RESUMEN
The asymmetric synthesis of the orthogonally protected N-mannosyl d-ß-hydroxyenduracididine (N-Man-d-ßhEnd) is described, starting from enantiopure silylated (S)-serinol. The key steps are: (i) glycosylamine formation between protected serinol and a benzylated d-mannose; (ii) guanidinylation; and (iii) cyclic guanidine formation. This synthesis constitutes a breakthrough in our studies towards a total synthesis of mannopeptimycin and should also allow for other studies in the field of mannopeptimycin research, including the synthesis of derivatives.
Asunto(s)
Productos Biológicos/síntesis química , Glicopéptidos/síntesis química , Manósidos/síntesis química , Pirrolidinas/síntesis química , Productos Biológicos/química , Glicopéptidos/química , Manósidos/química , Conformación Molecular , Pirrolidinas/química , EstereoisomerismoRESUMEN
Preparation of Lipidâ II analogues containing an enzymatically uncleavable 1-C-glycoside linkage between the disaccharide moiety and the pyrophosphate- or pyrophosphonate-lipid moiety is described. The synthesis of a common 1-C-vinyl disaccharide intermediate has been developed that allows easy preparation of both an elongated sugar-phosphate bond and a sugar-phosphonate moiety, which are coupled with the polyprenyl phosphate to give the desired molecules. Inhibition studies show how a subtle structural modification results in dramatically different potency toward bacterial transglycosylase (TGase), and the results identify Lipidâ II-C-O-PP (IC50 =25 µM) as a potential TGase inhibitor.
Asunto(s)
Inhibidores Enzimáticos/síntesis química , Enzimas/química , Glucolípidos/síntesis química , Glicosiltransferasas/química , Lípidos/química , Monosacáridos/química , Monosacáridos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Glucolípidos/química , Glucolípidos/metabolismo , Glicósidos , Glicosiltransferasas/metabolismoRESUMEN
A straightforward synthesis of novel, 2-heterocyclyl polyhydroxylated pyrrolidines is described. Stereocontrolled additions of nucleophiles to cyclic nitrones generated the corresponding 2,3-trans adducts, allowing the synthesis of the corresponding pyrrolidines via key intermediates bearing an alkyne and a nitrile oxide. Three hybrid systems, including a pyrrolidine with two isoxazoles and one triazole, are efficiently prepared via 1,3-dipolar cycloaddition. Biological testing of the product alkaloids showed that subtle structural variations have drastic effects on their inhibitory activities against glucosidases.
RESUMEN
Isofagomine (IFG) and its analogues possess promising glycosidase inhibitory activities. However, a flexible synthetic strategy toward both C5a-functionalized IFGs remains to be explored. Here we show a practical synthesis of C5a-S and R aminomethyl IFG-based derivatives via the diastereoselective addition of cyanide to cyclic nitrone 1. Nitrone 1 was conveniently prepared on a gram scale and in high yield from inexpensive (-)-diethyl D-tartrate via a straightforward method, with a stereoselective Michael addition of a nitroolefin and a Nef reaction as key steps. A 268-membered library (134 × 2) of the C5a-functionalized derivatives was submitted to enzyme- or cell-based bio-evaluations, which resulted in the identification of a promising ß-glucocerebrosidase (GCase) stabilizer demonstrating a 2.7-fold enhancement at 25 nM in p.Asn370Ser GCase activity and a 13-fold increase at 1 µM in recombinant human GCase activity in Gaucher cell lines.
RESUMEN
The rapid discovery of ß-glucocerebrosidase (GCase) inhibitors and pharmacological chaperones for Gaucher disease is described. The N-aminobutyl DNJ-based iminosugar was synthesized and conjugating with a variety of carboxylic acids to generate a N-diversely substituted iminosugar-based library. Several members of this library were found to be nanomolar-range inhibitors of GCase; the inhibition constant Ki of the most potent was found to be 71nM. Although these new molecules showed reasonable chaperoning activity (1.5- to 1.9-fold) in the N370S fibroblast of Gaucher patient-derived cell line, this was accompanies by a concomitant decrease in the cellular α-glucosidase activity, which might limit their further therapeutic potential. Next, newly developed N-substituents were assembled with pyrrolidine-based scaffolds to generate new molecules for further evaluation. The new 2,5-dideoxy-2,5-imino-d-mannitol (DMDP)-based iminosugar 22 was found to exhibit a satisfactory chaperoning activity to enhance GCase activity by 2.2-fold in Gaucher N370S cell line, without impairment of cellular α-glucosidase activity.
Asunto(s)
Inhibidores Enzimáticos/química , Enfermedad de Gaucher/enzimología , Glucosilceramidasa/antagonistas & inhibidores , Iminoazúcares/química , Sitios de Unión , Línea Celular , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Enfermedad de Gaucher/patología , Glucosilceramidasa/metabolismo , Humanos , Iminoazúcares/síntesis química , Iminoazúcares/metabolismo , Simulación del Acoplamiento Molecular , Unión Proteica , Estructura Terciaria de ProteínaRESUMEN
The rapid discovery of a pharmacological chaperone toward human α-Gal A for the treatment of Fabry disease is described. Two polyhydroxylated pyrrolidines with the (3R,4S,5R) configuration pattern underwent rapid substituent diversity by conjugating the primary aminomethyl moiety of each with a variety of carboxylic acids to generate two libraries (2 × 60 members). Our bioevaluation results showed one member with the (2R,3R,4S,5R) configuration pattern and bearing a 5-cyclohexylpentanoyl group as a substituent moiety possessed sufficient chaperoning capability to rescue α-Gal A activity in the lymphocyte of the N215S Fabry patient-derived cell line and other α-Gal A mutants in COS7 cells.
Asunto(s)
Diseño de Fármacos , Enfermedad de Fabry/tratamiento farmacológico , Pirrolidinas/química , Pirrolidinas/farmacología , Bibliotecas de Moléculas Pequeñas/química , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Células COS , Chlorocebus aethiops , Estabilidad de Medicamentos , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Humanos , Hidroxilación , Cinética , Mutación , Pirrolidinas/síntesis química , Pirrolidinas/uso terapéutico , Bibliotecas de Moléculas Pequeñas/síntesis química , Bibliotecas de Moléculas Pequeñas/uso terapéutico , Estereoisomerismo , Temperatura , alfa-Galactosidasa/antagonistas & inhibidores , alfa-Galactosidasa/genéticaRESUMEN
A unique molecular library consisting of all sixteen synthetic ADMDP (1-aminodeoxy-DMDP) stereoisomers has been prepared and evaluated for inhibitory activity against α-Gal A, and ability to impart thermal stabilization of this enzyme. The results of this testing led us to develop a novel pharmacological chaperone for the treatment of Fabry disease. 3-Epimer ADMDP was found to be an effective pharmacological chaperone, able to rescue α-Gal A activity in the lymphoblast of the N215S Fabry patient-derived cell line, without impairment of cellular ß-galactosidase activity. When 3-epimer ADMDP was administered with rh-α-Gal A (enzyme replacement therapy) for the treatment of Fabry patient-derived cell lines, improvements in the efficacy of rh-α-Gal A was observed, which suggests this small molecule can also provide clinical benefit of enzyme replacement therapy in Fabry disease.