Identification of benzoylisoquinolines as potential anti-Chagas agents.

A set of three 3-benzoyl substituted isoquinolones was synthesized in good yields and assayed for in vitro trypanocidal activity against Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease. Depending on the concentration evaluated, a greater or equivalent reduction in the number of bloodborne trypomastigotes compared to that observed with benznidazole, a drug currently used to attack the parasite, was observed for two of the samples. In order to assess the potential of the 3-benzoylisoquinolone nucleus as a possible scaffold in the design of novel anti-trypanosomal lead structures, a computational analysis was performed using structural and inhibition information from both functional and target assays archived in the online database, ChEMBL. Chemical space projection of the synthesized compounds along with 3067 structures with known activities against T. cruzi shows that the isoquinolones occupy a sparsely-populated region of chemical space, indicating their potential for development as a novel class of trypanocidals. In addition, 2D and 3D structural similarity analyses revealed micromolar and submicromolar inhibitors of T. cruzi in ChEMBL with high similarity to the synthesized structures.

1,2,3,3',4',6'-Hexaacetyl-4,6-O-benzyl-idenesucrose.

In the title compound, C(31)H(38)O(17), the 1,3-dioxane and pyran-oside rings both show (4)C(1) chair conformations while for the d-fructofuran-oside moiety an envelop 3E conformation is observed. The phenyl ring is oriented almost perpendicular to the 1,3-dioxane ring [dihedral angle = 79.3 (2)°], and the acetate groups are equatorial for the pyran-oside ring and axial for the furan-oside ring. The analysis of potential hydrogen bonds shows both intra- and inter-molecular C-H⋯O contacts to be present.

Gibberellic acid production by free and immobilized cells in different culture systems.

Gibberellic acid production was studied in different fermentation systems. Free and immobilized cells of Gibberella fujikuroi cultures in shake-flask, stirred and fixed-bed reactors were evaluated for the production of gibberellic acid (GA3). Gibberellic acid production with free cells cultured in a stirred reactor reached 0.206 g/L and a yield of 0.078 g of GA3/g biomass.

Synthesis of phenylazonaphtol-ß-D-O-glycosides, evaluation as substrates for beta-glycosidase activity and molecular studies.

BACKGROUND: Phenylazonaphtol-ß-D-O-glycosides are alternative substrates for the detection of enzymatic activity of ß-glycosidases which are involved in various important processes. These azoic compounds are currently exploited as prodrugs for colonic disease due the presence of ß-glycosidase activity in the gut flora and therefore allowing the release of the drug at the specific site. RESULTS: Phenylazonaphtol-ß-D-O-glucoside 3a and galactoside 3b were prepared via diazonium salt conditions under weak acidic conditions which do not compromise the O-glycosidic bond stability, by coupling reaction between 2-naphtol sodium salt with aminoglycosides 1a and 1b. The resulting phenylazonaphtol glycosides 2a and 2b were deprotected affording the phenylazonaphtol glycosides 3a and 3b in quantitative yield. The galactoside glycoside 3b was assayed as substrate for in vitro ß-galactosidase enzymatic activity showing strong absorbance after releasing of the azoic chromophore. Also, docking studies were performed to determine the best pose as well as the interactions between the ligand and the residues located at the active site. CONCLUSIONS: The methodology developed for synthesizing the phenylazonaphtol glycosides described proved to be convenient for generating azoic functionalities in the presence of glycosidic bonds and the glycosides suitable as alternative substrates and potentially useful prodrugs in the treatment of colonic diseases.

Synthesis of tricolorin F.

A hetero-trisaccharide resin glycoside of jalapinolic acid known as tricolorin F has been synthesized. The approach involved the preparation of intermediate 5 and a subsequent coupling reaction with imidate 6 to produce disaccharide 7, which after deacetylation generated intermediate 8. A further coupling between this glycosyl acceptor and the quinovose glycosyl donor 9 resulted in the formation of the tricoloric acid C derivative 10. Basic hydrolysis afforded the intermediate 11, which was subsequently lactonized under Yamaguchi conditions to produce protected macrolactone 12. Removal of acetonide and benzyl protecting groups afforded pure tricolorin F (1).

A comparative analysis of mono- and disaccharide benzyl fucopyranosides.

The syntheses and X-ray analyses of two fucopyranosides, the monosaccharide benzyl 3,4-di-O-acetyl-2-hydroxy-beta-D-fucopyranoside, C(17)H(22)O(7), and the disaccharide 1-benzyl O-(2,3-di-O-acetyl-4,6-O-benzylidene-beta-D-glucopyranosyl)-(1-->2)-3,4-O-isopropylidene-beta-D-fucopyranoside, C(33)H(40)O(12), are described. The different substituents induce small conformational changes on the fucopyranoside ring. However, the conformation of the benzyl group varies from (+)gauche for the monosaccharide to synperiplanar for the disaccharide.