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

• skeleton, are rare examples of naturally occurring 9,9′-bisnorlignans. In in vitro bioassays, compound 3 was found to show a moderate inhibitory effect on NO production in LPS-induced RAW 264.7 cells with an inhibitory rate of 42.06 ± 2.02% at 50 μM. Experimental General experimental procedures Optical

• , 1593.0, 1241.6, 814.9 cm−1; 1H and 13C NMR data, see Table 1; HRESIMS (m/z): [M + COOH]− calcd for C20H23O8, 391.1398; found, 391.1394. Nitric oxide production inhibitory assay The inhibitory activity against the production of NO was evaluated using LPS induced RAW 264.7 cells as previously reported [24

• ]. The cells were seeded in 96-well plates and co-incubated with the test compounds and positive control drug at a concentration of 50 μM or 12.5 μM, followed by stimulation with 1 μg/mL LPS for 18 h. The viability of RAW 264.7 cells was determined by an MTS assay to exclude the interference of the

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• films, both emitters showed good photoluminescence quantum yields of 71% and 61%, and delayed lifetimes of 316.6 μs and 241.7 μs, respectively, for DiKTa-OBuIm and DiKTa-DPA-OBuIm, leading to reverse intersystem crossing rates of 2.85 × 103 s−1 and 3.04 × 103 s−1. Light-emitting electrochemical cells

• were prepared using both DiKTa-OBuIm and DiKTa-DPA-OBuIm as active emitters showing green (λmax = 534 nm) and red (λmax = 656 nm) emission, respectively. Keywords: electroluminescence; light-emitting electrochemical cells; multiresonance; purely organic emitters; thermally activated delayed

• fluorescence; Introduction Light-emitting electrochemical cells (LEECs) are thin film light-emitting devices typically consisting of an emissive layer containing ionic species that facilitate charge transport and an emissive semiconductor material. The emissive layer is sandwiched between two air-stable

Make or break: the thermodynamic equilibrium of polyphosphate kinase-catalysed reactions

• Michael Keppler,
• Sandra Moser,
• Henning J. Jessen,
• Christoph Held and
• Jennifer N. Andexer

Beilstein J. Org. Chem. 2022, 18, 1278–1288, doi:10.3762/bjoc.18.134

• ; Introduction Polyphosphate (polyP, Figure 1) is a linear polymer of up to thousands of phosphate residues connected by phosphate anhydride bonds. It serves as a phosphate storage molecule and plays a crucial role in biofilm formation and stress responses of cells [1]. So far polyP has been detected in every

• (phosphoenolpyruvate as phosphate donor) is strongly favouring ATP synthesis both in vivo and in vitro, this reaction was originally considered to be irreversible in cells and a point of flux control. Newer findings showed the reaction to be actually an equilibrium, although positioned far on the product side [27][28

Synthesis of tryptophan-dehydrobutyrine diketopiperazine and biological activity of hangtaimycin and its co-metabolites

• Houchao Xu,
• Anne Wochele,
• Minghe Luo,
• Gregor Schnakenburg,
• Yuhui Sun,
• Heike Brötz-Oesterhelt and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2022, 18, 1159–1165, doi:10.3762/bjoc.18.120

• growth occurred up to the highest concentration tested (256 µg/mL). In the Gram-negative Escherichia coli, the outer membrane protects the cells from the impact of 1. When the integrity of the outer membrane was compromised by adding the outer-membrane permeabilizing polymyxin B nonapeptide (PMBN, 10 μg

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• ]. The resulting expression vectors were individually introduced into E. coli BL21(DE3) for protein expression. Cells harboring expression plasmid were inoculated into LB medium with 50 µg/mL kanamycin and incubated at 37 °C until the culture reached an OD600 of 0.4–0.6. The cultures were then cooled to

• 16 °C and induced with 0.1 mM isopropyl β-ᴅ-1-thiogalactopyranoside (IPTG) for 16 h. Cells were harvested by centrifugation (10 min, 8,000 rpm, 4 °C). For protein purification, cell pellets were resuspended in lysis buffer (50 mM NaH2PO4, 400 mM NaCl, 1 mM TCEP, pH 7.5) and lysed by sonication. After

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

• 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

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

• . To this end, we assessed the cytotoxic activities of azodyrecin B (2), 1’-trans-azodyrecin B (5), together with the most abundant new analogs azodyrecin D (7), and azodyrecin E (8), against human ovarian adenocarcinoma SKOV-3 cells, malignant pleural mesothelioma MESO-1 cells, immortalized T

• 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

Isolation and biosynthesis of daturamycins from Streptomyces sp. KIB-H1544

• Yin Chen,
• Jinqiu Ren,
• Ruimin Yang,
• Jie Li,
• Sheng-Xiong Huang and
• Yijun Yan

Beilstein J. Org. Chem. 2022, 18, 1009–1016, doi:10.3762/bjoc.18.101

• Bertani (LB) supplemented with 100 μg/mL ampicillin at 37 °C until OD600 reached 0.6. IPTG (0.2 mM) was added to the final concentration of 0.4 mM and incubated at 16 °C overnight. The cells were centrifuged at 4000 rpm for 25 min and resuscitated with lysis buffer (buffer A: 50 mM Tris-HCl, 300 mM NaCl

• , 20 mM imidazole, pH 8.0). After ultrasonic cell crushing, the cells were centrifuged at 24,000 rpm for 60 min to remove cell fragments. The supernatant was filtered through 0.22 μm of the filter membrane and then loaded into the nickel column of the rebalanced lysate (HisTraqTM FF, GE Healthcare

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• as slow rates of conversion, low selectivity and reproducibility [26]. As a matter of fact, these problems can be addressed by using flow electrochemistry, usually achieving higher rates of conversion of reagents to products [27]. Moreover, electrochemical flow cells can have a very small gap between

• the electrodes so that lower concentrations of supporting electrolytes are needed to provide sufficient conductivity [28]. Applications of flow electrochemistry reported in the literature are mainly devoted to anodic oxidations, carried out in undivided cells, in which the counter electrode reaction

• at the cathode is usually H2 evolution [29]. The use of divided cells is less common in organic electrosynthesis, mainly due to complications inherent with membranes. Useful cathodic processes are less exploited in organic electrochemistry. In the context of NHC organocatalysis in flow

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• , which extends the degree of π-conjugation [1]. In this way, the HOMO–LUMO gap can be narrowed [2]. Low HOMO–LUMO gaps are desirable for organic solar cells as the maximum photoflux density of the sun is at ca. 700 nm, corresponding to 1.77 eV [3]. However, fused systems have the drawback of being prone

• (the basic unit of processors) [6], solar cells, and LEDs [7]. Inorganic compounds, e.g. III-V type inorganics are widely used, however, in recent years, organic molecules with semiconducting and fluorescent properties have emerged as an alternative with advantages such as solution processing [8][9][10

• example, ITIC (10), is shown in Figure 4. ITIC [17], in combination with polymer 11, achieved a power conversion efficiency (PCE) of 6.8%, which was the best value for NFA organic solar cells at the time of publication. Fluorination of ITIC, obtaining IT-4F (12), shown in Figure 5, reduced ELUMO. Combined

Anti-inflammatory aromadendrane- and cadinane-type sesquiterpenoids from the South China Sea sponge Acanthella cavernosa

• Shou-Mao Shen,
• Qing Yang,
• Yi Zang,
• Jia Li,
• Xueting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 916–925, doi:10.3762/bjoc.18.91

• spectra were obtained by TDDFT calculations performed with the B3LYP/6-311G** level of theory with IEFPCM solvent model for acetonitrile. Finally, the Boltzmann-averaged ECD spectra were obtained with SpecDis1.62 [41]. In vitro anti-inflammatory assay. RAW264.7 cells, a murine macrophage cell line, was

• purchased from American Type Culture Collection (ATCC, Manassas, VA, USA). RAW264.7 cells were cultured in DMEM (Dulbecco’s modified Eagle medium) supplemented with 10% fetal bovine serum, antibiotics (100 U/mL penicillin and 100 U/mL streptomycin), and maintained at 37 °C in a humidified incubator of 5

• % CO2. RAW264.7 cells (1.6 × 105/well) were seeded in a 24-well plate overnight for cell adherence. Cells were treated with LPS alone (100 ng/mL, dissolved in DMSO) or with compounds at the indicated concentrations for 24 h. Total RNA was harvested from cells using TRIzolTM reagent (Invitrogen, USA

Synthesis and HDAC inhibitory activity of pyrimidine-based hydroxamic acids

• Virginija Jakubkiene,
• Gabrielius Ernis Valiulis,
• Markus Schweipert,
• Asta Zubriene,
• Daumantas Matulis,
• Franz-Josef Meyer-Almes and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 837–844, doi:10.3762/bjoc.18.84

• (HDACs) play an essential role in the transcriptional regulation of cells through the deacetylation of nuclear histone and non-histone proteins and are promising therapeutic targets for the treatment of various diseases. Here, the synthesis of new compounds in which a hydroxamic acid residue is attached

Identification of the new prenyltransferase Ubi-297 from marine bacteria and elucidation of its substrate specificity

• Jamshid Amiri Moghaddam,
• Huijuan Guo,
• Karsten Willing,
• Thomas Wichard and
• Christine Beemelmanns

Beilstein J. Org. Chem. 2022, 18, 722–731, doi:10.3762/bjoc.18.72

• added to a final concentration of 0.1 mM. Cells were cultivated overnight at 16 °C before harvesting. Cultures were centrifuged, the cell pellet resuspended in Tris-HCl buffer (50 mM, pH 7.8) supplemented with dithiothreitol (DTT, 10 mM), and sonicated on ice (12 min, 100% C, 40% A, 2 seconds on and 3

• continued at 30 °C (3 d). Subsequently, cultures were extracted twice with ethyl acetate (400 mL), the solvent was removed in vacuo, the residue redissolved in MeOH, and subjected to HRMS/MS analysis. Fermentation and purification: Fermentation of E. coli BL21 cells harboring the pET28-297 vector was

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

• , Staphylococcus aureus, Klebsiella pneumoniae, and Staphylococcus pneumoniae were responsible for most of bacteremia deaths related to antimicrobial resistance in 2019 [2]. Current antibacterial drugs are facing various challenges, due to the inability to accumulate inside human cells made them inactive [3] and

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

• structure elucidation was performed for the five new compounds (1–5) using 1D and 2D NMR, HRESIMS, DP4+ and ECD calculations, and chemical methods. All the isolates (1–9) were assessed for their antineuroinflammatory activities on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells

• , nerve growth factor (NGF) secretion stimulation activities in C6 glioma cells, and cytotoxic activities against four human cancer cell lines (A549, SK-OV-3, SK-MEL-2, and HCT15). Compounds 2 and 5–7 exhibited inhibitory effects on the NO production with IC50 values of 52.21, 47.90, 61.61, and 25.35 μM

• isolated compounds (1–9) and assessment for their antineuroinflammatory activity on NO production in lipopolysaccharide (LPS)-activated BV-2 cells, NGF secretion-stimulation activities in C6 glioma cells, and cytotoxic activities are described. Results and Discussion Compound 1 was purified as a colorless

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

• molecule overexpressed in cancer cells, through host–guest competitive substitution since TBTQ-CB6 has a stronger binding affinity toward SM than MV and DOX. The host–guest interactions of the complexes of TBTQ-CB6 with MV, DOX and SM were investigated by NMR spectroscopy and fluorescence spectroscopy. The

• targeting of cancer cells, resulting in low bioavailability and systemic side effects [6]. To address these drawbacks, various approaches have been developed to improve the bioavailability of these and other drugs and to enable their targeted delivery to cancer cells [7][8][9][10]. In recent years

• , 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

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

• cytotoxic activities of compounds 3b and 10d were studied, as they influence the applicability of the compounds in other assays comprising mammalian cells. We incubated the murine fibroblast L929 cell line with different concentrations of the compounds for 72 h and quantified the residual viability of the

• cells. Non-linear regression of the dose–response data led to IC50 values of 1.4 µM for 3b and of 0.6 µM for 10d. Thus, for both compounds similar cytotoxic properties in the low µM range were determined. The compounds were also tested in a viral infection model comprising SARS-CoV-2 and VeroE6 cells

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• , good electrical and optical properties, and easy chemical modification is a desired structural unit in organic structures targeted for numerous applications including organic photovoltaic solar cells (OPV) [12][13][14], organic field-effect transistors (OFETs) [15][16][17], chemical and biosensors [18

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

• amount were evaluated for their antibacterial activity against S. aureus ATCC25923 and methicillin-resistant S. aureus SK1, antifungal activity against C. neoformans ATCC90113 as well as cytotoxic activity against KB, MCF-7, and noncancerous Vero (African green monkey kidney fibroblast) cells. None of

• . 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

• , demethylgorgosterol [9][10]. Thus, the structure of compound 4 was assigned as shown in Figure 1. Biological activity The cytotoxic activities of compounds 1–7 were evaluated against three cancer cell lines (HL-60, K562, and Hela), but only compound 1 exhibited weak cytotoxic activity against K562 cells with an IC50

• methyl group at C-4. The absolute configuration of 1–3 was determined by X-ray diffraction analyses. Compounds 1–7 were subjected to a cytotoxic activity evaluation against HL-60, K562, and Hela cells, only compound 1 exhibited weak cytotoxic activity against K562 cells with an IC50 value of 19.03 μM. In

Anomeric 1,2,3-triazole-linked sialic acid derivatives show selective inhibition towards a bacterial neuraminidase over a trypanosome trans-sialidase

• Peterson de Andrade,
• Sanaz Ahmadipour and
• Robert A. Field

Beilstein J. Org. Chem. 2022, 18, 208–216, doi:10.3762/bjoc.18.24

• acid from the human host glycoconjugates onto its surface mucins to generate α-2,3-linked sialylated β-galactopyranose units, thus contributing directly to the parasite adhesion and invasion of host cells [12]. Although TcTS is the major parasite virulence factor [13], there is no nanomolar inhibitor

• of Trypanosoma cruzi trans-sialidase (TcTS) A recombinant T. cruzi trans-sialidase (TcTS) plasmid containing the pTrcHisA TcTS 6 11/2 expression construct [41] was transformed into E. coli BL21 (DE3) cells and inoculated in 1 L of LB medium containing the transformant and ampicillin (100 μg/mL

• ). Incubation at 37 °C along with shaking (200 rpm) was continued until optical density (OD600) reached 0.6. Heterologous protein expression was induced by adding isopropyl β-ᴅ-1-thiogalactopyranoside (IPTG) to a final concentration of 1 mM and incubating for 4 hours at 30 °C with shaking (180 rpm). The cells

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• for the first time. All co-isolates were evaluated for their in vitro inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in murine RAW264.7 macrophage cells. The antibacterial activity of the selected compounds was also tested. Our work enriches the structure

• /z) [M + Na]+, calcd for C29H28O15Na, 639.1320; found, 639.1309. Anti-inflammatory assay The RAW 264.7 cells (2 × 105 cells/well) were incubated in 96-well culture plates with or without 1 µg/mL LPS (Sigma Chemical Co., USA) for 24 h in the presence or absence of the test compounds. Aliquots of

The role of chemistry in the success of oligonucleotides as therapeutics

• Pawan Kumar and
• Tom Brown

Beilstein J. Org. Chem. 2022, 18, 197–199, doi:10.3762/bjoc.18.22

• conditions using therapeutic oligonucleotides. There were many challenges including, but not limited to, poor stability of unmodified DNA strands and short RNA duplexes in cells, large anionic charge, poor drug-like properties, and a tendency to trigger the immune response in the body. Chemists have been at

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

• cells by a naphthyl-capped phosphopeptide (Nap-ffpy, 1), we conjugated the heteroaromatic dipyrrole or tripyrrole motif at the N-terminal of short peptides containing phosphotyrosine or phosphoserine and examined the bioactivity of the resulting phosphopeptides (2–10). Although most of the

• phosphopeptides exhibit comparable activities with that of 1 against HeLa cells at 200 μM, they, differing from 1, are largely compatible with HeLa cells at 400 μM. Enzymatic dephosphorylation of 2–10, at 400 μM is unable to induce a dramatic morphological transition of the peptide assemblies observed in the case

• controlling cell fate. Keywords: cells; enzyme; N-terminal; peptides; pyrroles; self-assembly; Introduction Biomacromolecular assemblies have received considerable attention recently in the field of biomaterials [1][2][3][4][5][6][7], among which peptides are of particular interest because of their unique

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

• unit is shifted and the indole ring is flipped (D). Isomer D has been shown to be a potent tubulin-polymerase inhibitor, while B was only mildly cytotoxic towards cancer cells at a concentration of 1 µM [5][6]. Backbone C, despite being very similar to the other three scaffolds, remained a synthetic

• nanomolar concentration range and selectivity for cancer cells over normal ones [22]. The synthesis of core structures A, B, and D is well-documented in the literature [2][6]. Herein we describe the first synthesis of 7,8-dihydroindolo[2,3-d][1]benzazepin-6(5H)-one (C) (Figure 1). Results and Discussion