Mechanistic characterization and inhibition of sphingomyelinase C over substituted Iron Schiff bases of chitosan adsorbed on glassy carbon electrode.

The medical treatment of laxoscelisms is based solely on supportive measures. Although equine antiserum for Sphingomyelinase C (SMASE) and D isomers are available, it is not used due to the risk of an anaphylactic reaction and its unproven efficacy. As potential enzyme inhibitors, derivatives of Iron chitosan complexes were studied (Shiff base having -R = -H, -Cl, -Br, -F, -OCH3, -CH3, -NO2). These chitosan complexes were chosen because they have revealed good results in medicine and catalysis due to their biodegradable characteristics and bioavailability. Besides considering that these complexes have not been studied in relation to this toxin. The mechanisms underlying the catalytic and catcher effects of Iron chitosan complexes were studied using electrochemistry, UV-Vis spectroscopy and microscopic assay at physiological pH. The electrochemical studies showed that one of seven Schiff bases of chitosan adsorbed on glassy carbon electrode was electrocatalytically active for the oxidation of sphingomyelinase at 1.27 V, and that allowed proposing a reaction scheme for SMASE oxidation by adsorbed Iron complexes. On the other hand, even though the spectroscopic studies indicated that there was no chemical bond formation between the complex and SMASE in solution, the microscopic studies showed that this complex proved to be a remarkable cellular protector in presence of the enzyme. In conclusion, Shiff base of chitosan with R = -CH3 was the only active complex in front of sphingomyelinase C, protecting red blood cells, according to our electrochemical and microscopic studies.

Structural studies of the exopolysaccharide produced by a submerged culture of entomopathogenic fungus Metarhizium anisopliae / Estudio estructural del exopolisacárido producido por un cultivo sumergido del hongo entomopatogénico Metarhizium anisopliae

The exopolysaccharide (EPS) separated from the entomopathogenic fungus Metarhizium anisopliae was determined by gel permeation chromatography to be homogeneous. The high-performance anion-exchange chromatography with pulsed-amperometric detection (HPAE-PAD) showed a content of monosaccharides D-galactosamine and D-fucose at a molar ratio of about 2:1. The results obtained from Fourier transform-infrared spectroscopy (FT-IR) and second derivative FT-IR spectrum confirmed the proposed structure.

El exopolisacárido (EPS) separado desde el hongo entomopatogénico Metarhizium anisopliae determinado por cromatografía de exclusión en gel ser homogéneo. La cromatografía iónica de alto rendimiento con detección de pulso amperométrico (HPAE-PAD) mostró un contenido de monosacáridos D-galactosamina y D-fucosa en una relación molar de alrededor de 2:1. Los resultados obtenidos desde la espectroscopía infrarroja con transformada de Fourier (FT-IR) y la segunda derivada del espectro FT-IR confirmaron la estructura propuesta.

Antibacterial activity of an oligosaccharide of native Paecilomyces sp. and its aminoglycosylated derivative.

This study reports the antibacterial activity of an oligosaccharide, prepared by partial acid hydrolysis of a native Paecilomyces sp. exopolysaccharide, and of its aminoglycosylated derivative, prepared by reductive alkylation of the oligosaccharide, against E. coli and S. aureus.

Solubility effects on antibacterial activity of chemically modified chitooligosaccharides of fungal origin / Efectos de la solubilidad sobre la actividad antibacteriana de quitooligosacáridos modificados químicamente de origen fúngico

Chitin and chitosan are a class of metabolites that occurring in some fungi species that are associated with commercial and medicinal plants, this is in Mucor sp. for example with an ample number of biological activities, being antibacterial and antifungal one of the most important. Into our program of search of biopesticides and natural compounds with biological activities, we have studying chitosan that was obtained from the culture medium of the fungus Mucor ruoxii. Chitooligosaccharides were prepared by partial acid hydrolysis of native chitosan and an aminoglycosylated derivative was obtained by reductive amination of the chitooligosaccaride. The solubilities of these compounds were measured at different pHs and its antibacterial activity against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). Chitosan and the derivatives tested exhibited a good antibacterial activity against S. aureus.

Quitina y quitosano son una clase de metabolitos que producen algunas especies de hongos que están asociados con plantas medicinales y comerciales, esto es por ejemplo en Mucor sp., con un amplio número de actividades biológicas, siendo la antibacteriana y antifúngica unas de las más importantes. En nuestro programa de investigación de biopesticidas y compuestos naturales, estamos estudiando quitosano obtenido de el medio de cultivo del hongo Mucor ruoxii. Quitooligosacáridos fueron preparados por hidrólisis parcial ácida de quitosano nativo y un derivado aminoglicosilado fue obtenido por aminación reductiva del quitooligosacárido. Las solubilidades de estos compuestos fueron medidas a diferentes pHs y su actividad antibacteriana frente a Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). Quitosano y los derivados testeados exhiben una buena actividad antibacteriana frente a S. aureus.

Antibacterial activity of chitooligosaccharides.

The aim of this study was to investigate the antibacterial activity of chitooligosaccharide, prepared by partial acid hydrolysis of chitosan, and of an aminoglycosylated derivative, prepared by reductive alkylation of the chitooligosaccharide, against E. coli and S. aureus.

Structural studies of native Paecilomyces sp. Exopolysaccharide.

A polysaccharide separated from Paecilomyces sp. was determined by gel permeation chromatography to be homogeneous. HPLC showed a monosaccharide containing D-glucose and D-fructose at a ratio of about 2:1. The results obtained from IR, 1H NMR, and 13C NMR analyses confirmed the proposed structure.

Production of exopolysaccharides by a submerged culture of an entomopathogenic fungus, Paecilomyces sp.

Exopolysaccharide basic was obtained from a submerged culture of a native Paecilomyces sp. strain isolated from Chilean soil.