19940-17-1Relevant academic research and scientific papers
Total synthesis of jadomycins B, S, T, and ILEVS1080
Yang, Xiaoyu,Yu, Biao
, p. 8431 - 8434 (2013/07/19)
Sweetening up jadomycin A: The first total synthesis of jadomycins B, S, T, and ILEVS1080 has been achieved, featuring construction of the unique 8H-benz[b]oxazolo[3,3-f]phenanthridine skeleton by biomimetic condensation of a quinone aldehyde with amino acid sodium salts and elaboration of the glycosides by Mitsunobu condensation (see figure). Copyright
Synthesis of L-altrose and some derivatives
Lunau, Nathalie,Meier, Chris
, p. 6260 - 6270 (2013/01/15)
A convenient approach to the chemical synthesis of L-altrose (1) and its 6-deoxy derivative 2 has been developed by starting from D-galactose (9) and D-fucose (10), respectively. The 5-epimerization by a Mitsunobu inversion of the open-chain D-hexoses was the key step for these routes. Furthermore, the conversion of 2 into peracetylated TDP-6-deoxy-α-L-altrose (3a) was achieved by the cycloSal approach. However, the final deacetylation led to an unexpected side-reaction resulting in the previously unknown 6-deoxy-α-L-altropyranose 1,3-cyclophosphate (4).
A nonself sugar mimic of the HIV glycan shield shows enhanced antigenicity
Doores, Katie J.,Fulton, Zara,Hong, Vu,Patel, Mitul K.,Scanlan, Christopher N.,Wormald, Mark R.,Finn,Burton, Dennis R.,Wilson, Ian A.,Davis, Benjamin G.
scheme or table, p. 17107 - 17112 (2011/02/25)
Antibody 2G12 uniquely neutralizes a broad range of HIV-1 isolates by binding the high-mannose glycans on the HIV-1 surface glycoprotein, gp120. Antigens that resemble these natural epitopes of 2G12 would be highly desirable components for an HIV-1 vaccine. However, host-produced (self)-carbohydrate motifs have been unsuccessful so far at eliciting 2G12-like antibodies that cross-react with gp120. Based on the surprising observation that 2G12 binds nonproteinaceous monosaccharide D-fructose with higher affinity than D-mannose, we show here that a designed set of nonself, synthetic monosaccharides are potent antigens. When introduced to the terminus of the D1 arm of protein glycans recognized by 2G12, their antigenicity is significantly enhanced. Logical variation of these unnatural sugars pinpointed key modifications, and the molecular basis of this increased antigenicity was elucidated using high-resolution crystallographic analyses. Virus-like particle protein conjugates containing such nonself glycans are bound more tightly by 2G12. As immunogens they elicit higher titers of antibodies than those immunogenic conjugates containing the self D1 glycan motif. These antibodies generated from nonself immunogens also cross-react with this self motif, which is found in the glycan shield, when it is presented in a range of different conjugates and glycans. However, these antibodies did not bind this glycan motif when present on gp120.
FORMATION OF 6-DEOXY-6-IODOHEXOPYRANOSIDES AS SUBSTRATES FOR THE HEX-5-ENOSE DEGRADATION
Aspinall, Gerald O.,Carpenter, Roshan C.,Khondo, Lev
, p. 281 - 298 (2007/10/02)
The synthesis of 6-deoxy-6-iodohexopyranosides as potential substrates for the hex-5-enose degradation has been examined for a range of mono-, di-, and poly-saccharide derivatives.It is shown that (1) unsubstituted D-glucopyranosides undergo selective, primary iodination without unwanted side-reactions; (2) primary iodination of D-galactopyranosides is accompanied by 3,6-anhydride formation, so that the desired reaction is only possible with protection of secondary hydroxyl groups; and (3) the extent of iodination in substrates of higher molecular weight is conveniently determined by reaction of acetylated (or methylated) derivatives with tributylstannane, followed by analysis of the resulting 6-deoxyhexopyranosides.The formation of 6-deoxy-6-iodohexopyranosyl residues in otherwise methylated plant galactomannans proceeds satisfactorily for (terminal) α-D-galactopyranosyl groups but incompletely for unbranched β-D-mannopyranosyl residues.
OXYAMINATION OF UNSATURATED SUGAR DERIVATIVES. PART III. CIS-ADDITION OF β-TOLUENESULFONAMIDO AND HYDROXYL GROUPS TO THE DOUBLE BOND OF METHYL 3,4-DIDEOXY-α-DL-THREO- AND ERYTHRO-HEX-3-ENOPYRANOSIDES
Banaszek, Anna
, p. 583 - 598 (2007/10/02)
Vicinal oxyamination of fifteen derivatives of methyl 3,4-dideoxy-α-DL-threo- and erythro-hex-3-enopyranosides with chloramine-T--osmium tetroxide (Sharpless reagent) was investigated.Under the conditions employed several methyl 3- and 4-deoxy-3- and 4-p-toluenesulfonamido-α-DL-hexopyranosides of altro, allo and galacto configuration, as well as their 6-amino-6-deoxy, and 6-deoxy analogs have been prepared.The oxyamination reaction was completely supressed if an allylic acyloxy group was present in the substrate; instead, dihydroxylated products, i.e. methyl hexopyranosides have been formed.
