N-doped carbon dots covalently functionalized with pillar[5]arenes for Fe³⁺ sensing

• Jia Gao,
• Ming-Xue Wu,
• Dihua Dai,
• Zhi Cai,
• Yue Wang,
• Wenhui Fang,
• Yan Wang and
• Ying-Wei Yang

Beilstein J. Org. Chem. 2019, 15, 1262–1267, doi:10.3762/bjoc.15.123

• stability, and high resistance to photobleaching. Thus, fluorescent C-dots have been widely applied in the fields of imaging, catalysis, and sensing [5][6][7]. With the rapid development of fluorescent C-dots, much effort has been made to tune their electrical, optical, and chemical properties via doping

Molecular recognition using tetralactam macrocycles with parallel aromatic sidewalls

• Dong-Hao Li and
• Bradley D. Smith

Beilstein J. Org. Chem. 2019, 15, 1086–1095, doi:10.3762/bjoc.15.105

• tetralactams with parallel aromatic sidewalls are well-suited for various practical supramolecular applications such as molecular machines [72], optical imaging [73], organocatalysis [55], detection [74], and separations [24]. X-ray crystal structures of various squaraine rotaxanes show that the macrocycle

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

• sciences. These applications include spin-labels [5][6][7], fluorophore-nitroxide probes [8], contrast agents in magnetic resonance imaging (MRI) [9], polarization transfer agents for nuclear magnetic resonance (NMR) [10][11][12][13], and radical batteries [14][15]. Furthermore, the efficient synthesis of

Cyclopropene derivatives of aminosugars for metabolic glycoengineering

• Jessica Hassenrück and
• Valentin Wittmann

Beilstein J. Org. Chem. 2019, 15, 584–601, doi:10.3762/bjoc.15.54

Synthesis and SAR of the antistaphylococcal natural product nematophin from Xenorhabdus nematophila

• Frank Wesche,
• Hélène Adihou,
• Thomas A. Wichelhaus and
• Helge B. Bode

Beilstein J. Org. Chem. 2019, 15, 535–541, doi:10.3762/bjoc.15.47

• irreversible to a potential target, instead of the α-keto amide in 11 and 12 are stalled as it led to a complete loss of bioactivity. To the best of our knowledge, no one has ever tried to incorporate azaindole moieties in small natural products and tried to use them for fluorescence imaging. This approach may

• , the azaindole derivatives are currently under investigation upon their use for fluorescence imaging. Furthermore, derivatives 3 and 6 will be further studied for identification of their actual target in S. aureus. This could be a serine protease that can also be addressed in the future by more stable

Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

• Andrejs Šišuļins,
• Jonas Bucevičius,
• Yu-Ting Tseng,
• Irina Novosjolova,
• Kaspars Traskovskis,
• Ērika Bizdēna,
• Huan-Tsung Chang,
• Sigitas Tumkevičius and
• Māris Turks

Beilstein J. Org. Chem. 2019, 15, 474–489, doi:10.3762/bjoc.15.41

• as cell imaging tools [31][32], biosensors and sensors for detection of heavy metals [33]. The tendency of these structures to form hydrogen bonds, to respond to medium effects (solvatochromism) [34] and to certain impurities (e.g., coordination complexes with metal ions) make these compound classes

• fluorescence quantum yield to 74% in the case of 7-deazapurine derivative 11c. The solvent change provided a fluorescence shift from dark blue (≈440 nm) to orange (≈620 nm) color. Finally, the purines and 7-deazapurines were tested in live cell imaging on breast cancer cell lines MCF-7 and MDAMB231. They are

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• a few steps into (2S,5'S)-tricholomic acid [47]. The absolute configuration of (R)-(−)-carnitine was established by enzymatic decarboxylation of (2S,3R)-3-hydroxyglutamic acid followed by exhaustive methylation [121]. Fluoroglutamic acids are of special interest for PET imaging [122] and among other

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• recognition, imaging, and drug delivery in aqueous media [4][5][6][67]. They have a low tendency to entangle and can rapidly self-assemble in selective solvents even at very low concentrations forming large-domain microstructures. The facile synthesis of norbornenyl-terminated di- and triblock poly

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

• ) and CHO-β (FR +ve) cell lines and their respective competition experiments demonstrate the specificity of the newly synthesized bioconstructs for future application in fluorescent guided intra-operative imaging. Keywords: chelating linker; confocal studies; continuous synthetic process; fluorescent

• imaging (MRI) are exploited and each modality has its own strengths and weaknesses [3]. However, imaging studies using fluorescent probes [4] or radioactive isotopes [5][6] offers real-time, non-invasive, high-resolution images, during the examination of pathological diseased state. Prostate specific

• -operative imaging tools that would otherwise be produced by our methodology with a single purification step. Even though Universal Nova tag resin [36] (Figure 1a) has resolved this problem to some extent, it suffers from a problem of employing acidic condition to deprotect side chain 4-methoxytrityl (Mmt

Transition metal-free oxidative and deoxygenative C–H/C–Li cross-couplings of 2H-imidazole 1-oxides with carboranyl lithium as an efficient synthetic approach to azaheterocyclic carboranes

• Lidia A. Smyshliaeva,
• Mikhail V. Varaksin,
• Pavel A. Slepukhin,
• Oleg N. Chupakhin and
• Valery N. Charushin

Beilstein J. Org. Chem. 2018, 14, 2618–2626, doi:10.3762/bjoc.14.240

• functional derivatives of carboranes, in particular heterocyclic ones, are undeniably of increased interest in the chemistry of organoboron compounds due to wide opportunities to use these boron-enriched substances as diagnostic tools for tumor radio imaging [4][5][6][7], promising agents for boron neutron

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

• . [4Lys(Bu)]-GnRH-III(Dau=Aoa) possessing the butyryl side chain acting as a “second drug” proved to be the best candidate for targeted tumor therapy due to its cytotoxicity and immobilizing effect on tumor cell spreading. The applicability of impedimetry and holographic phase imaging for characterizing

• parameters – migration (shortest distance), motility (actual path) and motility speed (ratio of actual path and time) were quantified by tracking single cells in time-lapse videos recorded by a HoloMonitorTM M4 microscope (Phase Holographic Imaging AB, Lund, Schweden). Based on the results, the GnRH-III(Dau

• imaging are useful and suitable techniques for the characterization of cancer cell behavior and for the evaluation of effects of drug targeting conjugates with small structural differences (e.g., length of the side chain in 4Lys). Based on the overall cell biological effects of [4Lys(Bu)]-GnRH-III(Dau=Aoa

Hydroarylations by cobalt-catalyzed C–H activation

• Rajagopal Santhoshkumar and
• Chien-Hong Cheng

Beilstein J. Org. Chem. 2018, 14, 2266–2288, doi:10.3762/bjoc.14.202

• limited to terminal alkynes. Additionally, they applied this methodology to design a mitochondria-targeted imaging dye from electron-withdrawing formyl-substituted indoles and alkynes. Later, Maji’s group reported an N-tert-butyl amide-directed mono- and di-alkenylation reactions using a cobalt catalyst

Rational design of boron-dipyrromethene (BODIPY) reporter dyes for cucurbit[7]uril

• Mohammad A. Alnajjar,
• Jürgen Bartelmeß,
• Robert Hein,
• Pichandi Ashokkumar,
• Mohamed Nilam,
• Werner M. Nau,
• Knut Rurack and
• Andreas Hennig

Beilstein J. Org. Chem. 2018, 14, 1961–1971, doi:10.3762/bjoc.14.171

• dye are regenerated. This principle has enabled, for example, real-time monitoring of enzymatic activity [18][19][20], the detection of membrane-transport activity [21] and membrane fusion [22], and even cellular imaging appears to be a potential future prospect [23][24]. However, most combinations of

• (BODIPYs) with an aniline substituent in the meso-position as fluorescent dyes in this type of anchor approach (Figure 1). BODIPYs are a class of fluorescent dyes that are particularly suitable for applications in medical imaging, and as fluorescent labels in biology, biochemistry and related fields [29

• stability under various conditions, particularly under physiological conditions. Although most BODIPYs are insensitive to pH changes, pH-activatable optical probes for cancer imaging have been reported, in which an aniline substituent in the meso-position of the BODIPY core led to efficient fluorescence

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• its receptor [44][45][46], clustered RGD-containing compounds were developed and were shown to exhibit attractive biological properties for the imaging of tumors [47][48][49][50] and for the targeted drug delivery [51][52][53]. In the course of designing phototherapeutic agents that could specifically

Natural and redesigned wasp venom peptides with selective antitumoral activity

• Marcelo D. T. Torres,
• Gislaine P. Andrade,
• Roseli H. Sato,
• Cibele N. Pedron,
• Tania M. Manieri,
• Giselle Cerchiaro,
• Anderson O. Ribeiro,
• Cesar de la Fuente-Nunez and
• Vani X. Oliveira Jr.

Beilstein J. Org. Chem. 2018, 14, 1693–1703, doi:10.3762/bjoc.14.144

• 2.0 μmol L−1 staurosporine in water (positive control). The apoptosis assay was performed according to Matias et al. [36]. AFM measurements The AFM imaging of MCF-7 cells untreated (control) and treated with peptide (50 μmol L−1 solutions of Dec-NH2 and [Leu]8-Dec-NH2, which presented low activity

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

• Alberto Spinella,
• Marco Russo,
• Antonella Di Vincenzo,
• Delia Chillura Martino and
• Paolo Lo Meo

Beilstein J. Org. Chem. 2018, 14, 1498–1507, doi:10.3762/bjoc.14.127

• different alkyl diazides A1–A4 (Scheme 1b), in which the two azido groups are separated by spacers having different length and rigidity. The materials obtained were characterized by means of combined spectroscopic (FTIR, solid state 13C{1H} CP-MAS NMR), calorimetric (DSC) and imaging (SEM) techniques. Then

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• including photocatalysis [6], bio-imaging [7][8], and solar-energy conversion [9], just to cite a few. Thompson and Forrest reported in 1998 on the first example of a phosphorescent emitter, namely 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (Pt(OEP)), used as dopant for the fabrication of

• found numerous applications as emitting materials in areas such as emitters in PhOLEDs [55][56] and luminescent probes in bio-imaging [57][58][59]. Noteworthy, NIR-emitting OLED were fabricated by using complexes 23g and 23h, which presented a π-delocalized substituent at the 5-position of the central

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• , thereby changing the efficiency of the FRET process between the two fluorophores and exhibiting a significant red shift in the emission spectrum. Moreover, the conjugate 43 could be used as an attractive tool for imaging of nuclear DNA in the cells due to its low cytotoxicity. A series of water-soluble

On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site

• Eirinaios I. Vrettos,
• Gábor Mező and
• Andreas G. Tzakos

Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80

• presence of oxygen, rendered his observation puzzling for scientists, who still struggle to elucidate the complete mechanism of action of diseased cells. Following the Warburg effect, 18F-deoxyglucose positron emission tomography (FDG–PET) imaging was developed in order to visualize the phenomenon of

Synthesis and in vitro biochemical evaluation of oxime bond-linked daunorubicin–GnRH-III conjugates developed for targeted drug delivery

• Sabine Schuster,
• Beáta Biri-Kovács,
• Bálint Szeder,
• Viktor Farkas,
• László Buday,
• Zsuzsanna Szabó,
• Gábor Halmos and
• Gábor Mező

Beilstein J. Org. Chem. 2018, 14, 756–771, doi:10.3762/bjoc.14.64

• cytometry, the cellular uptake and localization of K1, K2, 1, 2, 4 and 5 were studied on MCF-7 cells by CLSM. After 6 h incubation with the GnRH-III–Dau conjugates (c = 10 µM, 40 µM and 160 µM), MCF-7 cells were fixed and prepared for confocal laser scanning imaging. In order to gain insight into a possible

• analyzed by FACSDiVa (BD Bioscience) 5.0 software. Confocal microscopy imaging Cells were seeded to cover glass containing (thickness 1, Assistant, Karl Hecht GmbH & Co KG, Sondheim/Rhön Germany) 24-well plates one day prior to the experiment in complete cell medium. Treatment was performed in serum-free

Fluorogenic PNA probes

• Tirayut Vilaivan

Beilstein J. Org. Chem. 2018, 14, 253–281, doi:10.3762/bjoc.14.17

• clamping and, at the same time, as a sensor probe in combination with another dye-labeled DNA probe in a single-tube operation by real-time fluorescence monitoring [86]. More challenging applications of binary PNA probes for imaging mRNA expression in living cells is possible at a proof-of-concept stage

• been successfully employed in one case [111]. A PNA-based strand displacement probe was delivered into mammalian cells by employing cationic shell cross-linked nanoparticles, whereupon its application in the imaging of cellular mRNA expression was demonstrated [112]. Related to the concept of strand

Synthesis and spectroscopic properties of β-meso directly linked porphyrin–corrole hybrid compounds

• Baris Temelli and
• Hilal Kalkan

Beilstein J. Org. Chem. 2018, 14, 187–193, doi:10.3762/bjoc.14.13

• quantum yield properties of the new hybrid compounds are promising for many applications such as organic optoelectronics or biological imaging. Conclusion In summary, we have synthesized the first examples of β-porphyrin, meso-corrole substituted directly linked porphyrin–corrole hybrid compounds via a

Microfluidic radiosynthesis of [¹⁸F]FEMPT, a high affinity PET radiotracer for imaging serotonin receptors

• Thomas Lee Collier,
• Steven H. Liang,
• J. John Mann,
• Neil Vasdev and
• J. S. Dileep Kumar

Beilstein J. Org. Chem. 2017, 13, 2922–2927, doi:10.3762/bjoc.13.285

• Thomas Lee Collier Steven H. Liang J. John Mann Neil Vasdev J. S. Dileep Kumar Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA Advion, Inc., Ithaca, NY, USA Molecular Imaging and Neuropathology Division, New York State

• -18; 5-HT1A; microfluidics; PET; Introduction The development of serotonin 1A receptor (5-HT1AR) agonist radiotracers for applications in molecular imaging with positron emission tomography (PET) has been avidly sought over the past two decades, albeit with limited success. The current status of

• longer half-life enables imaging protocols that can provide a better match of the pharmacokinetics of binding to the half-life of the radionuclide, as well as simplified radiochemistry protocols and the long-term goal of distribution for multicenter clinical trials. Several reports on the use of

Halogen-containing thiazole orange analogues – new fluorogenic DNA stains

• Aleksey A. Vasilev,
• Meglena I. Kandinska,
• Stanimir S. Stoyanov,
• Stanislava B. Yordanova,
• David Sucunza,
• Juan J. Vaquero,
• Obis D. Castaño,
• Stanislav Baluschev and
• Silvia E. Angelova

Beilstein J. Org. Chem. 2017, 13, 2902–2914, doi:10.3762/bjoc.13.283

• valuable properties as nucleic acid stains have made these dyes an irreplaceable tool in the active and developing area of bioanalytical chemical research [9][10]. Cyanine dyes have found various bioanalytical applications as soluble DNA intercalators (e.g., in living cell imaging [11] and flow cytometry

Reagent-controlled regiodivergent intermolecular cyclization of 2-aminobenzothiazoles with β-ketoesters and β-ketoamides

• Irwan Iskandar Roslan,
• Kian-Hong Ng,
• Gaik-Khuan Chuah and
• Stephan Jaenicke

Beilstein J. Org. Chem. 2017, 13, 2739–2750, doi:10.3762/bjoc.13.270

• antimicrobial [35][36], antitumor [37][38][39], antibacterial [40], and anti-allergic agents [41]. In addition, compounds with this backbone are employed as kinase inhibitors and receptors [42][43][44] and as a tracer for PET imaging of β-amyloid plaques [45][46]. The conventional approach for the construction