Dimethyl-2-[(acridin-9-yl)methylidene]-malonate as fluorescent probe for histochemical analysis.

Fluorescent compounds have been widely used for biomolecule labeling in cytochemistry and histochemistry analysis. Here, it is described the optical properties of dimethyl 2-[(acridin-9-yl)methylidene]-malonate (LPSF/IP-81), an acridine derivative. This compound was conjugated to Concanavalin A (Con A) lectin and applied as sugar probe in lectin histochemistry. Evaluation of luminescent properties showed that LPSF/IP-81 is photoluminescent with excitation at 360 nm and emission at 428 nm. Con A hemagglutinating activity and LPSF/IP81 photoluminescence were unaltered after conjugation. Circular dichroism of Con A-LPSF/IP81 conjugate showed the maintenance of the Con A structure. Lectin histochemistry with Con A-LPSF/IP81 conjugate demonstrated different pattern recognition studying normal, fibroadenoma, and invasive ductal carcinoma of human breast. These findings indicate that LPSF/IP-81 can be proposed as an alternative probe for histochemical analysis.

Biological and immunological activity of new imidazolidines against adult worms of Schistosoma mansoni.

The only drug available for treating schistosomiasis is praziquantel, however there are already reports of resistance to its use in treatment, making it necessary to search and develop new compounds to combat schistosomiasis. We tested, in vitro, two new products, Laboratório de Planejamento de Síntese de Fármacos (LPSF)/5-(4-chloro-benzylidene-3-(4-nitrebenzyl)-4-thioxo-imidazolidin-2-one (RZS-2) and LPSF/5-(4-fluoride-benzylidene-3-(4-nitrebenzyl)-4-thioxo-imidazolidin-2-one (RZS-5) imidazolidines, against adult worms of Schistosoma mansoni. Efficacy and safety of these compounds were analyzed through IC50 cytotoxicity, immune response and cell viability tests. At different concentrations ranging from 40-640 microM, the imidazolidines produced motor abnormalities, inhibition of pairing and oviposition and mortality within 24 h at the higher concentrations. Although not triggering changes in IFN-gamma and IL-10, LPSF/RZS-2 and LPSF/RZS-5 induced production of nitric oxide and showed similar behavior to praziquantel in the cell death test.