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Search for "ligation" in Full Text gives 93 result(s) in Beilstein Journal of Organic Chemistry.
Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins
Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68
- ) ameliorates myocardial ischemia or myocardial infarction induced by coronary ligation. Although crocin and crocetin derivatives exhibit a diverse scope of biological activity, they are characterized by poor stability and low bioavailability, which has significantly impeded clinical developments. Recently
New variochelins from soil-isolated Variovorax sp. H002
Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63
- library preparation with a Ligation Sequencing Kit (SQK-LSK 109), following the 1D genomic DNA by ligation protocol. The library was applied to a MinION flowcell (FLO MIN106 R9.41revD) operated by the MinKNOW (20.06.9) software, and then processed by Guppy basecaller (4.0.11) in the high accuracy mode. As
Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin
Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31
- supplier instructions (New England Biolabs, #T1020S) and ligation using the DNA ligation kit, Mighty Mix (Ozyme, Takara, #TAK6023Z), at room temperature to form the pET40b-TEV-CMA11 plasmid. The N-terminal domain of CMA1 (6–132 in mature protein) was amplified by PCR using the following primers: forward
Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration
Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146
- ligation from shorter 20 to 60 nt ODNs produced by automated de novo chemical synthesis. While these methods have made many projects in areas such as synthetic biology and protein engineering possible, they have various drawbacks. For example, they cannot produce genes and genomes with long repeats and
- synthesized ODNs of 20–60 nt in length using PCR or ligation [8]. While these methods have made possible the emergence of research areas such as synthetic biology [9][10][11][12][13][14], they have various drawbacks [3]. (1) Owing to the short length of the starting ODNs, a large number of them are needed in
- long ODN synthesis and purification, correct sequence selection, gene construction to protein synthesis has been established. Because the present long ODN synthesis method does not need PCR assembly or ligation of short ODNs and secondary structures of ODNs are prevented by protecting groups during de
Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry
Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15
- benefits from the leaving group ligation at the latest stages of the cross coupling. This is particularly interesting since it can hamper the usual decomposition of the iron catalyst, which tends to afford unreactive reduced aggregates at the end of the catalytic transformation, when the coupling kinetics
BINOL as a chiral element in mechanically interlocked molecules
Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53
- ]. Macrocycle (S)-61, featuring two iodotriazole units, was reacted with bis-iodoalkyne 62 and azides 63a/b in order to establish the mechanical bond in an active metal template approach (using the conformational flexibility of the iodotriazole groups for copper N-ligation). Subsequent N-methylation of the
Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides
Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47
- only is environmentally friendly, but also finds significant applications in biological systems (e.g., click reactions, bio-conjugation, and bio-orthogonal chemistry). One of such applications is ligation chemistry, in which “click” chemistry through a [3 + 2] biorthogonal cycloaddition between nitrile
Synthesis of novel [1,2,4]triazolo[1,5-b][1,2,4,5]tetrazines and investigation of their fungistatic activity
Beilstein J. Org. Chem. 2022, 18, 243–250, doi:10.3762/bjoc.18.29
- labeling proteins and visualizing cancer due to the ability of s-tetrazine to fast and biocompatible ligation with alkenes via the inverse electron demand Diels–Alder reactions [29][30][31]. At the same time, azolo-annulated 1,2,4,5-tetrazines remain to be a scarcely studied class of compounds, mainly due
Progress and challenges in the synthesis of sequence controlled polysaccharides
Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129
Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs
Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122
- -NH tryptophan. Notably, alkenylative ligation of tryptophan-containing peptides and alkynes containing biomolecular motifs including sugar, menthol, or coumarin units was successful, delivering unprecedented hybrid complex peptides 34d–f in good yield. Based on the developed intermolecular process
Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications
Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116
Synthetic strategies of phosphonodepsipeptides
Beilstein J. Org. Chem. 2021, 17, 461–484, doi:10.3762/bjoc.17.41
- , indicating that this strategy was not suitable for the synthesis of γ-phosphonodepsipeptides (Scheme 13) [28]. Folylpolyglutamate synthetase catalyzes an ATP-dependent ligation reaction. The reaction results in the synthesis of poly(γ-glutamate) metabolites of folates and some antifolates. Three γ
Novel library synthesis of 3,4-disubstituted pyridin-2(1H)-ones via cleavage of pyridine-2-oxy-7-azabenzotriazole ethers under ionic hydrogenation conditions at room temperature
Beilstein J. Org. Chem. 2021, 17, 156–165, doi:10.3762/bjoc.17.16
- a sacrificial metal cation, preventing Pd ligation and permitting the reaction to turnover resulting in albeit poor isolated yields of 9d,e (Table 2). All attempts to carry out the reaction using only CuI failed, confirming that Pd was necessary to catalyze this transformation. It was preferential
A metal-free approach for the synthesis of amides/esters with pyridinium salts of phenacyl bromides via oxidative C–C bond cleavage
Beilstein J. Org. Chem. 2019, 15, 1864–1871, doi:10.3762/bjoc.15.182
- [6][7], anhydrides [8], esters [9], and acyl azides [10] with amines by employing coupling reagents [11]. Alternative protocols include the Staudinger–Vilarrasa reaction [12], Schmidt reaction [13][14], Beckmann rearrangement [15], aminocarbonylation of aryl halides [16], Staudinger ligation [17
Steroid diversification by multicomponent reactions
Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121
- and complexity-generating processes [2][3] have proven success in peptide ligation [4] and macrocyclization [5][6], protein glycoconjugation [7], lipidation of peptides [8] and glycosides [9], and carbohydrate modification [10]. A special class of lipidic biomolecules are the steroids, which can be
- was also employed for the ligation of amino acids to spirostanic seco-steroids at ring B and for the simultaneous incorporation of two amino acid residues [19]. Ramírez and co-workers have extended the application of the Ugi-4CR to the diversity-oriented functionalization of androstanic and preganinc
- two different steroidal scaffolds [65], but it failed for the ligation of larger peptides to steroids due to the poor solubility of the former ones. In this sense, Rivera’s group introduced a solid-phase multicomponent procedure enabling the conjugation of steroids and lipids to peptides longer than
Diaminoterephthalate–α-lipoic acid conjugates with fluorinated residues
Beilstein J. Org. Chem. 2019, 15, 981–991, doi:10.3762/bjoc.15.96
- -free click reactions) [14]. The second functional unit, the maleimide moiety, is a reactive probe for mercaptane, which could be, e.g., a protein holding a cysteine residue on its surface [15][16][17]. The successful ligation by conjugated addition can be followed by the changes of the fluorescence
Cyclopropene derivatives of aminosugars for metabolic glycoengineering
Beilstein J. Org. Chem. 2019, 15, 584–601, doi:10.3762/bjoc.15.54
- glycoengineering (MGE). They readily react with tetrazines in an inverse electron-demand Diels–Alder (DAinv) reaction, a prime example of a bioorthogonal ligation reaction, allowing their visualization in biological systems. Here, we present a comparative study of six cyclopropene-modified hexosamine derivatives
- bioorthogonal ligation reaction [5][6]. Mannosamine derivatives are of special interest because they are metabolized to sialic acids and then displayed as terminal structures on the cell surface [7]. Various carbohydrate derivatives with different reporter groups have been applied for MGE [2][3][4]. For example
- , azides and alkynes can be visualized by the Staudinger ligation [8] or the azide–alkyne cycloaddition, that can be performed either copper-catalyzed [9][10] or strain-promoted [11][12]. Another type of reporter group that has been proven to be a valuable tool are electron-rich or strained alkenes, that
Synthesis of a tubugi-1-toxin conjugate by a modulizable disulfide linker system with a neuropeptide Y analogue showing selectivity for hY1R-overexpressing tumor cells
Beilstein J. Org. Chem. 2019, 15, 96–105, doi:10.3762/bjoc.15.11
- three cell lines was determined as proof for targeted delivery. Results and Discussion Synthesis of tubugi-1 building blocks We established the Ugi reaction as a powerful tool for peptide synthesis and ligation, including the first syntheses of tubulysine derivatives by us and later also others [44][53
Repurposing the anticancer drug cisplatin with the aim of developing novel Pseudomonas aeruginosa infection control agents
Beilstein J. Org. Chem. 2018, 14, 3059–3069, doi:10.3762/bjoc.14.284
- conducted for two biological replicates of each sample. The rRNA-depleted RNA was fragmented to 150–200 bp fragments, then first and second strand cDNA were synthesized with a cDNA-synthesis kit (ThermoScientific), followed by end repair and adapter ligation. After 12 cycles of PCR enrichment, the quality
Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics
Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267
- peptides for their ability to disrupt PPIs in the β-sliding clamp of Staphylococcus aureus. In this elegant study, from a library of 900,000 cyclic peptides, which was intracellularly generated using the split-intein circular ligation of peptides and proteins (SICLOPPS) technology [66], three hits
Artificial bioconjugates with naturally occurring linkages: the use of phosphodiester
Beilstein J. Org. Chem. 2018, 14, 1946–1955, doi:10.3762/bjoc.14.169
- synthesis, otherwise subsequent steps are complicated. Synthetic chemists, armed with various elegant artificial orthogonal bond formations, including alkyne–azide cycloaddition [27][28][29][30][31][32][33][34], thiol–ene ligation [35][36][37][38], Staudinger ligation [39][40], inverse-electron-demand Diels
Anomeric modification of carbohydrates using the Mitsunobu reaction
Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138
- approach was recently adopted in a total synthesis of aurantoside G, involving the Mitsunobu ligation of a D-xylopyranose derivative 116 and N-nosylated methyl asparaginate 117 to give 118 (Scheme 22) [87]. Compared to N-sulfonylation, N-carbamoylation can also prove effective to enhance the acidity of a
Drug targeting to decrease cardiotoxicity – determination of the cytotoxic effect of GnRH-based conjugates containing doxorubicin, daunorubicin and methotrexate on human cardiomyocytes and endothelial cells
Beilstein J. Org. Chem. 2018, 14, 1583–1594, doi:10.3762/bjoc.14.136
- peptide and of the type of the linkage on the toxic effect. Dau was coupled to the GnRH-III derivatives via oxime linkage in all cases. The oxime ligation was carried out under slightly acidic (pH 5) conditions [26] and the drug was attached directly either to GnRH-III (4) or to its derivatives in which
Phosphoramidite building blocks with protected nitroxides for the synthesis of spin-labeled DNA and RNA
Beilstein J. Org. Chem. 2018, 14, 1563–1569, doi:10.3762/bjoc.14.133
- deprotection and enzymatic ligation. Amidite 6 has been applied to synthesize a full-length TAR RNA labeled with two nitroxide precursors. In the last step, the 2-nitrobenzyloxymethyl groups were removed by irradiation at 365 nm. After elimination of formic aldehyde induced by gentle heating, the resulting
- -labeled adenosine tends to be sluggish and incomplete [25]. Furthermore, the protection group present in 22a–27a also shields the nitroxide precursor if subsequent enzymatic ligation steps in thiol containing buffers are required [43]. A single case has been reported earlier of an O-acetyl protected TEMPO
[3 + 2]-Cycloaddition reaction of sydnones with alkynes
Beilstein J. Org. Chem. 2018, 14, 1317–1348, doi:10.3762/bjoc.14.113
- -methanol [42][43][44] or in 3,3,6,6-tetramethylthiacyclohept-4-yne [44] were recently suggested as highly reactive partners for bio-orthogonal ligation reactions [45][46]. It is also possible to generate highly unstable cyclopentyne or cyclohexyne in situ from the corresponding 2-trimethylsilylcycloalken-1
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