A concise synthesis of 4,6-dideoxy-4-base-6-amino-2,5-anhydro-l-mannitols

A short synthesis of carbohydrate derived N-benzyl aminocyclopentitols through N-O bond cleavage of the corresponding isoxazolidine derivatives: Evaluation of their anticancer properties using in vitro and in silico studies

A short synthesis of a potent glycosidase inhibitor N-benzyl-β-D-gluco aminocyclopentitol along with its 2-deoxy, and orthogonally protected 2-O-benzyl, 1,2,3-tri-O-benzyl and 1,2,3-tri-O-acetyl analogues through carbohydrate derived cyclopentane-fused isoxazolidine derivatives has been described herein. The key steps involve NaI mediated vinylation of d-glucose derived 5,6-di-O-mesylated compounds in sealed tube to produce 5,6-dideoxy-l,2-O-isopropylidene-α-D-xylo-hexo-5-enofuranos derivatives in very good yields. Subsequent acetonide deprotection and stereoselective intramolecular nitrone cycloaddition (INC) reaction involving C-4-vinyl functionalities and the latent aldehyde moiety at C-1 yielded various cyclopentano-isoxazolidines. The N-O bond cleavage of the isoxazolidine rings produced the targeted aminocyclopentitols. In vitro anticancer activities of the isoxazolidines and N-benzyl aminocyclopentitols were performed and found only 1,2,3-tri-O-benzyl analogue (20c) of N-benzyl-β-D-gluco aminocyclopentitols emerged as potent anticancer agent with IC50 value 54.90 μM. Furthermore, the molecular docking study confirmed that 20c, compared with the other derivatives, scores higher binding affinity for all the targeted receptors, HSP90, PLK1, and TOP2A.

A New Synthetic Protocol for One-Pot Preparations of 5-Halo-1,4-disubstituted-1,2,3-triazoles

In this paper, a new synthetic protocol for one-pot preparations of 5-halo-1,4-disubstituted-1,2,3-triazoles is provided by rational combination of a CuI catalyzed azide–alkyne cycloaddition (CuAAC) reaction and an oxidative halogenation reaction. CuI- N-chlorosuccinimide (NCS) and CuBr-NCS reaction systems are developed, respectively, for effective preparations of 5-iodo-1,4-disubstituted-1,2,3-triazoles and 5-bromo-1,4-disubstituted-1,2,3-trizoles under mild conditions with a high tolerance of various sensitive groups.

Syntheses of tricyclic pyrones and pyridinones and protection of Abeta-peptide induced MC65 neuronal cell death

The SbetaC gene is conditionally expressed a 99-residue carboxy terminal fragment, C99, of amyloid precursor protein in MC65 cells and causes cell death. Consequently, MC65 cell line was used to identify inhibitors of toxicity related to intracellular amyloid beta (Abeta) oligomers. Compounds that reduce the level of Abeta peptides, prevent Abeta aggregation, or eliminate existing Abeta aggregates may be used in the treatment of Alzheimer's disease (AD). Previously, we found that a tricyclic pyrone (TP) molecule, compound 1, prevents MC65 cell death and inhibits Abeta aggregation. Hence various TPs containing heterocycle at C7 side chain and a nitrogen at position 2 or 5 were synthesized and their MC65 cell protective activities evaluated. TPs containing N3'-adenine moiety such as compounds 1 and 11 are most active with EC(50) values of 0.31 and 0.35 microM, respectively. EC(50) values of tricyclic N5-analog, pyranoisoquinolinone 13, and N2-analog, pyranopyridinone 20, are 2.49 and 1.25 microM, respectively, despite the lack of adenine moiety. Further investigation of tricyclic N2- and N5-analogs is warranted.