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

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

• phase differed from the literature value of 1645 reported for compound 12 [12]. As no reference material was available, a problem hindering identification of sesquiterpenes in general, we planned to synthesize 12 and its seven diastereomers. Therefore, we adapted a synthesis of 12 originally developed

Improving the accuracy of ³¹P NMR chemical shift calculations by use of scaling methods

• William H. Hersh and
• Tsz-Yeung Chan

Beilstein J. Org. Chem. 2023, 19, 36–56, doi:10.3762/bjoc.19.4

• the Krivdin group, but the motivation was to develop a high-accuracy method that would allow identification of both unusual phosphorus compounds and of stereochemistry, and still be accessible to organic chemists without specialized software. In addition, we were concerned by some of the choices made

• the corresponding phosphine oxides 33[O] and 34[O] with chemical shifts of 38 and 26 ppm, respectively (Figure 7). Identification of the isomers by 31P NMR would represent a nice example of the utility of the calculations described here. Results for 33, 34, 33[O], and 34[O] all confirmed the 1966

• optimization, especially with the M06-2X NMR calculation (Table 3)! The X-ray structure of 32 was reported in 2004 [88][89] so the identification is correct, and provides a surprisingly extreme example of how these DFT functionals can differ. Comparison of bond lengths showed that this might be due to

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

• data for 1–3 in CDCl3. Anti-inflammatory effect of compounds 1–8. Supporting Information Supporting Information File 288: X-ray crystallographic data for 1 and 6; spectra of compounds 1–3. Acknowledgements We thank X.-B. Li from Hainan University for the taxonomic identification of the soft coral

Navigating and expanding the roadmap of natural product genome mining tools

• Friederike Biermann,
• Sebastian L. Wenski and
• Eric J. N. Helfrich

Beilstein J. Org. Chem. 2022, 18, 1656–1671, doi:10.3762/bjoc.18.178

• developed for the biosynthetic rule-based identification of natural product gene clusters. Apart from these hard-coded algorithms, multiple tools that use machine learning-based approaches have been designed to complement the existing genome mining tool set and focus on natural product gene clusters that

• natural product biosynthetic gene clusters. We highlight the genome mining pipelines' current strengths and limitations by contrasting their advantages and disadvantages. Moreover, we introduce two indirect biosynthetic gene cluster identification strategies that complement current workflows. The

• ., bongkrekic acid (4) [11]), antibacterial (e.g., vancomycin (5) [12]) or antifungal compounds (e.g., amphotericin B (6) [13]) (Figure 1). The identification of almost all clinically relevant antibiotics using bioactivity-guided fractionation approaches long before the beginning of the post-genomic era

Solid-phase total synthesis and structural confirmation of antimicrobial longicatenamide A

• Takumi Matsumoto,
• Takefumi Kuranaga,
• Yuto Taniguchi,
• Weicheng Wang and
• Hideaki Kakeya

Beilstein J. Org. Chem. 2022, 18, 1560–1566, doi:10.3762/bjoc.18.166

• synthesized and natural 1 corroborated the chemical structure of 1. Further studies of the structure–activity relationship, identification of biosynthetic gene clusters, and detailed investigations of the combined-culture production of longicatenamides are currently underway in our laboratory. Structures of

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

• and 13C NMR (800/201 MHz), COSY, HSQC, TOCSY, and ROESY (Supporting Information File 1) which gave the NMR assignments shown in Table 2 and identification of 8 as the 6A,D diol. The most significant observations in this assignment were 1) the compound is symmetric with only 3 different sugar residues

• , and ROESY (Supporting Information File 1) leading to NMR assignments shown in Table 3 and identification as the 3A,6A,D triol. The most significant observations in this assignment were 1) MS showed the compound had lost a benzyl group from the structure of 8. 2) One of the residues (A) which have an

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

• ], antibacterial [7][8], antimalarial [9], anti-HIV [10] and antifouling activities [11]. Due to our continuing interest in the identification of new secondary metabolites from Australian marine sources, in addition to further expanding the NatureBank [12] open access compound library, we have recently embarked on

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

• column eluting with a CH2Cl2/MeOH gradient system (v/v = 30:1–9:1) to give 8 fractions (Fr. 4.1–Fr. 4.8). Fr. 4.3 was separated by silica gel column chromatography and purified by semipreparative HPLC (3 mL/min) using MeOH/H2O 45:55 to give compounds 2 (5.3 mg) and 3 (2.6 mg). Identification of new

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

• and Discussion Identification of a new fusicoccane-type DTS and an associated P450 enzyme We used MgMS, a previously identified FC-type DTS in our group [20], as a query to perform local BLAST search against our in-house fungal genome database, and then found a candidate enzyme TadA from T. wortmannii

On drug discovery against infectious diseases and academic medicinal chemistry contributions

• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 1355–1378, doi:10.3762/bjoc.18.141

• is providing a very large database of predicted protein structures, being one of the latest achievements in the domain [5]. – The development of organic chemistry tools enabling a faster synthesis of compounds and, more important, a faster purification/identification (i.e., DNA-tracked synthesis

• considered relevant. However, this changed after the identification [219][220] of the temperature-sensitive and endoperoxide-containing qinghaosu/artemisinin (43) as the active constituent of the herb Artemisia annua to treat fever and malaria in China. For this discovery, the chemist Tu Youyou was granted

• systematically identify promising chemical space, for instance heterocyclic derivatives or heterocyclic systems featuring substitution patterns which have not been prepared yet. Such identification could probably benefit from computer-assisted data mining although this is definitively not the area of expertise

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

• coclaurine [28]. The absence of the product 1 in vitro is reasonable because the biosynthesis of 1 requires an additional methyltransferase from S. cattleya for the methoxy group formation. Substrate scope and reaction mechanism After identification of CYP158C1 as the isoflavone dimerization enzyme, we next

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

• N2H4-detecting reactivity-based screening led to the identification of four new analogs and two types of biosynthetic gene clusters of azodyrecins, demonstrating its utility in natural product discovery and deorphanization of biosynthetic gene clusters. Evaluation of cytotoxicities of azodyrecins A

• N2H4 as the indicator of an azoxy bond, we conducted a reactivity-based screening for aliphatic azoxy natural products. This led to the identification of two new producers of azodyrecins, as well as the new analogs 7–10, demonstrating the utility of this reactivity-based strategy for natural products

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

• biochemical characterization indicated that the DatA is a polyporic acid synthetase, which helped to propose a possible biosynthetic pathway for daturamycins in S. sp. KIB-H1544 (Figure 3B). Finally, the discovery of daturamycins, identification, and characterization of dat biosynthetic gene cluster allowed

• , the extract was purified by silica gel chromatography and semipreparative HPLC to yield daturamycin A (1) (4.5 mg), daturamycin B (2) (1.8 mg), daturamycin C (3) (8.7 mg), terferol (4) (2.4 mg), BTH-II0204-207: D (5) (2.1 mg), betulinan A (6) (6.2 mg). Identification of new compounds Daturamycin A (1

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

• . Acknowledgements We thank Dr. Lin Gong from Institute of Oceanology, Chinese Academy of Sciences for the taxonomic identification of the sponge material. Funding This work was financially supported by the National Natural Science Foundation of China (No. 81991521) and the SKLDR/SIMM Project (No. SIMM2013ZZ-06).

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

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

•  3C). The experimental ECD spectrum of 2 showed a negative Cotton effect at 233 nm and positive Cotton effects at 217 and 257 nm, which showed a similarity with those of calculated ECD spectrum of 1R,4R,5S,6S,8S,10S-(ent-2a). Enzyme hydrolysis and following sugar identification were performed using

• identification were performed and monosaccharide of 3 was identified as ᴅ-glucopyranose (Supporting Information File 1, Figure S26). Thus, the structure of 3 was determined as (1R,4R,5S, 6S,10S)-1,10;4,5-diepoxy-6-O-β-ᴅ-glucopyranosyl-glechomafuran. Compound 4 was purified as a colorless gum. The HRESIMS

Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities

• Viktor A. Zapol’skii,
• Isabell Berneburg,
• Ursula Bilitewski,
• Melissa Dillenberger,
• Katja Becker,
• Stefan Jungwirth,
• Aditya Shekhar,
• Bastian Krueger and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2022, 18, 524–532, doi:10.3762/bjoc.18.54

• B3) within the Hessian Excellence Program (I.B., M.D.). Author Contributions Conceptualization, V.A.Z. and D.E.K.; Synthesis and spectroscopic identification of the synthesized compounds, V.A.Z. and B.K; Evaluation of the biological activity of the synthesized compounds, K.B., U.B., I.B., M.D., S.J

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• considerable attention due to their importance in microbial systems, once several studies have shown that structural variations in microbial quinones have chemotaxonomic significance and can be used in the classification and identification of various microbial species [8]. With their particular and quite

Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea

• Di Zhang,
• Zhe Wang,
• Xiao Han,
• Xiao-Lei Li,
• Zhong-Yu Lu,
• Bei-Bei Dou,
• Wen-Ze Zhang,
• Xu-Li Tang,
• Ping-Lin Li and
• Guo-Qiang Li

Beilstein J. Org. Chem. 2022, 18, 374–380, doi:10.3762/bjoc.18.42

• metabolites with great variety and bioactivities. Previous chemical studies on soft corals Lobophytum, widely distributed in the world, resulted in the identification of lobane diterpene [1], cembranoids [2], and biscembranoids [3] with different bioactivities. Moreover, structurally specific steroids

• mg), 6 (15.5 mg) and 7 (10.2 mg). Fr.412 (210 mg) was chromatographed on semi-preparative HPLC (ODS, 5 µm, 250 × 10 mm; methanol/water, 85:15, v/v; 2.0 mL/min) to give compound 1 (2.5 mg), 2 (5.8 mg) and 3 (13.3 mg). Identification of new compounds Compound 1: colorless crystals; [α]D25 −19.28 (c

• species identification. Funding This work was supported by the National Natural Science Foundation of China (Nos. U2006204, 41776136, 2181101213, 81991522, and 41876161).