150772-52-4Relevant academic research and scientific papers
Efficient chemical synthesis of a dodecasaccharidyl lipomannan component of mycobacterial lipoarabinomannan
Fraser-Reid, Bert,Chaudhuri, Siddharfha Ray,Jayaprakash,Lu, Jun,Ramamurty, Changalvala V. S.
, p. 9732 - 9743 (2008)
(Chemical Equation Presented) Lipomannan (LM) is one of the domains of lipoarabinomannan (LAM) glycolipids, the latter being one of several cell surface organic molecules that fortify mycobacterial species against external attack. Some members of mycobacterial families are pathogenic, most notably Mycobacterium tuberculosis and Mycobacterium leprae, while others are nonpathogenic, and used in the clinic, such as Mycobacterium smegmatis. Additional biological significance arises from the fact that LM has been implicated in several health disorders outside of those associated with mycobacterial pathogens, notably for treatment of bladder cancer. LM is comprised of a heavily lipidated phosphoinositide dimannoside headgroup, from which a mannan array, of varied complexity, extends. The latter consists of a 1,6-α-linked backbone flanked at position O2, not necessarily regularly, with α-linked mannosides. This paper gives an example of lipomannan synthesis in which all of the sugar components, whether functioning as donors or acceptors, are obtained from n-pentenyl orthoesters, themselves in turn prepared in three easy steps from D-mannose. Assembly of the mannan array is facilitated by the exquisite regioselectivity occasioned by the use of ytterbium triflate/N-iodosuccinimide as the trigger for reaction of n-pentenyl orthoesters.
Regioselective strategies mediated by lanthanide triflates for efficient assembly of oligomannans
Jayaprakash,Chaudhuri, Siddhartha Ray,Murty, Changalvala V. S. R.,Fraser-Reid, Bert
, p. 5534 - 5545 (2008/02/08)
(Chemical Equation Presented) Readily prepared mannosyl n-pentenylorthoesters (NPOEs) serve as donors in themselves and as convenient intermediates for other glycosyl donors, such as n-pentenyl glycosides (NPGs), thioglycosides, and trichloroacetimidates.
Synthesis of a key Mycobacterium tuberculosis biosynthetic phosphoinositide intermediate
Jayaprakash,Lu, Jun,Fraser-Reid, Bert
, p. 3815 - 3819 (2007/10/03)
Regioselective mannosylations of a myoinositol acceptor diol are readily achieved by Lewis acid mediated iodinolysis of n-pentenyl ortho-esters. The procedure affords a psuedotrisaccharide to which the phosphoglyceryl and other lipid residues are added le
One-pot chemo-, regio-, and stereoselective double-differential glycosidation mediated by lanthanide triflates
Jayaprakash,Fraser-Reid, Bert
, p. 4211 - 4214 (2007/10/03)
(Chemical Equation Presented) Nuanced activation of n-pentenyl, thioglycoside, and trichloroacetimidate donors by lanthanide salts coupled with donor/acceptor matching can simplify oligosaccharide assembly. Thus, a one-pot, double-differential glycosidati
Comparing n-pentenyl orthoesters and n-pentenyl glycosides as alternative glycosyl donors
Mach, Mateusz,Schlueter, Urs,Mathew, Felix,Fraser-Reid, Bert,Hazen, Kevin C
, p. 7345 - 7354 (2007/10/03)
As is well known, cyclic 1,2-glycosyl orthoesters undergo ready acid catalyzed rearrangement to 2-O-acyl glycosides in which the alkoxy group is transferred from the orthoester to the anomeric center in a highly stereocontrolled process. The related n-pentenyl derivatives are unique in that either the orthoester (NPOE) or its rearrangement product (NPGAC) can function as a glycosyl donor, and mechanistic considerations indicate that both should (or could!) lead to the same product(s) arising from trans-orthoesterification, glycosidation, glycosyl esterification, etc. Experiments are described which show that the product obtained from a given reaction can be optimized by careful choice of the donor, NPOE or related NPGAC, and careful attention to reaction conditions, electrophilic promoter, 'size' of the glycosyl acceptor, and experimental protocol.
Studies related to synthesis of glycophosphatidylinositol membrane-bound protein anchors. 5. n-pentenyl ortho esters for mannan components
Roberts, Carmichael,Madsen, Robert,Fraser-Reid, Bert
, p. 1546 - 1553 (2007/10/02)
Procedures for rapid assembly of multigram amounts of mannan components have been examined. Although these studies are reported in the context of the mannan moiety of the glycan anchors of membrane-bound glycoproteins, the procedures should be applicable
