Synthesis, Structure, and Biological Evaluation of Novel N- and O-Linked Diinositols

Abstract

Several O-and N-linked inositols and/or aminoinositols have been prepared by iterative opening of epoxides and aziridines derived from homochiral cyclohexadiene cis-diols. The three inositols and their intermediate conduritols (conduramines) were tested against several glycosidases (alpha- and beta-glucosidase, alpha- and beta-galactosidase, alpha- and beta-mannosidase) in an assay that measured the rate of hydrolysis of p-nitrophenolglycosides rather than the concentration of p-nitrophenolate. Somewhat surprisingly, the best inhibition was seen against beta-galactosidase with several of the compounds. The inositols linked through oxygen or nitrogen were subjected to calcium binding studies performed in NMR experiments. Detailed analysis of the title compounds by NMR spectroscopy has been performed, and full assignments were made. One of the attendant benefits of the preparation of these compounds has been expressed in the design and synthesis of new salen catalysts whose effectiveness has been compared with Jacobsen's catalyst in the epoxidation of styrene.

Ring Opening of cis‐3‐substituted‐2‐Vinylaziridines with Amines

“…Efforts have been devoted to the search for alternative catalysts. InBr 3 , LiClO 4 , Yb(OTf) 3 , and silica gel have been successfully applied for the ring opening of aziridines. However, these alternative procedures typically employ aryl amines such as anilines, and ring opening by aliphatic amines is either unexplored or unsuccessful.…”

Differentiation of diastereomeric conduramine derivatives under electron ionization and chemical ionization mass spectral conditions

“…The present EI, CI and ESI-MS/MS study on isomeric conduramines (1)(2)(3)(4) showed that the isomers could be differentiated by the selective formation of a few characteristic fragment ions. Under EI conditions, the relative abundance of the RDA fragment ion is greater in the trans-isomers (2 and 4), whereas fragment ions due to simple cleavages are dominant in the cis-isomers (1 and 3).…”

“…Compared with CI, a few ions are not present in the CID spectra of [MþH] þ ions in 1-4 ( Fig. 3 To understand the observed differences in the relative abundances of fragment ions observed for cis-and trans-isomers (1)(2)(3)(4) in their CI and ESI-MS/MS spectra, we have performed B3LYP/6-31G(d) optimization for the protonated species of 1-4. Although in theory there are several protonation sites on each compound, we selected the most probable protonation sites (six) for protonation and then optimized the corresponding protonated species (refer to Theoretical calculations for 3H þ and 4H þ gave different results than for 1H þ and 2H þ .…”

“…1 Glycosidases play a vital role in the initial steps of cell penetration by viral material. 2 Inhibition of these glycosidases by a variety of chemical compounds has been widely studied and this has led to a new class of antibiotics, aminoglycoside antibiotics. Glycosidase inhibitors are widely used in antiviral, anticancer and genetic disorders.…”

Synthesis of Natural O-Linked Carba-Disaccharides, (+)- and (−)-Pericosine E, and Their Analogues as α-Glucosidase Inhibitors

“…Recent studies on thiosugar-containing α-glucosidase inhibitors have also made progress [ 3 ]. However, there have been only a few reports on pseudo-oligosaccharides constructed of only carbasugars [ 4 , 5 , 6 , 7 , 8 ]. Shing and Hudlicky independently synthesized such molecules, providing a new class of unique glycosidase inhibitors [ 4 , 5 , 6 , 7 ].…”