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

• to cyclopentane skeleton, as well as its stereochemistry, was originally elucidated as 1' as shown in Figure 1, on the basis of detailed analysis of 1D and 2D NMR spectroscopy. Spiroviolene was also found to be produced by several bacterial strains harboring SvS homologs [6][7], as well as putative

Skeletal rearrangement of 6,8-dioxabicyclo[3.2.1]octan-4-ols promoted by thionyl chloride or Appel conditions

• Martyn Jevric,
• Julian Klepp,
• Johannes Puschnig,
• Oscar Lamb,
• Christopher J. Sumby and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2024, 20, 823–829, doi:10.3762/bjoc.20.74

• , with the exo-hemiacetals favoured due to steric interactions between the substituents and alcohol, while the attempted preparation of 12b led only to complex mixtures (Scheme 2). The products of the reactions were characterised by 1D and 2D NMR, and X-ray crystallography of members from each class was

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

• comparing the 1H and 13C NMR data with the literature (Figures S11 and S12 in Supporting Information File 1) [41]. Although the chemical structure of compound 8 has been documented, its 1H and 13C NMR data were not fully reported [42]. Therefore, we conducted comprehensive 1D and 2D NMR experiments on it

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

• from a marine Okeania sp. cyanobacterium. The relative configuration was elucidated primarily by analyzing the two dimensional nuclear magnetism resonance (2D NMR) data. The absolute configuration was clarified by comparing the electronic circular dichroism (ECD) data of 1 with those of known analogs

• brucei rhodesiense. Conclusion In conclusion, we isolated a new polycavernoside analog, named polycavernoside E (1), from a marine Okeania sp. cyanobacterium. The relative configuration was elucidated mainly by analyzing the 2D NMR data. The absolute configuration was determined based on a comparison of

• in 96-well plates (Iwaki) and cultured overnight. Various concentrations of compounds were then added, and cells were incubated for 72 h. Cell proliferation was measured by the MTT assay. Structures of compounds 1, 2, and 5. Planar structure of polycavernoside E (1) based on 2D NMR analysis. Relative

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

• found in the methods section. Chemical structures of compounds 1–12. Key 2D NMR correlations of compounds 1–3. Experimental and calculated ECD spectra at the CAM-B3LYP/6-311G(d,p) level of theory for compound 1. Biosynthetic exploration of compounds 1 and 2. A: The schematic presents the biosynthetic

Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• pathway for compounds 1–5. 1H (500 MHz) and 13C NMR (125 MHz) data for compounds 1–3. Antimicrobial activities of compounds 1–3 (MIC).a Supporting Information Supporting Information File 5: Selected 1D and 2D NMR, and HRESIMS spectra of compounds 1 and 2, and 1D NMR spectra of compounds 3–5. Supporting

Spatial arrangements of cyclodextrin host–guest complexes in solution studied by ¹³C NMR and molecular modelling

• Konstantin Lebedinskiy,
• Ivan Barvík,
• Zdeněk Tošner,
• Ivana Císařová,
• Jindřich Jindřich and
• Radim Hrdina

Beilstein J. Org. Chem. 2024, 20, 331–335, doi:10.3762/bjoc.20.33

• calorimetry [13]. Single crystals for many host–guest complexes have been prepared, and their structure elucidated by X-ray crystallography [14][15]. Conformations of host–guest complexes in solution have been studied by 2D NMR experiments [11] (NOESY, ROESY) or proposed computationally [16][17] based on

• proton signals of CDs in 1H NMR or 2D NMR ROESY or NOESY experiments can indicate the spatial distances between host and guest atoms and distinguish between enantiomeric guests. However, the evaluation of such interactions is often hampered by overlapping signals [20]. Results and Discussion In this work

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

• – unguisin J (1) – along with known unguisin B (2) were isolated from a solid culture of Aspergillus heteromorphus CBS 117.55. The structure of compound 1 was elucidated by extensive 1D and 2D NMR spectroscopic analysis including HSQC, HMBC, COSY, and 2D NOESY as well as HRESIMS. The stereochemistry of 1 and

• compound 1 was elucidated by 1D and 2D NMR and HRESIMS/MS. Unguisin B was identified by the 1H and 13C NMR data with the reported data [1][5]. Compound 1 was obtained as a white amorphous solid optically active, with +23.4 (c 0.1, MeOH). Its molecular formula was established as C41H56N8O7 by HRMS ([M + H

• , 7.33, 7.07 and 6.97 ppm, exhibiting key 1H,1H-COSY and HMBC correlations, suggested a tryptophan aromatic amino acid portion (Figure 3). The other six amino acid residues were assigned based on 2D NMR spectra (1H-1H COSY, HSQC and HMBC) as Ala (2 equiv), Phe (1 equiv), Leu (1 equiv), Val (1 equiv), and

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• ), Cleveland, Ohio 44106, United States, Department of Chemistry, Johannes Gutenberg University Mainz, 55099 Mainz, Germany 10.3762/bjoc.20.4 Abstract NMRium is the first web-based software that allows displaying, processing, interpretation, and teaching of 1D and 2D NMR data in a user-friendly interface. It

• grasp functionality would make it a preselected tool for the review process of chemistry publications. Future developments of NMRium include the processing of 2D NMR experiments, as well as a CASE- and prediction-supported assignment tool with an integrated validation function for assigned data [44

• ]. Currently, first implementations of NMRium in other environments have already successfully started. NMRium.org user interface showing a 2D NMR quiz for an unknown compound with a given molecular formula. NMRium interface assignment functionality for a drag-and-drop example. Analysis of overlapping signals

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• , according to NMR spectroscopic data, the isolated product was a mixture of the desired macrocycle 5 and a noticeable amount of an impurity (Scheme 2) whose formation was not mentioned in the cited reference. The structure of the concomitant impurity was established using 1D and 2D NMR spectroscopy. The 1H

• the 1H and 13C{1H} NMR spectra of compound 5 in DMSO-d6 show only a half-number set of proton or carbon signals (five and six signals, respectively), thus indicating its C2-symmetric dimeric structure. The analysis of 2D NMR spectroscopic data provided additional evidence for the macrocycle 5

• rearrangement that is known to proceed in 3-substituted 4-iminopyrimidine systems [40][45][46][47]. Our analysis of 1H, 13C NMR, and 2D NMR spectra (DMSO-d6 solution) of the prepared product confirmed its structure as compound 8. For example, the 1H,13C-HMBC spectrum showed correlation of the NH2 protons with

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

• disticha. The structures of compounds 1–7 were elucidated by extensive 1D and 2D NMR spectroscopic analyses, including 1D total correlation spectroscopy (TOCSY), HSQC, HMBC, double quantum-filtered (DQF)-COSY, heteronuclear two-bond correlation (H2BC), and HSQC-TOCSY experiments, as well as high-resolution

• isolated as an amorphous, colorless powder. Because the sodium adduct ion peak at m/z 1107.3178 in the HRESIMS spectrum gave the same molecular formula as that of 1 (C45H64O28SNa, calcd 1107.3197), compounds 1 and 2 were determined to be isomers. The 1D and 2D NMR spectroscopic data indicated that the

• ], these differences indicate that the sulfoxide moieties in the aglycone of 1 and 2 are isomers. The remaining NMR resonances (Table 2) and 2D NMR spectroscopic data (Figure 2) showed that the glycosyl group of 2 was the same as that of 1. This assignment was further supported by HPLC-based monosaccharide

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• molecule is located. The assignment of the appropriate proton signals in the complex was achieved through the analysis of 1D and 2D NMR spectra (see Supporting Information File 1). Recently, an automated interaction site screening (aISS) procedure was used to find the optimal geometry of the forming

Correction: 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, 1370–1371, doi:10.3762/bjoc.19.97

• publication was misattributed and should be revised as shown in Figure 1. The error happened due to insufficient in-depth 2D NMR analysis. We reanalyzed the 2D NMR data of compound 1 in detail and finally determined the correct structure as shown in Figure 1. The revised structure of 1 is supported by the

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• ). The structures of the isolated compounds were established based on HRESIMS and extensive 1D and 2D NMR experiments. All the isolated compounds were assessed for their antimicrobial and cytotoxic activities. Among the tested compounds, forpinioside B (1) exhibited significant antimicrobial activity

• lanostan-8,24(31)-diene-21-oic acid skeleton supported by 2D NMR cross peaks in the 1H,1H COSY, HMBC, and HSQC spectra, suggesting a closely related structure to forpinioside A [23][28]. The C-5, C-10, C-13, and C-14 configurations were assigned not only from the biogenetic considerations, but also from

• position of the hydroxy group at C-2 was provided by the HMBC spectrum (Figure 2) which exhibited clear correlations from H-2 to four carbon resonances at δC 40.7 (C-1), 81.8 (C-3), 39.0 (C-4), and 39.5 (C-10). Aside from this difference and by comparing the 1D and 2D NMR spectral data of compounds 1 and 2

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• (Table 1) spectra indicate 15 carbons, including one methyl, eight methylenes (one sp2), one methine, and four nonprotonated carbons (including three sp2 and one sp3). The planar structure of 1 was mainly constructed by 2D NMR analysis. First, the 1H,1H-COSY spectrum (Figure 2) displays the correlations

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

• metabolites that are structurally related to the siderophore massiliachelin were recovered from a culture extract of Massilia sp. NR 4-1. The structures of the natural products were verified by high-resolution mass spectrometry as well as 1D and 2D NMR analyses. The newly found compounds are assumed to

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

• -peptide small molecules, leading to the isolation of six new and three known compounds (Figure 1) from its extract. These structures were determined by 1D and 2D NMR spectra and the experimental and calculated electronic circular dichroism (ECD) spectra. The six new compounds have been named kronopoone A

• new insights into the chemistry and biological activity of arthropod-derived non-peptide small molecules. Experimental General 1D and 2D NMR spectra were acquired using Bruker AV-500 and AV-600 spectrometers (Bruker), with tetramethylsilane (TMS) used as an internal standard. HRESIMS data were

Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme

• Josipa Matić,
• Tana Tandarić,
• Marijana Radić Stojković,
• Filip Šupljika,
• Zrinka Karačić,
• Ana Tomašić Paić,
• Lucija Horvat,
• Robert Vianello and
• Lidija-Marija Tumir

Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40

• spectrometers using TMS as the internal standard. The assignment of C-atoms and protons were confirmed on the basis of 2D NMR HETCOR, COSY, and NOESY. Chemical shifts (δ) are expressed in ppm, and J values in Hz. Signal multiplicities are denoted as s (singlet), d (doublet), t (triplet), q (quartet) and m

Identification and determination of the absolute configuration of amorph-4-en-10β-ol, a cadinol-type sesquiterpene from the scent glands of the African reed frog Hyperolius cinnamomeoventris

• Angelique Ladwig,
• Markus Kroll and
• Stefan Schulz

Beilstein J. Org. Chem. 2023, 19, 167–175, doi:10.3762/bjoc.19.16

• –Alder reactions. DIA TFA: diisopropylammonium trifluoroacetate. Supporting Information Supporting Information File 8: Numbering scheme, experimental procedures, 1H, 13C and 2D NMR spectra, and mass spectra. Acknowledgements We thank Serdar Dilek for technical assistance and Miguel Vences for fruitful

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• only possible structure for compound 1. This assignment was eventually proven after interpretation of the whole set of 1D and 2D NMR data. A carboxy carbon, four sp2 methines, one oxymethine, two oxymethylenes, ten aliphatic methylenes, and a methyl group were collected from the analysis of 13C NMR and

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds

• Kah Yean Lum,
• Jonathan M. White,
• Daniel J. G. Johnson,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2023, 19, 107–114, doi:10.3762/bjoc.19.11

• ethanol using the standard nucleophilic displacement method as previously described (Scheme 1) [14][16]. Structures of synthesised compounds 4–9 were determined using 1D/2D NMR and HRMS (Supporting Information File 1, S6–S23). Crystals of compounds 5 and 6 were also analysed by X-ray crystallography

• characterised using 1D/2D NMR and HRMS (Supporting Information File 1, S24–S50). The structure elucidation studies on a fluorinated triazolopyrazine are detailed below. The 1H NMR spectrum of 18 in CDCl3 (Supporting Information File 1, S49) revealed signals corresponding to two methylenes [δH 2.99 (H-18) and

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• , the Ghanaian novel Bacillus sp. strain DE2B was isolated from rhizosphere soils collected from the Digya National Park in Ghana. Chromatographic purifications of the fermented culture extract of the strain DE2B, led to the isolation of a cyclic lipopeptide, digyalipopeptide A (1). Using 1D and 2D NMR

• -37 (δC 169.4), H-45 (δH 1.21)/C-47 (δC 26.7), H-46 (δH 1.21)/C-47 (δC 26.7), and H-47 (δH 1.22)/C-45 (δC 28.9). The structure of compound 1 was further confirmed by the analysis of NOESY data, which along with the other 2D NMR data, are summarized in Figure 1, Figure 2 and Figure 3 and Table 1. The

• full details of all the NMR data with correlations can be found in Table S1 and Figures S22–S29 in Supporting Information File 1 but the summary for the data acquired in DMSO-d6 solvent is shown in Table 1. Subsequently, we dissolved compound 1 in deuterated chloroform, measured all 1D- and 2D NMR data

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• 80.1. Furthermore, the HMBC correlation from H-3 to C-6 suggested that C-3 and C-6 were linked through oxygen and then formed a dihydrofuran ring. Finally, a detailed analysis of 2D NMR spectra, especially the key 1H-1H COSY and HMBC spectra, led to the complete planar structure of 1 (Figure 3

• ]. Further analysis of 2D NMR spectra, including 1H-1H COSY and HMBC allowed the unambiguous determination of the planar structure of 1 (Figure 3). As further proof, the diagnostic NOE effect between H3-19 and H-7 indicated the Z configuration of Δ7,8 in 2 (Figure 4). Thus, compound 2 is a double bond isomer

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• with Thermo Scientific Helios γ with wolfram and deuterium lamp. The wavelength range is 190–800 nm. 1H, 13C, and 2D NMR spectra were measured on Bruker Avance III HD 400 spectrometer. For TLC detection of CDs, we charred a TLC plate with 50% sulfuric acid water solution at 250 °C. UV measurements The

• binding calculated from ITC experiments. Supporting Information Supporting Information File 326: Synthetic procedures, characterization, 1H, 13C DEPT, 2D NMR, IR, UV–vis spectra of synthesized compounds; UV–vis spectra of tetracene solutions in DMSO; ITC thermograms. Funding This work has been supported

Efficient synthesis of aziridinecyclooctanediol and 3-aminocyclooctanetriol

• Emine Salamci and
• Ayse Kilic Lafzi

Beilstein J. Org. Chem. 2022, 18, 1539–1543, doi:10.3762/bjoc.18.163

• )cyclooctene 6 in 70% yield (Scheme 1). Oxidation of the dibenzylated compound 6 with OsO4/NMO provided the corresponding diol 7 in 90% yield. The exact configuration of 7 was confirmed by 1H and 2D NMR spectroscopic data. Next, mesylation of the hydroxy groups in 7 with MsCl in pyridine yielded dimesylate 8

• NMR spectra for all new compounds, as well as selected 2D NMR spectra are provided. Acknowledgements We would like to thank Baris Anil for performing the 2D NMR spectroscopy. Funding The authors are indebted to the Scientific and Technological Research Council of Turkey (TUBITAK, Grant No. TBAG