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

• host against oxidative radicals generated by UV irradiation [25][32]. To verify the antioxidative effect of the isoflavone dimers, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)-based antioxidant activity was performed [33]. The results showed that while 2 and 3 had an activity roughly

• equal to the monomers 4 and 6, 1 displayed a roughly twofold radical scavenging capacity (Figure S9, Supporting Information File 1). This is in agreement with the previous report that the configuration of the hydroxy group of the B-ring plays a key role in the antioxidant activity [34]. Thus, CYP158C1

• might provide an alternative pathway for antioxidant biosynthesis by using exogenous metabolites as substrates. The native substrate for CYP158C1, presumably produced by the clustered T3PKS, has yet to be identified. The broad substrate specificity of CYP158C1 towards plant polyphenols suggests a

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

• Streptomyces species [1][2][3][4]. Meanwhile, these types of compounds exhibit a broad spectrum of bioactivities, including antitumor [5][6], antibacterial [7][8], antioxidant [9][10][11][12], immunosuppressive [13], and antithrombotic activities [14]. The biosynthesis of the p-terphenyls has been studied

Synthetic strategies for the preparation of γ-phostams: 1,2-azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides

• Jiaxi Xu

Beilstein J. Org. Chem. 2022, 18, 889–915, doi:10.3762/bjoc.18.90

• analogues of γ-lactams, showing various biological activities, such as anti-inflammatory [15][16], antioxidant [17][18], and antitumor [18][19][20] (Figure 1). Various synthetic methods of 1,2-azaphospholidine 2-oxide and 1,2-azaphospholine 2-oxide derivatives have been developed to date. Two major

• tautomerization and intramolecular aminolysis. Non-aminolysis byproduct 234 was obtained in 25% (Scheme 37). Both of the chromene-fused 5-oxo-1,2-azaphospholidine 2-oxide derivatives 233 and 234 showed good antioxidant and antitumor activities [17]. [4 + 1] Annulation via formations of both C–C and C–N bonds When

• dioxane for 2 h. It was generated from the intramolecular aminolysis of diphenyl 3,5-di(tert-butyl)-4-hydroxyphenyl-(2,6-diaminopyridin-3-yl)methylphosphonate (251) and showed excellent antioxidant activity (Scheme 40) [18]. Conclusion 1,2-Azaphospholidine 2-oxides and 1,2-azaphospholine 2-oxides are

Synthesis of bis-spirocyclic derivatives of 3-azabicyclo[3.1.0]hexane via cyclopropene cycloadditions to the stable azomethine ylide derived from Ruhemann's purple

• Alexander S. Filatov,
• Olesya V. Khoroshilova,
• Anna G. Larina,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77

• substances. Many biologically active natural products have a spirocyclic skeleton in their structure [1][2]. In this regard, there is interest in studying heterocyclic spiro compounds for drug discovery. These compounds were found to exhibit a broad range of biological activities, including antioxidant [3

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

• falciparum strain [19]. Certain 7-chloroquinolinyl-pyrazole derivatives have also shown antibacterial [20], hypoglycemic as well as antioxidant activity [21] or can be used as selective nonpeptide neurotensin receptor type 2 compounds [22]. Some azolylquinolines have been used as agrochemical fungicides

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

• ) for the preparation of 32 with antioxidant properties was investigated by Gouda in 2012 [81]. Intermediate 18 was treated with two equivalents of 30 resulting in bispyrazolopyridine 31, which after treatment with refluxing acetic acid produced imidazopyrazole 32 (Scheme 7). Compounds 31 and 32 were

• evaluated against their antioxidant activity and exhibited promising activity. Protein tyrosine phosphatase 1B (PTP1B) is essential in the dephosphorylation of the activated insulin receptor, and inhibition of this enzyme would be an excellent strategy for the treatment of type 2 diabetes. Ahn and co

Host–guest interaction and properties of cucurbit[8]uril with chloramphenicol

• Lin Zhang,
• Jun Zheng,
• Guangyan Luo,
• Xiaoyue Li,
• Yunqian Zhang,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2021, 17, 2832–2839, doi:10.3762/bjoc.17.194

• cucurbit[n]urils can be used as non-toxic and safe drug carriers [29][30][31], among which cucurbit[8]uril (Q[8]) [32] has a large cavity. Q[8] interacts with a variety of small drug molecules such as chrysin, oroxin A and B, baicalein, etc., which can enhance the solubility, stability, antioxidant and

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

• imines, Schiff bases have the general organic function -C=N- [2], and are known to have a wide range of biological activities, including antioxidant [3], antitubercular [4], antibacterial [5], antimicrobial [6], and antifungal properties [7], in addition to their role as chemosensors [8] (Figure 1

• trifluoromethylated hybrid system comprising the Schiff base scaffolds from some 6-aminoquinolines and salicylaldehyde derivatives in order to analyze and evaluate their photophysical, photostability, and antioxidant properties for possible future applications in the pharmacological areas or materials sciences

• here highlights their potential as dyes in photobiological applications. Conclusion In conclusion, we reported the synthesis and photophysical and antioxidant properties of a new series of ten novel Schiff bases 3. The scaffolds 3 could be synthesized by a simple condensation reaction between 6

Transition-metal-free intramolecular Friedel–Crafts reaction by alkene activation: A method for the synthesis of some novel xanthene derivatives

• Tülay Yıldız,
• İrem Baştaş and
• Hatice Başpınar Küçük

Beilstein J. Org. Chem. 2021, 17, 2203–2208, doi:10.3762/bjoc.17.142

• , antitumor, antioxidant, and anticarcinogenic. Experimental General information The majority of the chemicals used in this work were commercially available from Merck or Aldrich. The starting compounds 1a–l were prepared by Ullmann coupling of 2-fluorobenzaldehyde and substituted phenols. Compounds 2a–l were

Catalyzed and uncatalyzed procedures for the syntheses of isomeric covalent multi-indolyl hetero non-metallides: an account

• Ranadeep Talukdar

Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137

• displayed high efficiency for activating AhR. Bis(indol-3-yl)selanes possess antioxidant properties. Pioneered by Wilshire [94], their syntheses were studied by Abele [95], Naidu [96], Yang [83], Thurow [97], and Talukdar [98]. The work of Abele in 2004 involved refluxing SeO2 with N-unprotected indole in

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• effects (85–89, Scheme 31A), such as antioxidant, α-amylase inhibitor, anticancer, and anti-inflammatory activities [164]. The reaction was promoted by non heme-Fe catalyst, behaving similarly to the bioinspired iron catalyst in a redox-selective way. The combination of Fe(phen)3(PF6)3 and tertiary

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• first gave ester 181 and then acid 182 (Scheme 31), the sodium and potassium salts of which are well soluble in water. The compound has antiviral and anticancer activity as well as pronounced antioxidant properties combined with low toxicity. Diarylmethanofullerene 183 was synthesized according to

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• antibacterial, antifungal, antioxidant, anti-inflammatory, and anticancer effects [4]. Later on, also heterocyclic compounds including 2-vinyl-4H-1,3-dithiine (6) and 3-vinyl-3,4-dihydro-1,2-dithiine (7) were discovered [5]. The formation of these volatile sulfur compounds starts from alliin (9) [6], a non

Regioselective chemoenzymatic syntheses of ferulate conjugates as chromogenic substrates for feruloyl esterases

• Olga Gherbovet,
• Fernando Ferreira,
• Apolline Clément,
• Mélanie Ragon,
• Julien Durand,
• Sophie Bozonnet,
• Michael J. O'Donohue and
• Régis Fauré

Beilstein J. Org. Chem. 2021, 17, 325–333, doi:10.3762/bjoc.17.30

• preparation of bioactive compounds with potential antioxidant properties [2][3][4][5]. Operating via a two-step serine protease mechanism involving a conserved Ser-His-Asp/Glu catalytic triad [6][7], Faes catalyze the hydrolysis of ester bonds linking hydroxycinnamoyl groups to the glycosyl moieties of plant

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• properties of OA was investigated through comparative experiments. The solubility of OA in water increased 22.47-fold when the concentration of Q[8] was 1 × 10−4 mol·L−1. Q[8] hardly affected the antioxidant capacity of OA, while the cumulative release of OA in gastric juice increased 2.3-fold after forming

• beneficial biological effects of OA, which include antioxidant, antidiabetic, anticancer, antibacterial, anti-inflammatory and antiviral properties [25][26][27][28][29][30]. Herein, we selected Q[8] as a host molecule and investigated its host–guest interactions with OA, as well as its effect on the

• addition of Q[8]. When the concentration of Q[8] was 1.0 × 10−4 mol·L−1, the solubility of OA was increased 22.47-fold. The solubility curve equation was S = 0.01c + 0.0575, R2 = 0.9986. Antioxidant activity OA has strong antioxidant activity and effectively eliminates ABTS+• radicals. If the antioxidant

Synthesis of 1,4-benzothiazinones from acylpyruvic acids or furan-2,3-diones and o-aminothiophenol

• Ekaterina E. Stepanova,
• Maksim V. Dmitriev and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2020, 16, 2322–2331, doi:10.3762/bjoc.16.193

• use. Particularly, some enaminones I and II were found to show antioxidant [3], antimycotic [7][8], antimycobacterial [9][10], anti-Alzheimer’s disease (JNK3 inhibitors) [11], platelet aggregation inhibitory [12], antimicrobial [7] and analgesic [13] activities. Enaminones II were reported as

Et₃N/DMSO-supported one-pot synthesis of highly fluorescent β-carboline-linked benzothiophenones via sulfur insertion and estimation of the photophysical properties

• Dharmender Singh,
• Vipin Kumar and
• Virender Singh

Beilstein J. Org. Chem. 2020, 16, 1740–1753, doi:10.3762/bjoc.16.146

• products [1][2][3][4] and pharmacologically active compounds endowed with anticancer [5][6][7][8][9], anti-inflammatory, antioxidant, antimalarial, antifungal, and antileishmanial activities (Figure 1) [10][11][12][13]. Notably, this privileged scaffold is incorporated in several marketed drugs such as

• a variety of biological activities such as anticancer [24], inhibition of tyrosine phosphatase 1B, antioxidant properties, etc. [25][26][27]. Due to their numerous applications, they have found diverse uses such as thioindigo-like dyes, photoresponsive devices, and photoswitchable biomolecules [28

Synthesis of new dihydroberberine and tetrahydroberberine analogues and evaluation of their antiproliferative activity on NCI-H1975 cells

• Giacomo Mari,
• Lucia De Crescentini,
• Serena Benedetti,
• Francesco Palma,
• Stefania Santeusanio and
• Fabio Mantellini

Beilstein J. Org. Chem. 2020, 16, 1606–1616, doi:10.3762/bjoc.16.133

• , or induce the manifestation of new features. The choice to insert an hydrazonic function on the DHBER skeleton was suggested by its wide range of interesting biological activities like antimicrobial [43], antioxidant [44], analgesic [45], anti-inflammatory [45], antiplatelet [45], anticonvulsant [46

• activity [61]. Furthermore, THBER and its derivatives are effective antioxidant agents [62][63][64][65]. To extend our investigations in this field, the obtained arylhydrazono-functionalized DHBERs were reduced to the corresponding arylhydrazono-THBERs, whose antiproliferative properties have been

• , namely pyrrolino-tetrahydroberberines, synthesized by some of us [68], exhibited enhanced antioxidant properties in comparison to THBER against a wide variety of pathophysiologically relevant oxidants such as peroxyl radicals, ferrous ion, and hydrogen peroxide [65]. In continuation of our ongoing

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

• in the host organisms. Keywords: antioxidant; Burkholderia sp; quinolone; soil bacterium; Zn2+ enrichment culture; Findings 4-Hydroxy-2(1H)-quinolone (3) is a unique structural motif mostly found in alkaloids from rutaceous plants (family Rutaceae) [1][2]. This motif has several tautomeric forms

• -hydroxy-3-methyl-2(1H)-quinolone (1, Figure 1). This compound was recently reported from the root of woad (Isatis tinctoria, family Brassicaceae) with no details of structure characterization [17]. Herein we describe the isolation, unequivocal structure characterization, and antioxidant activity of

Synthesis of pyrrolidinedione-fused hexahydropyrrolo[2,1-a]isoquinolines via three-component [3 + 2] cycloaddition followed by one-pot N-allylation and intramolecular Heck reactions

• Xiaoming Ma,
• Suzhi Meng,
• Xiaofeng Zhang,
• Qiang Zhang,
• Shenghu Yan,
• Yue Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2020, 16, 1225–1233, doi:10.3762/bjoc.16.106

• crispine A isolated from Carduus crispus L has antitumor activity [3]. Erythrina alkaloids have curare-like neuromuscular blocking activities [4], and also antioxidant activity against DPPH free radicals [5]. Lamellarins isolated from marine invertebrates [6] are inhibitors for HIV-1 integrase and also

Synthesis and anticancer activity of bis(2-arylimidazo[1,2-a]pyridin-3-yl) selenides and diselenides: the copper-catalyzed tandem C–H selenation of 2-arylimidazo[1,2-a]pyridine with selenium

• Mio Matsumura,
• Tsutomu Takahashi,
• Hikari Yamauchi,
• Shunsuke Sakuma,
• Yukako Hayashi,
• Tadashi Hyodo,
• Tohru Obata,
• Kentaro Yamaguchi,
• Yasuyuki Fujiwara and
• Shuji Yasuike

Beilstein J. Org. Chem. 2020, 16, 1075–1083, doi:10.3762/bjoc.16.94

• variety of methods [14][15], and many of the targets exhibited biological activity (Figure 1). For example, bis(2-pyridyl) diselenide I has the potential to mitigate oxidative stress and inhibits the AChE activity [16], bis(quinolin-8-yl) diselenide (II) exhibited antioxidant activity in a skin cell model

Reaction of indoles with aromatic fluoromethyl ketones: an efficient synthesis of trifluoromethyl(indolyl)phenylmethanols using K₂CO₃/n-Bu₄PBr in water

• Thanigaimalai Pillaiyar,
• Masoud Sedaghati and
• Gregor Schnakenburg

Beilstein J. Org. Chem. 2020, 16, 778–790, doi:10.3762/bjoc.16.71

• cruciferous vegetables [15], has a wide range of biomedical applications as an anticancer [16], antioxidant, and antiatherogenic agent [17]. Organofluorine compounds have attracted much attention due to their potential biological applications in medicinal and agricultural sciences. Introducing fluoro groups

The interaction between cucurbit[8]uril and baicalein and the effect on baicalein properties

• Xiaodong Zhang,
• Jun Xie,
• Zhiling Xu,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 71–77, doi:10.3762/bjoc.16.9

• solution using 1H NMR, UV–vis and IR spectroscopy, and DTA. The properties of the BALE–Q[8] inclusion complex, such as stability, solubility, in vitro antioxidant activity and release performance were studied by means of UV–vis spectroscopy. Results and Discussion Host–guest interactions Q[8] and BALE in

• Supporting Information File 1). If the BALE–Q[8] complex significantly reduces its antioxidant activity, this will affect the medicinal value of BALE. Figure 9 shows that Q[8] has no significant influence on the antioxidant activity of BALE. At 0.0005–0.004 mmol·L−1, BALE exhibited a linear increasing

• 3.4 × 105 L·mol−1 (neutral water). The solubility of BALE increased 4.67-fold in the phase-solubility experiment when the concentration of Q[8] was 1 × 10−4 mol·L−1. A study of the UV–vis absorption spectra with time showed that Q[8] significantly increased the stability of BALE. The antioxidant

Construction of trisubstituted chromone skeletons carrying electron-withdrawing groups via PhIO-mediated dehydrogenation and its application to the synthesis of frutinone A

• Qiao Li,
• Chen Zhuang,
• Donghua Wang,
• Wei Zhang,
• Rongxuan Jia,
• Fengxia Sun,
• Yilin Zhang and
• Yunfei Du

Beilstein J. Org. Chem. 2019, 15, 2958–2965, doi:10.3762/bjoc.15.291

• antibacterical [4], antifungal [5][6], anticancer [7], antioxidant [8], anti-HIV [9], antiulcer, immunostimulator [10], anti-inflammatory [11], as well as biocidal [12], wound-healing [13], and immune-stimulatory activities [14]. For instance, flavoxate [15][16] is a chromone derivative that was employed as an

• of the obtained chromone derivatives was their conversion to chromone-derived natural products. Frutinone A, isolated from the leaves and root bark of Polygala fruticosa, shows various biological activities, including antibacterial, antioxidant, and potent cytochrome P450 1A2 inhibition (CYP1A2, IC50

In water multicomponent synthesis of low-molecular-mass 4,7-dihydrotetrazolo[1,5-a]pyrimidines

• Irina G. Tkachenko,
• Sergey A. Komykhov,
• Vladimir I. Musatov,
• Svitlana V. Shishkina,
• Viktoriya V. Dyakonenko,
• Vladimir N. Shvets,
• Mikhail V. Diachkov,
• Valentyn A. Chebanov and
• Sergey M. Desenko

Beilstein J. Org. Chem. 2019, 15, 2390–2397, doi:10.3762/bjoc.15.231

• -dihydrotetrazolo[1,5-a]pyrimidine derivatives. Under similar conditions using 4,4,4-trifluoroacetoacetic ester 5-hydroxy-4,5,6,7-tetrahydrotetrazolo[1,5-a]pyrimidines are obtained. The analogous reaction with acetylacetone requires scandium(III) triflate as catalyst. The antioxidant activity of selected compounds

• was assayed with 1,1-diphenyl-2-picrylhydrazyl. Keywords: 5-aminotetrazole; antioxidant activity; 1,3-dicarbonyl compounds; multicomponent synthesis; tetrazolo[1,5-a]pyrimidines; Introduction Tetrazolo[1,5-a]pyrimidines and their partially hydrogenated derivatives are known for their interesting

• biological properties. They have been reported to have anticancer [1], antimicrobial [2][3] and antioxidant [3] activities and to act as inhibitors of hepatitis B virus [4]. The dihydro derivatives of tetrazolo[1,5-a]pyrimidines belong to a bit special kind of dihydropyrimidines due to the strong electron