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

• . Further functionalization steps finally furnished (+)-ophiobolin A (8). In the fusicoccanes family, cotylenol (50), the aglycon of cotylenin A (131) (see section 3.1), is a fungal metabolite which displays various interesting biological activities [28]. For example, it expresses a moderate cytotoxicity

• the D-ring. It was isolated in 1958 from the fungus Ophiobolus miyabeanus, and displayed a remarkable cytotoxicity against several cancer cell lines [50]. Meanwhile, variecolin (3) was isolated from the fermentation broth of the fungus Aspergillus variecolor in 1991, and it appears to be a potent

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• biomedical applications, in particular as an alternative to the hydrophilic poly(ethylene glycol) (PEG), which is the polymer of choice for many biomedical applications due to its high solubility, low cytotoxicity and biocompatibility [3][4][5][6][7][8][9]. However, an ongoing discussion about pre-existing

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

• isolated from I. delavayi along with known (±)-rengyolone (3) [2]. (±)-Incarviditone (2) presents a new carbon-skeleton by being the first benzofuranone dimer connected by a C–C bond. The cytotoxicity of (±)-incarviditone (2) has been assayed against cell lines A549, LOVO, HL-60, 6TCEM, and HepG2 and

• displayed cytotoxicity against the HL-60 cell line with an IC50 value of 14.8 mg/mL and against the 6T-CEM cell line with an IC50 value of 22.2 mg/mL. Lawrence et al. [3] and Tang et al. [4] have reported the synthesis of (±)-incarvilleatone (1) and (±)-incarviditone (2) via biomimetic dimerization of

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

• Benedikt Kolb,
• Daniela Silva dos Santos,
• Sanja Krause,
• Anna Zens and
• Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

• displays pronounced cytotoxicity against two human cancer cell lines [1], epicocconone (2), a fluorescent compound from the fungus Epicoccum nigrum [2], β-ionone (3) from many plant-derived sources [3], epoxysorbicillinol (4) from the saltwater culture of the fungus Trichoderma longibrachiatum separated

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

• formulation approaches for targeting the colon through oral administration. In our previous studies, oral chemotherapy for colon tumors was aimed and promising results were obtained with formulation development studies, mucin interaction, mucus penetration, cytotoxicity, and permeability in 2D cell culture

• also had better release, physical stability, and cytotoxicity [13]. CPT is an anticancer small molecule drug that inhibits the topoisomerase I enzyme, which has a critical role in cellular DNA functions [14], and is effective in a wide spectrum of cancers such as metastatic colon cancer, breast cancer

• simulated colon. When compared to the equivalent CPT dose in solution, CPT-loaded poly-β-CD-C6 nanoparticles exhibited higher cytotoxicity in HT-29 cells. Permeability studies performed with the Caco-2 cell line revealed a 276% increase in drug permeability and significantly higher intestinal penetration

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

• and Dd2 strains) and the cytotoxicity against a human embryonic kidney (HEK293) cell line were tested. Some of the compounds demonstrated moderate antimalarial activity with IC50 values ranging from 0.2 to >80 µM; none of the compounds displayed any cytotoxicity against HEK293 cells at 80 µM

• hepatic intrinsic clearance of <8.1 µL/min/mg [5]. Furthermore, minimal poly-pharmacology and cytotoxicity have been identified for this series to date, giving confidence in its specificity and tolerability, and thus supporting on-going efforts towards the continued development of this unique antimalarial

• triazolopyrazines were all evaluated in vitro for antimalarial activity and cytotoxicity. Results and Discussion Previous structure–activity relationship (SAR) studies reported that any substitution at the C8 position of Series 4 triazolopyrazines can lower the potency for P. falciparum [14][15][16]. However, a

Digyalipopeptide A, an antiparasitic cyclic peptide from the Ghanaian Bacillus sp. strain DE2B

• Adwoa P. Nartey,
• Aboagye K. Dofuor,
• Kofi B. A. Owusu,
• Anil S. Camas,
• Hai Deng,
• Marcel Jaspars and
• Kwaku Kyeremeh

Beilstein J. Org. Chem. 2022, 18, 1763–1771, doi:10.3762/bjoc.18.185

• data for compound 1 in DMSO-d6. Antiparasitic activity data for compound 1. Antibacterial activity data for compound 1. Cytotoxicity and selectivity profiles of compound 1 using normal macrophages. Supporting Information Supporting Information File 338: Experimental protocols, phylogenetic data

Rhodium-catalyzed intramolecular reductive aldol-type cyclization: Application for the synthesis of a chiral necic acid lactone

• Motoyuki Isoda,
• Kazuyuki Sato,
• Kenta Kameda,
• Kana Wakabayashi,
• Ryota Sato,
• Hideki Minami,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1642–1648, doi:10.3762/bjoc.18.176

• monocrotaline There are several reports of bioactive natural products that have a 3-hydroxy-2-methyllactone scaffold in the molecular structure. For example, cytospolide K2 [50] containing a 10-membered lactone and feigrisolide [51] containing a 7-membered lactone are known to exhibit cytotoxicity and

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• compound was determined based on calculated electronic circular dichroism (ECD) spectra that were compared to the experimental ECD spectra of (+)-1 and (+)-2. Although these natural products did not exhibit antimicrobial activity or cytotoxicity against HeLa cells, their biological activities in other

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

• bromotyrosine derivatives, more complex natural products containing spirocyclohexadienylisoxazolines, spirooxepinisoxazolines and oximes have been reported [3][4]. This class of marine alkaloids possess unique functional groups, 3D architecture and interesting pharmacology such as cytotoxicity [5][6

• activity [31] and antimicrobial activity [32]; ianthesine E has rarely been tested for bioactivity, however, some weak binding has been identified for this molecule against human adenosine A1 receptor 19, along with some weak cytotoxicity towards HeLa cells [15]. Limited testing has also been conducted on

• ][36]. The psammaplysin structure class has also had antimalarial [28], cytotoxicity [37] and antimicrobial data reported, albeit with low to moderate potencies [7]. More recently psammaplysin F and several semi-synthetic analogues have been shown to cause loss of mitochondrial membrane potential

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

• = 44.4 and 14.29 µM, respectively). Although betulinic acid (1) exhibited greater antiviral activity than ursolic acid (2), the introduction of a nitroaryl-1,2,3-triazole substituent in 2 was more efficient than its introduction in scaffold 1. Moreover, all tested compounds showed low cytotoxicity in

• A549 cells, compared to the positive control (A549 cells infected with RSV without treatment). Furthermore, derivative 8 had low cytotoxicity in all non-infected cells tested, which is different to that observed for other derivatives where TI was expressively lower (Table 1 and Figure 2A). The effect

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

• cytotoxicity of the test compounds before the nitric oxide (NO) production assay. NO production in each well was assessed by measuring the accumulation of nitrite in the culture supernatants using Griess reagent. After 5 min of incubation, the absorbance was measured using a microplate reader (Thermo, Bio-rad

Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold

• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109

• readily available 3(2H)-isoquinolones followed by TfOH-promoted hydroarylation by an arene molecule. Screening of the novel 1,2,4-trisubstituted 1,4-DHIQs against cancer cell lines confirmed high cytotoxicity of selected analogs, which validates this new chemotype for further investigations as anticancer

• probe for protein–protein interactions, including oncogenic ones [26]. As the first step towards biological characterization of compounds 9, they were screened for cytotoxicity against the NCI-H460 lung carcinoma cell line. The most potent cytotoxic agent (9j) reduced the number of viable cells by >95

• -DHIQ adducts synthesized in this work, they were deemed efficient probes for the perturbation of vital cellular targets. Screening of these compounds against lung carcinoma cancer cell lines confirmed high cytotoxicity of selected analogs, which validates this new chemotype for further investigation as

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

• . Azodyrecins D–G, four new analogs of aliphatic azoxides, were identified from two Streptomyces species by a reactivity-based screening that targets azoxy bonds. A biological activity evaluation demonstrated that the double bond in the alkyl side chain is important for the cytotoxicity of azodyrecins. An in

• previous report demonstrated the cytotoxic activity of azodyrecins [21]; however, the relationships between the structure and cytotoxicity were not determined. With new azodyrecin analogs with saturated alkyl chains in hand, we attempted to gain insights into the effects of the double bond on cytotoxicity

• lymphocyte Jurkat cells, and P388 murine leukemia cells. The results revealed that the derivatives with unsaturated side chains, 2 and 5, exhibited moderate cytotoxicity against all tested cell lines, with the highest potency against Jurkat cells (IC50 at 3.36 μM for 5) (Table 2 and Figure S5 in Supporting

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• [27][28][29], and were used for ischemic stroke treatment [30], to decrease the cytotoxicity of anticancer drugs [31], and as amphiphilic copolymers as artificial ionophores [32]. Result and Discussion The synthetic strategy for the synthesis of the desired compounds 4a–v commenced from commercially

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

• ) cell line. Keywords: antineuroinflammation; cytotoxicity; Glechoma hederacea var. longituba; neurotrophic effect; terpenoid; Introduction Glechoma hederacea var. longituba is a perennial plant in the family Labiatae. It is commonly known as ‘ground ivy’ and ‘gill over the ground’ and is widely

• , and cytotoxicity. Compounds 2 and 5–7 caused significantly reduced NO levels. Compound 5 exhibited a neurotrophic effect. Interestingly, compounds 4 and 5 showed differences in antineuroinflammatory activity and neurotrophic effect according to the C-2' functional group of the glucopyranosyl group

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• , supramolecular chemotherapy has received considerable attention by utilizing a supramolecular strategy to decrease the cytotoxicity of anticancer drugs to normal cells while preserving their cytotoxicity against cancer cells [11]. Supramolecular systems derived from macrocycles [12][13], such as calix[n]arenes

• derivative with an extended cavity that can associate with anticancer drugs through host–guest interactions. The resulting host–guest complexes can be considered as camouflaged anticancer drugs that may exhibit low or no cytotoxicity in normal cellular environment. Furthermore, it is hoped that the release

Unusual highly diastereoselective Rh(II)-catalyzed dimerization of 3-diazo-2-arylidenesuccinimides provides access to a new dibenzazulene scaffold

• Anastasia Vepreva,
• Alexander S. Bunev,
• Andrey Yu. Kudinov,
• Grigory Kantin,
• Mikhail Krasavin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55

• interactions, including oncogenic ones [18]. As the first step towards biological characterization of compounds 2, they were screened for cytotoxicity against the A549 human lung adenocarcinoma cell line. Among the eleven compounds, N-aryl analogs 2a–e, 2h, and 2j had no effect on the cancer cell viability

• . However, the N-alkyl analogs 2f and 2k–m showed a pronounced cytotoxicity with IC50 values in the single to double-digit micromolar range (Figure 2). Conclusion In summary, we have shown that the reaction triggered by the Rh(II)-catalyzed decomposition of DAS in inert medium can proceed in two principal

• showed pronounced cytotoxocity against the A549 human lung adenocarcinoma cell line while N-aryl analogs were non-cytotoxic. Previously reported transformations of DAS (1) and their unusual dimerization investigated in this work. Cytotoxicity of N-alkyl-substituted dibenzoazulenodipyrroles 2 against the

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

• . However, no specific antiviral properties could be discovered, as the results were dominated by the cytotoxicity of the compounds. For details see Supporting Information File 1. Furthermore, we evaluated the antibacterial properties of 3b and 10d. Growth of the Gram-positive bacterial strain

Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346

• Wiriya Yaosanit,
• Vatcharin Rukachaisirikul,
• Souwalak Phongpaichit,
• Sita Preedanon and
• Jariya Sakayaroj

Beilstein J. Org. Chem. 2022, 18, 479–485, doi:10.3762/bjoc.18.50

• . Amphotericin B was used as a positive control for C. neoformans ATCC90113 and displayed a MIC value of 0.25 μg/mL. Cytotoxicity assay The activity assay against African green monkey kidney fibroblast (Vero) cells was performed in triplicate employing the method described by Hunt and co-workers [17

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

• structurally related compounds reported in the literature. The absolute configuration of 1–3 was determined by X-ray diffraction. All the compounds have assessed the cytotoxicity against HL-60, K562, and Hela cells. Compound 1 showed weak cytotoxicity against K562 cells with an IC50 value of 19.03 μM. In

• addition, compound 1 also showed a moderate anti-inflammatory effect in zebrafish. Keywords: anti-inflammatory; cytotoxicity; Lobophytum pauciflorum; soft coral; steroids; X-ray diffraction; Introduction The unique and complicated marine environment makes soft corals a treasure-house of secondary

• ]+ calcd for C29H47O2, 427.3571; found, 427.3569. Cytotoxicity assays In vitro cytotoxicity was determined by the MTT method against K562 (chronic myeloid leukemia) and HL-60 (human promyelocytic leukemia) cell lines, and by the SRB method against the Hela cell line. Zebrafish maintenance Adult zebrafish

Synthesis and bioactivity of pyrrole-conjugated phosphopeptides

• Qiuxin Zhang,
• Weiyi Tan and
• Bing Xu

Beilstein J. Org. Chem. 2022, 18, 159–166, doi:10.3762/bjoc.18.17

• second Py unit to give a Boc-capped product, 9. We added guanidinoacetic acid to Py-GGGffpy and (Py)2-GGGffpy for making 10a and 10b, respectively. All the products were purified by HPLC. Bioactivity We examined the cytotoxicity of the synthesized compounds by incubating them with HeLa cells because HeLa

• motif and one to three pyrrole motifs at the N-terminal, hardly inhibit the HeLa cells. Compound 7, formed by the introduction of a ᴅ-arginine residue into 2a, exhibits similar cytotoxicity as that of 2a. 8a and 8b, formed by replacing the ff motif in 2d and 2e with l4, exhibit slight and little

• cytotoxicity, respectively. Capping the N-terminus with a Boc-protecting group (9) or a guanidinoacetic acid motif (10a and 10b) renders the molecules with higher cytotoxicity (resulting in cell viabilities of about 70%) than those of 2f and 2g. Compounds without phosphorylation (11a, 11b and 12a–c) show

Ready access to 7,8-dihydroindolo[2,3-d][1]benzazepine-6(5H)-one scaffold and analogues via early-stage Fischer ring-closure reaction

• Irina Kuznetcova,
• Felix Bacher,
• Daniel Vegh,
• Hsiang-Yu Chuang and
• Vladimir B. Arion

Beilstein J. Org. Chem. 2022, 18, 143–151, doi:10.3762/bjoc.18.15

• copper(II) complexes prepared revealed an enhanced aqueous solubility and bioavailability indeed, along with very high cytotoxicity [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Moreover, the metal-free ligands and copper(II) complexes derived from backbone D revealed cytotoxicity in the

Tenacibactins K–M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum

• Yasuhiro Igarashi,
• Yiwei Ge,
• Tao Zhou,
• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku and
• Agus Trianto

Beilstein J. Org. Chem. 2022, 18, 110–119, doi:10.3762/bjoc.18.12

• repeated cadaverine–succinic acid motifs terminated by a hydroxamic acid functionality, were elucidated by NMR and negative MS/MS experiments. Compounds 1–3 were inactive against bacteria and a yeast but displayed cytotoxicity against 3Y1 rat embryonic fibroblasts and P388 murine leukemia cells at GI50 in

• related compounds such as nocardichelins [31] and MBJ-0003 [32], compounds 1–3 did not show appreciable antimicrobial activity against bacteria or a yeast (see Experimental) at 50 μg/mL but exhibited cytotoxicity against 3Y1 rat embryonic fibroblasts and P388 murine leukemia cells (Table 3). Among the

• Antimicrobial activity was examined as previously reported [41]. Kocuria rhizophila ATCC9341, Staphylococcus aureus FDA209P JC-1, Ralstonia solanacearum SUPP1541, Escherichia coli NIHJ JC-2, Rhizobium radiobacter NBRC14554, and Candida albicans NBRC0197 were used as indication strains. Cytotoxicity against 3Y1

Unsaturated fatty acids and a prenylated tryptophan derivative from a rare actinomycete of the genus Couchioplanes

• Shun Saito,
• Kanji Indo,
• Naoya Oku,
• Hisayuki Komaki,
• Masashi Kawasaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2021, 17, 2939–2949, doi:10.3762/bjoc.17.203

• ), 8.01 (d, J = 8.3 Hz, 1H, NH-11), 1.73 (s, 3H, H-13); HR–ESI–TOFMS (m/z): [M + Na]+ calcd for C27H31N3NaO4, 484.2207; found, 484.2207. Cytotoxicity assay The cytotoxicity assay was carried out against P388 murine leukemia cells in the same manner as reported previously [36]. The IC50 of a reference drug