Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• is regulated by such heat shock sensors. Although long-term high-temperature culture experiments are employed in this study, reactive oxygen species (ROS) may exert a stronger effect than high temperature. In actinomycetes, several sensor proteins for ROS have been reported (e.g., SoxR and OxyR

Research progress on the pharmacological activity, biosynthetic pathways, and biosynthesis of crocins

• Zhongwei Hua,
• Nan Liu and
• Xiaohui Yan

Beilstein J. Org. Chem. 2024, 20, 741–752, doi:10.3762/bjoc.20.68

• , and epileptic disorders [26][27]. Four mechanisms have been reported for the treatment of Alzheimer's disease with crocins. Crocins function as antioxidants that slow down the progression of the disease by increasing the ʟ-glutathione (GSH) level and reducing the presence of reactive oxygen species

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• proximity of the metallic centers which allows MMLCT transitions. These properties have been used to generate reactive oxygen species (ROS) and efficient photocatalytic oxidative cyanation of N-phenyl-1,2,3,4-tetrahydroisoquinoline. The photocatalytic activity of the catalyst could be allosterically imbibed

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• cancer [39], and bacterial, fungal, parasitic and viral infections [40][41]. In general, PDT operates on the basis of a photosensitizer, which generates reactive intermediates upon irradiation [42][43][44][45]. Hence, in the type-I mechanism the photosensitizer induces the formation of reactive oxygen

• species (ROS), such peroxyl, alkoxy and hydroxyl radicals, or carbon-centered radicals, which subsequently induce DNA strand cleavage. In the type-II mechanism, a triplet-excited photosensitizer reacts with molecular oxygen to give highly reactive singlet oxygen, 1O2, as reactive intermediate, which in

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• ][35][36]. Our lead compound INHHQ (or 8-hydroxyquinoline-2-carboxaldehyde isonicotinoyl hydrazone) has been successfully tested in the prevention of short- and long-term memory deficits in a mice model of sporadic AD [33]. Additionally, INHHQ decreases copper-mediated production of reactive oxygen

• species (ROS) in vitro, which may be another mechanism through which the compound exerts its protective effects in the brain. From a drug development perspective, however, INHHQ has some pharmacological limitations, such as low solubility and certain susceptibility to hydrolysis in a water-rich medium

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• ) protein [16][17], as well as perturbing carbohydrate metabolism to generate reactive oxygen species that damage the DNA [18], as modes of action for berberine’s antibacterial effects. The antitumor properties of berberine have been attributed to DNA binding, and in particular regulating the activity of

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

• molecular oxygen, or electrochemically generated superoxide (cathodic reduction of O2), which oxidize the Breslow intermediate [30][39]. In fact, the presence of some reactive oxygen species in the reaction environment was previously demonstrated by the formation of compound 1b (see Table 1). IL Recycling

Structural basis for endoperoxide-forming oxygenases

• Takahiro Mori and
• Ikuro Abe

Beilstein J. Org. Chem. 2022, 18, 707–721, doi:10.3762/bjoc.18.71

• endoperoxide-containing natural products, numerous synthetic analyses and biosynthesis of endoperoxide compounds have been reported [18][19][20][21]. In some cases; e.g., in the biosynthesis of artemisinin and ergosterol peroxides, a reactive oxygen species (ROS) such as singlet oxygen, which is generated by

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• reactive oxygen species (ROS) generation, resulted from the interactions between nucleophilic biomolecules and 1,4-naphthoquinonic nucleus of menadione and its derivatives. The presence of an α,β-unsaturated diketone in the quinone structures allows them to accept electrons through reduction processes

• ][38]. In the presence of oxygen, the reduced species is oxidized back to the quinone, thus completing the cycle. In case of naphthoquinones such as menadione, the quinone–semiquinone or quinone–hydroquinone interconversion generates reactive oxygen species (ROS), such as superoxide anion (O2

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

• damage caused by oxidative stress, especially by eliminating reactive oxygen species (ROS) such as hydroxyl radicals (•OH), superoxide anions (O2•‒), and singlet oxygen (1O2) [3][22][23]. Therefore, research in recent years has focused on new compounds obtained from natural sources or by synthetic

• possible reactive oxygen species in DMSO solution (e.g., hydroxyl and superoxide radical species) that are not identified by the type of photooxidation assay employed in this work. The good photostability and tendency of these Schiff base derivatives to generate 1O2 under light irradiation demonstrated

A visible-light-induced, metal-free bis-arylation of 2,5-dichlorobenzoquinone

• Pieterjan Winant and
• Wim Dehaen

Beilstein J. Org. Chem. 2021, 17, 2315–2320, doi:10.3762/bjoc.17.149

• nature makes them crucial players in both the regulation of reactive oxygen species and biological stress levels in human tissue [9], as well as in the photosynthesis of plants and bacteria [10]. Aside from their use in therapeutics, quinones possess unique photophysical and electronic properties

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

• acids and their metabolic derivatives, which may impact cellular homeostasis. In addition, proline metabolism is related to stress response and scavenging of reactive oxygen species in many organisms [62]. In E. coli, the main path for proline synthesis starts from glutamate, which is phosphorylated by

¹⁹F NMR as a tool in chemical biology

• Diana Gimenez,
• Aoife Phelan,
• Cormac D. Murphy and
• Steven L. Cobb

Beilstein J. Org. Chem. 2021, 17, 293–318, doi:10.3762/bjoc.17.28

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• accessible for MO and ii) the Au cores could perform as electron acceptors (Au+ to Au0), which prevents the recombination of the electron–hole pairs produced by TiO2. Such a system generated more excited electrons for the generation of reactive oxygen species (ROS) and also acted as an effective reaction

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

4-Hydroxy-3-methyl-2(1H)-quinolone, originally discovered from a Brassicaceae plant, produced by a soil bacterium of the genus Burkholderia sp.: determination of a preferred tautomer and antioxidant activity

• Dandan Li,
• Naoya Oku,
• Yukiko Shinozaki,
• Yoichi Kurokawa and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1489–1494, doi:10.3762/bjoc.16.124

• in liquid production cultures, quenched hydroxy radical-induced chemiluminescence emitted by luminol by 86%. Because some Burkholderia species are pathogenic to plants and animals, the above result suggests that 1 is a potential antioxidant to counteract reactive oxygen species-based immune response

• reactive oxygen species (ROS), is implemented in eukaryotic cells, including protists [32], as an innate immune response to deactivate foreign substances or as part of phagocytic digestion of internalized nutrients [33]. Pathogenic microbes are equipped with a multitude of strategies to circumvent host

Extension of the 5-alkynyluridine side chain via C–C-bond formation in modified organometallic nucleosides using the Nicholas reaction

• Renata Kaczmarek,
• Dariusz Korczyński,
• James R. Green and
• Roman Dembinski

Beilstein J. Org. Chem. 2020, 16, 1–8, doi:10.3762/bjoc.16.1

• HeLa and K562 cell lines [31]. The formation of a reactive oxygen species in the presence of cobalt compounds was determined in K562 cells. The results indicate that the mechanism of action for most antiproliferative cobalt compounds may be related to the induction of oxidative stress [31

α,ß-Didehydrosuberoylanilide hydroxamic acid (DDSAHA) as precursor and possible analogue of the anticancer drug SAHA

• Shital K. Chattopadhyay,
• Subhankar Ghosh,
• Sarita Sarkar and
• Kakali Bhadra

Beilstein J. Org. Chem. 2019, 15, 2524–2533, doi:10.3762/bjoc.15.245

• species (ROS) as some apoptotic features. Keywords: anticancer drug; cross metathesis; HDAC inhibition; hydroxamates; reactive oxygen species; Introduction Suberoylanilide hydroxamic acid (SAHA, 1, Figure 1, vorinostat [1][2], has now emerged as a FDA approved drug for the treatment of relapsed and

• preliminarily evaluated for anticancer activity towards HeLa cells. The administration of the analogues caused a significant decrease in the proliferation of HeLa cells. Furthermore, one of the analogues showed a maximum cytotoxicity with a minimum GI50 value of 2.5 µg/mL and the generation of reactive oxygen

Fluorescent phosphorus dendrimers excited by two photons: synthesis, two-photon absorption properties and biological uses

• Anne-Marie Caminade,
• Artem Zibarov,
• Eduardo Cueto Diaz,
• Aurélien Hameau,
• Maxime Klausen,
• Kathleen Moineau-Chane Ching,
• Jean-Pierre Majoral,
• Jean-Baptiste Verlhac,
• Olivier Mongin and
• Mireille Blanchard-Desce

Beilstein J. Org. Chem. 2019, 15, 2287–2303, doi:10.3762/bjoc.15.221

• . Indeed, photodynamic therapy is used in oncology for the treatment of certain types of tumors. It is based on the activation by light of photosensitizers, able to generate singlet oxygen and/or other reactive oxygen species (ROS), to induce the destruction of the targeted tissues [66]. The dendrimer

A review of the total syntheses of triptolide

• Xiang Zhang,
• Zaozao Xiao and
• Hongtao Xu

Beilstein J. Org. Chem. 2019, 15, 1984–1995, doi:10.3762/bjoc.15.194

• pathways involved in the regulation of reactive oxygen species (ROS) and/or nitric oxide (NO) [9], histone methyltransferase [10], HSP70 [11], Jak2, Bcl-2/Bax [12], caspase 8 [13], NF-κB [14], X-linked inhibitor of apoptosis protein (XIAP) [15], MAPK, PI3K [16], and MPK1, ERK-1/2, and JNK-1/2 [17]. The

Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response

• Yu-Ying Wang,
• Yong Kong,
• Zhe Zheng,
• Wen-Chao Geng,
• Zi-Yi Zhao,
• Hongwei Sun and
• Dong-Sheng Guo

Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139

• with substrates, typically oxygen, to produce reactive oxygen species. The competitive complexation can not only be applied in diagnosis via the aforementioned IDA but also be engaged in therapy. We proposed a host–guest strategy for activatable phototheranostics termed biomarker displacement

• activation (BDA) [27]. In that work, we employed the four PSs and studied their host–guest complexation with GC5A. Each PS has a strong binding affinity upon 1:1 complexation with GC5A (Table 1), accompanied by a drastic annihilation of both fluorescence and photoactivity (reactive oxygen species generation

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

• oxygen species (ROS) were detected in the cells irradiated in the 2a-containing medium, but not in the non-irradiated cells in 2a-containing medium or the irradiated cells without 2a-containing medium (Figure 6). Thus, the preliminary analyses indicated that the photochemical generation of radicals from

• also observed (Figure 5). To evaluate whether the cytocidal effect was due to photochemical radical generation, cells exposed to 360 nm light for 1 min and the unexposed congeners were stained by using a ROS-ID oxidative stress detection kit (Enzo Life Sciences, Farmingdale, NY, U.S.A.). Reactive

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

• the past it has been postulated that artemisinins kill intraerythrocytic parasites such as P. falciparum in the presence of Fe2+ forming reactive oxygen species (ROS) [4]. As artemisinin and similar derivatives are destroyed by Fe2+ in vitro (Fenton reaction), it is difficult for us to explain their

Tandem copper and photoredox catalysis in photocatalytic alkene difunctionalization reactions

• Nicholas L. Reed,
• Madeline I. Herman,
• Vladimir P. Miltchev and
• Tehshik P. Yoon

Beilstein J. Org. Chem. 2019, 15, 351–356, doi:10.3762/bjoc.15.30

• oxidant that would be compatible with the chemistry of the radical intermediates, would not generate any highly reactive oxygen species, and would not produce toxic or chromatographically problematic byproducts. As a starting point for our optimization studies, we examined the intramolecular oxyamination