Anomeric sugar boronic acid analogues as potential agents for boron neutron capture therapy

• Daniela Imperio,
• Erika Del Grosso,
• Silvia Fallarini,
• Grazia Lombardi and
• Luigi Panza

Beilstein J. Org. Chem. 2019, 15, 1355–1359, doi:10.3762/bjoc.15.135

• did not reveal the presence of any elimination product, while the negative mass spectrum showed only the pseudomolecular ion at m/z 145 corresponding to the [M − H]−. The toxicity of compounds 8 and 11, compared to commercial BPA, on cell viability, was evaluated on human primary fibroblasts. The

• cells were treated (24–72 h) with increasing concentrations (1–100 μM) of each compound, and cell viability measured by MTT assay. No toxicity was measured at all concentrations and times considered (see Supporting Information File 1), indicating that all compounds under evaluation are biocompatible and

• ester ring opening, while compound 11 demonstrated to be stable. The two compounds showed no toxicity on human primary fibroblasts. Further studies will be conducted to determine the cellular uptake of compounds 8 and 11. Structure of boronic acid analogues (for clarity, sugar numbering has been

Host–guest interactions between p-sulfonatocalix[4]arene and p-sulfonatothiacalix[4]arene and group IA, IIA and f-block metal cations: a DFT/SMD study

• Valya K. Nikolova,
• Cristina V. Kirkova,
• Silvia E. Angelova and
• Todor M. Dudev

Beilstein J. Org. Chem. 2019, 15, 1321–1330, doi:10.3762/bjoc.15.131

• molecules [27], including some amino acids [28] and proteins [29]. They are also biocompatible: compared to other types of macrocyclic molecules such as cyclodextrins and cucurbiturils (which are also water soluble), p-sulfonatocalix[n]arenes do not exhibit any toxicity, which makes them applicable in

Steroid diversification by multicomponent reactions

• Leslie Reguera,
• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Daniel G. Rivera

Beilstein J. Org. Chem. 2019, 15, 1236–1256, doi:10.3762/bjoc.15.121

• lateritium (causal agent of chlorotic leaf distortion in sweet potato) and Fusarium virguliforme (causal agent of sudden death syndrome in soy bean), without exerting in vitro toxicity on mammalian cells. Another interesting result came out from the comparison of the biological activity between homologous

Heck- and Suzuki-coupling approaches to novel hydroquinone inhibitors of calcium ATPase

• Robert J. Kempton,
• Taylor A. Kidd-Kautz,
• Soizic Laurenceau and
• Stefan Paula

Beilstein J. Org. Chem. 2019, 15, 971–975, doi:10.3762/bjoc.15.94

• cytotoxic agent. The problem of concomitant toxicity to healthy cells has been circumvented by attaching a short peptide (His-Ser-Ser-Lys-Leu-Gln-Leu) to a tether at TG’s C-8 position (1b). This modification renders the inhibitor inactive [3]. Prostate cancer cells produce on their surface the serine

• synthetic route to BHQ analogues with a tether that could serve as the basis for future efforts aimed at the attachment of deactivating peptides. The rationale is analogous to the Denmeade group’s strategy for circumventing TG’s toxicity to healthy cells by selective transesterification of the ester group

Mechanochemical synthesis of poly(trimethylene carbonate)s: an example of rate acceleration

• Sora Park and
• Jeung Gon Kim

Beilstein J. Org. Chem. 2019, 15, 963–970, doi:10.3762/bjoc.15.93

• Discussion Aliphatic polycarbonates are found in many biomedical applications since they have many desirable properties such as high biocompatibility, easy degradation, good mechanical properties, and low toxicity [21][22][23]. Many synthetic methods have been developed, and the chain-growth ring-opening

Photochemical generation of the 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical from caged nitroxides by near-infrared two-photon irradiation and its cytocidal effect on lung cancer cells

• Ayato Yamada,
• Manabu Abe,
• Yoshinobu Nishimura,
• Shoji Ishizaka,
• Masashi Namba,
• Taku Nakashima,
• Kiyofumi Shimoji and
• Noboru Hattori

Beilstein J. Org. Chem. 2019, 15, 863–873, doi:10.3762/bjoc.15.84

• described above, nitroxides are not toxic to normal host cells and exhibit toxicity only to tumor cells. Thus, nitroxides are ideal candidates as anticancer therapeutic agents. Based on this knowledge, the cytocidal effect of the radical released from compound 2a on lung cancer cells was tested in vitro, in

Synthesis and biological investigation of (+)-3-hydroxymethylartemisinin

• Toni Smeilus,
• Farnoush Mousavizadeh,
• Johannes Krieger,
• Xingzhao Tu,
• Marcel Kaiser and
• Athanassios Giannis

Beilstein J. Org. Chem. 2019, 15, 567–570, doi:10.3762/bjoc.15.51

• not show any toxicity against L6 cells (a primary cell line derived from rat skeletal myoblasts). These results contribute to a better understanding of artemisinins mechanism of action. Keywords: artemisinin; biomimetic synthesis; Diels–Alder reaction; malaria; peroxides; Introduction The isolation

• against the drug-sensitive P. falciparum NF54 strain as described previously [14]. We found them to be inactive. In addition, 2 did not show any toxicity against L6 cells (a primary cell line derived from rat skeletal myoblasts). In both assays the highest concentration used was 100 μg/mL. Conclusion In

Synthesis of a tubugi-1-toxin conjugate by a modulizable disulfide linker system with a neuropeptide Y analogue showing selectivity for hY1R-overexpressing tumor cells

• Rainer Kufka,
• Robert Rennert,
• Goran N. Kaluđerović,
• Lutz Weber,
• Wolfgang Richter and
• Ludger A. Wessjohann

Beilstein J. Org. Chem. 2019, 15, 96–105, doi:10.3762/bjoc.15.11

• (Ewing`s sarcoma), MDA-MB-468, MDA-MB-231 (both breast cancer) and 184B5 (normal breast; chemically transformed) were investigated. As hoped, the toxicity of tubugi-1 was masked, with IC50 values decreased by ca. 1,000-fold compared to the free toxin. Due to intracellular linker cleavage, the cytotoxic

• very potent, mostly cytotoxic drug molecules while avoiding or at least limiting the off-target toxicity that would be characteristic for the stand-alone cytotoxic drugs. Currently, four therapeutic ADCs are approved, e.g., with brentuximab vedotin and trastuzumab emtansine as the first ones on the

• cells’ membrane by unspecific, receptor-independent pathways, not discriminating between normal and transformed cells. For that reason it is very difficult to adjust a practicable therapeutic window for these toxins. All the more, it is important to mask the high toxicity of tubulysin A and tubugi-1

Mechanistic studies of an L-proline-catalyzed pyridazine formation involving a Diels–Alder reaction with inverse electron demand

• Anne Schnell,
• J. Alexander Willms,
• S. Nozinovic and
• Marianne Engeser

Beilstein J. Org. Chem. 2019, 15, 30–43, doi:10.3762/bjoc.15.3

• lower toxicity, air sensitivity and lower costs [34]. A huge repertoire of organocatalyzed reactions have been published in recent years with high efficiencies and selectivities [29][33][35][36][37][38][39]. Proline as a natural amino acid is a perfect example of an organocatalyst. Both enantiomers are

Repurposing the anticancer drug cisplatin with the aim of developing novel Pseudomonas aeruginosa infection control agents

• Mingjun Yuan,
• Song Lin Chua,
• Yang Liu,
• Daniela I. Drautz-Moses,
• Joey Kuok Hoong Yam,
• Thet Tun Aung,
• Roger W. Beuerman,
• May Margarette Santillan Salido,
• Stephan C. Schuster,
• Choon-Hong Tan,
• Michael Givskov,
• Liang Yang and
• Thomas E. Nielsen

Beilstein J. Org. Chem. 2018, 14, 3059–3069, doi:10.3762/bjoc.14.284

• antibiotics. Although cisplatin is highly toxic for humans upon systemic exposure, a low toxicity was demonstrated with topical treatment. This indicated that higher-than-minimal inhibitory concentration (MIC) doses of cisplatin could be topically applied to treat persistent and recalcitrant P. aeruginosa

• effective than the clinically used antibiotic tobramycin in eradicating biofilms. Although cisplatin is highly toxic for intravenous applications, we showed that it has low toxicity when applied topically to wounds, as 25 mM (0.75 mg mL−1) did not have adverse effect on wound healing. This meant that higher

• doses (5–10 × MIC) of cisplatin could be safely used for topical applications. Given the low topical toxicity of cisplatin, it may be utilized as an attractive therapeutic agent for prevention and treatment of P. aeruginosa biofilm infections. Materials and Methods Bacterial strains and culture media

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• chemistry. Thanks to the development of photoredox catalysts of polymerization, a drastic reduction of the amount of photoinitiators could be achieved, addressing the toxicity and the extractability issues; high performance initiating abilities are still obtained due to the catalytic approach which

• catalysts For some specific applications, it can be essential to develop metal-free systems because of potential toxicity, storage stability or bioaccumulation of metal for example. Organic photoredox catalysis has been largely studied in the past few years and is the topic of many reviews [17][40][45][49

• conditions tested. The choice of the photoredox catalyst has also to be done regarding the application: final toxicity, choice of the device to perform the polymerization (light irradiation, under air or not…), price of the formulation, etc. For both free radical and cationic polymerizations, only a very

Protein–protein interactions in bacteria: a promising and challenging avenue towards the discovery of new antibiotics

• Laura Carro

Beilstein J. Org. Chem. 2018, 14, 2881–2896, doi:10.3762/bjoc.14.267

• -positive pathogens such as methicillin-resistant S. aureus and S. pneumoniae but also Gram-negative bacteria strains such as P. aeruginosa and A. baumannii (MIC ≤ 3 μg/mL and ≤51 μg/mL, respectively) [95]. In spite of the efficiency of the bis-aminoguanidine derivative 42, unfortunately, its toxicity was

• not display toxicity to mammalian cells. Even though the NusB/NusE interaction is still in its infancy, and further investigations are needed to both elucidate off-target effects and apparent preferential inhibitory activity against Gram-positive pathogens, the identification of promising small

An overview on recent advances in the synthesis of sulfonated organic materials, sulfonated silica materials, and sulfonated carbon materials and their catalytic applications in chemical processes

• Hashem Sharghi,
• Pezhman Shiri and
• Mahdi Aberi

Beilstein J. Org. Chem. 2018, 14, 2745–2770, doi:10.3762/bjoc.14.253

• organic chemistry [12][13][14][15][16]. On the other hand, to reduce the toxicity and increase the efficiency, sulfonic acids are heterogenized on the various solid supports [17][18][19]. In fundamental, heterogeneous catalysis is interminably fascinating and perennially novel [20]. The few reports on

Novel solid-phase strategy for the synthesis of ligand-targeted fluorescent-labelled chelating peptide conjugates as a theranostic tool for cancer

• Sagnik Sengupta,
• Mena Asha Krishnan,
• Premansh Dudhe,
• Ramesh B. Reddy,
• Bishnubasu Giri,
• Sudeshna Chattopadhyay and
• Venkatesh Chelvam

Beilstein J. Org. Chem. 2018, 14, 2665–2679, doi:10.3762/bjoc.14.244

• malignancy [23] and inflammatory diseases. They are also utilized for targeted drug delivery [24][25] of therapeutics to avoid any off-site toxicity to normal and healthy cells. Unfortunately, strategies to construct diagnostic and therapeutic chemical tools consisting of a polypeptidic spacer, a homing

• would cause unwanted toxicity and inaccuracy in the biological study. The SH group present in the bioconjugate handle or chelating core of compound 13 and 17 can be utilized for the attachment of drugs [47], nanomaterial and radionuclide for therapeutic purposes. This added advantage makes the

• non-specific uptake. The specificity of bioconjugates is indispensable to prevent collateral damage and toxicity to healthy cells when the chelating core is tethered to deliver radionuclides or cytotoxic drugs. The confocal microscopic images in Figure 3, panel (ii) shows the uptake of chelating DUPA

Pathoblockers or antivirulence drugs as a new option for the treatment of bacterial infections

• Matthew B. Calvert,
• Varsha R. Jumde and
• Alexander Titz

Beilstein J. Org. Chem. 2018, 14, 2607–2617, doi:10.3762/bjoc.14.239

• acute toxicity/virulence are likely to be successful as future therapies against the impending threat of highly antibiotic-resistant pathogens. In some cases, it was already shown that virulence blockers act synergistically in combination with antibiotics, for example against P. aeruginosa biofilms [44

Impact of Pseudomonas aeruginosa quorum sensing signaling molecules on adhesion and inflammatory markers in endothelial cells

• Carmen Curutiu,
• Florin Iordache,
• Veronica Lazar,
• Aurelia Magdalena Pisoschi,
• Aneta Pop,
• Mariana Carmen Chifiriuc and
• Alina Maria Hoban

Beilstein J. Org. Chem. 2018, 14, 2580–2588, doi:10.3762/bjoc.14.235

• vascular endothelial cadherin (VE-cadherin) is the major structural component of endothelial AJ with a pivotal role in endothelial barrier integrity. LasB protease released by P. aeruginosa during infection determines VE-cadherin cleavage and facilitates type III secretion system toxicity in endothelial

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• environmental pollution, resulting in very chronic diseases [78]. However, it was known that the toxicity of organic arsenics is generally much lower than inorganic ones. For example, the acute toxicity of arsenobetaine (AB) is about one three-hundredth that of arsenic trioxide [79]; trimethylarsine oxide (TMAO

• ) that is an intermediate in the synthesis of AB also has lower toxicity than inorganic arsenics. Moreover, inorganic arsenics could be converted to methylated arsenics via human or animal metabolism involving a methyltransferase and a reductase [80][81][82]. Thus, biomimetic transformation from

Comparative cell biological study of in vitro antitumor and antimetastatic activity on melanoma cells of GnRH-III-containing conjugates modified with short-chain fatty acids

• Eszter Lajkó,
• Sarah Spring,
• Rózsa Hegedüs,
• Beáta Biri-Kovács,
• Sven Ingebrandt,
• Gábor Mező and
• László Kőhidai

Beilstein J. Org. Chem. 2018, 14, 2495–2509, doi:10.3762/bjoc.14.226

• ; Introduction The application of more selective, targeted drugs has become increasingly important in the treatment of tumors, where the use of chemotherapeutics with low therapeutic index is restricted by the adverse events coming from the toxicity of these drugs to normal cells [1]. One of the most promising

• (Dau=Aoa) ~ GnRH-III(Dau=Aoa). While there were no significant differences between [4Lys(Ac)]-GnRH-III(Dau=Aoa) and [4Lys(Bu)]-GnRH-III(Dau=Aoa) in terms of long-term (48 h) toxicity, the conjugate with butyryl side chain proved to be more effective after 6 h-long exposure. It seems that the short-term

Semi-synthesis and insecticidal activity of spinetoram J and its D-forosamine replacement analogues

• Kai Zhang,
• Jiarong Li,
• Honglin Liu,
• Haiyou Wang and
• Lamusi A

Beilstein J. Org. Chem. 2018, 14, 2321–2330, doi:10.3762/bjoc.14.207

• applied in pest control and crop protection due to their broad pest spectrum, high insecticidal activity, low environmental impact, and low toxicity to non-target species [4]. So far, more than 24 natural spinosyns and 800 semi-synthetic spinosyn analogues have been obtained and characterized, and their

• codling moth (Cydia pomonella), a major pest of pome fruits, tobacco budworm, cotton and vegetable crops [8]. Like spinosad, spinetoram elicits toxicity in the pest species via a neurotoxic mode of action. Although the exact mechanism of action has yet to be characterized, it is hypothesized that the

• a broad-pest spectrum and crop-uses, spinosad and spinetoram are both environment- and human-friendly. In addition, spinosad and spinetoram show high specificity to target insects and low toxicity to both mammals and beneficial insects [11]. Therefore, spinosad and spinetoram were successively

The enzymes of microbial nicotine metabolism

• Paul F. Fitzpatrick

Beilstein J. Org. Chem. 2018, 14, 2295–2307, doi:10.3762/bjoc.14.204

• Paul F. Fitzpatrick Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, 78229, USA 10.3762/bjoc.14.204 Abstract Because of nicotine’s toxicity and the high levels found in tobacco and in the waste from tobacco processing, there is a great

Synthesis of a water-soluble 2,2′-biphen[4]arene and its efficient complexation and sensitive fluorescence enhancement towards palmatine and berberine

• Xiayang Huang,
• Xinghua Zhang,
• Tianxin Qian,
• Junwei Ma,
• Lei Cui and
• Chunju Li

Beilstein J. Org. Chem. 2018, 14, 2236–2241, doi:10.3762/bjoc.14.198

• specific structures and interesting host–guest properties [21][22][23][24][25][26][27][28][29][30][31][32]. Water-soluble pillar[n]arene derivatives, especially those containing carboxylato moieties, showed low cell toxicity and good biocompatibility, and have been applied in biomedical applications such

A general and atom-efficient continuous-flow approach to prepare amines, amides and imines via reactive N-chloramines

• Katherine E. Jolley,
• Michael R. Chapman and
• A. John Blacker

Beilstein J. Org. Chem. 2018, 14, 2220–2228, doi:10.3762/bjoc.14.196

• ]. Whilst Cl2 gas is atom efficient it is difficult to handle, with associated toxicity, and the acid byproduct which leads to N-chloramine hydrolysis [16]. On the other hand, N-chlorosuccinimide or chloramine-T are commonly employed, being commercially available, stable and straightforward to handle

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• achieve this as well. This is the most energetically sustainable way possible to carry out a chemical transformation. A result of this use of the energy of photons is that photochemical transformations often require fewer and/or less reactive (which correlates to toxicity and environmental impact

Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3⁺ + 2]-cycloaddition/rearrangement reactions

• Lin-bo Luan,
• Zi-jie Song,
• Zhi-ming Li and
• Quan-rui Wang

Beilstein J. Org. Chem. 2018, 14, 1826–1833, doi:10.3762/bjoc.14.155

• examples of such clinically drugs having enhanced effects on the neurotransmitter γ-aminobutyric acid (GABA) at the GABAA receptor and low toxicity (Figure 1) [15]. Although 1,4-benzodiazepines are widely prescribed medicines, side effects like drowsiness, drug resistance, addiction and withdrawal

Recent advances in hypervalent iodine(III)-catalyzed functionalization of alkenes

• Xiang Li,
• Pinhong Chen and
• Guosheng Liu

Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154

• used in organic synthesis since the 1990s, due to their stability, low toxicity and mild reaction conditions [1][2][3][4][5][6][7][8][9][10]. Structurally, they always adapt a distorted trigonal bipyramidal geometry in which the less electronegative aryl ring and two lone pairs of electrons are