-
The Journal of Organic Chemistry Dec 2021A series of α-amino acid-BODIPY derivatives were synthesized using commercially available -Boc-l-amino acids, via boron functionalization under mild conditions. The...
A series of α-amino acid-BODIPY derivatives were synthesized using commercially available -Boc-l-amino acids, via boron functionalization under mild conditions. The mono-linear, mono-spiro, and di-amino acid-BODIPY derivatives were obtained using an excess of basic (histidine, lysine, and arginine), acidic (aspartic acid), polar (tyrosine, serine), and nonpolar (methionine) amino acid residues, in yields that ranged from 37 to 66%. The conformationally restricted mono-spiro- and di-amino acid-BODIPYs display strong absorptions in the visible spectral region with high molar extinction coefficients and significantly enhanced fluorescence quantum yields compared with the parent BF-BODIPY. Cellular uptake and cytotoxicity studies using the human HEp2 cell line show that both the presence of an ,-bidentate spiro-ring and basic amino acids (His and Arg) increase cytotoxicity and enhance cellular uptake. Among the series of BODIPYs tested, the spiro-Arg- and spiro-His-BODIPYs were found to be the most cytotoxic (IC ∼ 22 μM), while the spiro-His-BODIPY was the most efficiently internalized, localizing preferentially in the cell lysosomes, ER, and mitochondria.
Topics: Amino Acids; Boron; Boron Compounds; Crystallography, X-Ray; Humans
PubMed: 34807610
DOI: 10.1021/acs.joc.1c02328 -
Journal of Trace Elements in Medicine... Dec 2020Boron is a trace element that plays an important role in numerous biological functions, including calcium metabolism, growth and maintenance of bone tissue. However,... (Review)
Review
BACKGROUND
Boron is a trace element that plays an important role in numerous biological functions, including calcium metabolism, growth and maintenance of bone tissue. However, there are still no precise indications regarding a possible role of boron supplementation, and its amount of supplementation, to maintain bone health. So the aim of this narrative review was to consider the state of the art on the effectiveness of boron supplementation (alone or with other micronutrients) on growth and maintenance of bone in humans through control of calcium, vitamin D and sex steroid hormone metabolism in order to suggest a daily dosage of boron supplementation.
MAIN FINDINGS
This review included 11 eligible studies: 7 regarding the supplementation with boron alone and 4 regarding supplementation with boron and other nutrients. Despite the number of studies considered being low, the number of subjects studied is high (594) and the results are interesting.
CONCLUSIONS
The studies considered in this narrative review have evaluated the positive effectiveness on bone, in humans, through control of calcium, vitamin D and sex steroid hormone metabolism, considering a dietary supplementation of 3 mg/day of boron (alone or with other nutrients); this supplementation is demonstrably useful to support bone health (in order to prevent and maintain adequate bone mineral density), also considering the daily dose of 3 mg is much lower than the Upper Level indicated by EFSA in the daily dose of 10 mg.
Topics: Bone Density; Bone and Bones; Boron; Calcium; Dietary Supplements; Female; Gonadal Steroid Hormones; Humans; Male; Vitamin D
PubMed: 32540741
DOI: 10.1016/j.jtemb.2020.126577 -
International Journal of Environmental... Aug 2022Boron overabundance in aquatic environment raises severe concerns about the environment and human health because it is toxic to various crops and induces many human and... (Review)
Review
Boron overabundance in aquatic environment raises severe concerns about the environment and human health because it is toxic to various crops and induces many human and animal diseases with long-term consequences. In response to the boron pollution of water resources and the difficulty of eliminating boron from water for production and living purposes, this article summarizes the progress in research on boron removal technology, addressing the following aspects: (1) the reasons for the difficulty of removing boron from water (boron chemistry); (2) ecological/biological toxicity and established regulations; (3) analysis of different existing processes (membrane processes, resin, adsorption, chemical precipitation, (electric) coagulation, extraction, and combined methods) in terms of their mechanisms, effectiveness, and limitations; (4) prospects for future studies and possible improvements in applicability and recyclability. The focus of this paper is thus to provide a comprehensive summary of reported deboronation processes to date, which will definitely identify directions for the development of boron removal technology in the future.
Topics: Adsorption; Boron; Humans; Technology; Water; Water Pollutants, Chemical; Water Purification
PubMed: 36078388
DOI: 10.3390/ijerph191710671 -
Scientific Reports Aug 2017Boron clusters are polyhedral boron hydrides with unique properties, and they are becoming increasingly widely used in biology and medicine, including for boron neutron...
Boron clusters are polyhedral boron hydrides with unique properties, and they are becoming increasingly widely used in biology and medicine, including for boron neutron capture therapy (BNCT) of cancers and in the design of novel bioactive molecules and potential drugs. Among boron cluster types, icosahedral boranes, carboranes, and metallacarboranes are particularly interesting, and there is a need for basic studies on their interaction with biologically important molecules, such as proteins. Herein, we report studies on the interaction of selected boron clusters and their derivatives with serum albumin, the most abundant protein in mammalian blood. The interaction of boron clusters with albumin was examined by fluorescence quenching, circular dichroism, dynamic and static light scattering measurements and MALDI-TOF mass spectrometry. Our results showed that metallacarboranes have the strongest interaction with albumin among the tested clusters. The observed strength of boron cluster interactions with albumin decreases in order: metallacarboranes [M(CBH)] > carboranes (CBH) >> dodecaborate anion [BH]. Metallacarboranes first specifically interact with the binding cavity of albumin and then, with increasing compound concentrations, interact non-specifically with the protein surface. These findings can be of importance and are useful in the development of new bioactive compounds that contain boron clusters.
Topics: Boron; Humans; Hydrodynamics; Kinetics; Molecular Conformation; Molecular Structure; Protein Binding; Serum Albumin; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Spectrum Analysis
PubMed: 28852112
DOI: 10.1038/s41598-017-10314-0 -
Current Opinion in Chemical Biology Jun 2019The β-lactams remain the most important antibacterials, but their use is increasingly compromised by resistance, importantly by β-lactamases. Although β-lactam and... (Review)
Review
The β-lactams remain the most important antibacterials, but their use is increasingly compromised by resistance, importantly by β-lactamases. Although β-lactam and non-β-lactam inhibitors forming stable acyl-enzyme complexes with nucleophilic serine β-lactamases (SBLs) are widely used, these are increasingly susceptible to evolved SBLs and do not inhibit metallo-β-lactamases (MBLs). Boronic acids and boronate esters, especially cyclic ones, can potently inhibit both SBLs and MBLs. Vaborbactam, a monocyclic boronate, is approved for clinical use, but its β-lactamase coverage is limited. Bicyclic boronates rapidly react with SBLs and MBLs forming stable enzyme-inhibitor complexes that mimic the common anionic high-energy tetrahedral intermediates in SBL/MBL catalysis, as revealed by crystallography. The ability of boronic acids to 'morph' between sp and sp hybridisation states may help enable potent inhibition. There is limited structure-activity relationship information on the (bi)cyclic boronate inhibitors compared to β-lactams, hence scope for creativity towards new boron-based β-lactamase inhibitors/antibacterials.
Topics: Anti-Bacterial Agents; Boron; Structure-Activity Relationship; beta-Lactamase Inhibitors
PubMed: 31004962
DOI: 10.1016/j.cbpa.2019.03.001 -
Advanced Science (Weinheim,... Jul 2022BN-heteroarenes, which employ both boron and nitrogen in aromatic hydrocarbons, have gained great attention in the fields of organic chemistry and materials science.... (Review)
Review
BN-heteroarenes, which employ both boron and nitrogen in aromatic hydrocarbons, have gained great attention in the fields of organic chemistry and materials science. Nevertheless, the extensive studies on BN-heteroarenes are largely limited to 1,2-azaborine-based compounds with B-N covalent bonds, whereas 1,3- and 1,4-BN-heteroarenes are relatively rare due to their greater challenge in the synthesis. Recently, significant progresses have been achieved in the synthesis and applications of BN-heteroarenes featuring 1,4-azaborines, especially driven by their significant potential as multiresonant thermally activated delayed fluorescence (MR-TADF) materials. Therefore, it is timely to review these advances from the chemistry perspective. This review summarizes the synthetic methods and recent achievements of 1,4-azaborine-based BN-heteroarenes and discusses their unique properties and potential applications of this emerging class of materials, highlighting the value of 1,4-BN-heteroarenes beyond MR-TADF materials. It is hoped that this review would stimulate the conversation and cooperation between chemists who are interested in azaborine chemistry and materials scientists working in the fields of organic optoelectronics, metal catalysis, and carbon-based nanoscience etc.
Topics: Aza Compounds; Boron; Boron Compounds; Hydrocarbons, Aromatic; Nitrogen
PubMed: 35419988
DOI: 10.1002/advs.202200707 -
Ecotoxicology and Environmental Safety Dec 2021Both cadmium (Cd) contamination and boron (B) deficiency in farmland soils pose a threat to the yield and quality of crops in Southern China. The present study...
Both cadmium (Cd) contamination and boron (B) deficiency in farmland soils pose a threat to the yield and quality of crops in Southern China. The present study investigated the mechanisms by which B reduces Cd accumulation in rice (Oryza sativa) seedlings. Boron supplementation partially restored the decline in shoot and root biomass caused by Cd treatment (26% and 33%, respectively), with no significant difference between the B+Cd and control groups. We also found that B significantly reduced shoot and root Cd concentrations (by 64% and 25%, respectively) but increased Cd concentration (by 43%) and proportion (from 38% to 55%) in root cell walls. Transcriptome analysis and biochemical tests suggested that B supplementation enhanced lignin and pectin biosynthesis, pectin demethylation, and sulfur and glutathione metabolism. Moreover, B decreased the expression of some Cd-induced transporter-related genes (i.e., HMA2, Nramp1, and several ABC genes). These results indicate that B relieved Cd toxicity and reduced Cd accumulation in rice seedlings by restraining Cd uptake and translocation from root to shoot by improving Cd tolerance and chelation ability. These novel findings would benefit further investigations into how B influences Cd uptake, translocation, detoxification, and accumulation in crops.
Topics: Boron; Cadmium; Crops, Agricultural; Oryza; Seedlings
PubMed: 34537586
DOI: 10.1016/j.ecoenv.2021.112776 -
PloS One 2021Turkey ranks second in watermelon (Citrullus lunatus L.) production globally and the highest production is witnessed for Çukurova plains the country. Although...
Turkey ranks second in watermelon (Citrullus lunatus L.) production globally and the highest production is witnessed for Çukurova plains the country. Although watermelon is extensively cultivated in the Çukurova region, studies on optimum nitrogen (N) and boron (B) doses for watermelon cultivation are quite limited. This study, evaluated the impact of increasing N (0, 90, 180 and 270 kg ha-1) and B (0 and 2 kg ha-1 B) doses on nutrient uptake in rind (exocarp) and flesh (endocarp) of watermelon fruit. Grafted watermelon variety 'Starburst', widely cultivated in the region was used as experimental material. The concentrations of different macro and micronutrients were analyzed from fruit rind and flesh. Individual and interactive effect of N and B doses significantly altered macro and micronutrients' uptake in rind and flesh. Higher amounts of macro and micronutrients were accumulated in rind than flesh. Nutrients' uptake was increased with increasing N doses, whereas B had limited impact. The accumulated nutrients were within the safe limits for human consumption. The N concentrations of rind and flesh increased with increasing N dose. Similarly, B concentration in rind and flesh and N concentration in rind significantly increased, while N concentration in flesh decreased with B application. It was concluded that 270 kg ha-1 N and 2 kg ha-1 B are optimum for better nutrient uptake in watermelon fruit. Thus, these doses must be used for watermelon cultivation in Çukurova plains of the country.
Topics: Boron; Citrullus; Fruit; Micronutrients; Nitrogen
PubMed: 34043729
DOI: 10.1371/journal.pone.0252437 -
Environmental Research Apr 2019Experimental studies show developmental toxicity of boron and we recently found impaired weight and length in newborns of mothers exposed to boron through drinking water...
BACKGROUND
Experimental studies show developmental toxicity of boron and we recently found impaired weight and length in newborns of mothers exposed to boron through drinking water during pregnancy.
OBJECTIVES
To evaluate potential impact of pre- and postnatal boron exposure on infant anthropometry.
METHODS
In our mother-child cohort (n = 177) in Argentinean Andes, where drinking water concentrations of boron, lithium and arsenic have been found to vary considerably, we collected maternal blood and urine during and after pregnancy, placenta, breast milk, as well as infant urine and blood during the first 6 months of life. In all samples, boron and other potentially toxic elements were measured by ICP-MS. Infant weight (g), length (cm) and head circumference (cm) were measured at birth, 0-3 (n = 120) and/or 3-6 months (n = 120; 79 overlap) of age.
RESULTS
Boron concentrations in breast milk (range: 46-786 µg/L) correlated strongly with those in maternal serum (range: 47-624 µg/L; r = 0.94) 0-3 months post-partum. In multivariable-adjusted linear regression, urinary boron (log-transformed; range 60-9200 µg/L) in the youngest infants, but not maternal serum boron during pregnancy, was inversely associated with body weight at both 0-3 months (B: -141, 95% CI: -240; -42, p = 0.006) and 3-6 months (B: -200, 95% CI: -377; -23, p = 0.027). Infant urinary boron was also inversely associated with head circumference at 0-3 months (B: -0.39, 95% CI: -0.74; -0.04, p = 0.028), as well as length (B: -0.57, 95% CI: -1.1; -0.03, p = 0.040) and head circumference (B: -0.30, 95% CI: -0.64; 0.04, p = 0.083) at 3-6 months.
CONCLUSIONS
The observed first evidence that elevated environmental boron exposure in early infancy may adversely affect growth supports previous findings of boron-related impaired fetal growth. More research is needed to verify the findings at older age and in other populations.
Topics: Aged; Argentina; Boron; Cohort Studies; Environmental Exposure; Environmental Pollutants; Female; Humans; Infant; Infant, Newborn; Maternal Exposure; Mothers; Pregnancy
PubMed: 30654250
DOI: 10.1016/j.envres.2019.01.012 -
The New Phytologist Mar 2019Although a requirement for boron is a well-established feature of vascular plants, its designation, for almost a century, as essential is challenged and, instead, the... (Review)
Review
Although a requirement for boron is a well-established feature of vascular plants, its designation, for almost a century, as essential is challenged and, instead, the proposal is made that it has never been so as conventionally defined. This is because an alternative interpretation of published evidence negates its compliance with one of the criteria for essentiality, that its effects are direct. The alternative, here postulated, is that boron is, and always has been, potentially toxic, a feature which, for normal growth, development and reproduction, needed to be nullified. This was enabled by exploitation of boron's ability to be chemically bound to compounds with cis-hydroxyl groups. Although particular cell wall carbohydrate polymers, glycoproteins and membrane glycolipids are among candidates for this role, it is here proposed that soluble phenolic metabolites of, or related to, the components of the pathway of lignin biosynthesis, themselves potentially toxic, are primarily used by vascular plants. When metabolic circumstances allow these phenolics to accumulate endogenously in the cytoplasm, their own inherent toxicity is also alleviated, partially at least, by formation of complexes with boron. This chemical reciprocity, enhanced by physical sequestration of the complexes in vacuoles and/or apoplast, thus achieves, in a flexible but indirect manner, a minimization of the inherent toxicities of both boron and relevant phenolics. In these ways, the multifarious outcomes of impairments, natural or experimental, to this interplay are responsible for the lack of consensus to explain the diverse effects observed in the many searches for boron's primary metabolic role, here considered to be nonexistent. In particular, since a toxic element cannot have 'deficiency symptoms', those previously so-called are postulated to be largely due to the expressed toxicity of phenylpropanoids. A principal requirement for the otherwise toxic boron is to nullify, by means of its indirect chemical and physical sequestration, such expression. In these ways, it is therefore neither an essential nor a beneficial element as currently strictly defined.
Topics: Boron; Lignin; Plant Development; Plant Roots; Pollination; Trace Elements; Tracheophyta
PubMed: 30289999
DOI: 10.1111/nph.15519