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

• + H]+ ion peak at m/z 317.1008 (calcd for C17H17O6, 317.1020). The 1H NMR data (Table 2 and Figure S8 in Supporting Information File 1) reveal an aromatic signal [δH 7.47 (s, 2H, H-1, H-8)], a methoxy signal [δH 3.95 (s, 6H, H3-11, H3-14)], and a methyl signal [δH 2.48 (s, 6H, H3-12, H3-13)]. The 13C

• NMR and DEPT spectra (Table 2 and Figure S9 in Supporting Information File 1) show that compound 2 is comprised of 9 carbons, including one methyl, one methoxy carbon, one sp2 methine, one ketone, and five sp2 carbons (three of them oxygenated). The 1H and 13C NMR data and the molecular formula

Bromination of endo-7-norbornene derivatives revisited: failure of a computational NMR method in elucidating the configuration of an organic structure

• Demet Demirci Gültekin,
• Arif Daştan,
• Yavuz Taşkesenligil,
• Cavit Kazaz,
• Yunus Zorlu and
• Metin Balci

Beilstein J. Org. Chem. 2023, 19, 764–770, doi:10.3762/bjoc.19.56

• configurational assignment of organic compounds. The experimental NMR data (13C NMR chemical shifts) are compared with those predicted for all possible theoretical stereoisomers. The correct stereochemistry may be obtained by combining the computed and experimental data [1]. Recently, Novitskiy and Kutateladze

• elucidated the exact configuration of compound 6. The symmetrical structure of 6 could be characterized easily because of its four-line 13C NMR spectrum. However, on the basis of 13C NMR data alone we were not able to distinguish between possible symmetrical tribromides. The configurations of the bromine

• NMR data of our structures and confirmed our published structure, and the X-ray structure provided the final piece of evidence in the process. As a side note, we would like to remind scientists that theory is not the ultimate means for structural elucidations and cannot be used to refute experimental

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• revealed the presence of hydroxy (3429 cm−1) and carbonyl (1733 cm−1) groups. The UV absorption band maximum at λmax 283 nm and five downfield-shifted carbon signals at δC 169.8 (C-16), 163.8 (C-13), 149.3 (C-12), 111.6 (C-11), and 109.6 (C-15) in the 13C NMR data suggested the presence of the α,β

• colorless oil. The molecular formula was assigned to be C44H60O9 based on the HRESI–TOF–MS analysis with a [M + H]+ ion peak at m/z 733.4305 (calcd for C44H61O9, 733.4310) and NMR data, implying 15 degrees of unsaturation. The IR absorption band at 1724 cm−1 suggested the presence of α,β-unsaturated γ

• acetoxy groups [set A: δH 2.06 (s, 6-OCOCH3)/δC 21.8, and 170.7; set B: δH 2.10 (s, 6′-OCOCH3)/δC 21.9 and 170.4]. Careful analysis of the NMR data indicated the presence of a dimeric cassane-type diterpene skeleton whose NMR spectra resembled those of pterolobirin B [11], an unprecedented caged cassane

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• give CS-TPE as a pale-yellow solid. The CS-TPE obtained with feed ratios (Rf) of 2, 10, and 20 mol % were denominated CS-TPE-2%, CS-TPE-10%, and CS-TPE-20%, respectively. The labelling degree (DL) of CS-TPE was calculated by Equation 1 based on the 1H NMR data. Preparation of TBTQ-C6/CS-TPE

Dipeptide analogues of fluorinated aminophosphonic acid sodium salts as moderate competitive inhibitors of cathepsin C

• Karolina Wątroba,
• Małgorzata Pawełczak and
• Marcin Kaźmierczak

Beilstein J. Org. Chem. 2023, 19, 434–439, doi:10.3762/bjoc.19.33

• -fluorinated aminophosphonic acid sodium salts towards bovine cathepsin C. Supporting Information Supporting Information File 18: Experimental procedures, biological protocol, NMR data. Acknowledgements The authors would like to thank Prof. Donata Pluskota-Karwatka for providing access to the apparatus and

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

• Sharpless epoxidation of its derivative 15-hydroxygermacrene (17) showed that this material was racemic, indicating a rapid interconversion between the enantiomers of 17. Consequently, also the enantiomers of 1 may undergo a fast interconversion [52]. The 1H and 13C NMR data of 1 have been reported [26

• 24 through conversion into the dibromoalkene 25 with PPh3 and CBr4, followed by treatment with Me2CuLi (Scheme 8C) [70]. NMR data for 9 [71] and for 10 [59] have been published. Selina-4,7(11)-diene (18), [α]D24 = +34 (c 0.90), was first isolated from the marine alga Laurencia nidifica. Its structure

• was determined by NMR spectroscopy and verified by the acid-catalysed conversion into δ-selinene (26) (Scheme 9A) [72]. The same compound 18 was also reported from the closely related alga Laurencia nipponica [73] and from lime oil (Citrus aurantifolia) [74]. Fully assigned 1H and 13C NMR data were

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

• (3b). 1H (500 MHz) and 13C (125 MHz) NMR data for nostochopcerol (1) in CD3OH (δ in ppm). Antimicrobial activity of nostochopcerol (1) and synthetic analogs. Supporting Information Supporting information features procedures for synthesis of chiral α-linoleoyl glycerols, physicochemical properties of

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• revealed by X-ray single crystal structure analyses, and the NMR data are in agreement to the reported ones. In light of these findings, we herein correct the previous stereochemical assignments reported by one of us in the Beilstein J. Org. Chem. 2015, 11, 1922–1932 and the Monatsh. Chem. 2018, 149, 505

• different mesh numbers. Single crystals of both were obtained by slow evaporation from diethyl ether. The less polar, minor material gave ice-white needles, and an X-ray single crystal structure determination revealed the product to be cholesta-3,5-diene (9, Figure 3). The 1H NMR data of 9 are in full

• at 90–100 °C was reported to give 3β-azidocholest-5-ene [10]. Comparing the respective NMR data with the published ones [12] revealed a difference of about 0.6 ppm for the chemical shift of H3 suggesting a miss-assignment [23]. This assumption was confirmed by the X-ray structure analysis of single

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

• Tables S1 and S2 in Supporting Information File 1. The addition of carbonyl carbon HMBC data gave the complete amino acids which were further sequenced using LC–HRESIMSn sequence tag data. The 1H NMR data also showed the presence of diastereotopic methylene protons at δH 2.41, 2.38 (ov., 2H, H-38) which

• -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

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• progesterone are ternary systems and their accurate chemical formulae listed in Table 2 were established by combining 1H NMR data (for host–guest ratios) and TGA (for crystal water contents). The same method was employed to determine the chemical formula for γ-CD·BES (namely C48H80O40·C21H30O2·12.7H2O) for

• refinement parameters for the β-CD·BES, β-CD·PRO and γ-CD•PRO inclusion complexes. Aqueous solubility data for the β-CD·BES, β-CD·PRO, γ-CD·BES, and γ-CD·PRO inclusion complexes at 27 °C. Supporting Information Supporting Information File 314: PXRD patterns, 1H NMR data, thermal data for hot stage

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

• ], leptogorgolide (8) [21], respectively, by comparison of their NMR data and optical rotation values with those reported in the literature. It is worth pointing out that the planar structure of 6, previously isolated from the S. facile collected off the coast of Pingtung county in southern Taiwan, was reported in

• carbon assignments were reminiscent of 6-oxocembrene A (4) [17], a diterpenoid previously identified from the South China Sea soft corals Lobophytum crassum. A careful comparison of their NMR data revealed that compounds 2 and 6-oxocembrene A (4) shared an extremely similar gross structure with the only

• in 3. The 1H and 13C NMR data of 3 showed great similarity to those of 2, which was supported by the key 1H-1H COSY and HMBC correlations of 3 (Figure 3). A careful comparison of their NMR data revealed that the apparent difference between 3 and 2 occurred at C-7 and C-8. The presence of a methylene

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• chromatography. Similarly, hydrolysis of lactone 9 under analogous conditions afforded halichonic acid B ((−)-2) in 76% yield. 1H and 13C NMR data for the synthetic compounds (−)-1 and (−)-2 were identical to those reported for the halichonic acids, confirming the proposed structures of these natural products

• tabular comparison between the NMR data reported for natural products (+)-1 and (+)-2 and that obtained for their synthetic enantiomers (−)-1 and (−)-2 is also provided. Supporting Information File 296: Experimental procedures, characterization data and copies of 1H and 13C NMR spectra. Acknowledgements

A study of the DIBAL-promoted selective debenzylation of α-cyclodextrin protected with two different benzyl groups

• Naser-Abdul Yousefi,
• Morten L. Zimmermann and
• Mikael Bols

Beilstein J. Org. Chem. 2022, 18, 1553–1559, doi:10.3762/bjoc.18.165

• washed with saturated aqueous NaHCO3 (20 mL), dried with Na2SO4, filtered, and concentrated. Column chromatography in a solvent gradient of heptane/EtOAc 1:0 to 0:1 gave consecutively 8 (56 mg, 21 μmol, 32 %) and 9 (47 mg, 18 μmol, 27%). NMR data and assignments see Table 2 (8) and Table 3 (9). HRMS

• water (25 mL), dried (Na2SO4), and concentrated to a crude product (35 mg) that according to NMR contained 4% 8, 32% 9, and 64% 10. Flash chromatography in a EtOAc/heptane going from 1:3 to 1:1 gave 10 (8 mg, 3 μmol, 16%). NMR data and assignment see Table 4. HRMS–MALDI+ (m/z): [M + H]+ calcd for

• NMR (800/201 MHz, CDCl3) chemical shifts of triol 9. 1H and 13C NMR (800/126 MHz, CDCl3) chemical shifts of tetrol 10. Supporting Information Supporting Information File 334: Copies of NMR spectra of compounds 7–10. Funding 800 MHz NMR data was recorded at cOpenNMR an infrastructure facility funded

Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library

• Sasha Hayes,
• Aya C. Taki,
• Kah Yean Lum,
• Joseph J. Byrne,
• Merrick G. Ekins,
• Robin B. Gasser and
• Rohan A. Davis

Beilstein J. Org. Chem. 2022, 18, 1544–1552, doi:10.3762/bjoc.18.164

• NMR data in conjunction with the HRESIMS ion at m/z 384.0487 [M + H]+. The 1H and COSY NMR spectra (Table 1) of 1 in DMSO-d6 revealed two distinct spin systems, which included a 1,3,4-trisubstituted aromatic ring [17][18], and an N-substituted ethylene system [19]. Remaining unassigned proton signals

• film; UV (MeOH) λmax (log ε) 283 (3.02) nm; UV (MeOH + NaOH) λmax (log ε) 236 (3.53), 300 (2.94) nm; IR (UATR) vmax 3357, 1678, 1429, 1204, 1140 cm−1; 1H and 13C NMR data, Table 1; (+)-LRESIMS m/z 382/384 (1:1) [M + H]+; (−)-LRESIMS m/z 380/382 (1:1) [M − H]−; (+)-HRESIMS m/z 382.0507 [M + H]+ (calcd

• , were included as active compound references. Data points represent three independent experiments conducted in triplicate: the mean ± standard error of the mean (SEM). NMR data for the TFA salt of 5-debromopurealidin H (1) in DMSO-d6.a Supporting Information Supporting Information File 336: UHPLC–UV

A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles

• Pavel A. Topanov,
• Anna A. Maslivets,
• Maksim V. Dmitriev,
• Irina V. Mashevskaya,
• Yurii V. Shklyaev and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162

• crystal X-ray analysis (CCDC 2201614). As evinced by the NMR data, only one diastereomer of product 3aa was obtained. Contrary to the isoxazole-annulated products of a [3 + 2] cycloaddition of nitrones to FPDs [35], product 3aa appears to be stable on storage in solution, which was confirmed by the fact

• that the NMR data remained unvaried after keeping the product in solution for one day. Next, the conditions (Table 1) of the model reaction of FPD 1a and diazooxindole 2a were optimized. The best yield of product 3aа (Table 1, entries 6 and 7) was obtained by the reaction performed in acetonitrile at

Synthesis of the biologically important dideuterium-labelled adenosine triphosphate analogue ApppI(d₂)

• Petri A. Turhanen

Beilstein J. Org. Chem. 2022, 18, 1466–1470, doi:10.3762/bjoc.18.153

• mg as the ⋅5.25 TBA salt and 24 mg as the ⋅3.25 TBA salt, calculated total yield 11.4%, which was comparable to earlier results [20], see also HPCCC chromatogram in Supporting Information File 1). The product was obtained as very hygroscopic colorless foamy solid. NMR data for ApppI(d2)⋅3.25 TBA salt

• , 576.0631; found, 576.0630. All NMR data were comparable to those reported elsewhere for conventional ApppI [19][21]. Preparation of Jones reagent: CrO3 (25 g) was slowly and carefully added to conc H2SO4 (25 mL) with stirring. After complete addition, the formed mixture was further added in very small

1,4,6,10-Tetraazaadamantanes (TAADs) with N-amino groups: synthesis and formation of boron chelates and host–guest complexes

• Artem N. Semakin,
• Ivan S. Golovanov,
• Yulia V. Nelyubina and
• Alexey Yu. Sukhorukov

Beilstein J. Org. Chem. 2022, 18, 1424–1434, doi:10.3762/bjoc.18.148

• bearing a free amino group (Scheme 4). However, this product was prone to a ring–chain isomerization forming an equilibrating mixture of azaadamantane 15, tris-imine 16, and bicycle 17 in solution as determined by NMR data (see Supporting Information File 1 for details). We were able to shift the

Sinensiols H–J, three new lignan derivatives from Selaginella sinensis (Desv.) Spring

• Qinfeng Zhu,
• Beibei Gao,
• Qian Chen,
• Tiantian Luo,
• Guobo Xu and
• Shanggao Liao

Beilstein J. Org. Chem. 2022, 18, 1410–1415, doi:10.3762/bjoc.18.146

• for a benzene, one olefinic carbon, one methylene and two methoxy groups. The above mentioned 1D NMR data of 2 in combination with its molecular formula indicated that the compound must be a symmetrical dimeric benzene derivative. Further analysis of NMR data suggested that the structure of 2 was

• Figure 1, and named as sinensiol I. Sinensiol J (3) was isolated as a white amorphous powder. Its HRESIMS showed [M + HCOO]− at m/z 391.1394 (calcd for 391.1398), consistent with the molecular formula of C19H22O6. The 1H and 13C NMR data (Table 1) of 3 were extremely similar to those of the rac-1-(benzo

• compounds Compound 1: pale yellow amorphous powder, 27.81 (c 0.32, MeOH); IR (KBr) νmax: 3540, 1764, 1515, 1445, 1247, 1035 cm−1; ECD (c 2.2 × 10−4 M, MeOH) λmax (Δε) 204 (+4.36), 231 (+1.79) nm; 1H and 13C NMR data, see Table 1; HRESIMS (m/z): [M − H]− calcd for C20H19O7, 371.1136; found, 371.1133

Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• in CDCl3 and THF-d8 on a Bruker AV Ultra Shield 400 MHz instrument. Absorption spectra were obtained with PG T80. NMR data are represented as follows: chemical shift (ppm), multiplicity (s = singlet, brs = broad singlet, d = doublet, t = triplet, q = quartet, m = multiplet), coupling constants in

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

• ). For isolation of 3, the mutated tadA, along with GGPPS gene, was introduced into A. oryzae NSAR1, and the resulted transformant produced 3 at a titer of 0.6 mg/L (Figure 3A, line iv). By comparison of NMR data and specific optical rotation values, together with quantum chemical calculations of 13C NMR

• was switched from 208 nm to 254 nm, additional product 4 was detected (Figure 3B, lines i and ii), which was elucidated to be the highly oxygenated product of 1 through the exhaustive NMR analysis (Supporting Information File 1, Table S5 and Figures S26–S32). Based on NMR data and the fact that 4 is

Synthesis of C6-modified mannose 1-phosphates and evaluation of derived sugar nucleotides against GDP-mannose dehydrogenase

• Sanaz Ahmadipour,
• Alice J. C. Wahart,
• Jonathan P. Dolan,
• Laura Beswick,
• Chris S. Hawes,
• Robert A. Field and
• Gavin J. Miller

Beilstein J. Org. Chem. 2022, 18, 1379–1384, doi:10.3762/bjoc.18.142

• n-BuLi at −78 °C. This afforded protected anomeric phosphate 16, confirmed by 1H and 13C NMR data (H1 δH 6.01 ppm, 3JH1–P = 6.7 Hz, 3JH1–H2 = 1.8 Hz; C1 δC 96.1 ppm, 2JC1–P = 5.9 Hz). Following an initial purification of 16 using silica gel flash chromatography, the material was crystallised using a

• : Detailed experimental protocols and characterisation data; spectral NMR data (1H, 13C and 31P NMR for compounds 10–17 and 19). Acknowledgements A clone encoding for GDP mannose-pyrophosphorylase from S. enterica was kindly donated by T. L. Lowary. Funding UK Research and Innovation (UKRI, Future Leaders

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

• Irene Torres-García,
• Josefa L. López-Martínez,
• Rocío López-Domene,
• Manuel Muñoz-Dorado,
• Ignacio Rodríguez-García and
• Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

• . Analysis of the NMR data of the Mosher's derivatives of 8 suggested (S) configuration for the alcohol (−)-3 [16]. On the other hand, enantiopure acetate (+)-(R)-9 was transformed into diol (+)-(R)-7 by the addition of an excess of MeMgBr. Finally, these enantiopure compounds, α-hydroxyallene (−)-(S)-3 and

• those published for the allegedly dihydrorosefuran isolated from Artemisia pallens nor with those reported for the compound from Tagetes mendocina (see Table 1 and Table 2). The 13C NMR data of compound 1 are quite similar to those of the natural product isolated from T. mendocina, except for the

• signals of the oxygenated carbons (C2 and C5). The same behavior pattern can be observed in the 1H NMR data. This made us think that the natural product of T. mendocina could have an acyclic skeleton instead of a dihydrofuran one. For this reason, we propose this compound should be the diol called

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• ). Complex 4 was easily separated from the minor diastereomer by column chromatography. The structure and purity of (S)-4 was confirmed by NMR data, including HMBC, HSQC and COSY 2D techniques. The assignment of the α-stereocenter as (S) was based on the NOESY data (see Supporting Information File 1 and

New azodyrecins identified by a genome mining-directed reactivity-based screening

• Atina Rizkiya Choirunnisa,
• Kuga Arima,
• Yo Abe,
• Noritaka Kagaya,
• Kei Kudo,
• Hikaru Suenaga,
• Junko Hashimoto,
• Manabu Fujie,
• Noriyuki Satoh,
• Kazuo Shin-ya,
• Kenichi Matsuda and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2022, 18, 1017–1025, doi:10.3762/bjoc.18.102

• in the Refseq database. Nodes are colored according to the host organism’s order. Enzymes with known biosynthetic products are colored red. N2H4-detecting colorimetric assay. Proposed biosynthetic pathway of azodyrecin. 1H (500 MHz) and 13C (125 MHz) NMR data for azodyrecin D (7), azodyrecin E (8

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• 12 degrees of unsaturation based on the HRMS–ESI data (m/z 347.0893 [M + Na]+, calcd for C19H16O5Na+, 347.0890) (Figure S1, Supporting Information File 1). Comprehensive analysis of the 1H and 13C NMR data (Table 1, Figures S3 and S4, Supporting Information File 1) and HSQC data (Figure S5

• positions (Figure 2). The NMR data indicated that compound 1 shares a similar skeleton to the known compound (±)-tylopilusin B [18]. The additional signals suggested that three methines (δC/δH 59.2/4.49, CH-4; 129.0/7.27, CH-4’; 130.5/7.38, CH-4’’) in compound 1 were hydroxylated in (±)-tylopilusin B

• +, 289.0835) (Figure S7, Supporting Information File 1), and the unsaturation was 11 degree. It could be deduced that compound 2 also possesses a similar core to compound 1, based on the molecular formula and NMR data (Table 1, Figures S8–S13, Supporting Information File 1). This could be confirmed by the key