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Search for "isolation" in Full Text gives 939 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

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

Graphical Abstract
  • investigations, accompanied by fermentation media optimization, of a newly isolated fungus, Penicillium shentong XL-F41, led to the isolation of twelve compounds. Among these are two novel indole terpene alkaloids, shentonins A and B (1 and 2), and a new fatty acid 3. Shentonin A (1) is distinguished by an
  • , given the application of suitable activation techniques. Results and Discussion Compound isolation and structure elucidation To activate the silent BGCs in Penicillium shentong XL-F41, we conducted small-scale fermentations using various media. Analysis revealed that HPLC peaks, which correspond to
  • extract was partitioned between EtOAc and H2O. The EtOAc fraction was chromatographed repeatedly over silica gel and reversed-phase high-performance liquid chromatography (RP-HPLC), resulting in the isolation of pure compounds 1–12 (Figure 2). According to literature reports of known compounds, some of
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Published 15 Mar 2024

Entry to new spiroheterocycles via tandem Rh(II)-catalyzed O–H insertion/base-promoted cyclization involving diazoarylidene succinimides

  • Alexander Yanovich,
  • Anastasia Vepreva,
  • Ksenia Malkova,
  • Grigory Kantin and
  • Dmitry Dar’in

Beilstein J. Org. Chem. 2024, 20, 561–569, doi:10.3762/bjoc.20.48

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  • also in the alpha position of the furanone ring. Reactions with allenic acids 11 were carried out according to a similar scheme, in the one-pot mode, without isolation of OH-insertion intermediates 12 (Scheme 4). In order to accelerate the cyclization step in this case, moderate heating was used after
  • previously tested using 3-bromopropanol. When the reaction was carried out in a one-pot format, with the replacement of DCM by acetone, the desired product 5a could only be isolated in moderate yield (52%). In the case of preliminary isolation of the OH-insertion product 16a (flash chromatography), the
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Published 11 Mar 2024

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

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  • actinomycetes, with 70% from Streptomyces and the rest from rare actinomycetes (non-Streptomyces) [5]. Rare actinomycetes are defined as actinomycete strains with low isolation rates when compared with the isolation of Streptomyces [6]. Currently, the discovery of new natural compounds is focusing on rare
  • 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
  • applied in various industries, such as pharmaceutics, agriculture, and environmental remediation [21][22]. However, the discovery of bioactive compounds from rare actinomycetes comes with challenges, such as the difficulty of isolation from environments. In this study, we searched for new secondary
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Published 29 Feb 2024

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

Graphical Abstract
  • sesquiterpenoids (1, 2), together with three known related analogs (3–5) [10][11][12][13] have been isolated and identified from the bioactive fraction of P. boydii CS-793. Details of the isolation and purification, structure elucidation, and biological evaluation of compounds 1–5 are described herein. Results and
  • Discussion For chemical investigation, the solvent EtOAc was used to extract the fermentation culture of the fungus P. boydii CS-793 to afford an organic extract. Isolation and purification of the crude extract with a combination of column chromatography (CC) by Lobar LiChroprep RP-18, silica gel, Sephadex
  • (IOCAS). Fermentation, extraction, and isolation. Fermentation and extraction were performed in a manner analogous to reference [6]. For chemical investigations, rice solid medium containing rice (100 g/flask), peptone from animal (0.3 g/flask), yeast extract (0.5 g/flask), corn steep liquor (0.2 g/flask
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Published 28 Feb 2024

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

  • Alexander S. Hampton,
  • David R. W. Hodgson,
  • Graham McDougald,
  • Linhua Wang and
  • Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

Graphical Abstract
  • extraction. Indeed, attempts to grow a single crystal of 5e from a mixture of EtOH and water led to the isolation of the corresponding gem-diol (Figure 3). There are very few examples of organic structures containing a C(OH)2–CF2–C fragment in the CCDC and only three acyclic examples (CSD 5.43 (Nov. 2021
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Published 28 Feb 2024

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

  • Nataliia V. Kirij,
  • Andrey A. Filatov,
  • Yurii L. Yagupolskii,
  • Sheng Peng and
  • Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

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  • of stereoisomers in 2:1 ratio. After isolation by distillation, 2,3-dibromo-1,1,1,4,4,4-hexafluorobutane (2) was characterized by 1H, 19F, 13C NMR and mass spectra. We studied the reaction of dibromoalkane 2 with various bases such as DBU, Hünig’s base (iPr2NEt), and potassium hydroxide (Table 1). In
  • . The reaction mixture gave a complex mixture, in which (E)-butene 3a was identified as a major component. Product 3a was removed from bulk diglyme in vacuum and after subsequent distillation it was isolated with a yield of 23%. As the isolation of the 2-dehydrobromination products from organic bases
  • method it was possible to achieve complete dehydrobromination of (Z)-isomer 3b and isolation of (E)-isomer 3a in pure form in 35% yield (Scheme 2). Unexpectedly the (E)-isomer 3a, upon long-term storage, transforms into the (Z)-isomer 3b. Therefore, we studied the isomerization of olefin 3a in the
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Published 27 Feb 2024

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

  • Periklis X. Kolagkis,
  • Eirini M. Galathri and
  • Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

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Review
Published 22 Feb 2024

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

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  • facilitate release from the NRPS. Of the fungal NRPS studied to date, many appear to have some tolerance for the range of amino acids incorporated by the A domains and the C domain has been highlighted as a gatekeeper [13]. Here, we describe the isolation of unguisin B, and a new congener named unguisin J
  • . heteromorphus CBS 117.55 on rice solid medium yielded an organic-soluble extract, which was subjected to fractionation using preparative HPLC-PDA-ELSD and purification by semipreparative HPLC-PDA; this led to the isolation of a new cyclic peptide 1, along with unguisin B (2, Figure 2). The structure of the new
  • ). To the best of our knowledge these are the first metabolites reported from A. heteromorphus CBS 117.55. The co-isolation of unguisins B and J indicates that module 4 of the NRPS is able to accept two different amino substrates and so may possess subtle differences to UngA from A. violaceofuscus CBS
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Published 19 Feb 2024

Catalytic multi-step domino and one-pot reactions

  • Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

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  • because they are time-saving, waste-reducing, and atom efficient [1][2][3][4][5][6]. These efficient and straightforward synthetic methods make the isolation and purification of intermediate products after each reaction step superfluous, thereby drastically reducing the number of workup and purification
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Editorial
Published 08 Feb 2024

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

  • Ekaterina V. Kolupaeva,
  • Narek A. Dzhangiryan,
  • Alexander F. Pozharskii,
  • Oleg P. Demidov and
  • Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

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  • several minutes with a good yield (Scheme 4). The spectral data fully confirmed the purity and asymmetric structure of product 11. It should be emphasized that the isolation and purification of nitro compounds 10 and 11 is complicated by their low solubility in traditional organic solvents, sensitivity to
  • difficult to purify compound 8. At the same time, isolation of the new product 8 turned out to be more convenient on using the simple KOH/EtOH system. These conditions did not affect the yield of acenaphthylene 8 (Scheme 9). Compound 8 possesses fluorescence in solutions and the solid state both as the base
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Published 08 Feb 2024

Photochromic derivatives of indigo: historical overview of development, challenges and applications

  • Gökhan Kaplan,
  • Zeynel Seferoğlu and
  • Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

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  • forward and backward isomerization of N,N'-diacetylindigo (9a) in toluene without isolation of the Z-form [49]. The Fischer method remains relevant up to date and is frequently used for the characterization of the photoinduced forms of various indigoid photoswitches [50][51][52][53][54]. To assess an
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Review
Published 07 Feb 2024

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N3 linker for glycodendrimersomes preparation to study lectin binding

  • Mark Reihill,
  • Hanyue Ma,
  • Dennis Bengtsson and
  • Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

Graphical Abstract
  • , led to isolation of a mixture of 2 and a tin-related impurity (n-butyl chain evident by NMR). Acetylation of this material followed by flash chromatography proved ineffective in removing the unwanted entity. To overcome this problem, flash chromatography was performed before stirring with the ion
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Published 30 Jan 2024

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

  • Viktoria A. Ikonnikova,
  • Cristina Cheibas,
  • Oscar Gayraud,
  • Alexandra E. Bosnidou,
  • Nicolas Casaretto,
  • Gilles Frison and
  • Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

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  • leading to the isolation of dihydronaphthalenic product 4 in 82% yield (Table 1, entry 4, these conditions will later be taken as the reference). Trying to reduce this reagent stoichiometry only resulted in a poor yield of 4 and in the isolation of aldehyde 3 in 42% yield (Table 1, entry 5). By contrast
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Published 25 Jan 2024

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

  • Seiji Kawai,
  • Akito Yamada,
  • Yohei Katsuyama and
  • Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

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  • product produced by K. albida [30]. Although rare actinomycetes have been expected to be a source of novel natural products, reports of natural product isolation from rare actinomycetes are limited because of the difficulty in cultivation and genetic manipulation. This study demonstrates that heterologous
  • 2.6C18 Packed column (2.1 mm ID × 100 mm, Nacalai Tesque) coupled with a model LCMS-8040 liquid chromatography–mass spectrometer (LC–MS) (Shimazu Corp.). The compounds were eluted with a linear gradient of water/acetonitrile containing 0.1% formic acid. Isolation and structural determination of compound
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Published 02 Jan 2024

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

  • Yipeng Yin,
  • Reed Arneson,
  • Alexander Apostle,
  • Adikari M. D. N. Eriyagama,
  • Komal Chillar,
  • Emma Burke,
  • Martina Jahfetson,
  • Yinan Yuan and
  • Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

Graphical Abstract
  • have difficulty to produce sequences containing stable secondary structures. Here, we report a direct de novo chemical synthesis of 400 nt ODNs, and their isolation from the complex reaction mixture using the catching-by-polymerization (CBP) method. To determine the authenticity of the ODNs, 399 and
  • , the GFP gene was expressed in E. coli. The long ODN synthesis and isolation method presented here provides a pathway to the production of genes and genomes containing long repeats or stable secondary structures that cannot be produced or are highly challenging to produce using existing technologies
  • to address all the aforementioned problems, such as generating sequences having highly stable secondary structures [18]. In this paper, we report a method to access long ODNs involving automated direct de novo chemical synthesis and isolation of full-length sequences using the catching-by
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Published 21 Dec 2023

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

  • Nedra Touj,
  • François Mazars,
  • Guillermo Zaragoza and
  • Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

Graphical Abstract
  • NHC·CS2 zwitterions relies on the deprotonation of an azolium salt with a strong base, typically potassium tert-butoxide or potassium bis(trimethylsilyl)amide (also known as potassium hexamethyldisilazide, KHMDS) followed by the addition of carbon disulfide either in one pot or after the isolation of the
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Published 20 Dec 2023

Controlling the reactivity of La@C82 by reduction: reaction of the La@C82 anion with alkyl halide with high regioselectivity

  • Yutaka Maeda,
  • Saeka Akita,
  • Mitsuaki Suzuki,
  • Michio Yamada,
  • Takeshi Akasaka,
  • Kaoru Kobayashi and
  • Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

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  • -electron reduction of Gd@C2v-C82 for the addition reaction to occur at room temperature [22]. Supporting Information File 1, Figure S1 depicts the three HPLC separation steps including recycling for the isolation. The matrix-assisted laser desorption/ionization time-of-flight (MALDI–TOF) mass spectra of 2a
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Published 11 Dec 2023

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

  • Grigory Kantin,
  • Pavel Golubev,
  • Alexander Sapegin,
  • Alexander Bunev and
  • Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

Graphical Abstract
  • product 6b in high yield. The reaction with methyl pyrrole-2-carboxylate resulted in the isolation of only the C–H insertion product 9c in low yield. Similar reaction progress was observed in the case with imidazole, the product N–H insertion was observed only in trace amounts (according to NMR data of
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Published 07 Dec 2023

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

  • Yordanka Mollova-Sapundzhieva,
  • Plamen Angelov,
  • Danail Georgiev and
  • Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

Graphical Abstract
  • -substitution in R1 drove the yields of 3 below 50% and for this reason isolation and further elaboration of such products were considered impractical. Once prepared, the key intermediates 3 could be transformed either directly to 2-alkyl-4-quinolone-3-carboxamides 5 or to 2-alkyl-4-quinolones 8, after an
  • preferential isolation of N-hydroxy derivatives 7. Further experiments for palladium-catalyzed hydrogenation with H2 at atmospheric pressure did not show any advantage over the transfer hydrogenation conditions. Overall, the described synthetic approach (Scheme 1 and Scheme 2) allowed us to prepare in an
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Published 23 Nov 2023

Active-metal template clipping synthesis of novel [2]rotaxanes

  • Cătălin C. Anghel,
  • Teodor A. Cucuiet,
  • Niculina D. Hădade and
  • Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

Graphical Abstract
  • [2]rotaxanes was further confirmed by MS2 experiments, i.e., isolation of the peaks corresponding to the [2]rotaxanes followed by collision-induced dissociation (CID) yielded the protonated molecular ions of the axle 6 and macrocycles M1 and M2, respectively (Figures S18 and S28 in Supporting
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Published 20 Nov 2023

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

Graphical Abstract
  • isolation allows to remove residual impurities that arose from long-time reflux of aminopyrazole 3 in triethyl orthoformate (see the Experimental section). According to the DFT B3LYP/6-311++G(d,p) calculations in DMSO solution, the polyunsaturated 14-membered ring in 5 is almost planar with a maximum atom
  • -pyrazolo[3,4-d]pyrimidin-5-amine (8) was developed. Under the optimized conditions (1.5 equiv of N2H4·H2O, MeOH, reflux, 3 h), the macrocycle 5 was obtained in a 35% isolated yield after crystallization. We believe that, despite the moderate yield of the macrocycle, the ease of its isolation and
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Published 15 Nov 2023

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

  • Xiaofeng Zhang,
  • Xiaoming Ma and
  • Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

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  • for 6 h to afford the monocycloaddition compounds. Without isolation, the reaction mixtures were then used for the N-propargylation in the presence of K2CO3 under microwave heating at 110 °C for 1 h to give triazolobenzodiazepines 21a–f in 35–65% yields with 2:1 to 7:1 dr (Scheme 13). Other than 2
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Perspective
Published 06 Nov 2023

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

Graphical Abstract
  • four known spiroketals – probreynin I (4) [13], phyllaemblic acid (5) [10], breynin B (6) [2], and epibreynin B (7) [2] – from the roots of B. disticha, a species that has not previously been chemically investigated (Figure 1). Herein, we describe the isolation and structural elucidation of new
  • expert botanist, Ms. Hiroko Murata (Setsunan University, retired). A voucher specimen (GPU-0812) has been deposited at the Gifu Pharmaceutical University for future reference. Extraction and isolation The dried roots (767 g) of B. disticha were extracted with MeOH (5 L × 3 times) at room temperature, and
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Published 19 Oct 2023

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

  • Bel Youssouf G. Mountessou,
  • Élodie Gisèle M. Anoumedem,
  • Blondelle M. Kemkuignou,
  • Yasmina Marin-Felix,
  • Frank Surup,
  • Marc Stadler and
  • Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

Graphical Abstract
  • chemical constituents of another new species of Diaporthe. This genus contains many plant pathogenic, endophytic, and saprobic species [7]. So far, the investigations of chemical constituents of Diaporthe species, have led to the isolation and characterization of a myriad of potent natural products with
  • takes preference over Phomopsis. Regarding the potent talents of Diaporthe, we are on the quest to the exploration of structure–activity relationships of cytochalasins to establish their trends for various medical applications [5]. Along the same lines, we herein report the isolation and structural
  • acetic acid (data not shown), we can exclude that it is an isolation artefact. The fifteen known compounds isolated from Diaporthe cameroonensis extract, which included alternariol (3) [14], 2-hydroxyalternariol (4) [15], 4-hydroxyalternariol (5) [16][17], 2,5-dimethyl-7-hydroxychromone (6) [18
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Published 13 Oct 2023

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

  • Jessica Villegas,
  • Bryce C. Ball,
  • Katelyn M. Shouse,
  • Caleb W. VanArragon,
  • Ashley N. Wasserman,
  • Hannah E. Bhakta,
  • Allen G. Oliver,
  • Danielle A. Orozco-Nunnelly and
  • Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

Graphical Abstract
  • tumor cytotoxicity effects for a number of the berberine derivatives. Keywords: benzylisoquinoline; berberine; chelerythrine; drug discovery; plant-derived antimicrobials; Introduction The isolation, or creation of novel antimicrobial agents is currently at the forefront of modern healthcare due to
  • these optimized conditions still resulted in exclusive isolation of B2 with no evidence of the product lacking the oxygen at position-13. Subsequent variants B7 and B8 were synthesized as the expected berberine derivatives, without formation of the oxidation byproduct. Of this initial set of berberine
  • cell lines. Conclusion Motivated by our prior isolation of three phytochemicals from the extracts of the Argemone mexicana plant, a library of structural variants of berberine and chelerythrine were prepared. Due to a greater synthetic ease, a larger number of berberine derivatives were explored. The
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Published 29 Sep 2023
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