dependent manner with IC50 values of 0.7 and 1.7 microM, respectively. Compounds 1 and 2 showed a slight and potently selective inhibitory effect against MAO-B (IC50 0.5 and 0.6 microM, respectively) compared to MAO-A (IC50 1.3 and 34.6 microM, respectively). According to kinetic analyses derived by Lineweaver-Burk reciprocal plots, compounds 1 and 2 exhibited a competitive inhibition to MAO-B.

Animals↗
PubMed2004

Cytotoxic coumarins from the root of Angelica dahurica.

Ten coumarins were isolated from the root of Angelica dahurica by repeated silica gel column chromatography. Their chemical structures were elucidated on the basic of physicochemical and spectroscopic data. Among them, oxypeucedanin hydrate acetonide (7) was isolated for the first time from this plant. Cytotoxicity of coumarins isolated were determined in vitro against L1210, HL-60, K562, and B16F10 tumor cell lines by MTT method. Pangelin (5) and oxypeucedanin hydrate acetonide (7) showed a potent cytotoxic activity with the IC50 values of 8.6 to 14.6 microg/mL against four kinds of tumor cell lines. Other compounds showed the moderate cytotoxic activity or no activity against the tumor cell lines.

Angelica↗
PubMed1999

Inhibitory activity of monoamine oxidase by coumarins from Peucedanum japonicum.

Four coumarins were isolated from chloroform extract of the root of Peucedanum japonicum and identified as praeruptorin A(1), xanthotoxin (2), psoralen (3) and bergapten (4) on the basis of spectroscopic methods. The inhibitory activities of these coumarins on monoamine oxidase prepared by mouse brain were tested. The IC50 values of them were shown to be 27.4 microM (1), 40.7 microM (2), 35.8 microM (3), and 13.8 microM (4), in vitro.

Animals↗
PubMed1977

A spectrum of partially carboxylated prothrombins in the plasmas of coumarin-treated patients.

Prothrombin has been purified from the plasmas of normal human donors and from patients ingesting coumarins. Equimolar amounts of normal prothrombin or coumadin-induced prothrombin were incubated with phospholipid micelles in the presence of Ca2+. Subsequent gel filtration of the incubation mixtures demonstrated that all of the normal prothrombin was bound to the phospholipid; only half of the coumadin-induced prothrombin was bound. Normal prothrombin contains approximately 10 mol of gamma-carboxyglutamic acid per mol of prothrombin. The coumadin-induced prothrombin which was bound to phospholipid contains approximately 6.5 mol of gamma-carboxyglutamic acid per mol of prothrombin while that which failed to bind to phospholipid has only 2.8 mol of gamma-carboxyglutamic acid per mol of zymogen. Thus, partially carboxylated prothrombins exist in the plasmas of coumarin-treated patients. Furthermore, there is a striking electrophoretic heterogeneity in the prothrombin preparations from the plasmas of the coumadin-treated patients. This most likely results from a wide spectrum of abnormal prothrombins with varying quantities of gamma-carboxyglutamic acid per mol of zymogen.

Calcium↗
PubMed1990

3-Hydroxycoumarins: first direct preparation from coumarins using a Cu2(+)-ascorbic acid-O2 system, and their potent bioactivities.

First direct 3-hydroxylation of a coumarin ring via a purely chemical system, previously only possible using cytochrome P-450, was successfully conducted by a Cu2(+)-ascorbic acid-O2 system; the two 3-hydroxycoumarins obtained were novel compounds, 3-hydroxyscopoletin and 3-hydroxyisoscopoletin. 5-Lipoxygenase and alpha-D-glucosidase inhibitory activities of coumarins greatly increased through 3-hydroxylation. 3-Hydroxyscopoletin and 3-hydroxyumbelliferone had a high inhibitory potency for 5-lipoxygenase and for alpha-D-glucosidase respectively; they serve as lead compounds for new drugs.

Arachidonate 5-Lipoxygenase↗
PubMed1983

Mechanism of ticrynafen potentiation of coumarin anticoagulant action.

Administration of the antihypertensive drug ticrynafen [2,3-dichloro-4-(2-thienylcarbonyl)-phenoxyacetic acid] has been reported to potentiate the effects of coumarin anticoagulants and to have caused hemorrhagic incidents in some patients. This drug interaction has now been reproduced in the rat. Ticrynafen administration enhanced the degree of hypoprothrombinemia and altered plasma and hepatic vitamin K epoxide concentrations in warfarin-treated rats. Ticrynafen did not affect vitamin K-dependent carboxylase or vitamin K epoxide reductase activities in vitro. Cytosolic DT-diaphorase was very sensitive to ticrynafen inhibition in vitro, and inhibition of vitamin K reduction via this enzyme is a possible mechanism by which ticrynafen potentiates coumarin anticoagulant action. Inhibition of this enzyme may also contribute to the reported hepatotoxicity of ticrynafen.

Animals↗