197853-41-1Relevant academic research and scientific papers
Synthesis of Glucuronoxylan Hexasaccharides by Preactivation-Based Glycosylations
B?hm, Maximilian,Madsen, Robert,Underlin, Emilie N.,d'Errico, Clotilde
supporting information, (2020/05/16)
The synthesis of two glucuronoxylans is described, which both consist of a pentaxylan backbone and a glucuronic acid linked to the 2 position in the fourth xylose residue from the reducing end. The two target molecules differ in the 4 position of the glucuronic acid where one is unsubstituted while the other contains a methyl ether. The pentaxylan backbone is assembled in four glycosylation reactions with phenyl thioglycoside donors. The couplings are performed by preactivation of the donor with in-situ-generated p-nitrobenzenesulfenyl triflate prior to addition of the acceptor. The glucuronic acids are then attached by Koenigs-Knorr glycosylations followed by deprotections. The syntheses employ a total of 8 steps from monosaccharide building blocks and afford the two glucuronoxylans in 12 and 15 % overall yield. The hexasaccharide products are valuable substrates for investigating the activity and specificity of glucuronoxylan-degrading enzymes.
High-yield total synthesis of (-)-strictinin through intramolecular coupling of gallates
Michihata, Naoki,Kaneko, Yuki,Kasai, Yusuke,Tanigawa, Kotaro,Hirokane, Tsukasa,Higasa, Sho,Yamada, Hidetoshi
, p. 4319 - 4328 (2013/06/27)
This paper describes a total synthesis of (-)-strictinin, an ellagitannin that is 1-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl (HHDP)-β-d-glucose. In the study, total efficiency of the synthesis was improved to produce a 78% overall yield in 13 steps from d-glucose. In the synthesis, formation of the 4,6-(S)-HHDP bridge including the 11-membered bislactone ring was a key step, in which intramolecular aryl-aryl coupling was adopted. The coupling was oxidatively induced by CuCl2-n-BuNH2 with perfect control of the axial chirality, and the reaction conditions of this coupling were optimized thoroughly to achieve the quantitative formation of the bridge.
Contribution of phosphates and adenine to the potency of adenophostins at the IP3 receptor: Synthesis of all possible bisphosphates of adenophostin A
Sureshan, Kana M.,Riley, Andrew M.,Thomas, Mark P.,Tovey, Stephen C.,Taylor, Colin W.,Potter, Barry V. L.
, p. 1706 - 1720 (2012/05/04)
Although adenophostin A (AdA), the most potent agonist of d-myo-inositol 1,4,5-trisphosphate receptors (IP3R), is thought to mimic IP 3, the relative roles of the different phosphate groups and the adenosine motif have not been established. We synthesized all three possible bisphosphate analogues of AdA and glucose 3,4-bisphosphate (7, AdA lacking the 2′-AMP). 2′-Dephospho-AdA (6) was prepared via a novel regioselective dephosphorylation strategy. Assessment of the abilities of these bisphosphates to stimulate intracellular Ca2+ release using recombinant rat type 1 IP3R (IP3R1) revealed that 6, a mimic of Ins(4,5)P2, is only 4-fold less potent than IP3, while 7 is some 400-fold weaker and even 3′3-dephospho-AdA (5) is measurably active, despite missing one of the vicinal bisphosphate groups normally thought to be crucial for IP3-like activity. Compound 6 is the most potent bisphosphate yet discovered with activity at IP3R. Thus, adenosine has a direct role independent of the 2′-phosphate group in contributing toward the potency of adenophostins, the vicinal bisphosphate motif is not essential for activity at the IP3R, as always thought, and it is possible to design potent agonists with just two of the three phosphates. A model with a possible adenine-R504 interaction supports the activity of 5 and 6 and also allows a reappraisal of the unexpected activity previously reported for the AdA regioisomer 2′3-phospho-3′3- dephospho-AdA 40.
4,6-O-[1-cyano-2-(2-iodophenyl)ethylidene] acetals. Improved second-generation acetals for the stereoselective formation of β-D-mannopyranosides and regioselective reductive radical fragmentation to β-D-rhamnopyranosides. Scope and limitations
Crich, David,Bowers, Albert A.
, p. 3452 - 3463 (2007/10/03)
The [1-cyano-2-(2-iodophenyl)]ethylidene group is introduced as an acetal-protecting group for carbohydrate thioglycoside donors. The group is easily introduced under mild conditions, over short reaction times, and in the presence of a wide variety of oth
Synthesis of neomycin analogs to investigate aminoglycoside-RNA interactions
Seeberger, Peter H.,Baumann, Michael,Zhang, Guangtao,Kanemitsu, Takuya,Swayze, Eric E.,Hofstadler, Steven A.,Griffey, Richard H.
, p. 1323 - 1326 (2007/10/03)
A series of novel aminoglycoside oligosaccharide analogs containing a 2,5-dideoxystreptamine core scaffold was prepared to study aminoglycoside binding to the small subunit of 16S rRNA. A set of monosaccharide building blocks carrying amino groups in diff
Influence of the 4,6-O-benzylidene, 4,6-O-phenylboronate, and 4,6-O-polystyrylboronate protecting groups on the stereochemical outcome of thioglycoside-based glycosylations mediated by 1-benzenesulfinyl piperidine/triflic anhydride and N-iodosuccinimide/t
Crich, David,De la Mora, Marco,Vinod
, p. 8142 - 8148 (2007/10/03)
The effect of 4,6-O-benzylidene acetals, 4,6-O-phenylboronate esters, and 4,6-O-polystyrylboronate esters on the stereoselectivity of couplings to galacto-, gluco-, and mannopyranosyl thioglycosides, otherwise protected with benzyl ethers, has been invest
PARTIAL SUBSTITUTION OF THIOGLYCOSIDES BY PHASE TRANSFER CATALYZED BENZOYLATION AND BENZYLATION
Garegg, Per J.,Kvarnstroem, Ingemar,Niklasson, Annika,Niklasson, Gunilla,Svensson, Stefan C. T.
, p. 933 - 954 (2007/10/02)
Partial substitution by phase transfer catalysis giving monobenzoylated and monobenzylated products from 2,3- and from 4,6-diols in ethyl 1-thio-D-hexopyranosides with the β-gluco, β-galacto- and α-manno-configurations are described.Two disaccharide thiog
