From resource to innovation: A decision framework for sustainable boron research infrastructure

Evaluation of the biological effectiveness of L-4-boronophenylalanine in glioblastomas.

Abstract— Boron Neutron Capture Therapy (BNCT) is one of the innovative methods for treating oncological diseases. Its selectivity is based on the targeted delivery of the boron-10 isotope to tumor cells, followed by neutron irradiation, the 10 B(n, α) 7 Li reaction occurs with a local release of 2.79 MeV of energy. Budding boron delivery agents are nanoscale systems. This study evaluated in vitro cytotoxicity, accumulation, and retention of elemental boron nanoparticles, synthesized by laser ablation and laser fragmentation, in U87 and BT474 tumor cells and BJ-5ta fibroblasts. It was shown that both types of nanoparticles exhibit low cytotoxicity at therapeutically relevant concentrations. Boron accumulation was maximal after 24 h of incubation and was significantly higher in tumor cells, especially in the BT474 cell line, compared to fibroblasts. The obtained data indicate the promise of these nanoparticles as boron delivery agents for BNCT.

Objective. Boron neutron capture therapy is a cancer radiotherapy that uses the selective uptake of boron compounds by tumor cells, followed by neutron irradiation. Conventional dosimetry generally assumes a homogeneous boron distribution within tissues, yet evidence indicates intracellular heterogeneity. This work aims to improve the photon isoeffective dose model (PID) for glioblastoma multiforme (GBM) by incorporating subcellular-scale effects: (i) a correction factor for the stochastic nature of energy deposition due to intracellular boron localization, and (ii) the treatment of the nucleus-to-cytoplasm boron concentration ratio as a stochastic variable.Approach. The boron-10 microdistribution in U-87 glioblastoma cells was quantified for the first time through neutron autoradiography, revealing preferential accumulation in the nucleus. Following these experimental data, the nucleus-to-cytoplasm boron concentration ratio was described by a lognormal random variable, consistent with biological uptake processes. The correction factor was applied to the dosimetry of U-87 radiobiological data. Then, updated radiobiological parameters and subcellular-scale effects were integrated into the PID formalism and applied to a clinical case of GBM.Main results. The outcome was aMicrodosimetric PID, which extends conventional PID by explicitly including intracellular boron heterogeneity. Applied to U-87 data, proposed corrections revealed a 47% reduction in the compound biological effectiveness factor compared to conventional calculations, showing that neglecting subcellular distribution substantially overestimates the boron dose. For the clinical case, the total dose and 1 year progression-free survival (PFS) differed only by 4% and 3%, respectively, compared to conventional dosimetry. However, perturbation analyses indicated that under higher intracellular heterogeneity, plausiblein vivo, the deviations could become substantial (up to 22% in dose and 68% in PFS).Significance. These findings highlight the relevance of subcellular-scale modeling. The proposed microdosimetric model, grounded on experimentally derived microdosimetric corrections, provides a robust framework to improve both the accuracy and the personalization of BNCT treatment planning.

Sugar binding enhances fluorescence by strengthening the boron–nitrogen. Lewis acid–base interaction, which suppresses photoinduced electron transfer and quenched emission. As a result, these systems exhibit enhanced fluorescence in neutral aqueous solutions upon sugar binding. The use of substituted aryl boronic acids as chelating agents for saccharides has drawn significant interest in designing novel sugar sensing approaches. Over the past decade, numerous fluorescent probes for monosaccharides based on boronic acids have been developed. Three new diphenylazo-based boronic acid compounds (1–3) were synthesized. The sensing performance of the synthesized compounds toward glucose and fructose was investigated using UV-visible spectroscopy, fluorescence, time-resolved fluorescence, pH studies, cyclic voltammetry, and 1H NMR techniques. Upon the addition of sugars, changes were observed in both the absorption and fluorescence intensities of compounds 1, 2, and 3. The Benesi–Hildebrand plots yielded straight lines, indicating the formation of complexes between the sugars and the sensor molecules. The quantum yield and fluorescence lifetime values of the compounds in glucose and fructose media were higher than those in water, suggesting their sugar-sensing capabilities. At higher pH, the boronic acid group exists in its anionic form [B(OH)-3], leading to a change in the boron atom’s configuration from sp² to sp³, thereby facilitating binding with sugar molecules. A possible sugar-sensing mechanism is proposed. The conversion of the boron atom from an sp² to an sp³ configuration upon sugar binding is believed to cause the enhancement in fluorescence. Additionally, the observed increase in quantum yield and fluorescence lifetime confirms the interaction between the saccharide and probe molecules in the excited state.

We consider the thermochemical impact of post-CCSD(T) contributions to the total atomization energy (TAE, the sum of all bond energies) of first- and second-row molecules, and specifically their coupling with the subvalence correlation contribution. In particular, we find large contributions from (Q) when there are several neighboring second-row atoms. Otherwise, both higher-order triples T3-(T) and connected quadruples (Q) are important in systems with strong static correlation. Reoptimization of the reference geometry for core-valence correlation increases the calculated TAE across the board, most pronouncedly for second-row compounds with neighboring second-row atoms. We present a first proposal for a "W5 theory" protocol and compare computed TAEs for the W4-08 benchmark with prior reference values. For some key second-row species, the new values represent nontrivial revisions. Our predicted TAE0 values (TAE at 0 K) agree well with the ATcT (Active Thermochemical Tables) values, including for the very recent expansion of the ATcT network to boron, silicon, and sulfur compounds.

Design, synthesis, and anti-HPV activity evaluation of neocryptolepine derivatives with boronic acid modification.

Colorimetric and fluorometric dual-response system for rapid analysis of gentamicin in real samples.

Boron chemistry is one of the most interesting fields for synthetic organic chemists. In present investigation we synthesized 3-methyl-1-phenyl-2-pyrazolone from the reaction of ethyl acetoacetate and phenyl hydrazine. 3-methyl-1-phenyl-2- pyrazolone treated with benzene diazonium chloride to furnish arylazo pyrazolone ligand. Boric acid reacts with isopropanol in benzene to form boron isopropoxide as a colourless viscous liquid. Refluxing of boron isopropoxide with catechol in benzene gives isopropoxy-benzodioxaboron. isopropoxy-benzodioxaboron and 3-methyl-1-phenyl-2-pyrazolone was refluxed in benzene to give four coordinated boron complexes. The structures of all synthesized compounds were confirmed by physical and analytical data. All synthesized arylazo pyrazolone ligand were evaluated for drug-likeness under Lipinski’s, Ghose, Veber, Egan and Muegge’s rules and may have good drug candidature.

ConspectusIn 1981, the year he won the Nobel Prize, Roald Hoffmann together with Kazuyuki Tatsumi published two papers entitled "Metalloporphyrins with Unusual Geometries" that strongly influenced the state of the art in porphyrin and tetrapyrrole research at that time. The 1970s and 1980s saw the dramatic expansion of bioinorganic chemistry, using the tools of molecular coordination chemistry to model complex processes of metalloenzymes and metal cofactors. Synthetic porphyrin ligands emerged as key platforms for high-valent metal-oxo and -nitrido species, metal-metal multiple bonds and the emergence of organometallic chemistry with porphyrins as the supporting ligands. These developments were the drivers for the Hoffmann papers, which featured extended Hückel calculations to expand our then understanding of types of metalloporphyrins for which experimental evidence was just emerging, and which challenged the notion of porphyrin functioning simply as a tetradentate macrocycle with a coordinated metal ion sitting squarely in the middle.Another unquestioned assumption from that time was that porphyrin and tetrapyrrole coordination chemistry was anchored firmly in the d block of the periodic table, a not unreasonable stance given the origins of this field in heme and vitamin B12 featuring iron and cobalt. Surprisingly, the presence of group 2 element magnesium in chlorophyll had not tempted chemists to interrogate more deeply the role of main group elements in tetrapyrrole chemistry, and at the time of the Hoffmann papers, examples of s and p block elements as porphyrin complexes could be almost counted on one hand. In the nearly half century since then, as the chemistry of tetrapyrrole main group complexes has unfolded, major new examples of complexes with unusual geometries have emerged. The chemistry of the d block elements is largely governed by oxidation states and d-electron configurations while in the s and p blocks the fundamental properties of size and electronegativity dominate. Porphyrins and tetrapyrroles offer four nitrogen donors in a square-planar arrangement of fairly fixed radii, not an obvious fit for main group elements with their widely ranging sizes, electronegativities, coordination geometries and bonding types. Main group tetrapyrrole complexes are "misfits" in which the poor match between the ligand environment and the requirements of the coordinated elements stimulates unusual chemistry for both partners.In this Account, I will use the concept of metalloporphyrins with unusual geometries addressed in the Hoffmann papers to look at how tetrapyrroles bearing coordinated main group elements have extended these ideas well beyond those originally envisaged. Main group metals range from lightweight lithium to the p block heavies thallium, lead and bismuth; all are known to form porphyrin complexes, some with dramatic out-of-plane metal coordination. The classic p block elements carbon, boron, and phosphorus challenge the "metalloporphyrin" paradigm; these small, light nonmetals nevertheless exhibit a rich chemistry in a tetrapyrrole setting. The extensive range of diboron porphyrinoids feature tetrapyrroles acting as binucleating ligands, incorporating not one but two elements within the N4 coordination site. Silicon and germanium porphyrins and phthalocynanines demonstrate the interplay between redox properties of the ligand and central element. The underlying theme in this discussion will be the new concepts that can be translated into other areas of the chemical sciences.

Boron is a chemically distinctive bioelement whose electron-deficient structure enables reversible coordination with oxygen-rich functional groups such as diols and hydroxyls. This property allows boron to modulate molecular stability, conformation, and biological reactivity, giving rise to both beneficial pharmacological effects and toxicological outcomes. This review examines the dual biological role of boron through the framework of bioactive boron-containing natural products and natural compounds capable of forming reversible boron complexes. Particular attention is given to naturally occurring boron-containing antibiotics, including the polyketide macrodiolides boromycin, aplasmomycin, tartrolons, and hyaboron, where boron plays a direct structural and functional role in antimicrobial activity. These compounds demonstrate how boron coordination can influence ion transport, membrane interactions, and molecular assembly, contributing to potent antibacterial properties. Beyond intrinsically boron-containing metabolites, many natural antibiotics and toxins possess oxygen-rich architectures capable of forming transient borate complexes through vicinal 1,2-diol motifs. Examples include polyene macrolide antibiotics such as amphotericin B, fungichromin, and nystatin, as well as tetracyclines, rifamycins, and macrolides such as sorangicin A, where boron coordination may affect solubility, aggregation, ionophoric behavior, and biological selectivity. Similar chemistry is observed in marine neurotoxins and polyether toxins-including tetrodotoxin, saxitoxin derivatives, azaspiracids, pectenotoxins, ciguatoxins, and gambierones-whose hydroxyl-rich frameworks enable reversible interactions with boron species present in seawater. Such complexation may enhance aqueous stability and contribute to trophic transfer and bioaccumulation within marine ecosystems. By framing boron as a molecular "double edge," this review integrates chemical, biological, and environmental perspectives to highlight how boron coordination can simultaneously enhance antimicrobial activity while influencing toxicity and ecological persistence. Recognizing the role of boron in shaping the activity of natural products provides new insight into antibiotic function, toxin behavior, and the broader impact of boron chemistry in biological systems.

Boron Neutron Capture Therapy (BNCT) is a binary targeted radiotherapy modality based on nuclear capture reactions. This technique exploits the tumor-targeting capability of boron compounds and their high thermal neutron capture cross-section, inducing localized nuclear reactions within cancer cells that generate α particles and lithium ions. This process enables selective tumor cell destruction at the cellular level. Clinical evidence demonstrates significant therapeutic efficacy of BNCT in treatment-refractory malignancies including glioblastoma, recurrent head and neck carcinomas, and cutaneous melanoma. Compared to conventional radiotherapy, BNCT leverages its inherent biological selectivity to achieve precise eradication of geometrically complex tumors and microscopic metastases, demonstrating significant clinical potential. However, the widespread adoption of BNCT remains constrained by several limitations, most notably the inadequate tumor selectivity of boron delivery agents. This review examines the literature published since the emergence of BNCT clinical research in 1970 up to the present, summarizing key clinical practices and strategies to enhance therapeutic efficacy, including boron carriers, administration regimens, treatment planning systems, real-time boron monitoring, and combination therapies. It aims to provide guidance for the clinical application of BNCT and support its broader adoption in practice.

Siderophores are classically understood as microbial iron-acquisition metabolites: low-molecular-weight ligands secreted by bacteria to solubilize and transport Fe(III) under iron-limited conditions. In this review, we expand that paradigm by highlighting an emerging and underappreciated chemical axis—boron coordination by siderophores—that links terrestrial (soil/rhizosphere) and marine microbiomes. Across diverse bacterial taxa, siderophore production is widespread and central to competitive fitness because Fe(III) is poorly soluble and frequently sequestered in environmental or host matrices. Yet in boron-rich settings (seawater and borate-enriched soils), the same oxygen-donor architectures that support Fe(III) chelation can also engage boron chemistry. We synthesize evidence that carboxylate/α-hydroxyacid (dicitrate-type) and catecholate siderophores can form tetrahedral borate/boronate complexes, whereas hydroxamate siderophores generally lack the vicinal dianionic O,O motif required for stable boron binding. Structurally characterized examples—including vibrioferrin, rhizoferrin, and petrobactin—demonstrate that boron complexation is experimentally observable by ESI-MS and multinuclear NMR and can be modulated by pH and microenvironment. Integrating these findings with datasets on boron-tolerant bacteria, we propose that when iron is scarce and boron is available, boron–siderophore complexation becomes chemically feasible and may influence microbial physiology by altering ligand conformation, metal selectivity, and potentially extracellular signaling behavior—especially in marine systems where borate is abundant at oceanic pH. Overall, this review frames boron-binding siderophores as a cross-ecosystem phenomenon and a promising conceptual bridge between environmental boron geochemistry, microbial metal economy, and metalloid-mediated signaling.

Boron compounds, classified as prohibited food additives due to their high toxicity, persist in pesticides and fertilisers, industrial processes, food supply chains, and consumer goods, perpetuating multisource exposure risks. Chronic ingestion may induce fatal hepatorenal injury; however, mechanistic insights and epidemiological surveillance remain critically lacking amidst sector-wide regulatory gaps. This study employed integrated cellular and organismal models to elucidate the relationship between boron-induced hepatotoxicity and ferroptosis. We demonstrate that dietary boron accumulation in chicken livers is associated with histopathological damage, mitochondrial cristae dissolution and atrophy (a hallmark of ferroptosis), and elevated serum biomarkers AST and ALT. Boron exacerbates oxidative damage in hepatocytes by elevating malondialdehyde (MDA) production while modulating the Nrf2/ARE antioxidant signaling pathway-specifically downregulating key genes (Nrf2, HO-1, GCLM, CAT). Concurrently, it inhibits critical antioxidant enzymes (SOD, T-AOC), thereby depleting cellular antioxidant defenses. Crucially, boron disrupts iron homeostasis and induces ferroptosis by dysregulating the SLC7A11-GPX4 pathway: upregulating pro-ferroptotic genes (ACSL4, TF, TFR) and downregulating cytoprotective genes (SLC7A11, GPX4, FTH1). Co-treatment with the ferroptosis inhibitor ferrostatin-1 (Fer-1) attenuated boron-induced oxidative damage, whereas the ferroptosis inducer Erastin potentiated toxicity. Collectively, we pioneer the dual-pathogenic mechanism of boron hepatotoxicity-oxidative stress and ferroptotic cell death-establishing the SLC7A11/GPX4 axis as a novel therapeutic target against boron toxicity.

We present a workflow that iteratively combines ab-initio calculations with a machine-learning (ML) guided search for superconducting compounds with both dynamical stability and instability from imaginary phonon modes, the latter of which have been largely overlooked in previous studies. Electron-phonon coupling (EPC) properties and critical temperature (Tc) of 417 boron, carbon, and borocarbide compounds have been calculated with density functional perturbation theory (DFPT) and isotropic Eliashberg approximation. Our study addresses Tc convergence of Brillouin zone sampling with an ansatz test, stabilizing imaginary phonon modes for significant EPC contributions, and comparing the performance of two ML models, especially when including compounds of dynamical instability. We predict a few promising superconducting compounds with formation energy just above the ground state convex hull, such as Ca5B3N6 (35 K), TaNbC2 (28.4 K), Nb3B3C (16.4 K), Y2B3C2 (4.0 K), Pd3CaB (7.0 K), MoRuB2 (15.6 K), RuVB2 (15.0 K), RuSc3C4 (6.6 K) among others.

Organocatalytic [4+4] Annulation of Indole-4-Boronic Acid with o-Hydroxybenzyl Alcohols for Constructing Indole-fused Oxaborocanes

ABSTRACT Herein, five new π‐conjugated small organic molecules ( DD1‐DD5 ) were synthesized starting from dibenzosuberone ( 1 ), applying a modular approach based on Suzuki coupling and Diels–Alder/ retro ‐Diels–Alder (DA/ r DA) reactions. The key intermediate, dibromodibenzosuberenone 4 , was obtained in three steps, and its Suzuki couplings with aryl and heteroaryl boronic acids furnished compounds 10‐12 . A Sonogashira‐type modification of compound 4 enabled the preparation of the diacetylene derivative 14 , which, together with compounds 10‐12 , was reacted with tetrazines 20 and 22 via DA/ r DA reactions to afford the target cycloadducts DD1‐DD5 . All compounds were characterized by NMR, FT‐IR, and HRMS analyses. UV–vis and fluorescence studies demonstrated that all DD1‐DD5 derivatives exhibited pronounced selectivity and high sensitivity toward Pb 2+ ions, showing distinct absorbance changes, strong turn‐on emission, and >100 nm mega‐Stokes shifts. DD1 displayed the most significant Pb 2+ response, while electron‐withdrawing groups of DD4 (–NO 2 ) and DD5 (–CF 3 ) modulated their optical behavior. Additional but weaker selectivity toward Fe 3+ was observed for DD4 and DD5 . Job plot analysis indicated 1:1 binding for DD1‐DD2 and 2:1 Pb 2 + –ligand stoichiometry for DD3‐DD5 . 1 H NMR titrations supported Pb 2+ complexation and revealed multi‐dentate binding, particularly for DD3 . Overall, the DD scaffold provides a tunable platform for selective Pb 2+ sensing with complementary anion‐responsive behavior.

Boron's dynamic covalent reactivity and flexible coordination offer medicinal promise yet remain underexplored in metalloenzyme pharmacophore design. In this study, a series of novel boronic acid-based HDAC inhibitors were designed and further optimized via amide-to-imidazole cyclization to enhance potency and pharmacokinetics. Among these compounds, Z16 showed potent HDAC inhibition (IC50 37.73 nM) and broad-spectrum antiproliferative activity, with IC50 values of 0.02-0.10 μM in various cell lines. In vitro and in vivo pharmacokinetic evaluation revealed that Z16 possesses a set of characteristics─including species-dependent metabolic stability, extensive tissue distribution, and high absolute bioavailability following intraperitoneal administration (i.p.). Z16 also showed comparable antitumor activity in an HCT116 xenograft model without causing significant loss of body weight or toxicity. These findings establish Z16 as a promising lead for nonhydroxamate HDAC inhibitors and highlight boronic acid's potential as a metalloenzyme-targeted pharmacophore.

The shift from fossil resources to natural polymers as the building blocks of a global bioeconomy is hampered by the intrinsic flammability of these bio-derived materials. In this paper, the recent advances in boron-based fire retardancy of natural materials are reviewed, highlighting the transition from macro-scale salt impregnation to molecular-level engineering of boron chemistry. Boron compounds act as a dual Lewis acid catalyst for dehydration and subsequent char formation, and as a glassy physical barrier to slow down the release of fuel and the diffusion of oxygen. The boron chemistry in the context of the physical constraints dictated by the natural material is analyzed. In solid wood and bamboo, the challenge is to use in situ mineralization and covalent grafting to overcome water solubility and leaching. In engineered wood composites and bio-based adhesives, boron moves from a passive additive to a structural element in the form of borate ester crosslinks. In flexible textiles, boron forms sol-gel architectures and synergistic combinations with phosphorus and nitrogen to achieve wash durability. Boron plays a crucial role in stabilizing high porosity nanocellulose aerogels and foams. The key challenges are identified to fulfil the potential of boron chemistry as a safe and sustainable approach for high performance natural materials.

ConspectusThe electron deficiency of boron promotes the formation of multicenter σ and π bonds that endow its clusters and solids with exceptional structural diversity. While bulk boron favors cage-like frameworks, clusters often adopt planar or quasi-planar motifs composed of triangles that evolve into tubular and cage-like architectures as their size increases. Many of these clusters are stabilized by delocalized σ and π bonds that are associated with fluxional behavior and multiple aromaticity.Metal doping enriches this chemistry. Transition metals use their d or f orbitals to couple with the boron framework, generating metal-centered rings, metallo-boron nanotubes, and metalloborophenes. In contrast, alkali and alkaline-earth metals have long been viewed as simple counterions, yet recent findings reveal that they can orchestrate deep structural reorganizations by combining charge transfer with efficient orbital overlap. Lithium, for example, leads to a quasi-planar → tubular → cage evolution in B12 clusters via strong electrostatic attraction to the boron framework, whereas beryllium engages in pronounced covalent Be-B interactions that yield rare architectures such as the Archimedean Be4B12+ cage, the B-Be sandwich B7Be6B7, and four-ring tubular forms like Be2B24+.In heavier alkaline-earth systems, the participation of (n-1)d orbitals (Ca, Sr, Ba) introduces transition-metal-like covalent interactions, producing highly symmetric rings and tubular clusters. This Account summarizes how electrostatic and covalent interactions jointly control geometry and bonding in boron-metal systems, defining the rich landscape of boron chemistry.