Recent total synthesis of natural products leveraging a strategy of enamide cyclization

• Chun-Yu Mi,
• Jia-Yuan Zhai and
• Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

• notable example is (−)-cephalocyclidin A, a cytotoxic pentacyclic cephalotaxus alkaloid [33][34]. Although the molecular structure contains a benzo-bridge ring system, disconnection of this bridge reveals a critical tricyclic N-heterocycle. To efficiently synthesize this tricycle, polycyclization of

Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• , combining the specificity of antibodies with the potency of cytotoxic drugs to enhance therapeutic efficacy while minimizing off-target effects. The development of new chemical methods for bioconjugation is essential to generate ADCs and to optimize their stability, efficacy, and safety. Traditional

• designed in the context of cancer therapy [1], which combines the precision targeting of monoclonal antibodies (mAbs) with the therapeutic effects of cytotoxic drugs [2]. The ADCs are thus designed to deliver potent cytotoxic agents selectively and directly to cancer cells while minimizing damage to

• healthy tissues, reducing side effects compared to traditional chemotherapy. Enhanced potency: By delivering cytotoxic payloads directly to tumor or other target cells, ADCs achieve higher drug concentrations at the site of action. This potency enhances therapeutic efficacy. Treatment of refractory

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

• methacryloyl chloride, cinnamoyl chloride, 4-bromobenzoyl chloride, trans-2-methyl-2-butenoyl chloride, and crotonyl chloride. These compounds were evaluated for their cytotoxic activity against the murine fibroblasts L929, human cervix carcinoma KB-3-1, human lung carcinoma A549, human prostate cancer PC-3

• nematicidal activity with LD90 and LD50 of 100 and 12.5 µg/mL, respectively. Since the parent compound was not active, the present study supports the fact that the acylation reaction can improve bioactivities of some natural products. Keywords: acylation reaction; cytotoxic activity; massarilactone D

• ; nematicidal activity; Introduction Cancer continues to be responsible for morbidity and mortality all over the world. Endophytic fungi have been shown to be an important source of secondary metabolites endowed with interesting cytotoxic activities. However, resistance to cancer therapies is a persistent

Cryptophycin unit B analogues

• Thomas Schachtsiek,
• Jona Voss,
• Maren Hamsen,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

• University, Universitätsstraße 25, 33615 Bielefeld, Germany 10.3762/bjoc.21.40 Abstract Drug conjugates using toxic payloads are a promising approach for selectively combating cancer while sparing healthy tissue. The lack of highly cytotoxic and at the same time selective therapeutics against cancer is an

• cryptophycin-1, failed in clinical studies as a cytotoxic drug on its own due to severe side effects [4]. However, the embedment of cryptophycins as payloads in drug conjugates, increases specificity and minimises adverse effects [5][6]. Drug conjugates usually consist of three units, where the payload is

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• -(1,1-Dimethyl-1H-benzo[e]indolin-2-yl)-5,6,7-trichloro-1,3-tropolone exhibited high in vitro cytotoxic activity against A431 skin cancer and H1299 lung cancer cell lines. Keywords: cytotoxic activity; fluorescence; o-chloranil; quantum chemical DFT calculations; 1,3-tropolones; X-ray diffraction

• antibacterial [4] and cytotoxic activity [6][7]. Existing approaches to the synthesis of 1,3-tropolone derivatives have a number of drawbacks, namely, limited synthesis methodology and low yields of the target compounds [8][9][10][11][12][13][14][15]. Over the past decade, only a few reports have been published

• properties towards CN− and Hg2+ ions and evaluation of in vitro cytotoxic activity against A431 skin cancer and H1299 lung cancer cell lines. Results and Discussion We found that boiling of equimolar amounts of benzannelated 2,3,3-trimethylindolenines 2a,b and o-chloranil (3) (method A) in dioxane leads to

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• results showed that out of fourteen synthesized compounds, 7b (MIC90 = 16 μg/mL) and 7h (MIC90 = 8.0 μg/mL) exhibited potent antibiotic activity against different strains of S. aureus (susceptible, methicillin-resistant, and multidrug-resistant). Cytotoxic studies against the human colon cancer mammalian

• were evaluated for their antimicrobial, cytotoxic, and human carbonic anhydrase (hCA) inhibition potential. Results and Discussion Chemistry The targeted compounds were synthesized using the general scheme shown in Scheme 1. The ester group was introduced at the nitrogen of saccharine sodium (1) using

• experiments. Cytotoxic assays Single-dose MTT assays were performed for compounds 7a–n with the human colon cancer mammalian cell line (HCT-116, ATCC CCL-247) for evaluating the compounds’ inhibitory effects on cell viability [53][54][55][56]. Stock solutions of compounds were prepared in DMSO and cancer

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

• derivative, farinosone D (1), along with the known 2-pyridones, farinosones A (2) and B (3), and the known cyclodepsipeptides beauvericins A–C (4–6). All isolated compounds were assessed for their antimicrobial and cytotoxic activities while farinosones D (1) and A (2) were selected for biofilm inhibitory

• activity assay. Farinosone B (3) and beauvericins A–C (4–6) showed significant cytotoxic activities with IC50 values in the low micromolar to nanomolar range against several mammalian cell lines. On the other hand, farinosone A (2), which lacked potent cytotoxic effects, revealed potent antibiofilm

• the first 2-pyridone derivative, farinosone A (2) that through N-hydroxylation would reveal farinosone B (3). Biological evaluation All the isolated compounds were assessed for their cytotoxic activity against a panel of seven different cancer cell lines. The results (Table 2) revealed that farinosone

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

• Shin-ichiro Kurimoto,
• Kouta Inoue,
• Taito Ohno and
• Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

• ceratinadin G (1) was evaluated against L1210 murine leukemia cells and KB epidermoid carcinoma cells. Ceratinadin G (1) showed moderate cytotoxic activity against L1210 cells (IC50 = 4.7 μM) and KB cells (IC50 = 15.1 μM). Conclusion Ceratinadin G (1) is the first psammaplysin derivative identified to contain

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• cytotoxic compounds. For example, a cytotoxic effect was found in CAL 27 cells, presumably through a mechanism of TNF-α inhibition in vitro, which could be related to the anti-inflammatory effect identified in several studies of NSAIDs that inhibit cancer cell viability in vitro [37][38]. In another study

• aimed at inhibiting tubulin assembly, N-mesyl-2-(1-phenylvinyl)indoles were active against HCT-116 cells on the order of a GI50 of 10 mM, although the mechanism originally sought was not demonstrated [39]. Therefore, in this work, the cytotoxic activity of methanesulfonylindoles 18a–j was explored

• relevant for the cytotoxic activity. The 1,5-disubstituted tetrazole-1,2,3-triazole hybrids synthesized by our group [26] had similar effects to the present compounds, suggesting that 1,5-disubstituted tetrazole and indole are pharmacophoric fragments with significant biological and pharmacological

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• cytotoxic activity against melanoma and squamous cell carcinoma cells, lung cancer and glioblastoma cells [30]. It was shown in a WST-1 assay that these compounds exhibit a concentration-dependent inhibition of the metabolic activity of A375 and A431 cells, while the non-glycosylated derivative 34 proved to

• mitochondria was changed. The presence of β-33b provoked a significant upregulation of the enzyme heme oxygenase-1. In conclusion, mitochondria are attacked by compound β-33b in the context of its cytotoxic activity against skin cancer cells. Aglycon 35 again proved to be inactive in all assays. It was

• deprotection with NaOMe afforded β-81a in 98% yield. Likewise, rhamnosides β-81b,c mannosides β-81d–f, and glucoside β-80g were obtained in good yields. Some products exhibited weak cytotoxic activity against human ceratinocytes (HaCaT). However, in contrast to many indirubin-N-glycosides and their analogues

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• polysubstituted hydrogenated heterocyclic structures on their basis [25][26][27][28], including an acetanilide fragment. The introduction of this fragment into a molecule, often drugs, enhances the cytotoxic, antibacterial, and antiviral activity of the compounds, thus widening the range of their potential

• include the use of immunosuppressive and cytotoxic drugs, broad-spectrum antibiotic therapy, pre-existing illnesses such as AIDS or diabetes, and the use of central venous catheters, urethral catheters, and implantable medical devices [42]. The mainstay of therapy for these infections is the use of broad

Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

• Battini Veeraiah,
• Kishore Ramineni,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Hélène Solhi,
• Rémy Le Guevel,
• Chada Raji Reddy,
• Frédéric Justaud and
• René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

• describe a short and efficient synthesis for this type of novel skeleton and to prepare a focused library for these targets C. Further, we will report results on their cytotoxic activities. Results and Discussion Chemical synthesis For the preparation of our targets, we selected a flexible strategy which

• ). Cells are grown at 37 °C, 5% CO2 in ATCC recommended media: DMEM for HuH-7, MDA-MB-231, MDA-MB-468 and fibroblast, EMEM for MCF7 and CaCo-2, McCoy’s for HCT-116 and RPMI for PC3 and NCI-H727. All culture media are supplemented by 10% of FBS, 1% of penicillin-streptomycin and 2 mM glutamine. Cytotoxic

• desired targets 4. Cytotoxic studies (IC50 determination) of selected quinazolines 4.a Supporting Information Supporting Information File 2: Supplementary Table S1; spectral and analytical data for compounds 4b–s as well as all copies of 1H and 13C NMR spectra of compounds 4. Acknowledgements We thank

Cell-free protein synthesis with technical additives – expanding the parameter space of in vitro gene expression

• Tabea Bartsch,
• Stephan Lütz and
• Katrin Rosenthal

Beilstein J. Org. Chem. 2024, 20, 2242–2253, doi:10.3762/bjoc.20.192

• . CFPS show a high robustness against various additives including cytotoxic solvents, which was demonstrated by the synthesis of sfGFP and thscGAS-sfGFP. The combination of CFPS with activity assays would allow further parallelization and also miniaturization, for example into femtoliter-sized droplets

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

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

• V79 cells and in mouse lymphoma cells even at non-toxic or moderately cytotoxic concentrations [84]. AOH was further shown to cause strand-breaking in mammalian cell lines V79, HepG2, and HT-29 [85][86][87]. It was a significant finding by Marko et al. that AOH acts as a topoisomerase poison

• the detrimental effects of AOH [94][95][96]. AOH furthermore activated the nuclear translocation of the aryl hydrocarbon receptor (AhR) and the nuclear factor erythroid 2-related factor 2 (Nrf2) [97]. The possible anticancer effects of AOH through its cytotoxic, antiinflammatory, genotoxic, mutagenic

• has been investigated thoroughly on its biological activities, especially on its toxicity [6][12]. Its phytotoxicity has already been noted in the first reports; it induced chlorosis when injected to the leaves of tobacco plants [110]. It turned out to be cytotoxic against HeLa and lymphoma L5178Y

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• , product 17a shows cytotoxic activity against Hep G2 hepatocellular carcinoma and MCF-7 breast carcinoma cell lines. The synthesis of 3,5-bis(arylamino)pyrazoles 21 involves the preparation of bisarylthioamides 22 via nucleophilic addition and double retro-Claisen condensation of isothiocyanates 19 and

Allostreptopyrroles A–E, β-alkylpyrrole derivatives from an actinomycete Allostreptomyces sp. RD068384

• Marwa Elsbaey,
• Naoya Oku,
• Mohamed S. A. Abdel-Mottaleb and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2024, 20, 1981–1987, doi:10.3762/bjoc.20.174

• : Allostreptomyces; β-alkylpyrrole; conformer; cytotoxic; DFT; 4-formylpyrrole-2-carboxylic acid; Introduction β-Alkylpyrroles are key structural motifs in biomolecules and functional organic materials [1]. For instance, β-alkylpyrroles are the main building blocks for the life-essential tetrapyrrole pigments

Solvent-dependent chemoselective synthesis of different isoquinolinones mediated by the hypervalent iodine(III) reagent PISA

• Ze-Nan Hu,
• Yan-Hui Wang,
• Jia-Bing Wu,
• Ze Chen,
• Dou Hong and
• Chi Zhang

Beilstein J. Org. Chem. 2024, 20, 1914–1921, doi:10.3762/bjoc.20.167

• activity and thus block cancer formation [2]. Alangiumkaloids A, an isoquinolinone alkaloid isolated from Alangium salviiforlium, was reported to exhibit cytotoxic activity against cancer cells [3]. In 2018, duvelisib, a dual inhibitor of phosphoinositide-3 kinases, was firstly approved by the FDA for the

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

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• piperazinoquinazoline derivatives, a core found in fungal metabolites [25][26], systems with promising antitumour activity [27], as well as dipyrrolopiperazinone derivatives, substructure found in some alkaloids such as dibromophakellin or the palau’amine [28], which possess immunosuppressive and cytotoxic properties

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• on androgen-sensitive Shionogi cells, with weak binding to the androgen receptor detected. This suggests that the antiproliferative property may be attributed to antiandrogenic and cytotoxic activities. Moreover, the spiro derivatives did not show affinity to other steroid receptors, indicating a

• their antiproliferative activity against a panel of cancer cells, in which the activity of some compounds was close to that of cis-platinum in some cell lines. It should be noted that N-propylamide derivatives showed low cytotoxicity on cancer cells. Additionally, 167c did not present cytotoxic activity

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• proteusin family of RiPPs. They are produced by the tunicate symbiont Candidatus Entotheonella factor and exhibit membrane activity against Gram-positive bacteria and are highly cytotoxic. Cytotoxicity was tested with murine leukaemia cells; polytheonamide A, B, and C showed IC50 values between 68 and 78 pg

• member of the channel-forming, cytotoxic proteusins. It is biosynthesised by Microvirgula aerodenitrificans. Like polytheonamide B, aeronamide A shows cytotoxic activity against HeLa cells, with an IC50 of 1.48 nM. AerE, the PoyE homologue, installs five methylations on the amides of Asn25, Asn31, Asn37

• towards the C-terminus, named "axial amphipathicity". Thus, this methylation is thought to play an important role in correct target membrane insertion and the associated cytotoxic effect [125]. TsrM is another cob(II)alamin-dependent C-MT (Figure 10). This enzyme is involved in the biosynthesis of

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• bioactivities including analgesic, sedative, and cytotoxic [12][13][14]. In order to identify new potential burpitides, we searched the NCBI Sequence Read Archive (SRA) for Streptophyta (all land plants and most green algae) transcriptomes that could be assembled and examined with a custom hidden Markov model

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• ITC showed Kd values in the micromolar range with significant thermodynamic differences between E- and Z-azobenzene isomers, demonstrating the proof-of-concept of photomodulation of the ligand–lectin interactions. Results and Discussion Design of LecA photoswitchable ligands The cytotoxic LecA which

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• -inflammatory [6], antiviral [7], antibacterial [8], antifungal [9], cytotoxic [10], antioxidant [11], and analgesic [12] activities. For instance, celecoxib (I, Figure 1) (for treating rheumatoid arthritis and osteoarthritis), tepoxalin (II, Figure 1) (a veterinary painkiller used to relieve pain from muscle

• -ranging biological activities. Specifically, representative examples include fasicularin (IV, Figure 1), which possesses cytotoxic properties [21] and psammaplin B (V, Figure 1), which shows antimicrobial and mild tyrosine kinase inhibition activities [22]. In addition, Se-aspirin (VI, Figure 1) has been

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

• Manoel T. Rodrigues Jr.,
• Aline S. B. de Oliveira,
• Ralph C. Gomes,
• Amanda Soares Hirata,
• Lucas A. Zeoly,
• Hugo Santos,
• João Arantes,
• Catarina Sofia Mateus Reis-Silva,
• João Agostinho Machado-Neto,
• Leticia Veras Costa-Lotufo and
• Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

• achieved. Under both conditions, virtually no product mixtures were observed. Preliminary biological evaluation To investigate the cytotoxic activity of the indanone derivatives, in total 20 compounds were tested at a concentration of 5 and 50 μg/mL for 72 h in a panel of four histologically unrelated