Schistosomicidal Effects of the Essential Oils of Citrus limonia and Citrus reticulata Against Schistosoma mansoni

We report the in vitro schistosomicidal effects of the essential oil obtained from Citrus limonia leaves (CL ‐EO ) and C. reticulata fruit peels (CR ‐EO ), cultivated in Brazil, against Schistosoma mansoni worms. Limonene (29.9%), β ‐pinene (12.0%), sabinene (9.0%), citronellal (9.0%), and citronellol (5.8%) are the major constituents of CL ‐EO ; limonene (26.5%), γ ‐terpinene (17.2%), linalool (11.1%), octanal (8.0%), myrcene (6.2%), and capraldehyde (3.9%) predominate in CR ‐EO . CL ‐EO displayed moderate lethal concentration 50% (LC ₅₀) of 81.7 and 38.9 μg/ml against male and female worms at 24 and 72 h, respectively. At concentrations of 25 and 100 μg/ml, CL ‐EO separated between 50 and 75% of the coupled worm pairs during the evaluated period. CR ‐EO presented moderate LC ₅₀ of 81.7 μg/ml against male and female worms at 24 and 72 h. However, this oil separated coupled worm pairs more effectively than CL ‐EO and displayed lower cytotoxicity to GM 07492‐A cells (IC ₅₀ = 987.7 ± 88.9 μg/ml) as compared to CL ‐EO (IC ₅₀ = 187.8 ± 2.9 μg/ml). The enantiomers (+)‐(R )‐limonene and (?)‐(S )‐limonene did not affect S. mansoni adult worm pairs significantly. Taken together, these data indicate that CL ‐EO and CR ‐EO exhibit moderate in vitro schistosomicidal activity against adult S. mansoni worms.     

A new sequence data set of SSU rRNA gene for Scleractinia and its phylogenetic and ecological applications

Scleractinian corals (i.e. hard corals) play a fundamental role in building and maintaining coral reefs, one of the most diverse ecosystems on Earth. Nevertheless, their phylogenies remain largely unresolved and little is known about dispersal and survival of their planktonic larval phase. The small subunit ribosomal RNA (SSU rRNA) is a commonly used gene for DNA barcoding in several metazoans, and small variable regions of SSU rRNA are widely adopted as barcode marker to investigate marine plankton community structure worldwide. Here, we provide a large sequence data set of the complete SSU rRNA gene from 298 specimens, representing all known extant reef coral families and a total of 106 genera. The secondary structure was extremely conserved within the order with few exceptions due to insertions or deletions occurring in the variable regions. Remarkable differences in SSU rRNA length and base composition were detected between and within acroporids (Acropora, Montipora, Isopora and Alveopora) compared to other corals. The V4 and V9 regions seem to be promising barcode loci because variation at commonly used barcode primer binding sites was extremely low, while their levels of divergence allowed families and genera to be distinguished. A time‐calibrated phylogeny of Scleractinia is provided, and mutation rate heterogeneity is demonstrated across main lineages. The use of this data set as a valuable reference for investigating aspects of ecology, biology, molecular taxonomy and evolution of scleractinian corals is discussed.     

Changes in the metabolism of tryptophan in erythematosus

An abnormal tryptophan metabolism is present in patients affected by Erithematodes with high excretion particularly of kynurenines and xanthurenic acid.     

Preparation and properties of des-Tyr98 and des-Arg97-Tyr98 acylphosphatase (muscular isoenzyme).

Previous NMR reports indicated that Tyr98, the C-terminal residue of the muscular form of acylphosphatase, is likely to be part of the enzyme's active site. In addition, there is evidence that an arginine residue participates to the catalyzed reaction, possibly as phosphate binding site. Among all Arg residues present in the muscular forms of acylphosphatase, four, i.e. Arg23, Arg74, Arg77, and Arg97, appear to be conserved in all species checked thus far. We prepared the des-Tyr98 and des-Arg97-Tyr98 derivatives of the native acylphosphatase to investigate the properties of both modified enzymes. The enzyme lacking Tyr98 was found to be catalytically less effective than the native one, whereas the des-Arg97-Tyr98 acylphosphatase was completely inactive. This evidence suggests that Arg97 participates directly to the active site catalytic mechanism. Fluorescence and CD spectra revealed that the latter enzyme could have been undergone some conformational change that could account for the loss of activity; on the other hand, the one-dimensional NMR spectra of either native and des-Arg97-Tyr98 enzymes were strictly similar, thus demonstrating that the removal of the two C-terminal residues does not markedly affect the fold of the enzyme. The results reported are proof of a critical contribution of Arg97 to the acylphosphatase active site; however, we cannot exclude that the function of this residue is merely to stabilize the active site conformation and dynamics.