Maria Auxiliadora Fontes Prado

In vitro evaluation of the activity of aromatic nitrocompounds against Trypanosoma cruzi

Fourteen compounds were evaluated for their activity against Trypanosoma cruzi blood stream forms at the concentration of 500 g/ml. Six compounds were active and re-tested at lower concentrations.

Synthesis of New Five Membered Nitrogen Containing Heterocycles Bearing D-Galactose Side Chains

Abstract The synthesis of 5-[6′-deoxy-(1′,2′:3′,4′-di-O-isopropylidene-α-D-galactopyranos-6′-yl)]tetrazole and its reaction with acetic anhydride and 1,2:3,4-di-O-isopropylidene-6-O-(4-toluenesulfonyl)-α-D-galactopyranose are described.

Synthesis of Nitrogen Heterocycles from Methyl α‐ and β‐d‐Glucopyranosides

Eight nitrogen heterocycles, mono and disubstituted tetrazoles and oxadiazoles, were synthesized from methyl d‐glucopyranoside anomers. The monosubstituted tetrazoles resulted from the reaction of 6‐cyanoglucopyranoside derivatives with sodium azide. By alkylation of the monosubstituted tetrazoles, the 1,5 and 2,5 disubstituted tetrazoles were obtained. The monosubstituted tetrazoles were reacted with acetic anhydride to give the oxadiazoles.

Síntese de amidas e sulfonamidas de beta-D-galactopiranosilamina e beta-lactosilamina e avaliação de suas interações com lectinas de Erythrina cristagalli e de Ricinus communis

We report herein the synthesis of some b-D-galactopyranosylamine and b-lactosylamine amides and sulfonamides. The interactions of these compounds with lectins from the seeds of Erythrina cristagalli (LEC) and Ricinus communis (RCA120) were evaluated in a hemagglutination inhibitory activity assay. D-Galactose and lactose were used as reference compounds. The b-lactosylamine amides and sulfonamides were nearly as active as lactose in inhibiting LEC mediated hemagglutination and were less active against RCA120 agglutinin. The b-D-galactopyranosylamine amides and sulfonamides were, with one exception, considerably less active than D-galactose in the assay with both lectins.

Microwave‐Assisted Rapid Deacetalation of Carbohydrates

Abstract A simple and fast procedure to deprotect carbohydrate 4,6‐di‐O‐benzylidene acetals was accomplished by using domestic microwave‐oven irradiation in solvent‐free conditions and with silica‐gel‐supported reagents.

Synthesis of Benzomacrolactam by 12- endo Selective Aryl Radical Cyclization of N -(4-Allyloxybutyl)-2-iodobenzamide

Abstract Regioselective 12-endo aryl radical cyclization of N-(4-allyloxybutyl)-2-iodobenzamide (7) with tri-n-butyltin hydride provided benzomacrolactam 15. The structure of 15 is supported by 1H and 13C NMR spectroscopy and by DEPT, COSY, COSYLR and HMQC experiments.

Stereoselective synthesis of carbohydrate-based fused bicyclic delta-lactones

We describe in the present work the synthesis of carbohydrate-based chiral d-lactones by regio- and stereoselective radical cyclization reactions. The configuration of the newly stereogenic center was found to depend on the structure of the carbohydrate moiety.

Synthesis of Benzomacrolactam by 11endo Selective Aryl Radical Cyclization of 2Iodobenzamide Derived from DGalactose

Encouraged by our previous studies of tri-n-butyltin-mediated radical cyclization reaction of o-iodobenzamides, we applied this methodology to the synthesis of benzomacrolactam 2 from methyl 4-O-allyl-2,3-di-O-benzyl-6-deoxy-6-(2-iodobenzoylamino)- α-D-galactopyranoside 1. Apart from the macrolactam 2, resulting from regioselective 11-endo aryl radical cyclization, the hydrogenolysis produt 3 was obtained. The o-iodobenzamide 1 was prepared in eight conventional synthetic steps from methyl α-D-galactopyranoside. The unequivocal structures of 1, 2 and 3 were supported by 1H, 13C and DEPT NMR spectroscopy and by COSY and HMQC experiments.

A NEW APPROACH TO THE SYNTHESIS OF A KEY INTERMEDIATE IN THE SYNTHESIS OF LINCOMYCIN

Abstract 6-acetamido-6,8-dideox-1,2:3,4-di-O-isopropylidene- D -glycero-α-D-galacto-octopyranos-7-ulose (6), has been synthesised from D -galactose. The side chain elongation was carried out by cyano-amination of the protected dialdo sugar (2), followed by N-acetylation, and a subsequent Grignard reaction.

Synthesis of New Tetrazole Derivatives of α,α‐Trehalose

Abstract Five new nitrogen heterocycles, mono‐and disubstituted tetrazoles with potential synthetic and pharmacological interest, were synthesized from α, α‐trehalose via the alkylation of commercial tetrazoles. This method appears to have broad scope with respect to the variations at positions 1 and 2 of tetrazole.