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

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

• rat embryonic fibroblasts and P388 murine leukemia cells were evaluated according to the protocols described in references [40][41]. CAS assay Compounds 1–3, along with deferoxamine mesylate as a reference, were serially half-diluted in a 96-well round-bottomed microtitre plate. To each well were

1,2-Naphthoquinone-4-sulfonic acid salts in organic synthesis

• Ruan Carlos B. Ribeiro,
• Patricia G. Ferreira,
• Amanda de A. Borges,
• Luana da S. M. Forezi,
• Fernando de Carvalho da Silva and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 53–69, doi:10.3762/bjoc.18.5

• electrons through a redox cycle promoted by the 1,2- or 1,4-naphthoquinone system. In this cycle, transient reactive oxygen (ROS) and nitrogen (RNS) species are formed as free radicals, peroxides, superoxide anions, radical anions, or dianions. These species generated inside cells accelerate hypoxia and

• -workers synthesized other naphthoquinone derivatives 37 from β-NQSNa (18) [86]. These compounds were evaluated for their antiproliferative activities on human cancer cells, with three of them being the most active (37a–c). It has been shown that the mechanism of action passes through the production of

• synthesis of novel 4-amino-1,2-naphthoquinones 43a–c containing carbohydrates and evaluated their antitumor activity in vitro. These compounds were transformed into a series of hydrazones 44a–l with different substituted aryl groups, which were also evaluated against tumor cells. To prepare 43a–c, 18 was

Efficient N-arylation of 4-chloroquinazolines en route to novel 4-anilinoquinazolines as potential anticancer agents

• Rodolfo H. V. Nishimura,
• Thiago dos Santos,
• Valter E. Murie,
• Luciana C. Furtado,
• Leticia V. Costa-Lotufo and
• Giuliano C. Clososki

Beilstein J. Org. Chem. 2021, 17, 2968–2975, doi:10.3762/bjoc.17.206

• -, meta-, and para-substituted N-methylanilines as well as substituted anilines and furnished the corresponding 4-anilinoquinazolines in good yields. Preliminary screening of the synthesized compounds against tumor cells (HCT-116 and T98G) showed promising antiproliferative properties. Keywords: 4

• adenocarcinoma), and T98G (human glioblastoma). Initially, we evaluated all compounds at 50 µM, and we considered active the compounds that inhibited cell proliferation by over 75% for each cell line. Compounds 10b, 10c, 10g, 10k, 10l, 15a, 15b, and 15d were active against T98G cells, and compounds 10b, 15a, and

• 15b were also active against HCT-116 cells. However, none of the tested compounds was able to inhibit MCF-7 cell proliferation (Figure S1 in Supporting Information File 1). Next, we determined the IC50 of the active compounds against both HCT-116 and T98G cells; we employed doxorubicin as positive

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

• H-13 (Figure 6). Thus, an S-configuration, corresponding to an ʟ-chirality for tryptophan, was assigned. Compounds 1–6 were not cytotoxic against P388 murine leukemia cells (IC50 > 100 μM), nor antimicrobial against five bacteria, Bacillus subtilis, Staphylococcus aureus, Ralstonia solanacearum

• ), 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

• providing R. solanacearum SUPP1541. P388 cells were obtained from JCRB Cell Bank under an accession code JCRB0017 (Lot. 06252002). Funding This work was supported by JSPS KAKENHI Grant Number 19K05848 to Y. I.

Total synthesis of the O-antigen repeating unit of Providencia stuartii O49 serotype through linear and one-pot assemblies

• Tanmoy Halder and
• Somnath Yadav

Beilstein J. Org. Chem. 2021, 17, 2915–2921, doi:10.3762/bjoc.17.199

• polysaccharides are one of the important constituents of the surface lipopolysaccharides (LPS) of the cell wall of Gram-negative bacteria. These antigens are responsible for several functions that include adhesion to the host cells and are also found to contribute to the evasion of the host immune responses

Photophysical, photostability, and ROS generation properties of new trifluoromethylated quinoline-phenol Schiff bases

• Inaiá O. Rocha,
• Yuri G. Kappenberg,
• Wilian C. Rosa,
• Clarissa P. Frizzo,
• Nilo Zanatta,
• Marcos A. P. Martins,
• Isadora Tisoco,
• Bernardo A. Iglesias and
• Helio G. Bonacorso

Beilstein J. Org. Chem. 2021, 17, 2799–2811, doi:10.3762/bjoc.17.191

• interesting luminescent properties [14] that have attracted great interest because of their potential applicability in the composition of organic light-emitting diodes (OLED), organic solar cells (OSC), and biomolecular markers [15][16]. Moreover, the trifluoromethyl substituent (CF3) is an interesting

• methods, which provide active ingredients to prevent or reduce the effects of oxidative stress in cells. Recently, our research group reported the synthesis of 6-amino-4-(trifluoromethyl)quinolines, which were obtained through an electrophilic aromatic substitution reaction catalyzed by sulfuric acid from

Highly stereocontrolled total synthesis of racemic codonopsinol B through isoxazolidine-4,5-diol vinylation

• Lukáš Ďurina,
• Anna Ďurinová,
• František Trejtnar,
• Ľuboš Janotka,
• Lucia Messingerová,
• Jana Doháňošová,
• Ján Moncol and
• Róbert Fischer

Beilstein J. Org. Chem. 2021, 17, 2781–2786, doi:10.3762/bjoc.17.188

• lines U87-MG, HepG2, JEG-3 and MOLM-13 (AML cell line) as well as immortalized proximal tubular cells HK2. We have very recently found out that even enantiomerically pure polyhydroxylated pyrrolizidine alkaloids with proven antiglycosidase activities may not exhibit antiproliferative effects against

• (±)-Codonopsinol B (1) and its N-nor-methyl analogue 2 were evaluated for their antiproliferative activity against the four cancer cell lines U87-MG, HepG2, JEG-3, MOLM-13 and against immortalized proximal tubular cells HK2 (see Supporting Information File 1, Table S1, Figures S4–S8). The IC50 values of all tested

• tubular cells HK2. (−)-Codonopsinol B (1) and its N-nor-methyl analogue 2; known inhibition activities against α-glucosidases from: (a) Bacillus stearothermophilus lyoph., (b) yeast [2]. Molecular structure of N-Cbz-protected pyrrolidine 12 confirmed by single-crystal X-ray crystallographic analysis

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• ranging from 0.5 µM to 50 µM (for detailed results, see Supporting Information File 1). It was found that the exemplarily chosen compounds of type 5, namely 5a, 5d–f, and 5h, did not reduce the viability of the human epithelial cervix carcinoma (HeLa) cells at every concentration tested. The derivatives

• viability of HeLa cells, their regioisomers 13a and 13d–h decreased the viability at high micromolar concentrations. A slightly increased cytotoxicity of some derivatives of compound class 12 compared to 13 was observed for 12b and 12c. The amides 9 had no influence on the viability except for derivate 9b

• ]triazines 5 and intermediates 9, 12, and 13 and their calculated IC50 values after treatment of HeLa cells with different concentrations of the respective compounds. Synthesis of 3,6-dihydro-4H-pyrazolo[3,4-d][1,2,3]triazin-4-ones 2a,b by diazotization of 3-amino-1H-pyrazole-4-carboxamides 1a or 3-amino-1H

The ethoxycarbonyl group as both activating and protective group in N-acyl-Pictet–Spengler reactions using methoxystyrenes. A short approach to racemic 1-benzyltetrahydroisoquinoline alkaloids

• Marco Keller,
• Karl Sauvageot-Witzku,
• Franz Geisslinger,
• Nicole Urban,
• Michael Schaefer,
• Karin Bartel and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2716–2725, doi:10.3762/bjoc.17.183

• -substituted 1-benzyl-1,2,3,4-tetrahydroisoquinolines (SG-005 and SG-094) as potent lead structures. For activity on TPC2 as well as tumor cells, these compounds were preferably bearing phenoxy and benzyloxy substituents on both aromatic rings, however, some analogues missing this “aromatic decoration

• comparison to tetrandrine and cepharanthine, we performed Ca2+ measurements in multiwell plates. Therefore, heterologously TPC2-expressing HEK293 cells were loaded with calcium indicator fluo-4/AM and Ca2+ entry was measured for 5 min after injection of various alkaloid concentrations (0.1–100 µM). None of

• the alkaloids exhibited the efficiency to activate TPC2 (data not shown). To evaluate the inhibitory potency, afterwards the same cells were stimulated with the TPC2 activators TPC2-A1-P (30 µM) and TPC2-A1-N (10 µM). Compared with the respective solvent control (DMSO), only rac-norcinnamolaurine (3b

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• , ʟ-nucleosides are typically endowed with lower host toxicity [11][12]. The antiviral activity and cytotoxicity in MT-4 cells showed that racemic (±)-BCH-189 (1c) possesses lower anti-HIV activity (ID50 = 0.37–1.31 µM) than AZT (ᴅ-nucleoside, ID50 = 0.0048–0.0217 µM). However, (±)-BCH-189 (1c

• ) appeared to be a more effective antiviral agent than AZT in PBM cells and U937 cells [13]. The BCH-189 core structure bears two stereocenters, and hence four stereoisomers are possible. The individual stereoisomers were also evaluated against HIV-1 activity in PBM cells and based on this study, it was

• found that out of four stereoisomers, the β-configured ʟ-(−)-enantiomer 1 (EC50 = 0.02 µM) is more potent in primary human lymphocytes than the β-configured ᴅ-(+)-enantiomer 1a (EC50 = 0.2 µM) in CEM cells [14]. Similarly, the 5-fluoro-substituted analogue of cytidine, i.e., β-configured ʟ

Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone

• Ilya A. P. Jourjine,
• Lukas Zeisel,
• Jürgen Krauß and
• Franz Bracher

Beilstein J. Org. Chem. 2021, 17, 2668–2679, doi:10.3762/bjoc.17.181

• electronic and optical properties [16][17][18][19][20][21], utilized in LEDs, semiconducting polymers, and solar cells. Consequently, synthetic approaches to fluorenones have attracted large interest and numerous methodologically diverse approaches have been published in the past decades. Among these are