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

• for the purification of ApppI(d2) [21]. HRMS spectra were recorded on a qTOF mass spectrometer using electrospray ionization (ESI) in negative mode. The purity of the products was determined from the 1H and 31P NMR spectra to be ≥95%, unless stated otherwise. ApppI(d2)⋅3.25 and ⋅5.25 TBA salts: ATP

• TBA salt), 22.6, 20.1 (from TBA salt), 13.8 (from TBA salt, used as calibration peak: value marked same as in the earlier characterization of ApppI [20]); 31P NMR (D2O): δ −11.2 d (2JPP = 19.4), −11.7 d (2JPP = 19.4), −23.4 t (2JPP = 19.4); HRMS–ESI (qTOF, m/z): [M − H]− calcd for C15H212H2N5O13P3

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

• rotations were carried out on an Autopol VI automatoc polarimeter. UV spectra were recorded on a Shimadzu UV-2401 PC spectrophotometer. IR spectra (KBr) were determined on a Bruker Vertex 70 infrared spectrometer. ESI and HRESIMS were performed on an UPLCIT-TOF spectrometer. ECD spectra were obtained on a

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

• hertz (Hz). IR spectra were recorded on FTIR spectrometer (Thermo Scientific, Nicolet IS10). HRMS were measured in ESI mode and the mass analyzer of the HRMS was TOF (Agilent 6224 TOF LC–MS). Flash column chromatography was performed on silica gel (230–400 mesh). 5-Substituted dipyrromethanes [35] and

Preparation of an advanced intermediate for the synthesis of leustroducsins and phoslactomycins by heterocycloaddition

• Anaïs Rousseau,
• Guillaume Vincent and
• Cyrille Kouklovsky

Beilstein J. Org. Chem. 2022, 18, 1385–1395, doi:10.3762/bjoc.18.143

• solvent using residual chloroform (7.26 ppm) as an internal reference. 13C NMR spectra were measured at 62.5, 75 or 90 MHz using residual chloroform (77.1 ppm) as an internal reference. High-resolution mass spectrometry (HRMS) analyses were conducted with electro spray ionization (ESI). 6

Cyclodextrin-based Schiff base pro-fragrances: Synthesis and release studies

• Attila Palágyi,
• Jindřich Jindřich,
• Juraj Dian and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2022, 18, 1346–1354, doi:10.3762/bjoc.18.140

• –97%). This method allows for easy recovery of the unreacted aldehyde as well as separation of the product (just by extraction by hexane and drying under reduced pressure) without its decomposition. The structure of the final imines was confirmed by 1H NMR, 13C NMR, ESI–MS, and the release of the VOCs

• 5-methylfurfural (2j) and 3.1 min for heptanal (2h). The mass spectra were measured by the Bruker ESQUIRE 3000 ES-ion trap and the samples were ionized using an electrospray technique (ESI). The samples were dissolved in methanol. Specific optical rotation was measured by the Rudolph Research

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

• ), 1.70 (td, J = 0.5, 3.2 Hz, 3H), 1.25 (t, J = 7.1 Hz, 3H) ppm; 13C NMR (75 MHz, CDCl3, DEPT) δ 204.8 (C), 174.0 (C), 101.6 (C), 77.0 (CH2), 71.5 (CH), 60.5 (CH2), 30.4 (CH2), 30.0 (CH2), 14.5 (CH3), 14.2 (CH3) ppm; HRMS–ESI (Q-TOF, m/z): [M + H]+ calcd for C10H17O3, 185.1178; found, 185.1158. A lactone

• , 3H) ppm; 13C{1H} NMR (75 MHz, CDCl3, DEPT) δ 206.0 (C), 177.0 (C), 98.0 (C), 80.4 (CH), 77.5 (CH2), 28.5 (CH2), 26.1 (CH2), 15.0 (CH3) ppm; HRMS–ESI (Q-TOF, m/z): [M + H]+ calcd for C8H11O2,139.0759; found, 139.0782. Silver(I)-promoted cyclization of ethyl 4-hydroxy-5-methylhepta-5,6-dienoate (3) A

• ), 86.4 (CH), 74.7 (CH2), 60.3 (CH2), 29.4 (CH2), 28.9 (CH2), 14.2 (CH3), 12.3 (CH3) ppm; HRMS–ESI (Q-TOF, m/z): [M + H]+ calcd for C10H17O3,185.1172; found, 184.1162. Synthesis of 2-methyl-4-(3-methyl-2,5-dihydrofuran-2-yl)butan-2-ol (6) Under an N2 atmosphere, methylmagnesium bromide (3 M in Et2O, 0.075

Experimental and theoretical studies on the synthesis of 1,4,5-trisubstituted pyrrolidine-2,3-diones

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Nguyen Ngoc Tri,
• Luc Van Meervelt,
• Nguyen Tien Trung and
• Wim Dehaen

Beilstein J. Org. Chem. 2022, 18, 1140–1153, doi:10.3762/bjoc.18.118

• electrospray ionization (ESI) source in a positive mode. The temperatures of the source were set at 300 °C. Curtain gas (25 psi) chambers were filled with high-purity nitrogen. The capillary voltage was constantly kept at 5500 V. Collision energies was set at 10 V and zero collision energy spread. IDA mode was

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• procedures NMR spectra were acquired on Bruker 500 and 600 MHz AVANCE NEO spectrometers with TMS as an internal standard. HPLC–UV analysis was performed on an Agilent 1260 Infinity II HPLC system. UHPLC–HRMS analysis was performed on a Waters Synapt-G2-Si UHPLC-ESI-QToF-MS system. UV and CD spectra were

• ) λmax (log ε) 257, 304 nm; for NMR spectral data, see Table S4, Supporting Information File 1; HRMS–ESI (m/z): [M + H]+ calcd for C31H20O9, 537.1180; found, 537.1206. Cattleyaisoflavone B (2): yellowish powder; UV (MeOH) λmax 255, 310 nm; for NMR spectral data, see Table S5, Supporting Information File

•  1; HRMS–ESI (m/z): [M + H]+ calcd for C30H18O8, 507.1074; found, 507.1091. Cattleyaisoflavone C (3): white powder; UV (MeOH) λmax 254, 300 nm; for NMR spectral data, see Table S6, Supporting Information File 1; HRMS–ESI (m/z): [M + NH+ calcd for C30H18O8, 507.1074; found, 507.1091. Feeding

Synthesis of N-phenyl- and N-thiazolyl-1H-indazoles by copper-catalyzed intramolecular N-arylation of ortho-chlorinated arylhydrazones

• Yara Cristina Marchioro Barbosa,
• Guilherme Caneppele Paveglio,
• Claudio Martin Pereira de Pereira,
• Sidnei Moura,
• Cristiane Storck Schwalm,
• Gleison Antonio Casagrande and
• Lucas Pizzuti

Beilstein J. Org. Chem. 2022, 18, 1079–1087, doi:10.3762/bjoc.18.110

• electrospray ionization (ESI) source (MicrOTOF-QII, Bruker Scientific) in positive mode. The compounds were individually dissolved in a solution of 50% chromatographic grade MeCN and 50% deionized H2O + 0.1% formic acid. General experimental procedure for the synthesis of hydrazones 1a–i In a 100 mL round

Electrochemical Friedel–Crafts-type amidomethylation of arenes by a novel electrochemical oxidation system using a quasi-divided cell and trialkylammonium tetrafluoroborate

• Hisanori Senboku,
• Mizuki Hayama and
• Hidetoshi Matsuno

Beilstein J. Org. Chem. 2022, 18, 1040–1046, doi:10.3762/bjoc.18.105

• spectra were measured at Instrumental Analysis Support Office, the Frontier Chemistry Center, Faculty of Engineering, Hokkaido University. ESI mass spectra were measured at the Instrumental Analysis Division, Global Facility Center, Creative Research Institution, Hokkaido University. The authors would

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

• . Furthermore, the absolute configuration of C-4 and C-5 in compound 1 was also confirmed as 4R and 5S by X-ray crystallography (Figure 2). (±)-Daturamycin B (2) was isolated as a white powder, and its molecular formula was determined as C17H14O3 by HRMS–ESI data (m/z 289.0833 [M + Na]+, calcd for C19H16O5Na

• , the DatA protein was expressed and purified (Figure 4B). Incubating DatA with substrate 7 and ATP resulted in a new product 8, which was confirmed by HRMS–ESI data (m/z 291.0663 [M − H]−, calcd for ([C18H12O4] − H)−, 291.0663) (Figure S22, Supporting Information File 1). The product was not present in

Molecular diversity of the base-promoted reaction of phenacylmalononitriles with dialkyl but-2-ynedioates

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 991–998, doi:10.3762/bjoc.18.99

• , 1H, CH2), 2.36 (s, 3H, CH3), 1.41 (t, J = 6.8 Hz, 3H, CH3), 1.14 (t, J = 6.8 Hz, 3H, CH3); 13C NMR (100 MHz, CDCl3) δ 163.2, 159.2, 152.7, 139.0, 136.8, 129.6, 129.5, 124.7, 113.7, 113.5, 86.9, 63.2, 62.7, 52.3, 38.1, 21.1, 13.9, 13.7; HRMS–ESI (m/z): [M + Na]+ calcd for C20H20NaN2O5, 391.1270; found

• = 7.2 Hz, 3H, CH3); 13C NMR (100 MHz, CDCl3) δ 166.5, 164.2, 163.4, 161.1, 160.4, 159.5, 159.4, 153.7, 150.8, 142.6, 131.8, 129.9, 127.8, 126.9, 125.9, 124.8, 122.9, 117.5, 114.7, 113.6, 113.4, 86.0, 72.7, 64.3, 62.5, 62.0, 61.8, 55.4, 55.3, 52.9, 51.4, 13.9, 13.8, 13.7, 13.6; HRMS–ESI (m/z): [M + Na

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• ; ECD (MeCN) λ max, nm (Δε): 222 (−9.7), 257 (+7.2), 340 (+1.3); IR (KBr) νmax: 3435, 2956, 2927, 2872, 1644, 1383, 1261, 1109, 1037 cm−1; 1H and 13C NMR data, see Table 1; HRMS–ESI (m/z): [M + H]+ calcd for C15H23O2, 235.1693; found, 235.1700. ent-4β,10α-Dihydroxyaromadendrane (2): colorless crystal

• ; mp 117.0–118.0 °C; +23.8 (c 0.40, MeOH). (+)-Maninsigin D [(+)-4]: white powder; +26.0 (c 0.08, MeOH); ECD (MeCN) λmax, nm (Δε): 203 (−0.5), 218 (+0.2); IR (KBr) νmax: 2925, 1699, 1632, 1435, 1384, 1259, 1243, 1116, 1069 cm−1; 1H and 13C NMR data, see Table 1; HRMS–ESI (m/z): [M + H]+ calcd for

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

• Virginija Jakubkiene,
• Gabrielius Ernis Valiulis,
• Markus Schweipert,
• Asta Zubriene,
• Daumantas Matulis,
• Franz-Josef Meyer-Almes and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

• out on a Dual-ESI Q-TOF 6520 (Agilent Technologies) mass spectrometer. The starting compounds 1 [39], 2 [39] and 19 [40] were prepared following the reported methods. Synthetic details, characterization and analytical data as well as 1H and 13C NMR spectra of all synthesized compounds are presented in

Copper-catalyzed multicomponent reactions for the efficient synthesis of diverse spirotetrahydrocarbazoles

• Shao-Cong Zhan,
• Ren-Jie Fang,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 796–808, doi:10.3762/bjoc.18.80

• , 121.8, 121.5, 120.2, 119.1, 110.7, 110.7, 109.0, 56.1, 50.0, 48.8, 43.6, 25.4; IR(KBr) υ: 3367, 3210, 3155, 3017, 2980, 2831, 2864, 1877, 1623, 1611, 1507, 1456, 1355, 1241, 1178, 1143, 955, 931, 849, 789 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C39H30N2O2, 581.2199; found, 581.2191. 2. General

• , 29.1; IR(KBr) υ: 3355, 3207, 3117, 3048, 2963, 2831, 2167, 1871, 1641, 1633, 1554, 1431, 1370, 1240, 1131, 1100, 972, 961, 881, 764 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C34H24N4O, 527.1842; found, 527.1849. 3. General procedure for the preparation of the tetrahydrospiro[carbazole-3,5'-pyrimidines

• , 129.1, 128.7, 128.3, 128.0, 126.3, 126.1, 125.5, 124.7, 124.2, 123.1, 120.8, 29.6, 28.8, 21.4, 21.3; IR (KBr) υ: 3219, 3158, 3043, 2966, 2900, 1843, 1755, 1648, 1617, 1537, 1466, 1358, 1318, 1266, 1150, 987, 899, 765 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C31H25N3O3, 510.1788; found, 510.1788. 4

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• , 128.0, 127.1, 127.0, 123.0, 112.3, 110.9, 60.3, 49.0, 44.6, 44.4, 42.6, 21.4, 21.2; IR (KBr) ν: 3727, 3405, 3029, 2921, 2863, 2317, 1911, 1709, 1609, 1501, 1443, 1362, 1295, 1185, 1049, 1022, 959, 920, 820, 732 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C38H31NaN3O2, 584.2314; found, 584.2306. 2. General

• , 3412, 2933, 2871, 2324, 1925, 1817, 1703, 1604, 1474, 1442, 1339, 1172, 1091, 1010, 904, 824, 716 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C38H34ClNaNO4, 626.2069; found, 626.2066. 3. General procedure for the preparation of the spiro[cyclohexane-1,3'-indolines] 8a–m: In an atmosphere of nitrogen

• , 60.1, 43.9, 20.9, 14.7; IR (KBr) ν: 3467, 3063, 3035, 2990, 2919, 2205, 1739, 1706, 1632, 1602, 1496, 1454, 1434, 1408, 1381, 1361, 1333, 1293, 1258, 1215, 1199, 1186, 1167, 1133, 1089, 1070, 1026, 997, 962, 933, 911, 895, 875, 836, 818, 776, 747 cm−1; HRMS–ESI (m/z): [M + Na]+ calcd for C36H28NaClN3O4

Terpenoids from Glechoma hederacea var. longituba and their biological activities

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

• a Jasco P-2000 polarimeter using methanol as solvent. High-resolution ESI mass spectrometer data were recorded on a Waters SYNAPT G2 mass spectrometer. ECD spectra were garnered with a JASCO J-1500 CD spectrometer (JASCO, Easton, MD, USA). The NMR spectra were recorded on a Bruker AVANCE III 700 NMR

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• recorded using either the ultrafleXtreme MALDI-TOF mass spectrometer (Bruker) with α-cyano-4-hydroxycinnamic acid (HCCA) as a matrix, or by electrospray ionization (ESI) on a Waters G2-XS QTOF instrument connected to a Waters H-class UPLC equipped with a Waters BEH C18 column using an eluent consisting of

• (t, J = 7.1 Hz, 18H); 13C NMR (100 MHz, DMSO-d6, 25 °C) δ 167.20, 147.89, 143.15, 137.57, 126.07, 110.42, 62.61, 62.55, 62.15, 61.50, 50.38, 27.48, 13.93; (+)-ESI-HRMS (m/z): [M + H]+ calcd for C65H73N18O18, 1393.5345; found, 1393.5354 (Δ = +0.7 ppm). Synthesis of compound 3. To a methanol solution

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• and 100 MHz for 1H and 13C, respectively). 1H NMR and 13C NMR spectra were referenced to residual solvent peaks. High-resolution mass spectrometry (HRMS) analyses were carried out on a Dual-ESI Q-TOF 6520 (Agilent Technologies) mass spectrometer. Photophysical properties were analyzed in 10−5 M

• = 8 Hz, 4H, CHCbz), 7.62 (d, J = 8 Hz, 4H, CHCbz), 8.18 (s, 4H, CHCbz), 9.23 (s, 1H, CHpy) ppm; 13C NMR (100 MHz, CDCl3) δ 15.2, 31.9, 34.9, 110.7, 116.6, 121.8, 124.2, 124.7, 137.8, 144.6, 157.1, 160.2 ppm; HRMS–ESI (m/z): [M + H]+ calcd for C45H53N4, 649.4265; found, 649.4265. 2-Aryl-4,6-bis[3,6-di

• 1.54 (s, 36H, (CH3)3C), 1.96 (s, 3H, CH3), 7.52–7.59 (m, 7H, ArH, CHCbz) 7.61–7.66 (m, 4H, CHCbz), 8.20 (s, 4H, CHCbz), 8.58–8.63 (m, 2H, ArH) ppm; 13C NMR (100 MHz, CDCl3) δ 15.2, 32.0, 34.86; 111.0, 116.5, 118.4, 124.0, 124.6, 128.4, 128.7, 131.1, 136.9, 137.9, 144.4, 160.2, 163.0 ppm; HRMS–ESI (m/z

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• -2000 polarimeter. ESI-TOF mass spectra were obtained using a TOF/Q-TOF Mass spectrometer. Thin-layer chromatography (TLC) and preparative TLC were performed on silica gel 60 GF254 (Merck). Column chromatography (CC) was conducted on silica gel (Merck) type 100 (70–230 mesh ASTM) and type 60 (230–400

• mg) was then washed with acetone to afford compound 5 (3.7 mg). Trichocitrinovirene A (1): Colorless gum; +46.1 (c 0.67, MeOH); UV (MeOH) λmax, nm (log ε): 210 (3.32); ECD (MeOH, c 0.0008) λmax, nm (Δε): 227 (+4.3); IR (neat) νmax: 3336, 1684, 1649 cm−1; 1H and 13C NMR (CD3OD) see Table 1; HRMS–ESI

• (m/z): [M + Na]+ calcd for C15H22O5Na, 305.1356; found, 305.1359. Trichocitrinovirene B (2): Colorless gum; +44.6 (c 0.67, MeOH); UV (MeOH) λmax, nm (log ε): 210 (3.67); IR (neat) νmax: 3386, 1683, 1645 cm−1; 1H and 13C NMR (CD3OD) see Table 1; HRMS–ESI (m/z): [M + Na]+ calcd for C15H22O6Na

Tosylhydrazine-promoted self-conjugate reduction–Michael/aldol reaction of 3-phenacylideneoxindoles towards dispirocyclopentanebisoxindole derivatives

• Sayan Pramanik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 469–478, doi:10.3762/bjoc.18.49

• (multiplet). HRMS with an ESI resource were acquired using a Waters XEVO-G2S Q TOF mass spectrometer. HPLC were recorded using an Agilent 1200 Series auto sampler HPLC system. Melting points were recorded with an open capillary on an electrical melting point apparatus and the single crystal structure of the

Ready access to 7,8-dihydroindolo[2,3-d][1]benzazepine-6(5H)-one scaffold and analogues via early-stage Fischer ring-closure reaction

• Irina Kuznetcova,
• Felix Bacher,
• Daniel Vegh,
• Hsiang-Yu Chuang and
• Vladimir B. Arion

Beilstein J. Org. Chem. 2022, 18, 143–151, doi:10.3762/bjoc.18.15

• hampered this transformation [24]. Therefore, the same synthetic way was repeated with ethoxymethyl ether as the protecting group to give 17. The ESI mass spectrum provided evidence that cyclization occurred with formation of 18. However, protection with chloromethyl ethyl ether was achieved only in 18

Bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reactions of 2-isothiocyanato-1-indanones with barbiturate-based olefins

• Jiang-Song Zhai and
• Da-Ming Du

Beilstein J. Org. Chem. 2022, 18, 25–36, doi:10.3762/bjoc.18.3

• an Agilent 6520 Accurate-Mass Q-TOF MS system equipped with an electrospray ionization (ESI) source. Optical rotations were measured with a Krüss P8000 polarimeter at the indicated concentration with the units of g/100 mL. Enantiomeric excesses were determined by chiral HPLC analysis using an Agilent

The enzyme mechanism of patchoulol synthase

• Houchao Xu,
• Bernd Goldfuss,
• Gregor Schnakenburg and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 13–24, doi:10.3762/bjoc.18.2

• natural product 17 [HRMS–ESI (m/z): 221.1904 [M + H]+, calculated for C15H25O+ 221.1900 and [α]D25 = −7.7, (c 0.26, benzene)] whose structure was elucidated by NMR spectroscopy (Table 1 and Figures S29–S35 in Supporting Information File 1). The 13C NMR spectrum showed signals for 15 carbons, including

Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes

• Shun Saito,
• Kanji Indo,
• Naoya Oku,
• Hisayuki Komaki,
• Masashi Kawasaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203

• determined to be C10H16O2 on the basis of its NMR and HR–ESI–TOFMS data (m/z 191.1044 [M + Na]+, Δ + 0.1 mmu). Three degrees of unsaturation, calculated from the molecular formula, a UV absorption maximum at 264 nm, and IR absorption bands at 1679 and 2800–3200 cm−1, suggested dienone and hydroxy

• this methyl proton (H-8/H-9) and a methine proton (H-7) and HMBC correlations from H-8/H-9 to the methine carbon (C-7) and the allylic methylene carbon (C-6). The deduced structure was consistent with a molecular formula C11H18O2 established by HR–ESI–TOFMS analysis (m/z 205.1202 [M + Na]+, Δ + 0.3 mmu

• molecular formula was determined to be C18H22N2O3 based on its NMR and HR–ESI–TOFMS data (m/z 313.1556 [M – H]–, Δ – 0.2 mmu), corresponding to nine degrees of unsaturation. The UV spectrum, exhibiting the absorption maxima at 229 and 282 nm, was typical of an indole functionality. The IR absorption bands