Activity assays of NnlA homologs suggest the natural product N-nitroglycine is degraded by diverse bacteria

• Kara A. Strickland,
• Brenda Martinez Rodriguez,
• Ashley A. Holland,
• Shelby Wagner,
• Michelle Luna-Alva,
• David E. Graham and
• Jonathan D. Caranto

Beilstein J. Org. Chem. 2024, 20, 830–840, doi:10.3762/bjoc.20.75

• (Scheme 1) [20][21]. Vs NnlA contains a Per-Arnt-Sim (PAS) domain – protein domains that often bind heme and function as gas or redox sensors [20]. Indeed, Vs NnlA was shown to contain a heme cofactor [21]. Mutagenesis of a predicted histidine ligand to this heme resulted in loss of the heme and the

• activity even in the presence of millimolar concentrations of 2-NAE (Table S4, Supporting Information File 1). This observation suggests that binding in the substrate pocket is dependent on an electrostatic interaction with the NNG α-carboxylate, most likely from a lysine, arginine, histidine side chain or

• the N-terminus. An alignment of orthologous protein sequences reveals several conserved basic residues (Figure S4, Supporting Information File 1). The only conserved histidine residue is H73, which has been assigned as a heme ligand. Conserved arginine and lysine residues are colored magenta in the Vs

Genome mining of labdane-related diterpenoids: Discovery of the two-enzyme pathway leading to (−)-sandaracopimaradiene in the fungus Arthrinium sacchari

• Fumito Sato,
• Terutaka Sonohara,
• Shunta Fujiki,
• Akihiro Sugawara,
• Yohei Morishita,
• Taro Ozaki and
• Teigo Asai

Beilstein J. Org. Chem. 2024, 20, 714–720, doi:10.3762/bjoc.20.65

• determined to be (−)-sandaracopimaradiene (Figure 3B). We then turned our attention to the individual function of these enzymes. With this aim, AsPS and AsCPS were expressed in Escherichia coli as N-terminal hexa-histidine-tagged proteins and purified by Ni-affinity chromatography (see Supporting Information

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• with a histidine like group for the development of theranostic agents. Firstly, zinc triazole-porphyrins 63 and 66a were synthesized by the click reaction between water-soluble azidoporphyrin 61 and ᴅ-propargylglycine 62 or trifunctional-propargyllysine 65 in 83.6% and 77% yield, respectively, under

Functionalization of imidazole N-oxide: a recent discovery in organic transformations

• Koustav Singha,
• Imran Habib and
• Mossaraf Hossain

Beilstein J. Org. Chem. 2022, 18, 1575–1588, doi:10.3762/bjoc.18.168

• histidine and the related local-immune hormone histamine. In the structural view of DNA and RNA, purine bases contain imidazole moieties. Also, imidazole N-oxides have various and intriguing applications in natural products synthesis, catalysis, and coordination chemistry [3]. Derivatives of imidazole

Characterization of a new fusicoccane-type diterpene synthase and an associated P450 enzyme

• Jia-Hua Huang,
• Jian-Ming Lv,
• Liang-Yan Xiao,
• Qian Xu,
• Fu-Long Lin,
• Gao-Qian Wang,
• Guo-Dong Chen,
• Sheng-Ying Qin,
• Dan Hu and
• Hao Gao

Beilstein J. Org. Chem. 2022, 18, 1396–1402, doi:10.3762/bjoc.18.144

• site, PaFS possesses a histidine residue (Supporting Information File 1, Figure S20). To test its role, Tyr91 in TadA was mutated to His, and then analyzed by an in vitro enzymatic assay. The result showed that the variant could give an additional product 3 (Supporting Information File 1, Figure S21

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

• Michael Keppler,
• Sandra Moser,
• Henning J. Jessen,
• Christoph Held and
• Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

• transfer likely proceeds via formation of a phospho-enzyme intermediate (Figure 2d). Two essential histidine residues for autophosphorylation were identified by mutagenesis experiments [9][13][14]. Variants carrying mutations at these histidine residues lost the ability to synthesise polyP or ATP in vitro

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• and amplified sequences were then cloned into an expression pET28 plasmid containing an N-terminal 6-histidine tag sequence. Heterologous production of enzymes was achieved in E. coli BL21 and western blot analysis indicated the accumulation of His-tagged UbiA-297 (35 kD) within concentrated cell

A photochemical C=C cleavage process: toward access to backbone N-formyl peptides

• Haopei Wang and
• Zachary T. Ball

Beilstein J. Org. Chem. 2021, 17, 2932–2938, doi:10.3762/bjoc.17.202

• , which leads to formyl products from formal oxidative cleavage of a C=C bond. Our interest in vinylogous analogues of 2-nitroaryl photoreactive groups stems from studies into alkenylboronic acid reagents for Chan–Lam-type modification of peptide backbone N–H bonds, directed by a proximal histidine

• alkenylation product ii, directed by a neighboring histidine residue. Upon exposure to 365-nm light, photocleavage of the caging group (red) was observed, producing the free peptide i. Irradiation longer than 10 minutes were sometimes necessary for maximal yield of photo-deprotected product i [16]. Furthermore

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• ]. This specific process is based on reversible interactions, which are integrated in the chemical structure of the proteins of the thread [5]. Zinc–histidine metal complexes which are part of the protein’s structure enable the material to regenerate its mechanical performance after a damage event [1][6

Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

• Emmanuel T. Oluwabusola,
• Olusoji O. Adebisi,
• Fernando Reyes,
• Kojo S. Acquah,
• Mercedes De La Cruz,
• Larry L. Mweetwa,
• Joy E. Rajakulendran,
• Digby F. Warner,
• Deng Hai,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2021, 17, 2390–2398, doi:10.3762/bjoc.17.156

• , respectively (Figure 3). Biochemical studies show that histamine and phenethylamine moieties were produced from histidine and phenylalanine substrates by a decarboxylase enzyme [41][42][43]. Pseudomobactin A (4) was proposed logically to have formed through direct amination of the unstable salimethyloxazolinyl

One-step synthesis of imidazoles from Asmic (anisylsulfanylmethyl isocyanide)

• Louis G. Mueller,
• Allen Chao,
• Embarek AlWedi and
• Fraser F. Fleming

Beilstein J. Org. Chem. 2021, 17, 1499–1502, doi:10.3762/bjoc.17.106

• central role of histidine in biological machinery, particularly as a base at enzymatic active sites [2]. As histidine mimics, imidazole-containing pharmaceuticals are often only N-substituted, as in the fungicides ketoconazole and econazole (Figure 1) [3], or disubstituted as illustrated by the anesthetic

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• hydrophobic residues, such as leucine, phenylalanine, tryptophan, and methionine, as well as polar residues, such as aspartate, glutamate, histidine, and arginine, tend to be part of bifurcated interactions. On the other hand, glutamine and lysine were the only amino acids that tend to not take part in such

Selected peptide-based fluorescent probes for biological applications

• Debabrata Maity

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

• fluorophore on one lysine. The four cationic lysine residues are closely mimicking the structure of polymyxin B, which has a strong affinity to the negative LPS. The second lipid 13 is designed by connecting 10,12-tricosadiyonic acid to histidine. PDA liposomes are formed after UV-light-irradiated

Ultrasound-assisted Strecker synthesis of novel 2-(hetero)aryl-2-(arylamino)acetonitrile derivatives

• Emese Gal,
• Luiza Gaina,
• Hermina Petkes,
• Alexandra Pop,
• Castelia Cristea,
• Gabriel Barta,
• Dan Cristian Vodnar and
• Luminiţa Silaghi-Dumitrescu

Beilstein J. Org. Chem. 2020, 16, 2929–2936, doi:10.3762/bjoc.16.242

• activity. The viability of Salmonella typhimurium TA98 and TA 100, respectively, was assessed by exposing the histidine dependent bacteria to compound 2c, 2i, and 2l, respectively, directly on minimal glucose agar plates in the presence or absence of the metabolic activation system S9. The number of

• histidine independent revertant colonies was scored on the test plates after 72 hours of incubation at 37 °C. The mutagenicity test results confirmed spontaneous colony numbers within the regular range (comparable to the number scored on the (negative) solvent control plates), thus indicating that no

Encrypting messages with artificial bacterial receptors

• Pragati Kishore Prasad,
• Naama Lahav-Mankovski,
• Leila Motiei and
• David Margulies

Beilstein J. Org. Chem. 2020, 16, 2749–2756, doi:10.3762/bjoc.16.225

• selectively bind a hexa-histidine tag (His-tag). ODN-1 can also be modified with a second functional group (X), such as a fluorescent dye, to afford X-ODN-1 (Figure 1A and Figure 1B). In this way, the binding of X-ODN-1 to the bacteria will lead to the presentation of X on the cell surface (Figure 1A). A

• binding of X-ODN-1 to a hexa-histidine tag (His-tag) fused to OmpC. A complementary strand (Y-ODN-2) modified with the desired functionality (Y) provides the means to ‘program’ the structure of the artificial receptors. (B) Structure of X-ODN-1. (A) Schematic illustration of the way the division of

Nocarimidazoles C and D, antimicrobial alkanoylimidazoles from a coral-derived actinomycete Kocuria sp.: application of ¹J_C,H coupling constants for the unequivocal determination of substituted imidazoles and stereochemical diversity of anteisoalkyl chains in microbial metabolites

• Md. Rokon Ul Karim,
• Enjuro Harunari,
• Amit Raj Sharma,
• Naoya Oku,
• Kazuaki Akasaka,
• Daisuke Urabe,
• Mada Triandala Sibero and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 2719–2727, doi:10.3762/bjoc.16.222

• -histidine, the 1JC,H values for H-2/C-2 (208 to ≈222 Hz) were found to be always larger by at least 15 Hz than those for H-4/C-4 (188 to ≈208 Hz) at any pH condition below 11 [24]. Because the sp2 methine group in 1 exhibited 1JC,H = 221 Hz in a coupled HSQC experiment, this was assignable to the imidazole

GlypNirO: An automated workflow for quantitative N- and O-linked glycoproteomic data analysis

• Toan K. Phung,
• Cassandra L. Pegg and
• Benjamin L. Schulz

Beilstein J. Org. Chem. 2020, 16, 2127–2135, doi:10.3762/bjoc.16.180

• O-glycan on fibrinogen alpha chain G272GSTSYGTGSETESPR (Figure 5a). HCC patients showed a relative decrease in disialylated and an increase in monosialylated O-glycan abundance on both plasma protease C1 inhibitor V45AATVISK and histidine-rich glycoprotein S271STTKPPFKPHGSR (Figure 5b and 5c

• G272GSTSYGTGSETESPR, (b) plasma protease C1 inhibitor V45AATVISK, and (c) histidine-rich glycoprotein S271STTKPPFKPHGSR. N = 3; values show mean; error bars show standard error of the mean; *, P < 0.05. Supporting Information Supporting Information File 548: Supplementary Tables S1–S42. Supporting Information File

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• was pointing away from the zinc ion [39]. The calculated distances from the Zn2+ ion and the different sites at the ligand and the protein are summarized in Table 5. The zinc chelation in MMP-9 occurred in a different way. The predicted orientation of the histidine residues at the catalytic site were

Fabclavine diversity in Xenorhabdus bacteria

• Sebastian L. Wenski,
• Harun Cimen,
• Natalie Berghaus,
• Sebastian W. Fuchs,
• Selcuk Hazir and
• Helge B. Bode

Beilstein J. Org. Chem. 2020, 16, 956–965, doi:10.3762/bjoc.16.84

• formula [28]. The general structure of the fabclavines is highly conserved and differs only in the specified moieties as shown in Table 1. The NRPS part of the full-length fabclavines harbors six amino acids, whereby the second position (R1) varies between phenylalanine (Phe), histidine (His), and alanine

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

Reactions of 2-carbonyl- and 2-hydroxy(or methoxy)alkyl-substituted benzimidazoles with arenes in the superacid CF₃SO₃H. NMR and DFT studies of dicationic electrophilic species

• Dmitry S. Ryabukhin,
• Alexey N. Turdakov,
• Natalia S. Soldatova,
• Mikhail O. Kompanets,
• Alexander Yu. Ivanov,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1962–1973, doi:10.3762/bjoc.15.191

• common motif present in some components of human organisms, histidine, vitamin B12, purines, histamine, biotin, and in natural compounds such as lepidiline A and B [6]. Over the years of active research, benzimidazole derivatives have been involved in medicinal chemistry covering a wide range of

Complexation of chiral amines by resorcin[4]arene sulfonic acids in polar media – circular dichroism and diffusion studies of chirality transfer and solvent dependence

• Bartosz Setner and
• Agnieszka Szumna

Beilstein J. Org. Chem. 2019, 15, 1913–1924, doi:10.3762/bjoc.15.187

• ), H-Val-OMe (∙HCl). After a few minutes, complexes of 1 with lysine, arginine and histidine methyl esters precipitated. The obtained solids were isolated and dried in vacuum. 1(LysOMe)2, yield 71% (10 mg). 1H NMR (600 MHz, methanol-d4, δ) 7.28 (s, 4H), 4.58 (t, J = 7.9 Hz, 4H), 4.26 (dd, J = 14.0 Hz

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• paraformaldehyde and benzyl isocyanide to form hybrid 11 in good yield. Similarly, the spirostanic lactone 12 was transformed into spirostanic acid 13 and amine 14, which were next ligated to alanine methyl ester and Boc-histidine leading to the amino acid–steroid conjugates 15 and 16, respectively. This approach

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• , yielding 85% of product 22 (Table 5). A substitution of lysine with histidine at position 198 (Table 5, entries 8 and 9) did not improve the catalytic efficiency of ArM 2 at pH 7.0. Jeschek et al. subsequently evolved ArM 1 in vivo by directed evolution of an artificial metathase [68]. Tethering an OmpA

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

• Daniel F. Sauer,
• Johannes Schiffels,
• Takashi Hayashi,
• Ulrich Schwaneberg and
• Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

• (NB) is a small, soluble β-barrel protein with a molecular weight of 19 kDa [49]. NB wild-type has 10 β-strands and contains a heme as a prosthetic group [49]. Upon modification of the axial histidine that coordinates the heme, the robust β-barrel structure with a relatively small cavity is retained

• methionines inside the cavity were substituted by leucines. This yielded the two mutants NB4 (leucine for histidine; mutations in comparison to NB wild-type: M75L/H76L/Q96C/M148L/H158L) and NB11 (alanine for histidine; mutations in comparison to NB wild-type: M75L/H76L/Q96C/M148L/H158A) [56]. Notably, the