Production of non-natural 5-methylorsellinate-derived meroterpenoids in Aspergillus oryzae

• Jia Tang,
• Yixiang Zhang and
• Yudai Matsuda

Beilstein J. Org. Chem. 2024, 20, 638–644, doi:10.3762/bjoc.20.56

• acid (5-MOA)-derived meroterpenoids. (C) Reactions catalyzed by the terpene cyclases involved in DMOA-derived meroterpenoid pathways. Generation of unnatural 5-MOA-derived meroterpenoids. (A) Working concept to synthesize unnatural 5-MOA-derived meroterpenoids. SAM: S-adenosyl-ʟ-methionine; FPP

NaI/PPh₃-catalyzed visible-light-mediated decarboxylative radical cascade cyclization of N-arylacrylamides for the efficient synthesis of quaternary oxindoles

• Dan Liu,
• Yue Zhao and
• Frederic W. Patureau

Beilstein J. Org. Chem. 2023, 19, 57–65, doi:10.3762/bjoc.19.5

• -active ester derived from methionine could be converted effectively to α-aminoalkylation product 3al in overall 70% yield, which thus provides a mild method for the functionalization and derivation of abundant natural or unnatural amino acids. Some functional groups such as a terminal alkene in 3am, a

The stereochemical course of 2-methylisoborneol biosynthesis

• Binbin Gu,
• Anwei Hou and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 818–824, doi:10.3762/bjoc.18.82

• suggested to proceed through degradation of a sesquiterpene [2], but first feeding experiments with 14C-labeled acetate and methionine pointed to a methylated monoterpene [22]. Further investigations by feeding of 13C-labeled methionine and deuterated mevalonolactone isotopomers to Nannocystis exedens

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• macrocyclisation product, which was confirmed by MALDI-ToF-MS of the crude reaction mixture after test cleavage (see Supporting Information File 1, Figure S1). However, deboronation and dehalogenation were observed as side reactions to some extent as well as oxidation, most likely of methionine (Met) [79]. The

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• methionine aminopeptidase type-2 (MetAP-2) enzyme [129]. MetAP-2 is involved in cell proliferation, translation and post-translational modifications of nascent polypeptides and is therefore essential for cell viability [130][131]. Additionally, fumagillin is also known to be overproduced upon caspofungin

• -adenosyl-methionine (SAM) dependent bisthiomethyltransferase GtmA which is not part of the gli-cluster. Amoebicidal secondary metabolites trypacidin and fumagillin of Aspergillus fumigatus. Intermediates of the DHN-melanin biosynthesis in Aspergillus fumigatus. Intermediates and products of the

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• compounds ethyl (E)-3-(methylsulfanyl)acrylate and 2-(methyldisulfanyl)benzothiazole were identified and their structures were verified by synthesis. Feeding experiments with [methyl-2H3]methionine, [methyl-13C]methionine and [34S]-3-(dimethylsulfonio)propanoate (DMSP) resulted in the high incorporation

• into dimethyl trisulfide and S-methyl methanethiosulfonate, and revealed the origin of the methylsulfanyl group of 2-(methyldisulfanyl)benzothiazole from methionine or DMSP, while the biosynthetic origin of the benzothiazol-2-ylsulfanyl portion could not be traced. The heterocyclic moiety of this

• Celeribacter strains are capable of methionine and DMSP degradation to widespread sulfur volatiles, but the analysis of trace compounds in natural samples must be taken with care. Keywords: GC–MS; isotopes; Roseobacter; sulfur metabolism; volatiles; Introduction Bacteria from the roseobacter group belong to

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

• methionine at position 35 was replaced by tfmMet (Aβ1−40-tfmMet35) [9][62]. The aggregation process was then monitored by 19F NMR over a period of several weeks [62]. Upon analysis, formation of at least six spectroscopically distinguishable intermediates could be detected during fiber formation (Figure 10

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

Semiautomated glycoproteomics data analysis workflow for maximized glycopeptide identification and reliable quantification

• Steffen Lippold,
• Arnoud H. de Ru,
• Jan Nouta,
• Peter A. van Veelen,
• Magnus Palmblad,
• Manfred Wuhrer and
• Noortje de Haan

Beilstein J. Org. Chem. 2020, 16, 3038–3051, doi:10.3762/bjoc.16.253

• the HYT glycopeptide cluster as well [17]. The C-terminal IgA1/2 glycopeptides (LAGC/Y) were found mainly with methionine oxidation. Unoxidized peptide moieties were also assigned but with low scores (below 50). The manual check of the data revealed that in some cases, the selection of the wrong

• a fixed modification for cysteine residues. Methionine oxidation was enabled as a variable modification. The search for N- and O-glycopeptides was separately performed. For this purpose, either the database “N-glycan 309 mammalian no sodium” (Supporting Information File 7) or “O-glycan 78 mammalian

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• dispersion and more favorable relaxation properties compared to CH2 groups, so they are mostly used to observe the interactions of a protein with its binding partners. Especially methyl groups bound to a hetero atom like sulfur (in methionine) or nitrogen (e.g., in methylated lysine) have unique chemical

• supramolecular binders to larger proteins or multimeric assemblies, but it could represent a useful tool in this context as well. The assignment of the labeled methyl groups can be challenging and cost-intensive. Methionine scanning introduces single methionine (Met) mutants in a specifically 13C1H3-Met labeled

• protein [126] to circumvent this problem. Methionines have a naturally low abundance in proteins and their methyl resonances are easily identified. A methionine mutation, which is introduced around the suspected ligand binding site, is easily assigned because it adds one signal to the spectrum. This

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• mixers [44]. The photocatalytic oxidation of methionine was performed in the Corning laboratory reactor. Two LED panels coupled with heat exchangers were placed on both sides of the reactor. Flow was supplied with an HPLC pump. Full conversion was achieved with a residence time ranging from 0.6 min to

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

• cysteines was set as a fixed modification, and dynamic modifications included deamidation of asparagine, monooxidised methionine, and the formation of pyroglutamate at N-terminal glutamic acid and glutamine. All variable modifications were set as “Common 1” allowing each modification to be present once on a

Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• iminosemiquinone redox-active ligand which was oxidized to iminobenzoquinone. The Canary group [30] reported a redox-reconfigurable copper catalyst that exhibits reversal of its helical chirality through redox stimuli (Scheme 8). Combining ʟ-methionine and catalytic urea groups with two different copper salts as

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• synthesized starting from ʟ-methionine. The subsequent enyne ring-closing metathesis in the presence of the Grubbs first-generation catalyst (5 mol %) afforded a pyrrolidine derivative in 76% yield (Scheme 12). This pyrrolidine was converted into a pyrrolo-1,4-benzodiazepinone bearing a vinyl side group

• . Synthesis of the anthramycin precursor 8 from ʟ-methionine by a tandem enyne metathesis–cross metathesis reaction. Synthesis of (−)‐clavukerin A (9) and (−)‐isoclavukerin A (10) by an enyne metathesis route starting from (S)- and (R)-citronellal. Synthesis of (−)-isoguaiene (11) through an enyne metathesis

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

Exploring the scope of DBU-promoted amidations of 7-methoxycarbonylpterin

• Anna R. Bockman and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2020, 16, 509–514, doi:10.3762/bjoc.16.46

• , pterins have been a useful scaffold in the development of inhibitors of ricin [3][4], methionine synthase [5], nitric oxide synthase [6], shigella [7], and aldose reductase [8], as well as for treatment of leishmaniosis [9]. In addition to their therapeutic potential, pterin derivatives have been an

Isolation and biosynthesis of an unsaturated fatty acid with unusual methylation pattern from a coral-associated bacterium Microbulbifer sp.

• Amit Raj Sharma,
• Enjuro Harunari,
• Tao Zhou,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2327–2332, doi:10.3762/bjoc.15.225

• analysis revealed that 1 is an unsaturated fatty acid in which a methyl group is located in an uncommon position as a natural product. Feeding experiments of 13C-labeled precursors clarified that ʟ-methionine-derived methylation takes place at the carbon which is derived from the carbonyl carbon of acetate

• biosynthetically unique: it has an uncommon methylation pattern in its carbon chain, derived from the C-methylation with ʟ-methionine at a carbon originated from a carbonyl carbon of acetate. In this paper, we report the isolation and structure determination of 1 and its biosynthetic origin proven by the feeding

• , C7, and C9 (Figure 4). A feeding experiment with ʟ-[methyl-13C]methionine was then carried out. The high level of enrichment was observed only for C11 in the 13C NMR spectrum, thereby confirming that the methyl group is derived from methionine via SAM. In addition to the fungal sphingolipids

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

• combinatorial library [88]. The work carried out by Davis and co-workers led to the metabolic incorporation of unnatural amino acids (uAAs) bearing a terminal alkene as CM substrates for protein modification [89]. The authors investigated the possibility to incorporate methionine (Met) analogues in a Met

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum

• Jan Rinkel,
• Alexander Babczyk,
• Tao Wang,
• Marc Stadler and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2018, 14, 2974–2990, doi:10.3762/bjoc.14.277

• that was supported by a feeding experiment with (methyl-2H3)methionine. Keywords: constitutional isomerism; gas chromatography; mass spectrometry; natural products; volatiles; Introduction Fungi release a large number of different volatiles that belong to all kinds of natural product classes [1

• (methyl-2H3)methionine. While the methylation pattern of the alternative structure 24c is difficult to understand via a polyketide biosynthesis mechanism, the formation of the assigned structure of 24 by a polyketide synthase (PKS) can be easily rationalised (Scheme 2). The acetate starter unit, bound to

• the acyl carrier protein (ACP) of an iterative fungal PKS, can be elongated with malonyl-SCoA (mal-SCoA) followed by C-methylation with S-adenosyl-L-methionine (SAM). Two more rounds of elongation with mal-SCoA, the first extension with C-methylation and action of a ketoreductase (KR), result in a

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• constant of 14 [11]. It is slightly basic, with a pKa lower than 1 for the Co–H complex [12]. The “supernucleophilic” cob(I)alamin is found in many enzymes such as methionine synthetases, adenosyltransferases, and reductive dehalogenases. In addition, the reactivity of cob(I)alamin has been investigated

• reactions The B12-dependent methionine synthase catalyzes the methyl transfer reaction as shown in Scheme 6a. In the active center of the enzyme, cob(I)alamin accepts the methyl group from methyltetrahydrofolate (CH3-H4-folate) and the resultant methylcobalamin donates it to homocysteine [65][66

• arrangements mediated by B12-vesicle artificial enzymes. Carbon-skeleton arrangements mediated by B12-HSA artificial enzymes. Photochemical carbon-skeleton arrangements mediated by B12-Ru@MOF. (a) Methyl transfer reaction mediated by B12-dependent methionine synthase. (b) Methyl transfer reaction from TsOCH3

Acyl-group specificity of AHL synthases involved in quorum-sensing in Roseobacter group bacteria

• Lisa Ziesche,
• Jan Rinkel,
• Jeroen S. Dickschat and
• Stefan Schulz

Beilstein J. Org. Chem. 2018, 14, 1309–1316, doi:10.3762/bjoc.14.112

• expressed in E. coli to allow in vitro experiments with suitable acyl precursors to probe AHL formation. After protein purification of the AHL synthases and incubation with the precursors S-adenosyl methionine (SAM) and different acyl derivatives (free fatty acids, SNAC esters, PCEs) the AHL production was

Volatiles from three genome sequenced fungi from the genus Aspergillus

• Jeroen S. Dickschat,
• Ersin Celik and
• Nelson L. Brock

Beilstein J. Org. Chem. 2018, 14, 900–910, doi:10.3762/bjoc.14.77

• an even number of carbons are much more widespread. Furthermore, esterification with S-adenosyl-l-methionine (SAM) by a methyltransferase is a very common process in nature, while ethyl esters are rarer and likely require a two-step pathway through reduction of acetyl-CoA to ethanol and its

Position-dependent impact of hexafluoroleucine and trifluoroisoleucine on protease digestion

• Susanne Huhmann,
• Anne-Katrin Stegemann,
• Kristin Folmert,
• Damian Klemczak,
• Johann Moschner,
• Michelle Kube and
• Beate Koksch

Beilstein J. Org. Chem. 2017, 13, 2869–2882, doi:10.3762/bjoc.13.279

• phenylalanine, tyrosine, tryptophan, and leucine in the P1 position. Secondary hydrolysis also occurs at the carbonyl end of isoleucine, methionine, serine, threonine, valine, histidine, glycine, and alanine [47][58][59][60]. The S2 subsite of α-chymotrypsin generally prefers to accommodate hydrophobic residues