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

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• massiliachelin was further supported by laboratory experiments involving the chrome azurol S (CAS) assay [20]. For these reasons, Massilia sp. NR 4-1 appeared to be a promising candidate for the discovery of further siderophores. The renewed analysis led to the identification of six previously overlooked iron

• (Supporting Information File 1, Figure S1). In the absence of sodium pyruvate, the identification and isolation of minor metabolites from Massilia sp. NR 4-1 is facilitated, as already observed in the discovery of massinidine [17]. In the present study, several batch fermentations with a total culture volume

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• identification Compound 1, a yellow gum, possesses the molecular formula C14H18O4 (six degrees of unsaturation), as deduced from its HRESIMS [M + H]+ ion peak at m/z 251.1274 (calcd for C14H19O4, 251.1278). The 1H NMR data (Table 1 and Figure S1 in Supporting Information File 1) display one aromatic proton [δH

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• identification of the variables that have significance for these classifications. FTIR–PCA was successfully applied for the discrimination of raw and thermally processed chicken lipid/β-CD complexes [16]. Moreover, raw and recrystallized β-CD samples (from water and alcohol–water solutions) were successfully

• samples and identification of the important FTIR variables for such classifications. PCA is a widely used multivariate statistical analysis technique that can extract valuable information from a large dataset. It is the case of FTIR data (both wavenumbers and intensities), where were assigned 20, 17, 34

• of FAMEs was purchased from Reactivul (Bucharest, Romania). The identification of the FAME components of the hazelnut oil involved FAME37 standard mixture, as well as C8–C20 linear alkane standard mixture for the determination of the specific retention index (RI) of compounds (both purchased from

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

• Robert N. Goldberg,
• Robert T. Giessmann,
• Peter J. Halling,
• Carsten Kettner and
• Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

• . Thus, attention must be paid to the identification of the substances, specification of the reaction(s), the conditions of reaction, the definition of the equilibrium constant(s) and standard states, the use of standard nomenclature, symbols, and units, and uncertainties. This document contains a

• involved in a reaction bind to H+, Mg2+ or Ca2+, the two types of equilibrium constants, K and K′, are distinctly different physical quantities and, in general, have different values. 3. Recommendations 3.1. Identification of substances and sources of materials The identity of the principal substances used

• literature to obtain the structure(s) of the substances used as well as avoid possible confusion regarding substance identification. A combination of the aforementioned methods is recommended. If substances have chirality, attention to which chiral forms are present is also required. The enzyme(s) used in a

Synthesis, α-mannosidase inhibition studies and molecular modeling of 1,4-imino-ᴅ-lyxitols and their C-5-altered N-arylalkyl derivatives

• Martin Kalník,
• Sergej Šesták,
• Juraj Kóňa,
• Maroš Bella and
• Monika Poláková

Beilstein J. Org. Chem. 2023, 19, 282–293, doi:10.3762/bjoc.19.24

• enzyme. Therefore, the next efforts should be focused on the identification of a novel N-substitution pattern of the DIM skeleton that would have more beneficial effects on the inhibition profile. Natural iminosugars (1,4-dideoxy-1,4-imino-ᴅ-mannitol (DIM) and swainsonine) and selected examples of

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• , but this study did not report on the isolation and structure elucidation [117]. Rather the identification was only based on GC–MS data, without a reference to a previous identification through rigorous structure elucidation. Conclusively, this compound has not been described thoroughly and its

• identification is doubtful. Information about the mass spectrum and Kovats retention index have been added to data bases such as the NIST Chemistry Webbook [118], which promoted the ambiguous detection of 54 in many other species, as described in more than 300 papers to date. Compound 55 can be formed from K2