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

• avicennae [18]. Inhibition of hepatitis C virus replication by 2-nonyl-4-quinolone, isolated from Ruta angustifolia leaves, has also been reported [19]. Another significant group of natural 4-quinolones are those of microbial origin. The function of these compounds in the microbial world is a matter of

• . Among the novel compounds, only compounds 4d and 4e gave inhibition zones of more than 20 mm and were further analyzed to determine their minimum inhibitory concentrations (MIC) by serial broth dilutions [72]. The MICs measured for 4d and 4e were ≤6.25 µg/mL and ≤3.12 µg/mL, respectively, with a MIC

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

• Stéphanie Hesse

Beilstein J. Org. Chem. 2023, 19, 1537–1544, doi:10.3762/bjoc.19.110

• with an OH group at position 2 and a methoxy substituent at position 5 was slightly more potent with 41.6% inhibition. Compounds without a OH group (like 3f–h) presented as expected a weak scavenging activity. Conclusion 5-Arylidenerhodanines were successfully synthesized in an ʟ-proline-based deep

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

• often attributed to high binding affinity to DNA, interference with protein biosynthesis, induction of membrane leakage, and affecting GTPase activity in bacteria cell division [12][13][14][15]. Recent reports have also pointed to inhibition of the ‘filamenting temperature-sensitive mutant Z’ (FtsZ

• ]. Similar to berberine, results have demonstrated that the antibacterial activity of chelerythrine can be tied to DNA intercalation and disruption to cell membrane permeability [11][24]. One particular mechanism of action noted for chelerythrine’s antitumor bioactivity is through the inhibition of protein

• inhibition in millimeters. An overall summary of the various plant extracts against the complete set of 12 microbes is displayed in Figure 1. Our synthetic work began with the construction of the berberine derivatives. Several synthetic routes to berberine have been reported [28][30][33][34], but by far the

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• inhibition [8], anti-inflammatory [10], antiasthmatic [11], antidiabetic [12], and antioxidant [13] activities, have been reported for agarwood extracts [14][15]. Our group recently reported five structurally intriguing and biologically active sesquiterpene dimers [16], which attracted our interest to gain

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

• ). The filter paper method was used to determine the inhibition zone diameters, which are reported in Supporting Information File 1, Table S1. It turned out that the compounds possess only modest inhibitory activities against B. subtilis. These results are consistent with previous studies [22][23

• being tested were dissolved in methanol at a concentration of 50 µg/10 µL. Each compound was impregnated onto filter papers at a volume of 10 µL per disc. The inoculated plates were then incubated at 30 °C for 48 hours. The antibacterial activity was evaluated by measuring the zone of inhibition against

Synthesis of imidazo[1,2-a]pyridine-containing peptidomimetics by tandem of Groebke–Blackburn–Bienaymé and Ugi reactions

• Oleksandr V. Kolomiiets,
• Alexander V. Tsygankov,
• Maryna N. Kornet,
• Aleksander A. Brazhko,
• Vladimir I. Musatov and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2023, 19, 727–735, doi:10.3762/bjoc.19.53

• structures containing a substituted imidazo[1,2-a]pyridine fragment, such as anticancer [5], antibacterial [6], antifungal [7], antiviral [8], anti-inflammatory [9], antimalarial [10], antiparkinsonian [11] and antituberculous activities [12]. In addition, some derivatives show enzyme inhibition [13] and can

Synthesis of medium and large phostams, phostones, and phostines

• Jiaxi Xu

Beilstein J. Org. Chem. 2023, 19, 687–699, doi:10.3762/bjoc.19.50

• efficient inhibitors of matrix metalloproteinases MMP-1, MMP-3, and MMP-9 with IC50 values varied from 5.0 nM to 10.0 μM. They are more efficient against MMP-3 and MMP-9 than against MMP-1. Phostams 5 and 6 show higher inhibition activities than 9 and 10 [23]. RCM is also an efficient strategy for the

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

• common metabolic disease that affects how the body uses blood glucose. In 2021, 537 million patients suffered from diabetes worldwide, and the number is feared to increase to 783 million in 2045 [1]. Type 2 diabetes account for the majority of the cases [2]. Currently, inhibition of α-glucosidase, the

• percent inhibition of activity was calculated as (A0 − A1)/A0 × 100, where A0 is the absorbance of control, and A1 is the absorbance with the sample. Acarbose was used as a standard drug and all experiments were evaluated in triplicate. Chemical structures of 1-3 isolated from P. macropterum. Key 1H,1H

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

• structures. As shown in Figure 7b, the emission of all CS-TPE in a solution at pH 5.3 was enhanced after the addition of the host TBTQ-C6. This effect can be attributed to the further inhibition of the intramolecular rotation of the phenyl rings of TPE after binding with the host molecule [31]. The

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

• first reported example of the application of fluorinated aminophosphonates in cathepsin C inhibition studies. The new molecules show moderate inhibition of the cathepsin C enzyme, which opens the door to consider them as potential therapeutic agents. Overall, our findings provide a new avenue for the

• in chemotherapies to support traditional anticancer drugs. Moreover, there is a growing interest in the topic of cathepsin C inhibition, which directly affects serine protease activity [5][6]. Inhibitors of cathepsin C can be cystatins that show activity against a large group of cysteine proteases [7

• to the corresponding phosphonic acids or their salts is often a necessary step to measure activity in enzyme inhibition bioassays [16][17][18][19][20][21][22]. Therefore, our goal was to determine the best conditions for carrying out the solvolysis reaction of synthesized dipeptide analogues of

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• characterized as an oxa[1.7]meta-paracyclophane framework. In the literature we can find reports about the isolation/synthesis of combretastatins D and their analogues which showed different biological activities, e.g., antineoplastic, anti-inflammatory, and α-glucosidase inhibition [13][14][15]. The presence

• ]. However, when tested against the murine P388 lymphocytic leukemia cell line, salts 184–187 did not show enhanced inhibition of the cancer cell line growth compared to combretastatin D-2 (2) or the methylated congener 28. Moreover, for structure–activity relationship studies, combretastatin D-4 (4) proved

• to be inactive indicating that the olefin was necessary for cancer cell growth inhibition. For salts 184–187, the authors attributed the decrease in the activity to the lack of phosphatases necessary for the cleavage of the prodrug ester bond and needed to regenerate the drug in the isolated cancer

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

• is no interference from the enzyme or from the solution in which the enzyme may be situated. 3.9. Definition and establishment of chemical equilibrium Loss of enzyme activity due to product inhibition and thermal instability can lead to a failure to achieve equilibrium and consequently large

• and kcat,rev are the catalytic rate constants for the forward and reverse reactions, respectively. The use of Equation 10 requires a knowledge of the Michaelis constants KM and KP (also called the product inhibition constant), kcat,for, kcat,rev, and [enzyme]. Since this information is often not

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

• inhibitor:enzyme complexes were analyzed by molecular modeling. Keywords: glycosidase inhibitor; Golgi mannosidase II; iminosugar; inhibition; molecular modeling; Introduction Iminosugars are analogs of monosaccharides in which the endocyclic oxygen atom is replaced with a nitrogen atom [1][2][3][4][5]. These

• modifications are possible and many of these compounds inhibit glycoprocessing enzymes [11][12][13][14]. One of the best known iminosugars is the natural alkaloid (−)-swainsonine, which is a nanomolar inhibitor of human Golgi α-mannosidase II (GMII, GH38 family, E.C.3.2.1.114). Although such inhibition has been

• found to suppress metastasis, the potentially positive effect of swainsonine on cancer patients is strongly reduced by its severe side effects [15][16]. These are associated with the accumulation of oligomannoside structures in tissues, serum, and urine, which is caused by the co-inhibition of lysosomal

Strategies to access the [5-8] bicyclic core encountered in the sesquiterpene, diterpene and sesterterpene series

• Cécile Alleman,
• Charlène Gadais,
• Laurent Legentil and
• François-Hugues Porée

Beilstein J. Org. Chem. 2023, 19, 245–281, doi:10.3762/bjoc.19.23

• commercial cyclopentenone 69. Protection of the alcohol function was mandatory prior to the cyclization as the free alcohol substrate failed to cyclize. As proposed by the authors, interaction between the free alcohol 70 and the molybdenum metal center may explain the reaction inhibition. Thus, after

An accelerated Rauhut–Currier dimerization enabled the synthesis of (±)-incarvilleatone and anticancer studies

• Tharun K. Kotammagari,
• Sweta Misra,
• Sayantan Paul,
• Sunita Kunte,
• Rajesh G. Gonnade,
• Manas K. Santra and
• Asish K. Bhattacharya

Beilstein J. Org. Chem. 2023, 19, 204–211, doi:10.3762/bjoc.19.19

• on the growth of the breast cancer cell line MCF7. For instance, we did not observe the 50% growth inhibition event at 100 µM. In contrast, 5-fluorouracil potently inhibited the growth of MCF7 cells with 50% growth inhibition at 7.1 ± 0.62 µM (Figure 2). Conclusion In summary, we have successfully

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• -C6 nanoparticle formulation decreased upon incubation. Based on previous studies with breast cancer cell lines, it is comprehensible that anionic nanoparticles induce cell proliferation inhibition earlier than polycationic nanoparticles. The impact of anionic nanoparticles on free cholesterol level

Synthesis and characterisation of new antimalarial fluorinated triazolopyrazine compounds

• Kah Yean Lum,
• Jonathan M. White,
• Daniel J. G. Johnson,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2023, 19, 107–114, doi:10.3762/bjoc.19.11

• ][8][9]. Interfering with this process means the parasite is unable to regulate Na+ [10], resulting in a significant increase in the acid load of the cell, which can lead to parasite growth inhibition and ultimately parasite death [8][9]. One of the current Series 4 aims includes lead optimisation to

Combining the best of both worlds: radical-based divergent total synthesis

• Kyriaki Gennaiou,
• Antonios Kelesidis,
• Maria Kourgiantaki and
• Alexandros L. Zografos

Beilstein J. Org. Chem. 2023, 19, 1–26, doi:10.3762/bjoc.19.1

• properties, such as potent inhibition of 11-β-hydroxysteroid dehydrogenase type I and inhibition of Candida albicans [48]. Although earlier syntheses have been reported recently for magninoids [50][51], Lou’s group envisioned a divergent plan based on a late-stage bioinspired semipinacol rearrangement

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• ]-pyrimidines) [7][8][9] have been in the center of attention and were found to be effective compounds for the inhibition of various molecular targets associated with dysfunction of the central nervous system (e.g., as GABA and serotonin receptor modulators, or as inhibitors of phosphodiesterase PDE10A

• nucleosides thereof [10][11][12], mostly associated with the inhibition of adenosine deaminase (ADA) [11] and as adenosine receptor antagonists [10]. Another important field of applications for deaza-modified nucleobases is their use in atom-specific mutagenesis experiments. For example, site specific 1-, 3

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

• (6), hexadellin A (9) and bastadin 4 (5) showed inhibition towards larval motility after 72 h of exposure with IC50 values of 1.6 µM, 10.0 µM and 33.3 µM, respectively. Keywords: alkaloid; anthelmintic; biodiscovery; bromotyrosine; 5-debromopurealidin H; Ianthella; NatureBank; sponge; Introduction

• ), 8 (6) and 13 (7), aerothionin (8) and hexadellin A (9). The extraction and isolation of these known compounds has been previously reported elsewhere [11][28][29][30] Compounds 1−9 were assessed for their activities and potencies in a dose-response assay by measuring the inhibition level on larval

• motility after 72 h of exposure (Figure 5). Compound 6 was the most potent compound at inhibiting exsheathed third-stage larvae (xL3) motility after 72 h, with an IC50 value of 1.6 ± 0.4 µM (65.2 ± 4.7% inhibition at 100 µM). Two other compounds showed relatively high potency: compounds 9 (IC50 = 10.0

New triazole-substituted triterpene derivatives exhibiting anti-RSV activity: synthesis, biological evaluation, and molecular modeling

• Elenilson F. da Silva,
• Krist Helen Antunes Fernandes,
• Denise Diedrich,
• Jessica Gotardi,
• Marcia Silvana Freire Franco,
• Carlos Henrique Tomich de Paula da Silva,
• Ana Paula Duarte de Souza and
• Simone Cristina Baggio Gnoatto

Beilstein J. Org. Chem. 2022, 18, 1524–1531, doi:10.3762/bjoc.18.161

• , Figure 1), is one of the few licensed drugs for treating RSV infections [8][9]. Although there are many suggested mechanisms of action, the main mechanisms for RBV involve the inhibition of the enzymes RNA-dependent RNA polymerase and inosine monophosphate dehydrogenase (IMPDH). IMPDH is required for the

• ) acids (Figure 1) have demonstrated various antiviral activities, such as by HIV protease inhibition (IC50 = 8 and 9 μM) [22]. In addition, compound 1 has demonstrated some anti-SARS-CoV activity (EC50 = 10 μM; SI = >10) by having an inhibitory effect on the 3CL protease function [21][23]. Moreover

• ). One of the main known mechanisms of action of RBV is the depletion of intracellular GTP pools via the inhibition of cellular IMPDH induced by the 5-monophosphate metabolite of RBV [44]. Thus, our finding based on these results is that compound 8 may act similarly to IMPDH inhibitors and the active

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

• Arisu Koyanagi,
• Yuki Murata,
• Shiori Hayakawa,
• Mio Matsumura and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

• corresponding 2-phenylbenzothiazole (9) was isolated in 93% yield. Tafamidis (13), a compound with a 2-arylbenzoxazole skeleton is a clinically used drug for transthyretin amyloid inhibition [38][39], and was first synthesized by Kelly et al. [40]. We synthesized compound 13 by the developed

• , and achieved the syntheses of 2-aryl- and 2-alkylbenzazoles, such as oxazoles, imidazoles, and thiazole, in satisfactory yields. The protocol was successfully applied to the synthesis of tafamidis, a clinically used drug for transthyretin amyloid inhibition. The reaction is simple, can be performed in

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

• the formation of ApppI, i.e., the isopentenyl ester of ATP (Figure 2), which may also isomerize to ApppD (Figure 2). The authors have also concluded that these compounds can act in two different ways: inhibition of the mevalonate pathway and blockade of mitochondrial ADP/ATP translocase, which is