Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles

• Kaylen D. Lathrum,
• Emily M. Hanneken,
• Katelyn R. Grzelak and
• James T. Fletcher

Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194

• sharing structural similarity regarding N center placement showed antimicrobial activity, as measured by minimum inhibitory concentration assays. MIC values of 2–16 μM towards Gram-positive bacteria Staphylococcus epidermidis and Bacillus subtilis and 8–16 μM towards Saccharomyces cerevisiae yeast were

Transformation of the cyclohexane ring to the cyclopentane fragment of biologically active compounds

• Natalya Akhmetdinova,
• Ilgiz Biktagirov and
• Liliya Kh. Faizullina

Beilstein J. Org. Chem. 2025, 21, 2416–2446, doi:10.3762/bjoc.21.185

• ) (Scheme 20). Indanes (benzocyclopentanes) and their derivatives are widely used in materials science and nanotechnology and have important biological properties such as anti-allergic, antitumor, anticonvulsive, antihypercholesteremic, herbicidal, fungicidal and antimicrobial activity [60]. In [58], a

An Fe(II)-catalyzed synthesis of spiro[indoline-3,2'-pyrrolidine] derivatives

• Elizaveta V. Gradova,
• Nikita A. Ozhegov,
• Roman O. Shcherbakov,
• Alexander G. Tkachenko,
• Larisa Y. Nesterova,
• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2025, 21, 2383–2388, doi:10.3762/bjoc.21.183

• -arylindoles with α,β-unsaturated ketones, followed by Fe(II)-catalyzed spirocyclization of readily accessible oxime acetates. The method exhibits a broad substrate scope and good functional group tolerance. The synthesized spirocyclic compounds showed no significant antimicrobial activity. Keywords: α,β

• synthesized spiro[indoline-3,2'-pyrrolidine] derivatives 4 were evaluated for antimicrobial activity via serial dilution assays across a concentration range of 0.5–1000 µg/mL. The minimum inhibitory concentration (MIC) and minimum bactericidal (fungicidal) concentration (MBC/MFC) against a diverse spectrum of

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• [14]. Massarilactones A and B were earlier shown to exhibit antimicrobial activity against Bacillus subtilis (ATCC 6051) and Staphylococcus aureus (ATCC 29213), affording zones of inhibition varying from 12 to 19 mm at 200 μg/disk [8], while massarilactone H displayed moderate cytotoxicity against

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

• Rita Toshe,
• Syeda J. Khalid,
• Blondelle Matio Kemkuignou,
• Esteban Charria-Girón,
• Paul Eckhardt,
• Birthe Sandargo,
• Kunlapat Nuchthien,
• J. Jennifer Luangsa-ard,
• Till Opatz,
• Hedda Schrey,
• Sherif S. Ebada and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

• potential cytotoxic molecules that might require further mechanistic investigation. In the antimicrobial activity assay (Table 2), farinosone B (3), beauvericins A (4) and B (5) were the most potent metabolites, especially against S. aureus and Bacillus subtilis with MIC values between 4.2 and 16.6 µg/mL

• . Intriguingly, farinosones D (1) and A (2) did not exhibit significant antimicrobial activity other than weak to moderate effects against S. aureus and B. subtilis. Therefore, 1 and 2 were selected as optimal candidates to assess their antibiofilm capacity against S. aureus. The results from biofilm assays

• with farinosones D (1) and A (2), microporenic acid A (MAA) as a positive control and methanol as a solvent control and taken as 100%. 1H and 13C NMR data of farinosone D (1). Cytotoxicity (IC50) and antimicrobial activity (MIC) of 1–6. Inhibition of biofilm formation of S. aureus by 1 and 2

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• for nutrient and space, and that “chemical weapons” of this sort are widespread in nature. Waksman used the BGF workflow to find more than 20 new antibiotics throughout his career, wherein microbial culture extracts were fractionated and then tested for antimicrobial activity. The active fractions

• would be fractionated further, tested again, and this process would be performed iteratively until a pure compound is obtained. Notably, BGF is not limited to the identification of metabolites with antimicrobial activity or those of bacterial origin. It is applicable to the screening of natural products

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

• , and 1.7 μM, respectively) [160], and further bacteria [164] and showed antimicrobial activity against Trypanosoma brucei rhodesiense, Leishmania donovani, and Plasmodium falciparum (IC50: 13.6, 7.5, 28.3 µM) [159]. It was cytotoxic against soybean cell cultures with an EC50 value of 0.63 µM [158] and

• sp. [172][180] and Rhizopycnis vagum [171]. Palmariol A and B showed weak antifungal activity against Mucor racemosus (8 mm inhibition zone at 20 μM/disc) and palmariol A was furthermore active against Bacillus subtilis (9 mm) [178]. Palmariol B was found to show a higher antimicrobial activity than

• could be confirmed by total syntheses [217][218]. Alterlactone showed antimicrobial activity against Bacillus subtilis (IC50 value of 41 µM) [210], Candida albicans, Trichophyton rubrum (MIC80: 17, 36 µg/mL) [211], Staphylococcus aureus (MIC: 31 µg/mL) [214], Trypanosoma brucei rhodesiense and

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

• Moisés Alejandro Alejo Hernandez,
• Katia Pamela Villavicencio Sánchez,
• Rosendo Sánchez Morales,
• Karla Georgina Hernández-Magro Gil,
• David Silverio Moreno-Gutiérrez,
• Eddie Guillermo Sanchez-Rueda,
• Yanet Teresa-Cruz,
• Brian Choi,
• Armando Hernández Garcia,
• Alba Romero-Rodríguez,
• Oscar Juárez,
• Siseth Martínez-Caballero,
• Mario Figueroa and
• Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

• of the purified lanthipeptide were confirmed by MS–MS/MS analysis for cellulosin, while clostrisin was not post-translationally modified. Both peptides demonstrated antimicrobial activity against multidrug-resistant bacteria, such as a clinical strain of Staphylococcus epidermidis MIQ43 and

• lanthipeptide synthetases exhibit antimicrobial activity against various pathogens, including drug-resistant strains [23][24]. These molecules are relevant as they have strong antibiotic effects against pathogenic bacteria such as Staphylococcus aureus, Enterococcus sp., Clostridioides difficile, and

• Information File 1). Moreover, findings from the MS2 experiment on the fragment with 5 net dehydrations suggested one internal tryptic cleavage between G41 and the C-terminus, with K48 as the likely cleavage site if C64 is macrocyclized (Figure S3, Supporting Information File 1). Antimicrobial activity of

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• -17, the crude extract of which demonstrated modest antimicrobial activity against several Gram-positive bacteria, molds, and yeasts [6]. The study further characterized another 23 Microbulbifer bacteria derived from different marine sources. Although they were able to produce 4HBA in lower amounts

• -695 showed antimicrobial activity against E. coli [14]. Bioassay-guided fractionation led to the isolation of two new acetamidobenzoate esters: bulbiferate A (13) and bulbiferate B (14, Figure 6). Their structures were established on the basis of comprehensive spectroscopic and spectrometric data

• synthesized and tested for antimicrobial activity. However, no clear trend was found between the ester length and bioactivity. In addition to the paraben derivatives, three known nucleosides, 4´,5´-didehydro-5´-deoxyinosine (18), 2´-O-methyladenosine (19), and 5´-methylthioinosine (20) were also identified

Chemoenzymatic synthesis of macrocyclic peptides and polyketides via thioesterase-catalyzed macrocyclization

• Senze Qiao,
• Zhongyu Cheng and
• Fuzhuo Li

Beilstein J. Org. Chem. 2024, 20, 721–733, doi:10.3762/bjoc.20.66

• brevis [27], can penetrate the lipid phase of a Gram-positive inner cell membrane [28][29]. Despite exhibiting high antimicrobial activity, this compound also disrupts the membranes of higher mammalian cells, as evidenced by their pronounced hemolytic activity [30]. Establishing a concise and diverse

New variochelins from soil-isolated Variovorax sp. H002

• Jabal Rahmat Haedar,
• Aya Yoshimura and
• Toshiyuki Wakimoto

Beilstein J. Org. Chem. 2024, 20, 692–700, doi:10.3762/bjoc.20.63

• : antimicrobial activity; siderophore; variochelin; Variovorax; Introduction Almost all organisms require iron as a crucial cofactor of enzymes essential for their physiological functions, encompassing primary and secondary metabolisms [1]. However, in an aerobic environment, iron predominantly exists in the

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

• −1; for 1H NMR (CDCl3, 600 MHz) and 13C NMR (CDCl3, 125 MHz) spectral data, see Table 1; LC–MS (m/z): [M − H]− calcd for 283.2; found, 283.2. Antimicrobial activity evaluation All isolated compounds were dissolved in 1% DMSO and introduced to pathogenic bacteria or fungi in LB or PDB media. The 96

• structure of compound 1. 1H and 13C data of compound 1 (recorded in CDCl3). 1H and 13C NMR data of compound 2 (recorded in CDCl3). 1H and 13C NMR data of compound 3 (recorded in CDCl3). Antimicrobial activity of compounds 1–12. Minimum inhibitory concentrations were shown in µg/mL. Biosynthetic gene

A myo-inositol dehydrogenase involved in aminocyclitol biosynthesis of hygromycin A

• Michael O. Akintubosun and
• Melanie A. Higgins

Beilstein J. Org. Chem. 2024, 20, 589–596, doi:10.3762/bjoc.20.51

• essential for in vivo antimicrobial activity suggesting a distinct biological function independent of ribosome binding. The hygromycin A biosynthetic gene cluster has been identified and the biosynthesis of the aminocyclitol has been proposed (Figure 1) [8][9]. Starting from glucose-6-phosphate, the pathway

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

• the presence of a new compound designated KR21-0001A (1). The structure was elucidated by NMR, and the absolute stereochemistry was determined by advanced Marfey’s method. The results indicated that 1 is a new analog of dihydroxybenzoic acid. 1 has no antimicrobial activity against bacteria and fungi

• ). Antioxidant activity of 1 was measured via the DPPH radical. 1 showed potent DPPH radical scavenging activity with an IC50 value of 5.0 μg·mL−1, which is lower than that of trolox (IC50; 7.5 μg·mL−1) (Table 2). In contrast, 1 did not show antimicrobial activity against Gram-positive and Gram-negative bacteria

• [16]. KR21-0001A (1) is a new analog of 2,3-DHBA connected to N-acetylcysteine (Figure 2b). 1 has a stronger antioxidant activity than trolox, which is a water-soluble analog of the free radical scavenger α-tocopherol [17][18]. 1 shows no antimicrobial activity against bacteria and fungi. Conclusion

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

• -spectrum inhibitory activities against several plant pathogens with MIC values ranging from 2 to 16 μg/mL. Keywords: antimicrobial activity; cold seep; Pseudallescheria boydii; sesquiterpenoid; Introduction Marine cold seeps are typical of chemosynthetically driven ecosystems, characterized by methane

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

• -quinolone-3-carboxamides 5a–i and some of their N-hydroxy derivatives 4a–e. Compounds of this type with C-2 substitution other than methyl [71] have not been previously described. All of the obtained products were screened for antimicrobial activity at a concentration of 1 mg/mL against S. aureus and E

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• organic light-emitting diodes (OLEDs) [9][10][11]. Moreover, studies involving N-acylhydrazonic derivatives have highlighted their suitability for the treatment of pathologies associated with infection and/or inflammation [12][13][14][15][16][17]. Antimicrobial activity is one of the most frequently

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

• isolated from Streptomyces [30] and whose antimicrobial activity is probably related to the glutarimide moiety. In compound 1, the lack of this moiety, in addition to the fact that it has been isolated as a racemate could not lead to any beneficial property. As for compound 2, it is a diacetylated

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

• these compounds have been reported before, they were still of interest, as neither compound has been thoroughly assessed for its antimicrobial activity. Our initial pool of berberine variants was screened against 12 microbial organisms (five Gram-positive and four Gram-negative bacteria, and three fungi

• complicated by both berberine and chelerythrine having multiple pathways associated with their antimicrobial activity [11][12][13][14][15][16][17][18][24]. In an effort to better understand the differences seen with our variants, we chose to focus on their effects on leakage of intercellular proteins, as

• , though it may be partially responsible for why variant B14 was significantly more potent. Having preliminarily explored the antimicrobial activity of these variants, we next turned to investigating their effects on tumor cells, given our previous research had identified antitumor properties for the crude

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• ). The structures of the isolated compounds were established based on HRESIMS and extensive 1D and 2D NMR experiments. All the isolated compounds were assessed for their antimicrobial and cytotoxic activities. Among the tested compounds, forpinioside B (1) exhibited significant antimicrobial activity

• against Staphylococcus aureus and Bacillus subtilis at MIC values comparable to gentamycin and oxytetracycline (positive controls), respectively. Keywords: antimicrobial activity; Fomitopsis carnea; lanostane glycosides; Polyporales; Introduction Great success was realized on antibiotic discovery

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

• chromatography on silica gel to yield several fractions. Some of them were tested and the ones that exhibited antimicrobial activity were further fractionated on silica gel chromatographic column eluted with hexane and acetone (8:2) to yield four different fractions. The fractions comprised 11-O

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• detected by in vitro testings, which further raised the expectation of its richness as the source of bioactive metabolites. However, at present, only a single drug discovery attempt has been made on this alga [13], which prompted further chemical study. We evaluated the antimicrobial activity of the

• (3b). 1H (500 MHz) and 13C (125 MHz) NMR data for nostochopcerol (1) in CD3OH (δ in ppm). Antimicrobial activity of nostochopcerol (1) and synthetic analogs. Supporting Information Supporting information features procedures for synthesis of chiral α-linoleoyl glycerols, physicochemical properties of