Discovery of a new sesquiterpenoid from Phellinus ignarius with antiviral activity against influenza virus

Seven natural products, including one new sesquiterpenoid (eudesm-1β, 6α, 11-triol, compound 1), one ergosta -4, 6, 8(14), 22-tetraen-3-one (compound 2), four polyphenols (compounds 3, 4, 5, 6), and one pyrone (3-hydroxy-2-methyl-4-pyrone, compound 7) were isolated from cultures of Phellinus ignarius by column chromatography. The detailed structure of compound 1 was determined using a combination of one- and two-dimensional nuclear magnetic resonance, mass spectrometry and infrared spectroscopy. The antiviral activity of these compounds against H5N1 influenza A virus was investigated using an MTT colorimetric assay system in Madin-Darby canine kidney cells. The results indicate that compound 1 possesses significant ability to inhibit influenza virus. The 50 % effective concentration was 0.14 ± 0.04 μM. Molecular modeling further suggested that the anti-influenza virus activity of this compound was partially attributed to the interactions of hydroxyl groups with an amino acid residue (Asn 170) of neuraminidase (NA) at the binding site. Moreover, the results of enzyme inhibition assays indicated that 50 % inhibition of NA was achieved by compound 1 at a concentration of 0.657 ± 0.325 mg/mL, which suggested that compound 1 is likely to interact with the NA enzyme.     

Isolation of Trichoderma atroviride from a liver transplant

Six species of Trichoderma have been associated with 24 human infections to date. This is the first report of Trichoderma atroviride, cultured from a liver biopsy specimen of a liver transplant recipient. In the settings of permissive environmental conditions, we may anticipate that emergent Trichoderma spp. infections will continue to develop.     

Butylmaduramycin, a new antibiotic from Actinomadura rubra

Butylmaduramycin, a new derivative of maduramycin was isolated from the culture medium of a mutant strain of Actinomadura rubra. This communication describes some biological and physico-chemical characteristics of the new antibiotic.     

Legiolysin, a new hemolysin from L. pneumophila

Legionella pneumophila generates exotoxins, cytolysins, proteases or hemolysins that damage host cells like erythrocytes or tissue culture cells. The gene for a new L. pneumophila hemolysin without a proteolytic activity was identified, cloned in E. coli and sequenced. The gene product was analysed by SDS-Polyacrylamide-gel-electrophoresis.     

Parana,a new tacaribe complex virus from Paraguay

Summary Parana virus, an agent isolated fromOryzomys buccinatus rodents trapped in the Misiones Department of Paraguay, was found to be related to the Tacaribe complex of viruses by complement-fixation tests, but was distinct by neutralization and direct immunofluorescent tests. It shares the basic properties of chloroform sensitivity, a ribonucleic acid core, and similar morphologic appearance with other viruses in the complex. No evidence for human infection was found in a limited survey. Neutralizing antibody was not demonstrable in 111 rodent sera, three of which were the animals from which the virus was isolated.     

Pro-inflammatory activity in rats of thiocyanate, a metabolite of the hydrocyanic acid inhaled from tobacco smoke

Objective  

To seek a mechanism linking tobacco smoking with the increased incidence and severity of rheumatoid arthritis, deduced from many retrospective surveys, by studying arthritis/fibrosis development in rats.     

An enzyme immunoassay for a metabolite of a new sleep inducer (450191-S), a ring-opened derivative of 1,4-benzodiazepine, in human serum

A competitive enzyme immunoassay was developed for metabolites of 450191-S, a ring-opened derivative of triazolobenzodiazepines, in human serum. Three kinds of labelled antigens, beta-D-galactosidase conjugates, and antisera from three kinds of immunogens, bovine serum albumin conjugates, were tested and the hapten heterologous assay was selected. B/F separation was performed using immobilized second antibody and the enzyme activity was measured using fluorescent substrate. One of the serum metabolites, the carboxyl form, was extracted from acidified serum and measured by the assay. The minimum detectable concentration was 1.5 ng/ml in serum, 15 pg/tube. The intra-assay and inter-assay variances were 5.5% and 7.7% at 6 ng/ml of serum, respectively. Standard curves of other related metabolites were assessed with various combinations of labelled antigens and antibodies.     

Tridacnin, a new mitogenic lectin from invertebrate sources.

A new group of invertebrate lectins with anti-beta-galactosyl specificity, the so-called Tridacnins from the Tridacnid bivalve clams have been found to show not only agglutinating and precipitating properties, but also mitogenic activity as tested with human lymphocytes.     

Preliminary disk diffusion susceptibility testing criteria for cefdaloxime (RU29246, HR-916 metabolite), a new orally administered cephalosporin.

Cefdaloxime (formerly RU29246; Hoechst-Roussel Pharmaceuticals Inc., Somerville, N.J.) a new active component of the HR-916 ester, was tested by dilution and two disk (10- and 30-micrograms) diffusion susceptibility tests against 391 clinical isolates. Interpretive criteria were proposed for three potential MIC breakpoints of less than or equal to 1, less than or equal to 2, and less than or equal to 4 micrograms/ml. Analyses by regression line and error rate bounding methods minimized false-susceptible (very major) errors and produced a greater than or equal to 90% absolute interpretive agreement between susceptibility test methods. The less than or equal to 2-micrograms/ml breakpoint seemed optimal when 10-micrograms disks and the available human pharmacokinetics were used. The following inhibition zone diameter criteria were proposed: susceptible, greater than or equal to 19 mm; resistant, less than or equal to 15 mm. These recommendations for clinical trials should remain tentative until additional information about cefdaloxime formulations, pharmacokinetics, and patient outcomes can be correlated with in vitro susceptibility test results.