Synthesis, anti-toxoplasma gondii and antimicrobial activities of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted derivatives

A novel series of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted (3a-p) has been synthesized. The intermediates 2-hydrazolyl-3-phenyl-4-thiazolidinone substituted (2a-p) were prepared by condensation of benzaldehyde 4-phenyl-3-thiosemicarbazone substituted (1a-p) with ethyl chloroacetate. Theses intermediates were submitted to reaction with ethyl 2-cyano-3-(4-nitrophenyl)-acetate to give the title compounds. The 4-thiazolidinones were screened for their anti-Toxoplasma gondii, and all derivatives promoted decrease of percentage of infection of Vero cells, with elimination of intracellular tachyzoites. The LD50 ranged around 0.5 mM for the intracellular parasites and were higher than 10 mM for Vero cells. According to results of antimicrobial activity, only two compounds showed significant inhibition against M. luteus, but demonstrated higher values of MIC and MBC when compared with standard drug.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Synthesis, anti-toxoplasma gondii and antimicrobial activities of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted derivatives

A novel series of 2-hydrazolyl-3-phenyl-5-(4-nitrobenzylidene)-4-thiazolidinone substituted (3a-p) has been synthesized. The intermediates 2-hydrazolyl-3-phenyl-4-thiazolidinone substituted (2a-p) were prepared by condensation of benzaldehyde 4-phenyl-3-thiosemicarbazone substituted (1a-p) with ethyl chloroacetate. Theses intermediates were submitted to reaction with ethyl 2-cyano-3-(4-nitrophenyl)-acetate to give the title compounds. The 4-thiazolidinones were screened for their anti-Toxoplasma gondii, and all derivatives promoted decrease of percentage of infection of Vero cells, with elimination of intracellular tachyzoites. The LD50 ranged around 0.5 mM for the intracellular parasites and were higher than 10 mM for Vero cells. According to results of antimicrobial activity, only two compounds showed significant inhibition against M. luteus, but demonstrated higher values of MIC and MBC when compared with standard drug.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Acidification of the parasitophorous vacuole containing Toxoplasma gondii in the presence of hydroxyurea

Toxoplasma gondii multiplies within parasitophorous vacuole that is not recognized by the primary no oxidative defense of host cells, mainly represented by the fusion with acidic organelles. Recent studies have already shown that hydroxyurea arrested the intracellular parasites leading to its destruction. In the present work we investigated the cellular mechanism involved in the destruction of intracellular Toxoplasma gondii. Fluorescent vital stains were used in order to observe possible acidification of parasitophorous vacuole-containing Toxoplasma gondii in presence of hydroxyurea. Vero cells infected with tachyzoites were treated with hydroxyurea for 12, 24 or 48 hours. Fluorescence, indicative of acidification, was observed in the parasitophorous vacuole when the cultures were incubated in presence of acridine orange. LysoTracker red was used in order to determine whether lysosomes were involved in the acidification process. An intense fluorescence was observed after 12 and 24 hours of incubation with hydroxyurea, achieving it is highly intensity after 48 hours of treatment. Ultrastructural cytochemistry for localization of the acid phosphatase lysosomal enzyme was realized. Treated infected cultures showed reaction product in vesicles fusing with vacuole or associated with intravacuolar parasites. These results suggest that fusion with lysosomes and acidification of parasitophorous vacuole leads to parasites destruction in the presence pf hydroxyurea

Embryo sac development in yellow passion fruit Passiflora edulis f. flavicarpa (Passifloraceae)

The yellow passion fruit, Passiflora edulis f. flavicarpa, is one of the most important Brazilian fruit crops. It is an allogamous, diploid, and self-incompatible species. It has hermaphrodite, solitary flowers, located in the leaf axils and protected by leaf bracts. The flower has an androgynophore, which is a straight stalk supporting its reproductive parts. There are usually five anthers, located at the tip of each of the five filaments. The ovary is borne just above the filaments, at the top of the androgynophore; there are three styles that are united at their base, and at the top there are three stigmas. The objective of this research was to observe embryo sac development in yellow passion flowers. Ovaries at different stages of development were fixed in FAA (formalin, acetic acid and alcohol solution), hydrated, stained with Mayer’s hemalum, and dehydrated. Ovules were cleared by using methyl salicylate, mounted on slides, and observed through a confocal scanning laser microscope. The yellow passion fruit ovule is bitegmic, crassinucellate, and anatropous, and its gametophyte development is of the Polygonum type. After meiosis, functional megaspores under go three successive mitotic divisions, resulting in an eight-nucleate megagametophyte: the egg apparatus at the micropylar end, two polar nuclei at the cell center, and three antipodals at the chalazal end. The egg apparatus is formed by an egg cell and two synergids, each with a filiform apparatus. The mature embryo sac has an egg cell, two synergids, two polar nuclei, and three antipodes, as has been described for most angiosperms