Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• [94]. Divamide A (Figure 4) was first isolated from a marine tunicate, Didemnum molle, extract, based on its anti-HIV activity in a bioassay-guided fractionation. Further investigation on the identification of the BGC revealed that the tunicate symbiont, Prochloron didemni, is actually responsible for

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• . coli from a marine Microbulbifer sp. ALW1 [59]. Enzyme structure and site-directed mutagenesis led to the identification of key residues in the enzyme active site that participated in the hydrolytic activity [59]. Carbohydrate esterases Carbohydrate esterases (CEs) catalyze the O- or N-deacylation of

• algae [17]. Further investigation indicated that the bioactive substance was mainly located in the cell-free supernatant of Microbulbifer sp. RZ01. Fractionation and spectroscopic characterization led to the isolation and identification of the extracellularly secreted molecule, 3,3´,5,5´-tetrabromo-2,2

Regio- and stereochemical stability induced by anomeric and gauche effects in difluorinated pyrrolidines

• Ana Flávia Candida Silva,
• Francisco A. Martins and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2024, 20, 1572–1579, doi:10.3762/bjoc.20.140

• 3,4-difluoropyrrolidines, compared to the CCSD/DGTZVP level [14][15]. The evaluated levels encompassed the B3LYP-GD3BJ [16][17][18], ωB97XD [19], and PBEPBE [20] functionals, along with the 6-311++G(d,p) [21] and DGTZVP [15] basis sets. Following the identification of B3LYP-GD3BJ/6-311++G(d,p) as the

Cofactor-independent C–C bond cleavage reactions catalyzed by the AlpJ family of oxygenases in atypical angucycline biosynthesis

• Jinmin Gao,
• Liyuan Li,
• Shijie Shen,
• Guomin Ai,
• Bin Wang,
• Fang Guo,
• Tongjian Yang,
• Hui Han,
• Zhengren Xu,
• Guohui Pan and
• Keqiang Fan

Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102

• -independent AlpJ-family oxygenases. Supporting Information Supporting Information File 44: Sequence comparison results and phylogenetic tree of AlpJ-family enzymes and anthrone oxygenases, crystal structures of AlpJ and ActVA-Orf6, SDS-PAGE of purified proteins, HPLC traces of prosthetic group identification

Novel analogues of a nonnucleoside SARS-CoV-2 RdRp inhibitor as potential antivirotics

• Luca Julianna Tóth,
• Kateřina Krejčová,
• Milan Dejmek,
• Eva Žilecká,
• Blanka Klepetářová,
• Lenka Poštová Slavětínská,
• Evžen Bouřa and
• Radim Nencka

Beilstein J. Org. Chem. 2024, 20, 1029–1036, doi:10.3762/bjoc.20.91

• suitably decorated benzoxazole derivative 12a. The benzoxazole core showed increased sensitivity towards a basic environment, resulting in the ring-opened side product 13 through saponification of the ester function of compound 12a. The identification of this side product proved to be challenging due to

A Diels–Alder probe for discovery of natural products containing furan moieties

• Alyssa S. Eggly,
• Namuunzul Otgontseren,
• Carson B. Roberts,
• Amir Y. Alwali,
• Haylie E. Hennigan and
• Elizabeth I. Parkinson

Beilstein J. Org. Chem. 2024, 20, 1001–1010, doi:10.3762/bjoc.20.88

• easily identifiable on liquid chromatography–mass spectrometry (LC–MS). The molecular probe, which undergoes this reaction with a variety of furans, was designed with both a UV-tag and a mass tag to enable easy identification. The probe has been tested with a variety of purified furans, including natural

• products, methylenomycin furan (MMF) hormones, and MMF derivatives. Moreover, the molecular probe has been tested in crude supernatants of various Streptomyces strains and enables identification of MMFs. Keywords: Diels–Alder reaction; furans; methylenomycin furan hormones; natural products; reactivity

• probe contains a UV-tag and MS-tag for easy identification utilizing LC–MS. Additionally, it is capable of covalently attaching to a variety of furan rings via a [4 + 2] Diels–Alder cycloaddition in relatively mild reaction conditions. It reacts with naturally occurring MMFs as well as their derivatives

Confirmation of the stereochemistry of spiroviolene

• Yao Kong,
• Yuanning Liu,
• Kaibiao Wang,
• Tao Wang,
• Chen Wang,
• Ben Ai,
• Hongli Jia,
• Guohui Pan,
• Min Yin and
• Zhengren Xu

Beilstein J. Org. Chem. 2024, 20, 852–858, doi:10.3762/bjoc.20.77

• either IM-9 or IM-11 cations. A direct dyotropic rearrangement, or two stepwise 1,2-alkyl migrations of IM-9, are possible pathways en route to cation IM-10. The presence of these intermediates IM-9, -10, -11 could be inferred by the identification of GJ1012B/D (5/6, Scheme 1D) [11], cattleyene (7) [19

Discovery and biosynthesis of bacterial drimane-type sesquiterpenoids from Streptomyces clavuligerus

• Dongxu Zhang,
• Wenyu Du,
• Xingming Pan,
• Xiaoxu Lin,
• Fang-Ru Li,
• Qingling Wang,
• Qian Yang,
• Hui-Min Xu and
• Liao-Bin Dong

Beilstein J. Org. Chem. 2024, 20, 815–822, doi:10.3762/bjoc.20.73

• subfamilies within the sesquiterpenoids. Our discovery significantly broadens the scope for future exploration of bacterial DMTs. Discovery and identification of a DMS in the cav BGC in S. clavuligerus To explore the BGC responsible for DMTs production in S. clavuligerus, we performed bioinformatics research

Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• , genome mining of the marine actinomycete Streptomyces seoulensis A01 enabled the identification of a giant type I polyketide synthase gene cluster (asm) [30]. Heterologous expression of the cryptic asm cluster using a bacterial artificial chromosome vector in a heterologous host led to the production of

• carbonate and terminal olefin functionalities [50]. Thus, artificial methods of genetic engineering and chemistry also play an important role in the identification of novel secondary metabolites. Culture conditions Medium composition, pH, oxygen supply, light Simply modifying the culture conditions is an

Substrate specificity of a ketosynthase domain involved in bacillaene biosynthesis

• Zhiyong Yin and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2024, 20, 734–740, doi:10.3762/bjoc.20.67

• organism shares the same habitat with the predator Myxococcus xanthus that feeds on other bacteria including B. subtilis, and bacillaene is the primary factor conferring B. subtilis cells resistance to predation by M. xanthus [8]. The identification of its biosynthetic gene cluster (bae) revealed that the

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• 2005, Sherman and co-workers reported a chemoenzymatic approach through the stereospecific macrocyclization based on the identification of the thioesterase domain (CrpTE) from the cryptophycin biosynthetic pathway, which demonstrated that the CrpTE has both high efficiency in generating the 16-membered

Evaluation of the enantioselectivity of new chiral ligands based on imidazolidin-4-one derivatives

• Jan Bartáček,
• Karel Chlumský,
• Jan Mrkvička,
• Lucie Paloušová,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2024, 20, 684–691, doi:10.3762/bjoc.20.62

• numerous instances, categorising them among the most efficient catalysts for this reaction type. A key finding of our research was the identification of position 2 on the imidazolidine-4-one unit as the crucial site for asymmetric induction. While the nature of the substituent at this chiral centre (i.e

Isolation and structure determination of a new analog of polycavernosides from marine Okeania sp. cyanobacterium

• Kairi Umeda,
• Naoaki Kurisawa,
• Ghulam Jeelani,
• Tomoyoshi Nozaki,
• Kiyotake Suenaga and
• Arihiro Iwasaki

Beilstein J. Org. Chem. 2024, 20, 645–652, doi:10.3762/bjoc.20.57

• pump and a UV detector was used. HPLC analysis was conducted using a pump (model PU-2080, Jasco) and a UV detector (model UV-2075, Jasco). All chemicals and solvents used in this study were the best grade available and obtained from a commercial source (Nacalai Tesque). Collection and identification of

Chemical and biosynthetic potential of Penicillium shentong XL-F41

• Ran Zou,
• Xin Li,
• Xiaochen Chen,
• Yue-Wei Guo and
• Baofu Xu

Beilstein J. Org. Chem. 2024, 20, 597–606, doi:10.3762/bjoc.20.52

• database confirmed its identification as Penicillium sp. This strain is preserved at the Shandong Laboratory of Yantai Drug Discovery. Fermentation in shaking flasks For large-scale fermentations, fresh mycelia of Penicillium shentong XL-F41 were first cultivated in liquid potato dextrose broth at 28 °C

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

• Sharmila Neupane,
• Marcelo Rodrigues de Amorim and
• Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

• powder, +37 (c 0.1, EtOH) [lit +40 (c 1.0, EtOH)] [5]; for the 1H and 13C NMR spectroscopic data, see Table S2 in Supporting Information File 1. By comparison with literature data this compound was identified as unguisin B (2) [1][5], further corroborating the identification of the new unguisin J (1

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• unique binding profile of specifically recognizing C2-substituted galactose in the context of glycans. Results and Discussion Identification and production of a new lectin from the melon Cucumis melo CMA1 is a predicted protein from whole-genome shotgun sequencing of leaves from the melon plant Cucumis

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• embryonic cells. Identification of the cause of the registered selective toxicity of the tested compounds requires further study. Conclusion Thus, we have introduced an effective base-catalyzed tandem reaction including a Cornforth-type rearrangement of 1-heteroaryl-1,2,3-triazole-4-carboximidamides and

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• identification of new catalysts as well as increasingly mild, economic and sustainable reaction conditions remain fundamental objectives for research in the field of organic chemistry. In recent years, alternative methods have been developed, including the use of different heterogeneous catalysts, to ensure

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• (position and anomericity). Based on this basic principle, the identification of an unknown carbohydrate proceeds as follows: the polymer is fragmented in monomers, yet maintaining information on the initial structure and the spectroscopic fingerprint (frequency and intensity of the vibrational modes) of

• each monosaccharide unit is measured, and subsequently identified by comparison with a library of reference spectra of synthetic monosaccharide standards. In the early days of MS–IR spectroscopy, ca. one hour was necessary to record the IR fingerprint of a single molecule and the identification was

•  1b, featuring three stereoisomers of C8H15NO6). With the rapid development of our approach, such method now reached a high data output since a single IR fingerprint can be obtained in few seconds. The fast and automatic identification and classification of the data becomes compulsory, which motivates

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• 13.96 and 22.16 min were coincident with those of the ᴅ-glucose and ʟ-rhamnose derivatives, respectively. Although the peak at 20.83 min was assumed to be attributable to apiofuranose, we were unable to obtain any standard for apiofuranose. In the reported monosaccharide identification method, the

• identification, which revealed peaks at retention times of 13.97 (ᴅ-glucose), 20.84 (ᴅ-apiose), and 22.17 (ʟ-rhamnose) min. Hence, 2 was identified as breynogenin-β-S-oxide 3-O-β-ᴅ-apiofuranosyl-(1→2)-[α-ʟ-rhamnopyranosyl-(1→3)]-β-ᴅ-glucoptranosyl-(1→2)-β-ᴅ-glucopyranoside. Furthermore, we investigated the

• Tesque) were used for column chromatography (CC). Silica gel 60 F254 and RP-18 F254S (Merck) were used for TLC analysis. Plant material B. disticha was cultivated in the greenhouse of Setsunan University medicinal plant garden (Osaka, Japan) in September 2014. Taxonomic identification was performed by an

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• measured in methanol by using an Anton Paar MCP-150 polarimeter (Seelze, Germany) at 20 °C. Isolation and identification of the endophytic fungus The fresh root of Trema guineesis was collected in January 2019 in Kala Mountain (near Yaoundé), in the Centre region of Cameroon. It was identified at the

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• in Table 1 and gas chromatograms are shown in Supporting Information File 1, Figures S2 and S3. After identification of the successful substrate-enzyme combinations, a preparative scale incubation of DA-4 and IA-1 with FPPS and 2MIBS resulted in the production of a terpenoid hydrocarbon that was

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• rearrangements. During the past decades numerous enzymes have been characterised from all branches of life. Only considering type I terpene synthases, after the identification of the 5-epi-aristolochene (1) synthase from Nicotiana tabacum [1] and the casbene (2) synthase from Ricinus communis [2] (Figure 1

• high yield of α-cadinene (11) (Figure 3C and 3D), and GGPP and GFPP were not accepted as substrate. For verification of the GC–MS-based identification the product was isolated from a preparative scale incubation of FPP (80 mg, 185 μmol) to obtain pure 11 (1.3 mg, 6.4 μmol, 3.5%). Structure elucidation

• success rate. This approach resulted in the identification of the first sesquiterpene synthases for (+)-δ-cadinol and (+)-α-cadinene, in addition to the first bacterial (−)-amorpha-4,11-diene synthase. This enzyme function was previously only known from Artemisia annua in which the (−)-amorpha-4,11-diene

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