Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Enhanced target cell specificity and uptake of lipid nanoparticles using RNA aptamers and peptides

• Roslyn M. Ray,
• Anders Højgaard Hansen,
• Maria Taskova,
• Bernhard Jandl,
• Jonas Hansen,
• Citra Soemardy,
• Kevin V. Morris and
• Kira Astakhova

Beilstein J. Org. Chem. 2021, 17, 891–907, doi:10.3762/bjoc.17.75

• dipalmitoyl-Dap-T7 and dipalmitoyl-Dap-Tat (Figure 1A). Double lipidation ensures a more stable lipid-membrane-anchoring compared to a single fatty acid chain or cholesteryl variant [27][28][29]. The careful choice of Dap and palmitic acid allows for the entire synthesis to be performed on solid support with

• -HAIYPRH-NH2 Tat: H-YGRKKRRQRRR-NH2 Modified Tat: dipalmitoyl-Dap-YGRKKRRQRRR-NH2 Peptide conjugation with a lipid reagent The peptides were N-terminally modified on solid support by coupling of Fmoc-Dap(Fmoc)-OH, followed by the coupling of palmitic acid to afford the complete peptide–lipid conjugates

• . Coupling of Fmoc-Dap(Fmoc)-OH and Fmoc deprotection were carried out as described above. To ensure the complete lipidation of the two free amines of Dap, 8 equiv of palmitic acid, 8 equiv of HATU, and 12 equiv of DIPEA in DMF were used. Cleavage of the peptide–lipid conjugates from the solid support and

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• . The position of the double bonds in the acyl chain of the esters can be explained by a biosynthetic pathway described in detail in Scheme 5. The double bond distribution is consistent with both desaturases acting on palmitic acid, leading to the respective hexadecenoic acids. These acids are the

• leading to the observed regioisomers of the isoprenyl esters. All acids shown were found in form of their isoprenyl esters. (Z)-9-Hexadecenoic acid is obtained from palmitic acid by a Δ9-desaturase (ds). Malonate elongation and reduction (red) leads to (Z)-3-hydroxy-11-octadecenoic acid, an intermediate

• -hydroxyoctadecanoic and stearic acids as well as (E)-2-octadecenoic acids are obtained similarly directly from palmitic acid. The proposed biosynthesis likely takes place in form of the conjugated acids, e.g., coenzyme A esters or acyl carrier proteins. Finally, the acids are converted into the isoprenyl esters and

N-Acylated amino acid methyl esters from marine Roseobacter group bacteria

• Hilke Bruns,
• Lisa Ziesche,
• Nargis Khakin Taniwal,
• Laura Wolter,
• Thorsten Brinkhoff,
• Jennifer Herrmann,
• Rolf Müller and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 2964–2973, doi:10.3762/bjoc.14.276

• verified by synthesis according to Scheme 2. Palmitoleic acid was synthesized in g-scale by standard procedures as shown in the Supporting Information File 1, Scheme S1. This acid and palmitic acid were converted into the respective chlorides and standard acylation delivered 2-aminobutyric acid derivatives

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

• Daniel I. Hădărugă,
• Mustafa Ünlüsayin,
• Alexandra T. Gruia,
• Cristina Birău (Mitroi),
• Gerlinde Rusu and
• Nicoleta G. Hădărugă

Beilstein J. Org. Chem. 2016, 12, 179–191, doi:10.3762/bjoc.12.20

• saturated fatty acids remained constant or slightly increased by a few percent after degradation (e.g., from 10.7% to 12.9% for palmitic acid). Co-crystallization of ASO with β-CD at a host–guest ratio of 1:1 and 3:1 from an ethanol–water mixture and kneading methods has been used for the preparation of β

Effects of RAMEA-complexed polyunsaturated fatty acids on the response of human dendritic cells to inflammatory signals

• Éva Rajnavölgyi,
• Renáta Laczik,
• Viktor Kun,
• Lajos Szente and
• Éva Fenyvesi

Beilstein J. Org. Chem. 2014, 10, 3152–3160, doi:10.3762/bjoc.10.332

• depends on the type, number and position of the substituents [18][19]. For example, water soluble palmitic acid and myristic acid complexed by RAMEB could be used for cultivation of otherwise non-cultivable leprosy-derived psychrophilic mycobacteria [20]. The methylated β-CDs are used as cholesterol

Automated solid-phase peptide synthesis to obtain therapeutic peptides

• Veronika Mäde,
• Sylvia Els-Heindl and
• Annette G. Beck-Sickinger

Beilstein J. Org. Chem. 2014, 10, 1197–1212, doi:10.3762/bjoc.10.118

• [134]. With respect to peptide stabilization techniques, Bellmann-Sickert et al. described a method for on-resin lipidation of hPP with palmitic acid and a strategy to synthesize PEGylated peptides [99]. For lipidation, lysine residues were protected with Dde during the automated peptide synthesis

The difluoromethylene (CF₂) group in aliphatic chains: Synthesis and conformational preference of palmitic acids and nonadecane containing CF₂ groups

• Yi Wang,
• Ricardo Callejo,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2014, 10, 18–25, doi:10.3762/bjoc.10.4

• palmitic acids are characterized by differential scanning calorimetry (DSC) to determine melting points and phase behaviour relative to palmitic acid (62.5 °C). It emerges that 6c, with the CF2 groups placed 1,4- to each other, has a significantly higher melting point (89.9 °C) when compared to the other

• analogues and palmitic acid itself. It is a crystalline compound and the structure reveals an extended anti-zig-zag chain. Similarly 8,8,11,11-tetrafluorononadecane (27) adopts an extended anti-zig-zag structure. This is rationalized by dipolar relaxation between the two CF2 groups placed 1,4 to each other

• in the extended anti-zig-zag chain and suggests a design modification for long chain aliphatics which can introduce conformational stability. Keywords: difluoromethylene; fatty acids; fluorination; organic fluorine chemistry; organo-fluorine; palmitic acid; Introduction The selective replacement of

Chemical modification allows phallotoxins and amatoxins to be used as tools in cell biology

• Jan Anderl,
• Hartmut Echner and
• Heinz Faulstich

Beilstein J. Org. Chem. 2012, 8, 2072–2084, doi:10.3762/bjoc.8.233

• Honeycutt et al. [14] used palmitic acid to deliver a protease inhibitor into cells, and Bradley et al. [15] used docosahexanoic acid to improve the uptake of paclitaxel into tumor cells. For a review see Wong and Toth [16]. Of particular interest was the incorporation of anti-sense oligonucleotides into

Synthesis and antifungal properties of papulacandin derivatives

• Marjolein van der Kaaden,
• Eefjan Breukink and
• Roland J. Pieters

Beilstein J. Org. Chem. 2012, 8, 732–737, doi:10.3762/bjoc.8.82

• stereochemistry of the double bonds. Moderate biological activity was observed for the derivatives with a side chain based on palmitic acid and linoleic acid. Keywords: antifungal agents; carbohydrate; papulacandins; spiroketal; Introduction In recent years, a steady increase in the incidence of opportunistic

• groups was also used (Supporting Information File 1). At this stage, four commercially available side-chain acids, comprising variations in their degree of unsaturation, length and branching, were coupled: sorbic acid (sor), palmitic acid (pal), linoleic acid (lin) and trans-retinoic (ret) acid. Their

• acid derivative 50 was measured as 100 μg/mL. The saturated palmitic acid derivative 49 was slightly more potent with an MIC of 88 μg/mL. Discussion Starting from glycal the synthesis of papulacandin D derivatives was undertaken with an initial focus on the acyl side chain, a clearly sensitive area for

An easy α-glycosylation methodology for the synthesis and stereochemistry of mycoplasma α-glycolipid antigens

• Yoshihiro Nishida,
• Yuko Shingu,
• Yuan Mengfei,
• Kazuo Fukuda,
• Hirofumi Dohi,
• Sachie Matsuda and
• Kazuhiro Matsuda

Beilstein J. Org. Chem. 2012, 8, 629–639, doi:10.3762/bjoc.8.70

• the sugar primary (6-OH) position. The fatty acids at the glycerol moiety are saturated, namely palmitic acid (C16:0) and stearic acid (C18:0). GGPL-I has a structural feature analogous to 1,2-di-O-palmitoyl phosphatidylcholine (DPPC) as a ubiquitous cell membrane phospholipid. Apparently, GGPLs are

Pyridinium based amphiphilic hydrogelators as potential antibacterial agents

• Sayanti Brahmachari,
• Sisir Debnath,
• Sounak Dutta and
• Prasanta Kumar Das

Beilstein J. Org. Chem. 2010, 6, 859–868, doi:10.3762/bjoc.6.101

• cells. The antibacterial activity conjugated with low cytotoxicity and water gelation ability makes this class of compound an attractive target for the development of antibacterial biomaterials. Experimental Materials Myristic acid, palmitic acid, stearic acid and ethyl bromide were purchased from SRL

N-acylation of ethanolamine using lipase: a chemoselective catalyst

• Mazaahir Kidwai,
• Roona Poddar and
• Poonam Mothsra

Beilstein J. Org. Chem. 2009, 5, No. 10, doi:10.3762/bjoc.5.10

• ; layer thickness 250 μm; plate height 30 μm). Ethanolamine (99.0% pure), lauric acid (>98.5% pure), capric acid (>95.5% pure), myristic (>98.5% pure) and palmitic acid (>98.5%), ethyl laurate (>95.5% pure), ethyl caprate (>95.5% pure), ethyl myristate (>95.5% pure) and ethyl palmitate (>95.5% pure) were