The First l-Iduronic Acid-Type 1-N-Iminosugars Having Inhibitory Activity of Experimental Metastasis

Concise synthesis of amino acid component of amicoumacins via dihydrooxazine formation through intramolecular conjugate addition

Amicoumacins are a family of antibiotics with a variety of important bioactivities. A concise and efficient method was developed for synthesizing the amino acid component of amicoumacins via the corresponding dihydrooxazine intermediate. The dihydrooxazine ring was formed with complete stereoselectivity through an intramolecular conjugate addition of a δ-trichloroacetimidoyloxy-α,β-unsaturated ester, which was obtained from a known 4,6-O-p-methoxybenzylidene-protected d-glucose. The synthesis developed in this study can be used to synthesize the building blocks of amicoumacins and can likely be adapted for the synthesis of other types of molecules possessing dihydrooxazine rings or amino alcohol moieties.

Synthesis and biological evaluation of gem-diamine 1-N-iminosugars related to L-iduronic acid as inhibitors of heparan sulfate 2-O-sulfotransferase

A variety of gem-diamine 1-N-iminosugars related to L-iduronic acid were synthesized and evaluated as inhibitors of heparan sulfate uronyl 2-O-sulfotransferase using an in vitro enzyme assay. Two iminosugars containing guanidino groups acted as potent in vitro inhibitors of the enzyme.

Synthesis of 6-acetamido-5-amino- and -5-guanidino-3, 4-dehydro-N-(2-ethylbutyryl)- 3-piperidinecarboxylic acids related to zanamivir and oseltamivir, inhibitors of influenza virus neuraminidases

[reaction: see text] 6-Acetamido-5-amino- and -5-guanidino-3, 4-dehydro-N-(2-ethylbutyryl)-3-piperidinecarboxylic acids (8 and 9) have been synthesized starting from natural siastatin B, a bacterial neuraminidase inhibitor isolated from Streptomyces culture in a stereospecific fashion. These compounds are related to zanamivir and oseltamivir, inhibitors of influenza virus neuraminidases.

All eight stereoisomeric D-glyconic-delta-lactams: synthesis, conformational analysis, and evaluation as glycosidase inhibitors

An efficient and general synthetic route to all eight stereoisomeric D-glycono-delta-lactams has been developed. The strategy involves, as a key step, a stereodivergent delta-lactam formation with configurational retention or inversion at C-4 of a starting gamma-lactone to lead to two epimers of delta-lactam from one parent gamma-lactone. Conformations of eight glycono-delta-lactams were examined by X-ray crystallographic analysis and molecular modeling. Analyses of conformation and glycosidase-inhibition provide useful information for the design of new glycosidase inhibitors.

gem-diamine 1-N-iminosugars of L-fucose-type, the extremely potent L-fucosidase inhibitors

An efficient route from D-ribono-gamma-lactone to gem-diamine 1-N-iminosugars of L-fucose-type, a new family of glycosidase inhibitor, has been developed in a formation of a gem-diamine 1-N-iminopyranose ring by the Mitsunobu reaction of an aminal as a key step. The analogues were proved to be the extremely potent inhibitors against alpha-L-fucosidase (IC50 approximately 3 ng mL(-1), Ki approximately 5 x 10(-9) M). The present study has shown that a cyclic methanediamine generated in media affects glycosidases as a real active-form of the gem-diamine 1-N-iminosugars of L-fucose-type.

Flexible synthesis and biological activity of uronic acid-type gem-diamine 1-N-iminosugars: a new family of glycosidase inhibitors

An efficient and flexible synthetic route to four gem-diamine 1-N-iminosugars of uronic acid-type (D-glucuronic, D-mannuronic, L-iduronic, and L-guluronic acid), a new family of glycosidase inhibitor, from l-galactono-1,4-lactone have been developed in an enantiodivergent fashion through a sequence involving as the key steps (a) the formation of gem-diamine 1-N-iminopyranose ring by the Mitsunobu reaction of an aminal and (b) the introduction of a carboxylic acid group by the Wittig reaction of a ketone, hydroboration and oxidation, and the Sharpless oxidation. D-Glucuronic and D-mannuronic acid-type 1-N-iminosugars, (3S,4R,5R, 6R)- and (3S,4R,5R,6S)-4, 5-dihydroxy-6-trifluoroacetamido-3-piperidinecarboxylic acid, were proven to be potent inhibitors for beta-D-glucuronidase (IC(50) 6.5 x 10(-)(8)M) and to affect human heparanase (endo-beta-glucuronidase).

Synthesis and antimetastatic activity of L-iduronic acid-type 1-N-iminosugars

L-Iduronic acid-type 1-N-iminosugars, (3R,4S,5R,6R)- and (3R,4S,5S,6R)-6-acetamido-4-amino-5-hydroxypiperidine-3-carboxylic acid (6 and 7, respectively), (3R,4S,5R,6R)-6-acetamido-4- guanidino-5-hydroxypiperidine-3-carboxylic acid (8), and (3R,4S,5R,6R)-4-amino- and -guanidino-5-hydroxy-6-(trifluoroacetamido) piperidine-3-carboxylic acid (9 and 10, respectively), were synthesized from siastatin B (1), isolated from Streptomyces culture, by the intramolecular Michael addition of O-imidate to its alpha,beta-unsaturated ester through cis oxiamination as a key step. Preincubation of B16 BL6 cells with these compounds inhibited invasion of the cells through reconstituted basement membranes. Pulmonary metastasis of B16 BL6 cells in mice was remarkably inhibited by pretreatment of the cells with these compounds in culture.