Secondary metabolites from Detarium microcarpum Guill. and Perr. (Fabaceae).

The chemical investigation of the ethanol/water (7:3) extract of the roots of Detarium microcarpum (Fabaceae) led to the isolation of one new labdane diterpenoid, microcarpin (1) and one new ceramide derivative, microcarpamide (2), along with eight known secondary metabolites (3-10) including, 5-(carboxymethyl)-5,6,8a-trimethyl-3,4,4a,5,6,7,8,8a-octahydronaphthalene-1-carboxylic acid (3), microcarposide (4), rhinocerotinoic acid (5), 1,7-dihydroxy-6-methylxanthone (6), ursolic acid (7), 3ß,23-dihydroxylup-20(29)-en-28-oic acid (8), alphitolic acid (9), and stigmasterol glucoside (10). The structures of these compounds were elucidated based on their spectroscopic data. Although compounds 3 and 4 are known, their crystalline structures are reported here for the first time. These compounds were evaluated in vitro for their antisalmonella activity. The results obtained showed that, microcarpamide (2), microcarposide (4), and rhinocerotinoic acid (5) were moderately active against three salmonella strains: Salmonella typhi, Salmonella enteritidis and Salmonella typhimirium, with minimum inhibition concentration values of 76.7 and 153.5 µM.

Usefulness of the phage display technology for the identification of a hepatitis C virus NS4A epitope recognized early in the course of the disease.

A dodecapeptide phage-displayed library was screened with the mouse monoclonal antibody (mAb) 2E3C2 which competed with human antibodies for the binding to the HCV c100 recombinant protein. Four mimotopes shared a consensus motif with the HCV 1701-1707 sequence corresponding to the carboxyl-terminal domain of the non-structural protein NS4A. However, these mimotopes reacted with 2E3C2 only, whereas the corresponding NS4 epitope defined at the sequence 1698-1709 and displayed on phage was recognized by both 2E3C2 and sera from HCV infected patients. Using the Spot method of multiple peptide synthesis and alanine replacement analysis, the respective reactivities of mAb 2E3C2 and anti-NS4A human antibodies against NS4 were shown to be directed against two slightly different overlapping minimal linear sequences and to involve different critical residues. The phage clone displaying the NS4 epitope was used to study the specific recognition of this epitope by different individual HCV positive sera as well as by two seroconversion panels of sera from HCV infected patients. Compared with the detection by RIBA of the different HCV antigens and c100 particularly, these results indicated that the antibodies directed against the NS4 (1698-1709) epitope were produced early during the course of the disease and decreased later.

The function of the superficial root mat in the biogeochemical cycles of nutrients in congolese eucalyptus plantations.

BACKGROUND AND AIMS: The importance of superficial root mats inside the forest floor for the nutrition of Amazonian rain forests has been extensively investigated. The present study was aimed at assessing the function of a root mat adherent to decomposing organic material observed in Eucalyptus plantations. METHODS: The development of the root mat was studied through micromorphological observations of thin litter sections, and the influence of soil microtopography and soil water repellency on root mat biomass was assessed in situ on an area of 5 m2. In addition, input-output budgets of nutrients within the forest floor were established from measurements of litterfall, dissolved nutrients in gravitational solutions, and forest floor nutrient contents. KEY FINDINGS: The amounts of nutrients released during litter decay in this ecosystem during the period of study were, on average, 46, 3, 4, 19 and 17 kg ha-1 year-1 for N, P, K, Ca and Mg, respectively. The simultaneous measurements of the chemical composition of throughfall solutions and leachates beneath the forest floor showed a very quick uptake of nutrients by the root mat during the decomposition processes. Indeed, the solutions did not become noticeably enriched in nutrients during their passage through the holorganic layer, despite large amounts of elements being released during litter decay. The root mat biomass decreased significantly during the dry season, and a preferential development in microdepressions at the soil surface was observed. A strong water repellency observed in these depressions might enhance the ability of the roots to take up water and nutrients during the dry periods. CONCLUSIONS: The root mat was active throughout the year to catch the flux of nutrients from the biodegradation of the forest floor, preventing the transfer of dissolved nutrients toward deeper soil horizons. This mechanism is involved in the successful adaptation of this Eucalyptus hybrid in areas covered by 'climacic' savannas in Congo.

Detection of antibodies to deiminated recombinant rat filaggrin by enzyme-linked immunosorbent assay: a highly effective test for the diagnosis of rheumatoid arthritis.

OBJECTIVE: To assay antifilaggrin autoantibodies, we developed an enzyme-linked immunosorbent assay (ELISA) using a "citrullinated" recombinant rat filaggrin. Our objectives were to assess its value for diagnosing rheumatoid arthritis (RA) and to compare the results with those obtained using 4 other reference methods for detection of antifilaggrin autoantibodies, including the commercially available ELISA that uses a modified "citrullinated" synthetic peptide derived from the sequence of human filaggrin (CCP-ELISA). METHODS: We analyzed 711 sera from patients with well-characterized rheumatic diseases, including 240 patients with RA. Antifilaggrin autoantibodies were detected by an ELISA using a recombinant rat filaggrin deiminated in vitro as immunosorbent (ArFA-ELISA). The results considered were the differences between the optical densities obtained on deiminated and nondeiminated proteins. Antibodies to rat esophagus epithelium were detected by indirect immunofluorescence, while antibodies to human filaggrin were detected by immunoblotting and by a recently described ELISA using a deiminated recombinant human filaggrin. Finally, CCP-ELISA was performed according to the manufacturer's recommendations. RESULTS: At the titer thresholds allowing diagnostic specificities of 0.95, 0.985, and 0.99 to be reached, the diagnostic sensitivities of the ArFA-ELISA were 0.76, 0.67, and 0.65, respectively. At these 3 thresholds, the sensitivities were significantly higher than those of the 4 other tests. Despite incomplete overlapping of the 5 tests, the high diagnostic performance of the ArFA-ELISA allows us to propose this test to replace all the other methods for antifilaggrin autoantibody detection. CONCLUSION: ArFA-ELISA appears to be the most efficient test among those available for the detection of antifilaggrin autoantibodies, in terms of diagnostic accuracy for RA. Its diagnostic performance in early RA and its prognostic value are currently under evaluation.