Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• chromene 5, which is a strong phenol. It is therefore easily separable as a nearly pure compound from the complex reaction mixture by extraction of the ether solution with NaOH. According to the literature, 5 should be converted into melifolione B (2) under acidic conditions [6]. Numerous attempts were

• of an alkaline solution of ferricyanide to a hydrogen peroxide containing solution of the melifoliones (1:2 ratio ca. 10:1) in acetonitrile, the color turns deep purple and later orange. After consumption of educts (TLC), extraction with ether yielded small amounts of a new substance as glistening

• . Successive extraction with 0.1 N NaOH (5 × 20 mL) afforded a clear alkaline water phase that was acidified with dilute sulfuric acid and extracted with diethyl ether (5 × 20 mL). The organic phase was washed with water, dried over MgSO4, filtered and evaporated under reduced pressure to give 3,1 g (51.2%) of

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• extractants. Here, we report the design and synthesis of PCP HA, a phenoxycalix[4]pyrrole scaffold functionalized with four hydroxamic acid (HA) groups, and evaluate its uranium(VI) extraction potential. PCP HA was synthesized from its ester precursor (PCP E) via hydroxyaminolysis using KOH, achieving a 95

• % yield. Its structure was confirmed by 1H NMR, 13C NMR, and HRMS. The uranium(VI) extraction efficiency of PCP HA was evaluated by solid–liquid extraction experiments, using uranyl acetate as the uranium source, with measurements performed by gamma spectroscopy. PCP HA demonstrated good performance

• , removing up to 95% of uranyl(VI) from aqueous solutions (1 mM) at acidic pH, likely due to the strong coordination provided by its hydroxamic acid groups. Further studies revealed that the extraction efficiency also depends on the ligand-to-metal molar ratio. These findings establish PCP HA as a promising

A facile and practical method for the synthesis of trans-(±)-taxifolin and its derivatives via Darzens reaction

• Bo Peng,
• Panpan Yang,
• Maaz Khan,
• Xiaotong Lin,
• Jiang Wu,
• Peng Fu and
• Qingqing Wu

Beilstein J. Org. Chem. 2026, 22, 443–450, doi:10.3762/bjoc.22.31

• [6] (Figure 1). Taxifolin can be obtained by extraction from natural plants [7][8][9], however, this is not economically viable due to the complicated extraction and purification process and low natural abundance of taxifolin. Enzymatic synthesis [10][11][12][13][14] is another method employed to

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• macrocyclic core through simple acylation of p-aminocalix[4]arenes with the respective phosphorous-containing activated esters. Such grafting of well-known receptor units onto a common platform has led to substantial amplification of the efficiency of lanthanide and actinide extraction from acidic media by

• carbamoylmethylphosphine oxides along with enrichment of the extraction selectivity [36][37][38][39][40][41][42][43][44][45]. Even more impressive is the effect from grafting of four urea groups at the wide rims of calix[4]arene macrocycles achieved by reacting p-aminocalix[4]arenes with aryl- or arylsulfonyl isocyanates

• copper complex (although an extraction procedure for complex destruction using Na2S2O3 was applied), which was difficult to separate from the relatively polar free calixarene 37 using column chromatography. In line with this, when toluene-soluble CuI·P(OEt)3 was used as a catalyst (in this case heating

Dialkylaminoalkylation of β-ketosulfones via ring-opening of 3-sulfonylpyrrolidines

• Evgeny M. Buev,
• Alexander V. Pavlushin,
• Vladimir S. Moshkin and
• Vyacheslav Y. Sosnovskikh

Beilstein J. Org. Chem. 2026, 22, 383–389, doi:10.3762/bjoc.22.26

• ] cycloaddition of azomethine ylides at various vinyl sulfones were well studied [38][39][40][41], a method for the preparation of 3-sulfonylpyrrolidines from β-ketosulfones was previously unknown. We synthesized a number of pyrrolidines 2a–f in 83–97% yield, which were purified by an acid-base extraction (Scheme

• extraction or column chromatography. On the other hand, upon performing the reaction with amines in acetonitrile we did not observe the formation of benzamides. Presumably, debenzoylation occurred in basic media with water traces and cesium benzoate was discarded upon work-up. The presumable mechanism of the

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

• Kazuya Asao,
• Seika Matsumoto,
• Haruka Mori,
• Riku Yoshimura,
• Takeshi Sasaki,
• Naoya Hirata,
• Yasuyuki Hayakawa and
• Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

• pyrophosphate ester intermediate because of its steric hindrance, and the yield of diaryl phosphate was low. Phytic acid extraction and phosphate ester synthesis The extraction of phytic acid from rice bran was based on a study conducted by Ida et al. [1]. As rice bran generally contains rice bran oil, it was

• first delipidated with n-hexane. Phytic acid was extracted with 1 M HCl for 1 h. After extraction, the pH value was adjusted to 4.5 with 8.0 M NaOH, which is the isoelectric point of rice bran protein. Solids were removed via filtration and centrifugation followed by supernatant collection. The phytate

• Chemical Industry. The rice bran used for phytic acid extraction was purchased from a rice-cleaning mill in Saga, Japan. Phytic acid extraction Phytic acid was extracted as described by Ida et al. [1]. n-Hexane (300 mL) was poured into rice bran (30 g) and the mixture was stirred with a magnetic stirrer

Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679

• Akiho Yagi,
• Hitomi Tomura,
• Ami Konno and
• Ryuji Uchida

Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12

• acetone; therefore, they may be artifacts that formed via the nucleophilic addition of acetone to a ketone-bearing precursor during the extraction process. Despite various modifications to fermentation conditions, it was not possible to detect or isolate the presumed natural precursor. We are currently

• formed during extraction. The discovery of streptoquinolines expands the structural and biological diversities of drimane–quinoline-type meroterpenoids and provides novel insights into their potential as scaffolds for the development of antibacterial agents targeting multidrug-resistant Gram-positive

One-pot synthesis of ethylmaltol from maltol

• Immanuel Plangger,
• Marcel Jenny,
• Gregor Plangger and
• Thomas Magauer

Beilstein J. Org. Chem. 2025, 21, 2755–2760, doi:10.3762/bjoc.21.212

• , needles, and bark of certain trees. In particular, the bark of larch trees contains 0.1–2 wt % maltol (2) and economic isolation methods using for example aqueous tannin liquors with extraction efficiencies of >90% have been developed [22][23][24]. Owing to the natural availability of maltol (2

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• competing dicyanoargentate(I) anions. We also examine the recyclability of the material and assess its stability in organic solvents, comparing its performance with that of a previously developed material containing noncovalently bound bambusuril. Keywords: anion binding; anion extraction; anion receptor

• ]. In the field of anion extraction, there is growing interest in solid-phase substrates functionalized with synthetic macrocyclic receptors. These materials employ a supramolecular approach based on specific host–guest interactions between the immobilized macrocycle and the guest in solution, often

• leading not only to improved extraction effectivity but also to enhanced selectivity [2]. Anion extractants based on functionalized polystyrene or silica gel typically incorporate calixarenes [6] and their analogues, calixpyrroles [7][8], azacalixarene derivatives [9], or expanded porphyrin-like sapphyrin

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• different sources [4][5]. In order to fulfil this requirement, a considerable number of green solvents of various classes have been developed for a range of applications, including the extraction of natural compounds [6][7][8][9], food analysis [10][11][12], pharmacology [13][14][15], and organic synthesis

• -cyclodextrin [123]. An attempt was made to synthesize compound 3a in water under the reaction conditions specified in Table 1, entry 10. TLC analysis after 10 minutes revealed the presence of the starting nitrone in the reaction medium. The isolation of the product was achieved through extraction with EtOAc

Conformational effects on iodide binding: a comparative study of flexible and rigid carbazole macrocyclic analogs

• Guang-Wei Zhang,
• Yong Zhang,
• Le Shi,
• Chuang Gao,
• Hong-Yu Li and
• Lei Xue

Beilstein J. Org. Chem. 2025, 21, 2369–2375, doi:10.3762/bjoc.21.181

• by enabling dynamic host–guest complementarity. Such insights are critical for designing adaptive receptors for applications like environmental sensing or selective ion extraction. Conclusion In summary, two carbazole-based macrocyclic structural analogs (PBG and WDG) were synthesized via a

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• for applications in anion transport, extraction, and separation technologies. Conclusion and Perspectives The development of photoswitchable rotaxanes has mainly focused on controlling the position and movement of the macrocycle along the axle. Consequently, the vast majority of systems reported to

Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• is in part due to limitations in the quantities obtained in the extraction processes. Other selected examples shown in Figure 1 all contain the same spirocyclic oxindole with a bridged azabicyclo[3.2.1]octane moiety. Several methods to access spirocyclic oxindole alkaloids have been reported [7][8][9

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• Wei Liu Xiaoyu Yang Key Laboratory of Subcritical High-Efficiency Extraction, College of Chemistry and Environmental Engineering, Anyang Institute of Technology, Anyang, Henan 455000, China School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China 10.3762/bjoc

Continuous-flow-enabled intensification in nitration processes: a review of technological developments and practical applications over the past decade

• Feng Zhou,
• Chuansong Duanmu,
• Yanxing Li,
• Jin Li,
• Haiqing Xu,
• Pan Wang and
• Kai Zhu

Beilstein J. Org. Chem. 2025, 21, 1678–1699, doi:10.3762/bjoc.21.132

• to achieve precise control of residence time, which is a key advantage of flow-chemistry technology. Conventional mixed-acid nitration systems utilize aqueous streams to rapidly deactivate nitration activity, necessitating simultaneous heat extraction to mitigate the substantial exothermic energy

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• acyclic heteroaromatics [26][27]. Thus, to a solution of 4 in CH2Cl2 was added 15 equivalents of PIFA at −78 °C and stirred for 3 h. The mixture was then allowed to warm to room temperature to give a dark solution. The system was worked-up with NaBH4/MeOH for 10 minutes followed by extraction with CH2Cl2

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• are required to remove copper salts, and aqueous ammonia has been used to improve the efficacy of liquid–liquid extraction (see Supporting Information File 1 and experimental procedure). This issue made liquid–liquid extraction time-consuming and wasteful, while chromatographic column purification is

Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• relevant role in aerospace technology, being used in satellites [13] and telescopes [14] to protect sensitive components against the damaging effects of solar radiation. Production of gold encompasses the mining stage, followed by one more processing steps. Post-extraction processing can be carried out by

• accumulation in soil and water [17]. The shortage of natural resources in tandem with the increasing market demand for gold are driving the need to obtain this commodity from low grade ores, typically containing less than 1 wt % in gold, materials of difficult extraction, such as the gold-bearing silicates and

• -waste [21], or to acidophilic microbes such as chemolithotrophic bacteria and archaea, which can accelerate the oxidative dissolution of gold sulfides in a biotechnological extraction process suited for sulfidic ores [22]. Microbial leaching methods are not, however, implemented at the industrial scale

Unraveling cooperative interactions between complexed ions in dual-host strategy for cesium salt separation

• Zhihua Liu,
• Ya-Zhi Chen,
• Ji Wang,
• Qingling Nie,
• Wei Zhao and
• Biao Wu

Beilstein J. Org. Chem. 2025, 21, 845–853, doi:10.3762/bjoc.21.68

• L as an anion receptor to extract cesium salts (chloride, nitrate, carbonate, sulfate, and phosphate) from the solid phase into chloroform. Remarkably, Cs3PO4 exhibits the highest extraction efficiency, driven by strong cooperative interactions involving ion-dipole coordination between Cs+ and

• dual-host systems for selective ion separation. Keywords: anion binding; cesium extraction; dual-host strategy; ion-pair interaction; solid–liquid extraction; Introduction Ion-pair interaction, defined as the electrostatic attraction between a positively charged cation and a negatively charged anion

• binding. Compared to the use of individual anion or cation receptors, the dual-host strategy can significantly enhance the efficiency of ion-pair extraction. However, the driving forces and cooperative interactions of the complexed ions remain poorly understood (Figure 1a). To the best of our knowledge

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• -trans-cinnamoyl, these results suggested that massarilactone H could be an artifact formed during the extraction/isolation of massarilactone D. The molecular formula of compound 4 was deduced to be C38H32O9 from its HRESIMS spectrum (Figure S19, Supporting Information File 1) which showed the protonated

• with cinnamoyl chloride suggests that these two polyketides can interconvert from each other and could be artifacts and vice versa formed during extraction and isolation. This finding suggests that, to improve the antiproliferative efficacy of these derivatives, the exo-methylene group should be

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• the reaction with Na2S2O3 resulted in a 2:1 mixture of 9-Br-10-BnF-ANTH and 9,10-ANTH(BnF)2 with no remaining 9,10-ANTH(Br)2. However, the high boiling point of PhCN and its miscibility with almost every solvent that could be used for liquid–liquid extraction made the determination of isolated yields

Identification and removal of a cryptic impurity in pomalidomide-PEG based PROTAC

• Bingnan Wang,
• Yong Lu and
• Chuo Chen

Beilstein J. Org. Chem. 2025, 21, 407–411, doi:10.3762/bjoc.21.28

• of iVeliparib. The UV trace of the initially purified iVeliparib-AP6 and the MS ion extraction traces of the desired product and the byproduct 5 on HPLC. The structures of 6 and 7 and the MS ion extraction traces of 3, 4, 6, and 7 from HPLC analysis of the reaction mixtures after purification by

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• ], cosmetics, and detergents. Carbohydrates are the most abundant and versatile renewable sources of energy on earth. However, extraction of naturally occurring complex glycans from natural sources is a laborious and cumbersome task. Moreover, the isolated samples provide a low-yield heterogenous mixture of

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

• Rita Toshe,
• Syeda J. Khalid,
• Blondelle Matio Kemkuignou,
• Esteban Charria-Girón,
• Paul Eckhardt,
• Birthe Sandargo,
• Kunlapat Nuchthien,
• J. Jennifer Luangsa-ard,
• Till Opatz,
• Hedda Schrey,
• Sherif S. Ebada and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

• isolated from a lepidopteran larva found on the leaf litter buried in the soil, on October 6, 2012. Cultivation and extraction Samsoniella aurantia was cultivated on potato dextrose agar (PDA: 200 g potato, 20 g dextrose, 15 g agar in 1 L distilled water, Difco). Mycelial plugs, each with a diameter of 7.0

• growth, the cultures underwent extraction. The mycelia were initially soaked in acetone overnight, followed by two rounds of ultrasonic extraction with freshly added acetone for each cycle. Resultant suspensions were filtered, and the liquid was collected. The combined liquid phases underwent vacuum

• evaporation at 40 °C, forming a semi-solid residue dispersed in water. Liquid–liquid extraction against EtOAc (1:1) was conducted twice. The organic phases were combined, filtered, and evaporated under vacuum, while the aqueous phase was discarded. Isolation of compounds 1–6 The obtained organic crude extract

Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• extraction process and copper(II) removal. However, the addition of DETA led to decreased yields and a deterioration of the phase separation. It was observed that using a 20% aqueous sodium hydroxide solution, instead of 35%, negatively impacted phase separation, making the extraction process more time

• is simplified thanks to the ability of 2-propanol to partition from the sodium hydroxide aqueous solution, which allows prompt extraction of the products. Once 2-propanol is evaporated, the products can also be isolated as free amines by dissolving the residue in diethyl ether, decanting it into