Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

Beilstein J. Org. Chem. 2020, 16, 2971–2982, doi:10.3762/bjoc.16.247

• bacteria [57]. It is a glycolipid consisting of a variable polysaccharide domain connected to a conserved glucosamine-based phospholipid called lipid A. It is highly negatively charged due to two phosphorylated groups in the lipid A part and carboxylated groups in the polysaccharide part. It is amphiphilic

Synthesis of monophosphorylated lipid A precursors using 2-naphthylmethyl ether as a protecting group

• Jundi Xue,
• Ziyi Han,
• Gen Li,
• Khalisha A. Emmanuel,
• Cynthia L. McManus,
• Qiang Sui,
• Dongmian Ge,
• Qi Gao and
• Li Cai

Beilstein J. Org. Chem. 2020, 16, 1955–1962, doi:10.3762/bjoc.16.162

• Chemistry, University of South Carolina Lancaster, 476 Hubbard Drive, Lancaster, South Carolina 29720, USA, Suzhou Jingye Medicine & Chemical Co., Ltd, 88 Sanlian Street, Suzhou, Jiangsu Province, 215129, China 10.3762/bjoc.16.162 Abstract Lipid A, the hydrophobic domain of lipopolysaccharide (LPS), is a

• strong immunostimulator and therefore a valuable target for the development of novel immunomodulators. Various lipid A derivatives have been chemically synthesized in order to reduce toxicity while retaining the immunostimulatory activity. In this work, we describe a novel approach to the frequently

• the molecule until the final global deprotection step. Our synthetic strategy is not only efficient in regards to the yield of the various chemical transformations, but also robust in regards to the potential application of this route to the production of other lipid A analogs. Keywords: lipid A

Synthesis of C-glycosyl phosphonate derivatives of 4-amino-4-deoxy-α-ʟ-arabinose

• Lukáš Kerner and
• Paul Kosma

Beilstein J. Org. Chem. 2020, 16, 9–14, doi:10.3762/bjoc.16.2

• derivatives. These intermediates will be of value for their future conversion into transition state analogues as well as for the introduction of various lipid extensions at the anomeric phosphonate moiety. Keywords: antibiotic resistance; glycosyl phosphonate; glycosyl transferase; lipid A

• mechanisms of pathogenic Gram-negative bacteria against antibiotics, such as polymyxin B and colistin [3]. The main effect of Ara4N incorporation into the lipid A part – and, less frequently, into the inner core region of LPS [4] – is thought to originate from blocking the electrostatic interaction of

• cationic antimicrobial peptides with the negatively charged phosphate and carboxylate groups in LPS domains. Suitable inhibitors intercepting the attachment of Ara4N units to the lipid A and inner core region might restore sensitivity towards the cationic antimicrobial drugs as a novel approach to combat

Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• ] or using natural glycolipids from Gram-negative bacteria such as lipid A [4]. This work represents the first step towards the formulation of an heterogeneous, stable systems (under biological conditions) that can be used for several biological purposes including synthetic vaccines, supramolecular

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

• cytokines, chemokines, prostaglandins and reactive oxygen species which manifest an acute inflammatory response to infection. The “endotoxic principle” of LPS resides in its amphiphilic membrane-bound fragment glycophospholipid lipid A which directly binds to the TLR4·MD-2 receptor complex. The lipid A

• content of LPS comprises a complex mixture of structural homologs varying in the acylation pattern, the length of the (R)-3-hydroxyacyl- and (R)-3-acyloxyacyl long-chain residues and in the phosphorylation status of the β(1→6)-linked diglucosamine backbone. The structural heterogeneity of the lipid A

• isolates obtained from bacterial cultures as well as possible contamination with other pro-inflammatory bacterial components makes it difficult to obtain unambiguous immunobiological data correlating specific structural features of lipid A with its endotoxic activity. Advanced understanding of the

Electrochemical generation of 2,3-oxazolidinone glycosyl triflates as an intermediate for stereoselective glycosylation

• Toshiki Nokami,
• Akito Shibuya,
• Yoshihiro Saigusa,
• Shino Manabe,
• Yukishige Ito and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2012, 8, 456–460, doi:10.3762/bjoc.8.52

• Stereoselective formation of glycosidic linkages is the key issue in oligosaccharide synthesis, because both 1,2-trans and 1,2-cis aminoglycosides are ubiquitous in biologically active oligosaccharides [1][2][3][4][5]. The 1,2-trans aminoglycosides, which are found in Nod factor [1] and lipid A [2], can be easily