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At least 163 records · Page 9Linked to original sources
PubMed1993

Sex pheromone for the brownbanded cockroach is an unusual dialkyl-substituted alpha-pyrone.

Female brownbanded cockroaches, Supella longipalpa, emit a sex pheromone that attracts males from a distance. This pheromone was isolated and identified as 5-(2,4-dimethylheptanyl)-3-methyl-2H-pyran-2-one (which we refer to as supellapyrone), and its structure was confirmed by synthesis. A racemic blend of the synthetic compound elicited behavioral and electrophysiological responses comparable to the natural pheromone across a range of doses. This compound is not only a very different type of cockroach pheromone but also makes up an additional class of natural products--namely, 3,5-dialkyl-substituted alpha-pyrones.

Journal Article↗
PubMed1989

The effects of 5,6 benzo-[a]-pyrone (coumarin) and DEC on filaritic lymphoedema and elephantiasis in India. Preliminary results.

A randomized double-blind, placebo-controlled, trial of 5,6 benzo-[alpha]-pyrone (coumarin, '56 BaP') and of diethylcarbamazine (DEC) is being performed on patients with filaritic lymphoedema and elephantiasis over two years, using matched groups. In 169 patients there were significant (1% level) reductions in the amounts of oedema for the patients taking 56 BaP. The excess limb volumes were reduced from 40 to 25% over two years. A similar, but less significant (5% level), improvement was found for the circumference measurements. The rate of reduction was increased when the initial amount of oedema was greater. This therapy, while much slower than many other methods of treatment, does convert a slowly worsening condition into a slowly improving one. There were no significant reductions in the amount of oedema following DEC treatment.

Analysis of Variance↗
PubMed1988

[Structure of a psoralen-thymine photoproduct: model for the interaction with DNA on the pyrone ring of psoralen].

Photoadduct 4-ethoxypsoralen-thymine (4a-methyl-11,1-epoxyethanofuro [3'',2'',:6',7']chromeno-[2',3':1,2]cyclobutal[4,3-d]pyrimid in e-2,4, 5-trione), C18-H14N2O6, Mr = 354.1, monoclinic, P21/c, a = 9.021 (3), b = 11.504 (1), c = 16.397 (3) A, beta = 110.45 (1) degrees, V = 1594.4 A 3, Z = 4, Dm = 1.46, D chi = 1.475 Mg m-3, lambda (Mo K alpha) = 0.71069 A, mu = 0.072 mm-1, F(000) = 736, T = 298 K, R = 0.032 for 1442 observed reflections. This original structure of an intramolecular photoproduct obtained photochemically gives structural information about the cycloaddition of the thymine base on the pyrone ring of the psoralen. The crystal structure displays deformations of the planes of the two rings which form a dihedral angle of 40.5 degrees and a cis-anti conformation relative to the cyclobutane bridging component.

Cross-Linking Reagents↗
PubMed1999

Genetic and biochemical characterization of a 2-pyrone-4, 6-dicarboxylic acid hydrolase involved in the protocatechuate 4, 5-cleavage pathway of Sphingomonas paucimobilis SYK-6.

Sphingomonas paucimobilis SYK-6 is able to grow on a wide variety of dimeric lignin compounds with guaiacyl moieties, which are converted into protocatechuate by the actions of lignin degradation enzymes in this strain. Protocatechuate is a key metabolite in the SYK-6 degradation of lignin compounds with guaiacyl moieties, and it is thought that it degrades to pyruvate and oxaloacetate via the protocatechuate 4,5-cleavage pathway. In a 10.5-kb EcoRI fragment carrying the protocatechuate 4,5-dioxygenase gene (ligAB) (Y. Noda, S. Nishikawa, K. Shiozuka, H. Kadokura, H. Nakajima, K. Yoda, Y. Katayama, N. Morohoshi, T. Haraguchi, and M. Yamasaki. J. Bacteriol. 172:2704-2709, 1990), we found the ligI gene encoding 2-pyrone-4, 6-dicarboxylic acid (PDC) hydrolase. PDC hydrolase is a member of this pathway and catalyzes the interconversion between PDC and 4-carboxy-2-hydroxymuconic acid (CHM). The ligI gene is thought to be transcribed divergently from ligAB and consists of an 879-bp open reading frame encoding a polypeptide with a molecular mass of 32,737 Da. The ligI gene product (LigI), expressed in Escherichia coli, was purified to near-homogeneity and was estimated to be a monomer (31.6 kDa) by gel filtration chromatography. The isoelectric point was determined to be 4.9. The optimum pH for hydrolysis of PDC is 8.5, the optimum pH for synthesis of PDC is 6.0 to 7.5, and the Km values for PDC and CHM are 74 and 49 microM, respectively. LigI activity was inhibited by the addition of thiol reagents, suggesting that the cysteine residue is a catalytic site. LigI is more resistant to metal ion inhibition than the PDC hydrolases of Pseudomonas ochraceae (K. Maruyama, J. Biochem. 93:557-565, 1983) and Comamonas testosteroni (P. J. Kersten, S. Dagley, J. W. Whittaker, D. M. Arciero, and J. D. Lipscomb, J. Bacteriol. 152:1154-1162, 1982). The insertional inactivation of the ligI gene in S. paucimobilis SYK-6 led to the complete loss of PDC hydrolase activity and to a growth defect on vanillic acid; it did not affect growth on syringic acid. These results indicate that the ligI gene is essential for the growth of SYK-6 on vanillic acid but is not responsible for the growth of SYK-6 on syringic acid.

Carboxylic Ester Hydrolases↗
PubMed1976

The use of a tissue tonometer as a diagnostic aid in extremity lymphoedema: a determination of its conservative treatment with benzo-pyrones.

With the aid of a tissue tonometer, we have been able to gain an estimate of the rate at which the lymphoedematous tissue loses its compressability and regains it upon treatment with the non-steroidal anti-inflammatory drugs: the benzo-pyrones. The values obtained by tonometry, unlike other objective methods of measurement of the effectiveness of a therapy, approximate closely to the patients subjective claims.

Coumarins↗
PubMed1985

[The behavior of blood clotting and its inhibitors under long term treatment with 5,6-benzo-alpha-pyrone (coumarin). Double blind study].

The analyses on hemostaseological variables are recorded in connection with blood tests in the course of a double-blind study in 41 patients suffering from chronic venous insufficiency of higher degrees of severity. They were treated in addition to compression measures with two active ingredients, a coumarin (5,6-benzo-alpha-pyrone)/troxerutin combination (Venalot Depot) (n = 20) or benzarone (n = 21) receiving 3 X 2 dragees daily for 6 weeks. Good clinical efficacy and the improvement of symptoms were observed together with almost no side-effects. The coagulation analysis showed no influence of the active principles on the global coagulation or the clotting factors and the inhibitors and factors of the fibrinolysis. In particular there was no phenprocoumon-like effect on the blood clotting system.

Anticoagulants↗
PubMed1977

Fine structural aspects of the influence of lymphatic blockage on cold injury of the brain and skin, and the effects of benzo-pyrones.

The fine structural changes of cold injury, lymphoedema, or both have been studied in the cerebral cortices and facial skin of rats, with and without treatment by a mixture of two benzo-pyrones (coumarin and rutin sulphate salts). It was found that cold injury opens the endothelial junctions of the blood vessels and injures their plasma membranes, thus allowing plasma protein and fluid to enter the tissues, producing oedema. Hence the lymphatics of the skin and the prelymphatics of the brain become dilated, contain excess protein, and the junctions of the former become opened. Macrophages (together with astrocytes in the brain) appear to phagocytise some of the protein. Apart from the injuries to the blood vessels, lymphostasis causes similar effects. The two injuries in combination considerably enhance the effects of either by itself. The benzopyrones greatly reduce the amounts of protein and fluid, particularly in the tissues: the lymphatics lag behind these, especially if they are obstructed.

Animals↗
PubMed1979

Semi-complete versus partial venous obstruction, with and without partial lymphatic obstruction, and benzo-pyrone treatment.

The alterations in the fine structure of the venous wall are reviewed, and the changes which occur with injury. These are very similar in both arteries and veins, and were also found by us in experiments in which the common iliac veins of rats were completely occluded, with or without partial lymphatic obstruction. It was found that the protein concentration was considerably increased in the vein wall, in the muscle, and in the skin of the leg--especially when the lymphatics were blocked as well as the veins. The effects of various procedures, including partial and semi-complete venous obstruction and lymphatic obstruction were examined. It was shown to be likely that in semi-complete venous obstruction the blood in the occluded vessels is ultrafiltered, causing great increases in protein concentration, which will be transmitted to the tissues in general--although not to the tissue channels and lymphatics. This will not happen in partial venous occlusion. In all of these cases the benzo-pyrones considerably reduced the amount of excess protein in the tissues. This was no doubt partly due to their abilities to cause increased proteolysis, but may also have been due to their effects on blood and lymph vascular tone and functioning.

Animals↗
PubMed1981

The effect of benzo-pyrones on the canine pancreas submitted to long-term hypothermic perfusion.

In 14 dogs pancreatectomy was performed and pancreas was submitted to 24 hour hypothermic pulsatile perfusion using Gambro machine. During the perfusion exocrine secretion subsequent to secretin and CCK stimulation was collected and the perfusion fluid was analyzed. In 7 of these animals, Venalot, a combination of coumarin and rutin sulphate, was added to the perfusion fluid and its effect was tested. The addition of Venalot was followed by a decreased vascular peripheral resistance, decreased weight of the perfused graft, and decreased level of LDH and lactic acid in the perfusion fluid. The release of potassium from the pancreatic cells was prevented. The parameters of the pancreatic secretion was better than in the control group. Benzo-pyrones reduced oedema formation and improved cell metabolism during hypothermic perfusion of the pancreas.

Amylases↗
PubMed1984

Postinflammatory oedema in two patients with contact dermatitis. Effect of benzo-pyrones.

Two female patients with oedema of the arms and legs due to contact dermatitis complicated with recurrent infections were examined. The concentrations of plasma proteins of different molecular weight in the oedema fluid (collected from suction blisters) were highly increased. Albumin outflux as measured with radiolabelled albumin from the vessels of oedematous skin was markedly decreased corresponding to a decreased lymphatic function. Treatment with benzo-pyrones for 6 months did reduce the protein concentrations of the oedema fluid, but the clinical response was disappointing.

Albumins↗
PubMed1996

The use of 5,6 benzo-[alpha]-pyrone (coumarin) and heating by microwaves in the treatment of chronic lymphedema of the legs.

Sixty patients with leg lymphedema from a variety of etiologies were divided into randomized two groups, matched by Grade, duration, age, sex, and cause of lymphedema. Using a double-blind format, one group received 5,6 benzo-[alpha]-pyrone (coumarin 1,2 benzopyrone, 400 mg/day) for six months; the other received a placebo. For the next six months, both groups received a standardized regimen of heat (using microwaves) coupled with compression garments. Benzopyrone produced approximately 20% reduction in the volume (p = 10(-4)) and improvement in circumferences and tonometry (p = 10(-5) and 10(-7)). Symptoms (feelings of swelling, pain, heaviness and loss of mobility) were also significantly improved (p = 0.03 to 10(-7)). During the second six months, when microwave heat therapy was added to drug therapy, the patients who had previously received the placebo showed significant improvement (p = 0.03 to 10(-9)) in signs and symptoms of lymphedema. Some, but not all, of the group that was receiving benzopyrones were also significantly improved by heat therapy (p = 0.8 to 0.002). Taking benzopyrones for 12 months plus heat treatment for six months was significantly better, for some criteria, than the placebo plus heat therapy (p = 0.7 to 0.04). On the other hand, heat plus either placebo or benzopyrone was often significantly better than either the active or inactive drug without heat (p = 0.8 to 10(-9)).

Administration, Oral↗
PubMed1998

Species-dependent enantioselective pharmacokinetics of PNU-103017, a pyrone HIV protease inhibitor.

PNU-103017, 4-Cyano-N-(3-(cyclopropyl(5,6,7,8,9,10-hexahydro-4-hydroxy- 2-oxo-2H-cycloocta(b) pyran-3-yl)methyl)phenyl)-benzenesulfonamide, is a selective HIV aspartyl protease inhibitor under evaluation as a potential oral treatment of Acquired Immunodeficiency Diseases. PNU-103017 is a racemic mixture of two enantiomers, designated PNU-103264 (R-) and PNU-103265 (S-). Stereoselective pharmacokinetics of the two enantiomers of PNU-103017 were observed in the dog, rat, and human after single and multiple dose administration of the racemate and were apparently species-dependent. Mean enantiomeric ratios of plasma concentrations (R-/S-) at each time point were greater than 1 in the dog, ranging from 1.22 to 3.06, but less than 1 in the rat and in the human, ranging from 0.44 to 0.80 and 0.23 to 0.73, respectively. A trend towards increased or decreased (farther from 1:1, R-/S-) enantiomeric ratio of plasma concentrations with time after each administration was also observed. The enantiomeric ratio remained unchanged after multiple dose administration in the rat, dog, and human although enzyme induction and increased plasma clearance were observed for both enantiomers.

Animals↗