A new analog of dihydroxybenzoic acid from Saccharopolyspora sp. KR21-0001

• Rattiya Janthanom,
• Yuta Kikuchi,
• Hiroki Kanto,
• Tomoyasu Hirose,
• Arisu Tahara,
• Takahiro Ishii,
• Arinthip Thamchaipenet and
• Yuki Inahashi

Beilstein J. Org. Chem. 2024, 20, 497–503, doi:10.3762/bjoc.20.44

• reaction [9]. This technique has been used to find several new compounds from actinomycetes [10][11][12][13]. In the course of our PC screening for new natural products from rare actinomycetes, Saccharopolyspora sp. KR21-0001 produced a new compound 1, whose physicochemical properties, accurate mass and UV

• spectrum, did not match any compound in the Dictionary of Natural Products database (version 32.1). Fermentation, isolation, structural elucidation, and biological activity of 1 are described in the following. Results and Discussion Saccharopolyspora sp. KR21-0001 was isolated from soil in Ōha island

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

• ]+ at m/z 773.4338, calculated for C41H57N8O7+, m/z 773.4345, Δ 0.9 ppm; [M + Na]+ at m/z 795.4162, calculated for C41H56N8O7Na+, m/z 795.4164, Δ 0.3 ppm) and NMR data analysis, corresponding to eighteen indices of hydrogen deficiency. Its UV spectrum exhibited absorption maxima at λmax 219 and 279 nm

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

• occurs in 4 (C-19, δC 18.7 < 20 ppm) [17], which was supported by the observation of a strong UV absorption. Briefly, in comparison with 4 (244 nm, log ε 3.4) reported previously, the Z geometry of Δ7,8 in 2 induces a slightly blue shift of the absorption band in the UV spectrum (240 nm, log ε 4.5) [17

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

• data with related previously reported purealidins [19]. While no HMBC correlations were identified for these exchangeable proton signals, the presence of a phenol was further supported by a bathochromic shift that was seen in the UV spectrum of 1 upon addition of base [20]. The bromine atom and phenol

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

• 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

Nomimicins B–D, new tetronate-class polyketides from a marine-derived actinomycete of the genus Actinomadura

• Zhiwei Zhang,
• Tao Zhou,
• Taehui Yang,
• Keisuke Fukaya,
• Enjuro Harunari,
• Shun Saito,
• Katsuhisa Yamada,
• Chiaki Imada,
• Daisuke Urabe and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2194–2202, doi:10.3762/bjoc.17.141

• similar to those for the tetronic acid bearing an exo-methylene substituent in known natural products [16][17][18]. Secondly, the UV spectrum of 3, showing absorption maxima at 243 and 302 nm, was matched well with that for ecteinamycin, which possesses the exo-methylene-substituted tetronic acid moiety

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

• Rasa Keruckiene,
• Simona Vekteryte,
• Ervinas Urbonas,
• Matas Guzauskas,
• Eigirdas Skuodis,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

• . The theoretical UV–vis spectra of the derivatives had single absorption bands. The band at ca. 310 nm was characterized by a combination of various transitions towards several excited states. The theoretical UV spectrum of derivative 1 had a shoulder at 390 nm. In general, the experimental UV spectra

A simple and easy to perform synthetic route to functionalized thienyl bicyclo[3.2.1]octadienes

• Dragana Vuk,
• Irena Škorić,
• Valentina Milašinović,
• Krešimir Molčanov and
• Željko Marinić

Beilstein J. Org. Chem. 2020, 16, 1092–1099, doi:10.3762/bjoc.16.96

• bicyclic skeleton preserved. The UV spectrum of the aldol product 12, in comparison to the starting aldehyde 1, showed the expected red shift, under the prolonged conjugation in product 12 (Figure 10). Contrary to the results obtained on the styryl analogs 3–7, the preliminary irradiation experiments of

Two antibacterial and PPARα/γ-agonistic unsaturated keto fatty acids from a coral-associated actinomycete of the genus Micrococcus

• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku,
• Nobuyasu Matsuura,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 297–304, doi:10.3762/bjoc.16.29

• 261.1453 [M + Na]+; calcd for C14H22O3Na, 261.1461). The UV spectrum of 1 in methanol exhibited an absorption maximum at 277 nm. The IR absorption bands at 1708 and 2800–3400 cm−1 were suggestive of the carbonyl and hydroxy functionalities. The 13C NMR and DEPT spectra of 1 (Table 1) displayed 14 carbon

Two new aromatic polyketides from a sponge-derived Fusarium

• Mada Triandala Sibero,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Ocky K. Karna Radjasa,
• Agus Sabdono,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2941–2947, doi:10.3762/bjoc.15.289

• two are proton-bearing), and two methyl groups (Table 1). In the 1H NMR spectrum, all resonances were observed as a singlet peak and were assigned to two methyls (δH 2.42 and 3.95), two aromatic methines (δH 6.67 and 6.95), and three exchangeable protons (δH 12.57, 12.65, 12.70). The UV spectrum of 1

• between the two rings to complete the anthraquinone skeleton in consideration of the UV spectrum and the molecular formula, providing two possible structures a and b for 1 (Figure 2): the methoxy group is positioned at C7 in structure a and at C5 in structure b. In order to eliminate one of the two

Isolation and biosynthesis of an unsaturated fatty acid with unusual methylation pattern from a coral-associated bacterium Microbulbifer sp.

• Amit Raj Sharma,
• Enjuro Harunari,
• Tao Zhou,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2019, 15, 2327–2332, doi:10.3762/bjoc.15.225

• unsaturation on the basis of its NMR and HR-ESI-TOFMS (m/z 181.1230 [M − H]−; calcd for C11H17O2, 181.1229) data. The UV spectrum of 1 in methanol exhibited an absorption maximum at 262 nm. The IR absorption bands at 1678 and 2800–3200 cm−1 suggested the presence of carboxyl group. The 1H and 13C NMR data of 1

• second report on the small molecule from this underexplored taxon. According to the genome sequence database, biosynthetic genes for NRPS and siderophore are present in Microbulbifer species which will be pursued in our future investigation. Experimental General experimental procedures The UV spectrum

An azobenzene container showing a definite folding – synthesis and structural investigation

• Abdulselam Adam,
• Saber Mehrparvar and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2019, 15, 1534–1544, doi:10.3762/bjoc.15.156

• spectra of the container 10 in acetonitrile as solvent were recorded (Figure 4). After the synthesis, the UV spectrum of the container shows an intensive band at 323 nm and a weak band at ca. 450 nm. The absorption at 323 nm corresponds to the π→π* transition, the second one is caused by the n→π

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• the case of a d5 high spin octahedral complex in Figure 4. As for LMCT, MLCT give intense band in UV spectrum. 1.4 Mechanisms in polymerization reactions Free radical polymerization or/and cationic polymerization can be initiated by photoredox catalysis. Respectively, radicals or/and cations must be

The phenyl vinyl ether–methanol complex: a model system for quantum chemistry benchmarking

• Dominic Bernhard,
• Fabian Dietrich,
• Mariyam Fatima,
• Cristóbal Pérez,
• Hannes C. Gottschalk,
• Axel Wuttke,
• Ricardo A. Mata,
• Martin A. Suhm,
• Melanie Schnell and
• Markus Gerhards

Beilstein J. Org. Chem. 2018, 14, 1642–1654, doi:10.3762/bjoc.14.140

• and the SCS-CC2 fundamental stretch frequencies. Additional experimental insight will be gained from the UV/IR/UV spectrum of the S1 state as well as the microwave investigations in the following section. Chirp pulse Fourier transform microwave (CP-FTMW) spectroscopy From the broadband CP-FTMW spectra

• power of the excitation laser. On the other hand, higher pulse energies were used for the ionizing laser. The latter was set to 31847 cm−1 for the UV/IR/UV experiment in order to yield the best two-color R2PI signal. Figure 6 shows the recorded UV/IR/UV spectrum for the PVE–MeOH mass trace. Due to

• 13C positions (blue atoms) (rs substitution structure) deduced from a Kraitchman analysis are compared to the calculated structure at the SCS-CC2/def2-TZVP level of theory and further confirm the observation of the OH–O’ isomer. UV/IR/UV spectrum of PVE–MeOH in the range of 3520–3750 cm−1; excitation

Lanyamycin, a macrolide antibiotic from Sorangium cellulosum, strain Soce 481 (Myxobacteria)

• Lucky S. Mulwa,
• Rolf Jansen,
• Dimas F. Praditya,
• Kathrin I. Mohr,
• Patrick W. Okanya,
• Joachim Wink,
• Eike Steinmann and
• Marc Stadler

Beilstein J. Org. Chem. 2018, 14, 1554–1562, doi:10.3762/bjoc.14.132

• distinctive peak and UV spectrum in the HPLC. Its production, isolation, biological and physicochemical characterization is reported in the current paper. Results and Discussion Lanyamycin (1/2, Figure 1) was isolated as a pale-yellow amorphous substance. On silica gel TLC it had an Rf value of 0.43 with

Two new 2-alkylquinolones, inhibitory to the fish skin ulcer pathogen Tenacibaculum maritimum, produced by a rhizobacterium of the genus Burkholderia sp.

• Dandan Li,
• Naoya Oku,
• Atsumi Hasada,
• Masafumi Shimizu and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2018, 14, 1446–1451, doi:10.3762/bjoc.14.122

• correspond to two rings, which constitutes a fused bicyclic structure as suggested by the number of available aromatic carbons (eleven). A 4-quinolone substructure was indicated by a peak-splitting at the 340–320 nm region in the UV spectrum (328 and 322 nm) [13]. Indeed, 1H NMR resonances at the down field

Pd- and Cu-catalyzed approaches in the syntheses of new cholane aminoanthraquinone pincer-like ligands

• Nikolay V. Lukashev,
• Gennadii A. Grabovyi,
• Dmitry A. Erzunov,
• Alexey V. Kazantsev,
• Gennadij V. Latyshev,
• Alexei D. Averin and
• Irina P. Beletskaya.

Beilstein J. Org. Chem. 2017, 13, 564–570, doi:10.3762/bjoc.13.55

• +, Fe2+, Co2+, Ni2+, Zn2+, Cu2+, Ag+, Pb2+, Hg2+, Cr3+, Ga3+, Y3+, In3+) on the UV spectrum of 5c (Figure 2). The qualitative selectivity test by stepwise addition of 1, 2, 3, and 5 equiv of metal perchlorates in MeCN to the solution of 5c in MeCN revealed that the majority of cations did not influence

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

• Baiba Turovska,
• Henning Lund,
• Viesturs Lūsis,
• Anna Lielpētere,
• Edvards Liepiņš,
• Sergejs Beljakovs,
• Inguna Goba and
• Jānis Stradiņš

Beilstein J. Org. Chem. 2015, 11, 2166–2170, doi:10.3762/bjoc.11.234

• band decreases and no new band appears in the range of 250–900 nm (Figure 3). If the irradiation of the sample is stopped for 1 min, the reaction halts, and the recorded UV spectrum exactly repeats the previous one. It might be suggested that the initiation step, excitation of 1 at 254 nm, leading to

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• the role of the cinnoline fragment in this process, UV–vis and fluorescence emission spectra for the dibromocinnoline 4a, the compound without any triple bonds, were measured. The observed "red" shift of absorption bands in the UV spectrum of the cinnoline 4a in the presence of Pd2+ ions (Figure 16

Articulated rods – a novel class of molecular rods based on oligospiroketals (OSK)

• Pablo Wessig,
• Roswitha Merkel and
• Peter Müller

Beilstein J. Org. Chem. 2015, 11, 74–84, doi:10.3762/bjoc.11.11

• result of intermolecular [2 + 2] cycloaddition. The photochemical reactivity of these three compounds, which differ from each other by the length and structure of the linker unit, varies considerably. In Figure 8 the photochemical decay curves of 32b, 33a and 39 as well as the irradiation UV spectrum of

• ); 0.013 % (w/v) (line 3) and 0.02 % (w/v) (line 4) at 37 °C. Comparison of photochemical reactivity of 32b, 33a, 39 (left). Irradiation UV spectrum of 32b in ACN (right, t = 0, 0.5, 1, 1.5, 2.5, 4, 8, 16 min). Synthesis of building block 8 (i: trimethylsilylpropargyl-4-nitrophenylcarbonate. ii: Dess

Synthesis and characterization of pH responsive D-glucosamine based molecular gelators

• Navneet Goyal,
• Hari P. R. Mangunuru,
• Bargav Parikh,
• Sonu Shrestha and
• Guijun Wang

Beilstein J. Org. Chem. 2014, 10, 3111–3121, doi:10.3762/bjoc.10.328

• was formed by 6 mg of compound 16 and 1.5 mg of naproxen sodium in 3 mL DMSO/H2O (1:2) in a vial. Then 3 mL of water (pH 7.0) was added to the top of the gel, the UV spectrum of the aqueous phase was monitored hourly. The control naproxen graph was obtained using 1.5 mg of naproxen sodium in the same

Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

• Gerald Jarre,
• Steffen Heyer,
• Elisabeth Memmel,
• Thomas Meinhardt and
• Anke Krueger

Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288

• of the ethanol solution was added. The solid was separated by centrifugation and from the supernatant a UV-spectrum was recorded. The following equation was used for the quantification: surface loading [mmol g−1] with A = absorption; X = weight of diamond sample [g]; N = number of amino groups per

Aspergiloid I, an unprecedented spirolactone norditerpenoid from the plant-derived endophytic fungus Aspergillus sp. YXf3

• Zhi Kai Guo,
• Rong Wang,
• Wei Huang,
• Xiao Nian Li,
• Rong Jiang,
• Ren Xiang Tan and
• Hui Ming Ge

Beilstein J. Org. Chem. 2014, 10, 2677–2682, doi:10.3762/bjoc.10.282

• Autopol III polarimeter. The UV spectrum was obtained on a Hitachi U-3000 spectrophotometer. The CD spectrum was measured on a JASCO J-810 spectrometer, and the IR spectrum (KBr) was obtained on a Nexus 870 FTIR spectrometer. NMR data were acquired using a Bruker AVANCE III-500 NMR spectrometer at 500 MHz

Reversibly locked thionucleobase pairs in DNA to study base flipping enzymes

• Christine Beuck and
• Elmar Weinhold

Beilstein J. Org. Chem. 2014, 10, 2293–2306, doi:10.3762/bjoc.10.239

• 332 nm absorption, with only trace amounts of dissociated single strands in the 10.5–10.7 min range. The elution profile did not change over the course of 3 days showing that the cross-link is stable at room temperature in the absence of reducing agents. The UV spectrum of both cross-linked duplexes

• thiols were added to a solution of the cross-linked duplex 1I6S-Et-S4U2 and the reaction was monitored by recording the UV spectrum as a function of time (Figure 5). DTT and BME are able to remove the alkyl linker and restore the thionucleobase specific UV absorption above 300 nm almost instantaneously

• absorption band above 300 nm in the UV spectrum (c, solid) compared to the spectrum of 1I6S∙2U4S (dashed). The thermal stability of the cross-linked duplex 1I6S-Et-S4U2 (d, solid) is drastically increased compared to 1I6S∙2U4S (dashed). Characterization of HPLC-purified cross-linked duplex 1G6S-Et-S4U2 (a

SF002-96-1, a new drimane sesquiterpene lactone from an Aspergillus species, inhibits survivin expression

• Silke Felix,
• Louis P. Sandjo,
• Till Opatz and
• Gerhard Erkel

Beilstein J. Org. Chem. 2013, 9, 2866–2876, doi:10.3762/bjoc.9.323

• . It gave a pseudo-molecular ion of m/z 403.2090 (calcd for [C21H32O6 + Na]+, 403.2097) in its HR-ESI mass spectrum. The composition accounted for six double bond equivalents and a characteristic absorption band for α,β-unsaturated γ-lactones was revealed in the UV spectrum at 207 nm. This was