EVALUATION OF HEMOLYTIC ACTIVITY OF YANGAMBIN ISOLATED FROM Ocotea duckei VATTIMO-GIL

Yangambin, a lignan isolated from the leaves of Ocotea duckei Vattimo-Gil, has several pharmacological activities described in literature. However, few information about its toxicity has been reported. Red cells represent about 90% of blood cells and have interesting structural and molecular characteristics as experimental models in toxicological studies. Thus, the aim of this study was to evaluate the hemolytic action of yangambin in sheep blood. The hemolysis assay was performed at concentrations of 50, 25 and 12.5 µg/mL of yangambin in triplicate and hemolysis percentage was defined through the absorbance resulting from the test concentrations compared to the positive control. The results showed that yangambin did not cause hemolysis at the concentrations tested, therefore it did not cause damage to the plasma membrane of sheep erythrocytes.

Psolusosides C3 and D2-D5, Five Novel Triterpene Hexaosides From the Sea Cucumber Psolus fabricii (Psolidae, Dendrochirotida): Chemical Structures and Bioactivities

Five new triterpene glycosides, psolusosides C3 (1), D2 (2), D3 (3), D4 (4), and D5 (5), have been isolated from the sea cucumber Psolus fabricii. The structures of these glycosides were elucidated by 2-dimensional nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. All the compounds contain hexasaccharide carbohydrate chains, differing from each other in the third monosaccharide residue: xylose was found in psolusosides of group C and glucose in group D. Aglycones of the isolated compounds belong to the holostane type, contain 9(11)-double bond and 16-keto-group and have different side chains. The hemolytic activity against mouse erythrocytes and cytotoxic activity against mouse Ehrlich carcinoma cells (ascite form) and neuroblastoma Neuro 2A cells of 1 to 5 as well as the psolusosides isolated by us earlier, C1, C2, and D1, 26-nor-25-oxo-holotoxin A1, and holotoxin A1, have been studied. Psolusosides C2, D1, and D2 (2) having the aglycones without hydroxy group in the side chain showed the strongest hemolytic action in this series. Psolusoside D3 (3) containing a peroxide group in the side chain of its aglycone was surprisingly highly cytotoxic in all the tests.

Long time not seen: Expanding the records of Loxosceles amazonica (Araneae: Sicariidae) in the Amazonas state, Brazil

ABSTRACT Spiders of the genus Loxosceles, commonly known as brown recluse spiders, can cause serious accidents in humans. Their venom has a powerful proteolytic and hemolytic action. Each year these spiders are the cause of a great number of araneism in Brazil. This work presents new records of Loxosceles amazonica for the municipal districts of Manaus and Iranduba, Amazonas, Brazil.

Review of surfactin chemical properties and the potential biomedical applications

Surfactin, a highly powerful biosurfactant produced by various strains of the genus Bacillus, exhibits antibacterial, antiviral, antitumor and hemolytic action. This anionic cyclic lipopeptide is constituted by a heptapeptide interlinked with a β-hydroxy fatty acid. Due to its amhipathic nature surfactin incorporates into the phospholipid bilayer and induces permeabilization and perturbation of target cells. The rising antibiotic resistance as well as a number of remarkable surfactin activities shows that it deserves special interest and is considered as a candidate compound for combating several health related issues. In this review, the current state of knowledge of surfactin properties, biomedical potential and limitations for its application is presented.