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A simple Ni(cod)2 and carbene mediated strategy facilitates the efficient catalytic cross‐coupling of methoxyarenes with a variety of organoboron reagents. Directing groups facilitate the activation of inert C−O bonds in under‐utilized aryl methyl ethers enabling their adaptation for C−C cross‐coupling reactions as less toxic surrogates to the ubiquitous haloarenes. The method reported enables C−C cross‐coupling with readily available and economical arylboronic acid reagents, which is unprecedented, and compares well with other organoboron reagents with similarly high reactivity. Extension to directing group assisted chemo‐selective C−O bond cleavage, and further application towards the synthesis of novel bifunctionalized biaryls is reported. Key to the success of this protocol is the use of directing groups proximal to the reaction center to facilitate the activation of the inert C−OMe bond. [ABSTRACT FROM AUTHOR]

Phenylboronic acids are used as synthetic intermediates in organic synthesis Suzuki-Miyaura reaction is important for the synthesis of many inhibitors of serine proteases. Geometry optimization was performed for the eight possible conformations of 3-formylphenylboronic acid (3FPBA) and 4-formylphenyl-boronic acid (4FPBA) using the DFT/B3LYP method with the 6-311++G(d,p) basis set. According to the theoretical calculation results, C3 conformation was found more stable than other conformations. The compounds 3FPBA and 4FPBA were investigated by using FT-IR (4000–400 cm–1), dispersive Raman (4000–40 cm–1) spectroscopy and theoretical DFT/B3LYP/6-311++G(d,p) calculations. The calculation results have been compared with observed values, which agree with each other. Natural bonding orbital (NBO) analysis was performed to analyze the hyper-conjugative stability of the molecule, molecular orbital interaction and charge delocalization. Frontier orbitals (FMOs) were identified to describe the reactivity of the title molecules. The calculated UV–Vis absorption spectrum was analyzed using the TD-DFT approach. Furthermore, molecular docking studies of 3FPBA and 4FPBA compounds were performed with anti-apoptotic proteins. Our finding shows compounds 3FPBA and 4FPBA have same binding affinity with each of anti-apoptotic proteins. [ABSTRACT FROM AUTHOR]

A convenient and efficient method for synthesizing β-fluorocinnamate and derivatives is reported. Palladium (II) catalysis was employed in β-F elimination and coupling reaction of phenylboronic acid and ethyl 3,3,3-trifluoropropionate with a high yield and E-selectivity. The reaction was conducted under mild conditions and could be widely adapted to boronic acid substrates. [ABSTRACT FROM AUTHOR]

Doxorubicin shows good anticancer activity, but poor pharmacokinetic property and high organ toxicity restrict its clinical application. The synthesized phenylboronic acid‐modified F127‐chitosan conjugate was used to prepare doxorubicin‐loaded micelles through dialysis method. The physicochemical properties of the doxorubicin‐loaded micelles were characterized. These micelles were further evaluated for in vitro release/cytotoxicity, in vivo activity/biosafety, and pharmacokinetic studies. in vitro release experiment demonstrated that the release of doxorubicin from drug‐loaded micelles was pH‐dependent. in vitro cytotoxic study showed that the introduction of phenylboronic acid resulted in lower IC50 against B16 cells than that in non‐modified F127‐chitosan micelles group, and the doxorubicin‐loaded micelles displayed lower in vitro activity against B16, A549, and HT‐29 cells than free doxorubicin did. However, in vivo experiments confirmed that the doxorubicin‐loaded micelles were safe for mouse main organs, obviously improved pharmacokinetic parameters of doxorubicin in rat and achieved comparable inhibition of tumor growth with no animal death in B16‐bearing mice models throughout the experiment when compared with free doxorubicin. The phenylboronic acid‐sialic acid interaction and pH‐sensitive drug release might play important roles in increased tumor targeting and therapeutic effect of the doxorubicin‐loaded micelles. [ABSTRACT FROM AUTHOR]

We developed a biosensor based on radio frequency micro-resonator for sensitive detection of aqueous glucose solutions. The device incorporates a modified interdigital capacitor-based multilayer resonator realized using integrated passive device technology. In addition, reduced graphene oxide was functionalized by phenylboronic acid aided with graphene oxide for the selective binding of glucose molecules under an electromagnetic field, resulting in a reliable concentration-specific resonance characteristic of the samples. The resonance frequency and bivariate (in terms of magnitude dip and phase reversal of the reflection coefficient) characteristics were found to be linearly related to the glucose concentration, thereby demonstrating the utility of the proposed microwave passive sensor in the detection of glucose with a sensitivity of 0.32 MHz per mg · dL-1. Furthermore, the corresponding variation in the capacitance and the impedance was accessed for each concentration of the glucose solutions.

We have developed a convenient and selective method for the detection of Gram-positive bacteria using a ditopic poly(amidoamine) (PAMAM) dendrimer probe. The dendrimer that was modified with dipicolylamine (dpa) and phenylboronic acid groups showed selectivity toward Staphylococcus aureus. The ditopic dendrimer system had higher sensitivity and better pH tolerance than the monotopic PAMAM dendrimer probe. We also investigated the mechanisms of various ditopic PAMAM dendrimer probes and found that the selectivity toward Gram-positive bacteria was dependent on a variety of interactions. Supramolecular interactions, such as electrostatic interaction and hydrophobic interaction, per se, did not contribute to the bacterial recognition ability, nor did they improve the selectivity of the ditopic dendrimer system. In contrast, the ditopic PAMAM dendrimer probe that had a phosphate-sensing dpa group and formed a chelate with metal ions showed improved selectivity toward S. aureus. The results suggested that the targeted ditopic PAMAM dendrimer probe showed selectivity toward Gram-positive bacteria. This study is expected to contribute to the elucidation of the interaction between synthetic molecules and bacterial surface. Moreover, our novel method showed potential for the rapid and species-specific recognition of various bacteria.

In this work, we successfully developed poly(acrylamido phenylboronic acid)/sodium alginate nanoparticles (NPs) via formation of cycloborates (glucose- and H 2 O 2 -responsive functional groups), as an improved glucose-mediated insulin delivery system loaded with glucose oxidase (GOx). Dynamic light scattering revealed that the GOx-loaded NPs showed better glucose-sensitivity than the GOx-unloaded NPs. In addition, compared to insulin-loaded NPs, the insulin/GOx-loaded NPs displayed faster glucose-responsive insulin release. Importantly, there was a significant hypoglycemic effect on diabetic mice following the subcutaneous injection of insulin/GOx-loaded NPs. Furthermore, the NPs exhibited favorable biocompatibility as demonstrated by cytotoxicity assay, hemolysis study, and histopathological examination. The NPs have the advantages of easy preparation, enhanced glucose-responsiveness, and good biocompatibility, making them as potential candidates for subcutaneous insulin delivery. [ABSTRACT FROM AUTHOR]

An efficient green synthesis of 1‐amidoalkyl‐2‐naphthol derivatives 4 a‐s has been developed, employing phenylboronic acid, by a three component one‐pot condensation reaction of 2‐naphthol, a wide range of functionalized aromatic aldehydes and acetamide, or acrylamide under solvent‐free conditions. This new protocol has the rewards of ecologically benign, easy workup along with good to excellent yields. Moreover, selected compounds were screened towards inhibition of cholinesterase. In vitro studies showed that some synthesized compounds have significant both AChE and BChE inhibitory activities compared to Galanthamine (reference drug). Compounds 4 p and 4 s were the most effective showing high potential AChE and BChE inhibitory activities with respective IC50 values of 13.81±0.54 μM and 31.70±1.29 μM. Subsequent evaluation of the α‐glucosidase inhibitory activity of the target molecules revealed that compound 4 s with an IC50 value of 2.05±0.05 μM exhibited highest activity. These preliminary results provide promising sources of multifunctional agents and sheds light on their potential usage in medicine and in the pharmaceutical industries. Using molecular docking approach, we tried to get insights into binding interactions of our synthesized compounds to act as AChE and BChE inhibitors and understand the facts that underlie the relationships between structural modifications on these ligands and their efficacy. [ABSTRACT FROM AUTHOR]

Due to the formation of dynamic boronate ester bonds between phenylboronic acid (PBA) and 1,2- and 1,3-diols, PBA-containing biomaterials show increasing applications in biomedical areas, including responsive nanobiomaterials for targeting delivery of chemical drugs, protein drugs, gene drugs and imaging agents in vitro and in vivo for detection of various bioactive molecules such as sialic acid, saccharides, adenosine triphosphate (ATP) and dopamine. With the specific reaction between PBA and sialic acid, which is overexpressed in many kinds of cancer cells, PBA has been used as a targeting moiety for tumor-targeting drug delivery. Additionally, PBA as an electron acceptor affords nanomaterials Lewis acid-base coordination with electron donor atoms such as nitrogen and oxygen, which can be exploited for developing drug delivery systems with high drug loading. Furthermore, PBA-containing materials can stoichiometric consume reactive oxygen species (ROS) and show a nucleus targeting ability. This current review outlined PBA-containing biomaterials with various responsive abilities including sialic acid-targeting, sugars-binding, ROS-response, ATP-response, dopamine-binding, and nuclear targeting. On this basis, their biomedical applications were summarized. [ABSTRACT FROM AUTHOR]

Deficiency of the essential nutrient boron (B) in the soil is one of the most widespread micronutrient deficiencies worldwide, leading to developmental defects in root and shoot tissues of plants, and severe yield reductions in many crops. Despite this agricultural importance, the underlying mechanisms of how B shapes plant developmental and morphological processes are still not unequivocally understood in detail. This review evaluates experimental approaches that address our current understanding of how B influences plant morphological processes by focusing on developmental defects observed under B deficiency. We assess what is known about mechanisms that control B homeostasis and specifically highlight: (i) limitations in the methodology that is used to induce B deficiency; (ii) differences between mutant phenotypes and normal plants grown under B deficiency; and (iii) recent research on analyzing interactions between B and phytohormones. Our analysis highlights the need for standardized methodology to evaluate the roles of B in the cell wall versus other parts of the cell. [ABSTRACT FROM AUTHOR]

A glucose-sensitive polymer, poly(N-isopropylacrylamide-co-2-acrylamidophenylboronic acid) (P(NIPAM-co-2-AAPBA)), was synthesized by reversible addition fragmentation chain transfer (RAFT) copolymerization. Addition of glucose results in reduced solubility and hence increased turbidity, rather than the normal increase in solubility (decreased turbidity) observed for other PBA-based glucose-sensitive polymers. The novel glucose-sensitive behavior is explained by a new mechanism, in which glucose acts as an additive and depresses the lower critical solution temperature (LCST) of the polymer, instead of increasing solubility by increasing the degree of ionization of the PBA groups. Experimental and theoretic analysis for the influence of glucose on the thermal behavior of P(NIPAM-co-2-AAPBA) reveals that glucose depresses the LCST of P(NIPAM-co-2- AAPBA) copolymers in a two-stage manner, a fast decrease at low glucose concentrations followed by a slow decrease at high glucose concentrations. For low glucose concentrations, the binding of glucose with PBA groups on the polymer chain increases the number of glucose molecules proximal to the polymer which influences the thermal behavior of the polymer, causing a rapid decrease in LCST. Importantly, the transition occurs at a glucose concentration equal to the reciprocal of the binding constant between PBA and glucose, thus providing a novel method to determine the binding constant. Other saccharides, including mannose, galactose and fructose, also depress the LCST of P(NIPAM-co-2-AAPBA) copolymer in the same way. [ABSTRACT FROM AUTHOR]

Based on the design of the fluorescent site of a fluorescent probe, we have created a unique system that changes its twisting response to sugar. Two probes were synthesized, in which phenylboronic acid and two kinds of aromatic fluorescent site (pyrene or anthracene) were conjugated by an amide bond. In the fluorescence measurement of pyrene-type probe 1, dimer fluorescence was observed at high pH. In induced circular dichroism (ICD) experiments, a response was observed only in the presence of glucose and γ-cyclodextrin, and no response was seen with fructose. On the other hand, in the fluorescence measurement of anthracene-type probe 2, dimer fluorescence was observed in the presence of both glucose and galactose, and the fluorescence was different from the case of fructose. When the ICD spectra of these inclusion complexes were measured, an inversion of the Cotton effect, which indicates a change in the twisted structure, was observed in galactose and glucose. These differences in response to monosaccharides may originate in the interaction between the fluorescent site and the cyclodextrin cavity. [ABSTRACT FROM AUTHOR]

The hydrotalcite‐supported palladium (Pd) catalyst is prepared with a green and environmentally friendly route, introducing the extract of withered leaves as a dispersant and reducing agent (Pd/LDHs‐B). Compared with the as‐prepared catalyst (Pd/LDHs‐P with the average diameter of 4.3 nm) using a chemical synthesis method with polyvinylpyrrolidone as a dispersant and ascorbic acid (Vc) as a reductant, the results indicate that the size of Pd nanoparticles in Pd/LDHs‐B is smaller (ca. 3.6 nm). The Pd‐LHDs‐B (0.5 mmol‰) exhibits higher activity (98.66%) than Pd/LDHs‐P (98.19%) in the Suzuki reaction of 4‐bromotoluene and phenylboronic acid at 60°C for 30 min. Also, the reusability of Pd/LDHs‐B is confirmed by recycling tests without a significant decrease in activity. [ABSTRACT FROM AUTHOR]

In this paper, we propose a highly sensitive and biocompatible glucose sensor using a semiconductor-based field effect transistor (FET) with a functionalized hydrogel. The principle of the FET device contributes to the easy detection of ionic charges with high sensitivity, and the hydrogel coated on the electrode enables the specific detection of glucose with biocompatibility. The copolymerized hydrogel on the Au gate electrode of the FET device is optimized by controlling the mixture ratio of biocompatible 2-hydroxyethylmethacrylate (HEMA) as the main monomer and vinylphenylboronic acid (VPBA) as a glucose-responsive monomer. The gate surface potential of the hydrogel FETs shifts in the negative direction with increasing glucose concentration from 10 μM to 40 mM, which results from the increase in the negative charges on the basis of the diol-binding of PBA derivatives with glucose molecules in the hydrogel. Moreover, the hydrogel coated on the gate suppresses the signal noise caused by the nonspecific adsorption of proteins such as albumin. The hydrogel FET can serve as a highly sensitive and biocompatible glucose sensor in in vivo or ex vivo applications such as eye contact lenses and sheets adhering to the skin.

In this study, gold nanoparticles (Au NPs) stabilized by a starch polymer have been successfully prepared and characterized via a number of techniques including X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), and dynamic light scattering (DLS) measurements. The catalytic activity of starch-stabilized Au NPs was also examined toward the homocoupling of phenylboronic acid in water using oxygen in air as oxidant at an ambient temperature (25 ± 1 °C). Several parameters including the catalyst loading, base equivalent (eq.), base type, and reaction time were studied. This study offers a simple, inexpensive and environmentally friendly procedure for the stabilization of colloidal gold catalysts using a hydroxyl-rich structure of starch polymer with a great promise through potential applications in related fields.

Carbon dot (Cdot) nanoparticles are an emerging class of carbon nanomaterials with a promising potential for drug delivery and bio imaging applications. Although the interaction between Cdots and non-immune cell types has been well studied, Cdot interactions with macrophages have not been investigated. Exposure of Cdot nanoparticles to J774.1 cells, a murine macrophage cell line, resulted in minimal toxicity, where notable toxicity was only seen with Cdot concentrations higher than 0.5 mg/ml. Flow cytometric analysis revealed that Cdots prepared from citric acid were internalized at significantly higher levels by macrophages compared with those prepared from bamboo leaves. Interestingly, macrophages preferentially took up phenylboronic acid (PB)-modified nanoparticles. By fluorescence microscopy, strong blue light-specific punctate Cdot fluorescence resembling Cdot structures in the cytosolic space was mostly observed in J774.1 macrophages exposed to PB-modified nanoparticles and not unmodified Cdot nanoparticles. PB binds to sialic acid residues that are overexpressed on diseased cell surfaces. Our findings demonstrate that PB-conjugated Cdots can be taken up by macrophages with low toxicity and high efficiency. These modified Cdots can be used to deliver drugs to suppress or eliminate aberrant immune cells such as macrophages associated with tumors such as tumor-associated macrophages.

Dry eye syndrome is a common eye disease that affects many people worldwide. It is usually treated with eye drops, which has low bioavailability owing to rapid clearance from the ocular surface and leads to poor patient compliance and side effects. For the purpose of improving the therapeutic efficacy, nanostructured lipid carrier (NLC)-loaded dexamethasone (DEX) was prepared and functionalized with (3-aminomethylphenyl)boronic acid-conjugated chondroitin sulfate (APBA-ChS). As APBA has a boronic acid group, it can form a high-affinity complex with sialic acids present in the ocular mucin, which contributes to extension of corneal retention time and improvement of drug delivery. Compared with eye drops, Rhodamine B (RhB)-labeled APBA-ChS-NLC could significantly prolong the residence time on the corneal surface. Moreover, the DEX-APBA-ChS-NLC showed no irritation to the rabbit eye as indicated in irritation studies and histological images. The pharmacodynamics study indicated that DEX-APBA-ChS-NLC could relieve symptoms of dry eye disease in rabbits. These results demonstrated that the developed mucoadhesive drug carrier could improve the delivery of drugs and have promising potential to treat anterior eye diseases. In this research, (3-aminomethylphenyl)boronic acid-conjugated chondroitin sulfate (APBA-ChS)-based nanostructured lipid carriers (NLCs) including dexamethasone (DEX) were designed and constructed. APBA-ChS, which is present on the surface of DEX-NLC and contains the boronic acid group, can form complex with sialic acids in the ocular mucin, hence leading to prolonged precorneal retention. This affinity between boronic acid and sialic acids was used to develop a mucoadhesive drug delivery system. The developed mucoadhesive drug carrier demonstrated prolonged retention time and alleviation of dry eye syndrome. APBA-ChS-based NLC may be considered a promising ocular drug delivery system for treating anterior eye diseases. [ABSTRACT FROM AUTHOR]

Owing to tailor-made functionalization, high specific surface areas and tunable pore sizes, covalent organic frameworks (COFs) have been increasingly used in the adsorption area. Herein, a novel COF TzDa-PBA containing phenylboronic acid groups was facilely prepared through a post-modification strategy. The COF TzDa-PBA was synthesized by amine-aldehyde condensation reaction of the 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)trianiline (Tz) and 2,5-diallyloxyterephthalaldehyde (Da-V) through a room-temperature synthetic process to form a vinyl-functionalized COF TzDa-V, followed by covalent linking of 4-mercaptophenylboronic acid (4-MPBA) through the thiol-ene "click" reaction. As a proof-of-concept, the as-obtained TzDa-PBA was used as an adsorbent to adsorb cis -diol containing flavonoids. Representatively, due to its distinctive structure and boronic acid group functional properties, TzDa-PBA showed exceptional adsorption performance for cis -diol containing flavonoids, affording luteolin (LTL) capacity of 219.3 mg g−1, surpassing all those of boronic acid-functionalized materials reported thus far. Furthermore, a commercially available LTL with 85% purity could be easily enriched and further purified by using TzDa-PBA. COF TzDa-PBA with good reusability is promising as adsorbent for selective capture of cis -diol containing flavonoids. [Display omitted] • One-step thiol-ene "click" reaction made boronic acid-functionalized COF TzDa-PBA. • Boronate affinity were conducive to selective adsorption cis -diol-containing flavonoids. • Fast binding kinetics, high adsorption capacity and remarkable recyclability were obtained. • A commercially available LTL with 85% purity can be easily enriched to 98.87% purity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fluorescent molecularly imprinted polymers (FMIPs) targeting ovalbumin were prepared. • The FMIPs have pH-dependent property for the recognition of ovalbumin. • The FMIPs can be used for ovalbumin assay in real samples with high recovery rate. Here, fluorescent artificial antibodies for sensing ovalbumin in food were synthesized by molecular imprinting technique in a microfluidic reactor. A phenylboronic acid-functionalized silane was employed as the functional monomer to enable the polymer has pH-responsive property. Fluorescent molecularly imprinted polymers (FMIPs) could be produced continuously in a short time. Both fluorescein isothiocyanate (FITC) and rhodamine B isothiocyanate (RB)-based FMIPs can specifically recognize the target ovalbumin, particularly FITC-based FMIP, giving an imprinting factor of 2.5 and cross-reactivity factors of 2.7 (ovotransferrin), 2.8 (β-lactoglobulin) and 3.4 (bovine serum albumin), and was applied for the detection of ovalbumin in milk powder with recovery rates of 93–110%; moreover, the FMIP can be reused at least four times. Such FMIPs have promising future in replacing the fluorophore-labelled antibodies to fabricate fluorescent sensing devices or establish immunoassay methods, which have extra merits of low-cost, high stability and recyclability, easy to carry and store at ambient environments. [ABSTRACT FROM AUTHOR]

[Display omitted] The catalytic activities of Pd(II) complexes synthesized from bidentate N,O-donor ligands were evaluated for the Suzuki-Miyaura C C coupling reaction between haloarenes (iodo-/bromo-/chloro-) and electron-donating/electron-withdrawing groups containing phenylboronic acids. The N,O-donor ligands were synthesized from salicylaldehyde, 3,5-di- tert -butylsalicylaldehyde, 3- tert -butylsalicylaldehyde, 5- tert -butylsalicylaldehyde with aniline and derivatives of aniline. The single crystal of complexes 5c , 5f , 5h, 5j, and 5t were diffracted by single crystal XRD, and crystal structure of these Pd(II) complexes represents trans geometry. Different Pd(II) complexes of the ligands with electronic and steric effects were evaluated in the Suzuki-Miyaura reaction were explored. Moreover, the reaction parameters such as substrate to base (K 2 CO 3) ratio, temperature, solvent, catalyst loading, steric and electronic effect of phenylboronic acid and aryl halides for the catalytic coupling were investigated. The Pd(II) catalyst 5a was highly active across a broad range of electron donating/electron withdrawing aryl iodides and aryl bromides. The catalyst 5a (0.05 mol%) in the presence of K 2 CO 3 base at 120 °C in DMF shows an excellent activity towards a wide range of phenyl boronic acids containing electron donating/electron withdrawing groups and the corresponding products were obtained in 45–99% yields after 2–4 h. Moreover, the Pd(II) complex 5a was reused in three continuous cycles by adding the reactants (iodobenzene and phenylboronic acid) after their complete conversion to the product, and the catalyst took a longer time for conversion of the substrate in each continuous recycle. The turnover number of the Pd(II) complex 5a was found to be 1960 which was comparatively better than other Pd(II) salen complexes 5b-u. [ABSTRACT FROM AUTHOR]

Monodisperse-porous SiO 2 microspheres carrying phenylboronic acid linked-flexible polycationic molecular brushes (SiO 2 @PEI-FPBA MS) was synthesized as a teamed boronate affinity (TBA) sorbent. The combination of enhanced porous properties of selected solid support with a multifunctional, macromolecular spacer arm allowed the synthesis of a superior boronate affinity sorbent (BAS) for batch and continous column chromatography. The sorbent was obtained by covalent binding of 4-formylphenylboronic acid (FPBA) to the polycationic macromolecular spacer-arm, polyethyleneimine (PEI) bound to SiO 2 MS 6.3 µm in size. Molecular boronate affinity team on the sorbent was obtained for the first time, by the complex formation between phenylboronic acid (PBA) groups of bound FPBA and remaining primary amine groups of spacer-arm (i.e. branched PEI), by controlling the FPBA feed concentration. SiO 2 @PEI-FPBA MS obtained by lowering FPBA feed concentration exhibited high binding capacities for cis-diol functionalized biomolecules under neutral conditions as a typical behavior observed with previously produced TBA sorbents. FPBA content, pore volume and specific surface area of the sorbent were determined as 160.4 mg/g, 0.92 cc/g and 141.7 m2/g, respectively. The formation of a TBA complex by intermolecular B-N coordination on SiO 2 MS was shown by X-ray photoelectron spectroscopy. The selection of PEI as a macromolecular, multifunctional spacer arm significantly enhanced either the cis-diol adsorption capacity by increasing FPBA content of the sorbent and also by forming a TBA complex with PBA groups. The selected cis-diol carrying agents and glycoproteins, β-nicotinamide adenine dinucleotide, ovalbumin (OVA) and transferrin (TRF) were isolated with the equilibrium adsorptions up to 149 mg/g sorbent and quantitative desorption yields. The comparison of cis-diol binding capacities of SiO 2 @PEI-FPBA MS obtained at neutral pH with the current TBA sorbents showed that the synthesis of a PEI-assisted TBA sorbent does not involve to include an external complexation agent in the synthesis. High glycoprotein binding capacities under neutral conditions can be obtained only by adjusting the FPBA content of a PEI assisted-TBA sorbent during the synthesis. A boronate affinity micro-chromatography system constructed by packing of SiO 2 @PEI-FPBA MS into a silica capillary (300 µm i.d.) was also successfully evaluated for the isolation of OVA with different flow rates. [Display omitted] [ABSTRACT FROM AUTHOR]

Diabetes is a significant public health issue worldwide and can cause serious consequences for daily functioning and health. Several molecular design strategies have been proposed to detect glucose, among these, phenylboronic acid (PBA) is considered to have the potential as a glucose binder. Nevertheless, most of the PBA derivatives are used in alkaline media to achieve glucose sensing. In this work, we first report the glucose sensor based on hydrazide-hydrazone PBA molecules that can function without the need for adding an alkaline agent. A series of novel pyrene-based hydrazide-hydrazone PBA with 1,2-, 1,3- and 1,4-substituted derivatives, namely 3a , 3b and 3c , respectively, were synthesized. The experimental and theoretical studies demonstrated that compound 3a might have intramolecular Lewis acid-base interactions between the boron and nitrogen atoms, leading to high sensitivity to glucose. Alternatively, compound 3c revealed intermolecular Lewis acid-base interactions and resulted in the selective glucose detection. We proved the cooperative effect of Lewis acid-base interaction, π-π stacking and hydrogen bonding may play an important role in the design of the alkaline-free activated glucose sensor. [Display omitted] • A series of novel pyrene-based hydrazide-hydrazone phenylboronic acid (PBA) with 1,2-, 1,3- and 1,4-substituted derivatives were synthesized. • The sensitivity and selectivity properties of a glucose sensor based on hydrazide-hydrazone PBA molecules were investigated. • This study demonstrates the significance of chemical structure-property relationships and provides new insights into the design of the novel alkaline-free activated glucose sensor. [ABSTRACT FROM AUTHOR]

A microneedle (MN) sensor coated with a sensing composite material was proposed for measuring glucose concentrations in interstitial fluid (ISF). The sensing composite material was prepared by blending a polymer containing glucose-responsive phenylboronic acid (PBA) moieties (i.e., polystyrene- block -poly(acrylic acid- co -acrylamidophenylboronic acid)) with conductive carbon nanotubes (CNTs). The polymer exhibited reversible swelling behavior in response to glucose concentrations, which influenced the distribution of the embedded CNTs, resulting in sensitive variations in electrical percolation, even when coated onto a confined surface of the MN in the sensor. We varied the ratio of PBA moieties and the loading amount of CNTs in the sensing composite material of the MN sensor and tested them in vitro using an ISF-mimicking gel with physiological glucose concentrations to determine the optimal sensitivity conditions. When tested in animal models with varying blood glucose concentrations, the MN sensor coated with the selected sensing material exhibited a strong correlation between the measured electrical currents and blood glucose concentrations, showing accuracy comparable to that of a glucometer in clinical use. [ABSTRACT FROM AUTHOR]

As a new target for tumor therapy, PAD4 protein, shows excellent antitumor activity, and phenylboronic acid (PBA) could combine with sialic acid on the tumor surface to achieve dual targeting in situ and for metastatic tumors. The purpose of this study was therefore to modify PAD4 protein inhibitors with different phenylboronic acid groups in order to obtain highly-targeted PAD4 inhibitors. The activity and mechanism of these PBA-PAD4 inhibitors were studied in vitro by MTT assay, laser confocal analysis, and flow cytometry. The effects of the compounds on primary tumor and lung metastasis in mice were evaluated in vivo using a S180 sarcoma model and a 4T1 breast cancer model. In addition, cytometry mass (CyTOF) was used to analyze the immune microenvironment, and the results show that the PAD4 inhibitor 5i modified by m -PBA at the carboxyl terminal of ornithine skeleton had the best antitumor activity. In vitro evaluation of this activity revealed that 5i could not directly kill tumor cells but had a significant inhibitory effect on tumor cell metastasis. Further mechanism studies showed that 5i could be taken up by 4T1 cells in a time-dependent manner and distributed around the cell membrane but could not be taken up by normal cells. In addition, although 5i was distributed in the cytoplasm of tumor cells while in the nucleus of neutrophils, it could both decrease the histone 3 citrullination (H3cit) in the nucleus. In vivo 4T1 tumor-bearing mouse models, 5i inhibited breast cancer growth and metastasis in a concentration-dependent manner, and NET formation in tumor tissues was significantly reduced. In conclusion, PBA-PAD4 inhibitors show high targeting of tumor cells and good safety in vivo. By specifically inhibiting PAD4 protein in the neutrophil nucleus, PBA-PAD4 inhibitors also show excellent antitumor activity toward growth and metastasis in vivo , which provides a new idea for the design of highly-targeted PAD4 inhibitors. [Display omitted] • Electron-withdrawing or electron-donating groups on the same side of BA reduced PAD4 enzyme activity and in vivo activity. • Hydrophobic groups on the basis of PBA enhanced the anti-tumor activity in vivo. • PBA-PAD4 inhibitors distributed in the cytoplasm of tumor cells and the nucleus of neutrophils. • 5i blocked the PAD4-H3cit-NETs pathway in tumor-associated neutrophils. • 5i could reduce the proportion of aging tumor-associated neutrophils, while promote the polarization of macrophages into M1 type. [ABSTRACT FROM AUTHOR]

We synthesized phenylboronic acid pinacol ester (PBPE)-conjugated hyaluronic acid (HA) via thiobis(ethylamine) (TbEA) linkage (abbreviated as HAsPBPE conjugates) to fabricate the radiosensitive delivery of caffeic acid phenetyl ester (CAPE) and for application in radioprotection. PBPE was primarily conjugated with TbEA and then PBPE-TbEA conjugates were conjugated again with hyaluronic acid using carbodiimide chemistry. CAPE-incorporated nanoparticles of HAsPBPE were fabricated by the nanoprecipitation method and then the organic solvent was removed by dialysis. CAPE-incorporated HAsPBPE nanoparticles have a small particle size of about 80 or 100 nm and they have a spherical shape. When CAPE-incorporated HAsPBPE nanoparticles were irradiated, nanoparticles became swelled or disintegrated and their morphologies were changed. Furthermore, the CAPE release rate from HAsPBPE nanoparticles were increased according to the radiation dose, indicating that CAPE-incorporated HAsPBPE nanoparticles have radio-sensitivity. CAPE and CAPE-incorporated HAsPBPE nanoparticles appropriately prevented radiation-induced cell death and suppressed intracellular accumulation of reactive oxygen species (ROS). CAPE and CAPE-incorporated HAsPBPE nanoparticles efficiently improved survivability of mice from radiation-induced death and reduced apoptotic cell death. We suggest that HAsPBPE nanoparticles are promising candidates for the radio-sensitive delivery of CAPE.

Sialic acid (SA) on the surface of cells is indispensable in numerous physiological and pathological processes, and sensitive and reproducible detection of SA is crucial for diagnosis and therapy in many diseases. Here, we developed a tri-functional nanoprobe as a sensitive and straightforward surface-enhanced Raman spectroscopy (SERS) nanoprobe for sialoglycan detection on cell surfaces. The reporter was designed to provide three key functionalities that make it ideal for SA detection. First, we employed two recognition groups, phenylboronic acid and an ammonium group, that enhance SA recognition and capture efficiency. Second, we used cyano as the Raman reporter because it emits in the cellular Raman silent region. Finally, thiol acted as an anchoring agent to conjugate the reporter to silver nanocubes to provide SERS enhancement. Our molecular nanoprobe design demonstrated the ability to detect SA on the cell surface with high sensitivity and spatial resolution, opening up new routes to cellular diagnostics.

This study reports a novel, fast, easy, and sensitive detection method for bacteria which is urgently needed to diagnose infections in their early stages. Our work presents a complex of poly(amidoamine) dendrimer modified by phenylboronic acid and labeled by a fluorescent dansyl group (Dan-B8.5-PAMAM). Our system detects bacteria in 20 min with a sensitivity of approximately 104 colony-forming units (CFU)·mL−1. Moreover, it does not require any peculiar technical skills or expensive materials. The driving force for bacteria recognition is the binding between terminal phenylboronic acids on the probe and bacteria’s surface glycolipids, rather than electrostatic interactions. The aggregation caused by such binding reduces fluorescence. Even though our recognition method does not distinguish between live or dead bacteria, it shows selective antibacterial activity towards Gram-negative bacteria. This study may potentially contribute a new method for the convenient detection and killing of bacteria.

Abstract The algorithmic, large-scale use and analysis of reaction databases such as Reaxys is currently hindered by the absence of widely adopted standards for publishing reaction data in machine readable formats. Crucial data such as yields of all products or stoichiometry are frequently not explicitly stated in the published papers and, hence, not reported in the database entry for those reactions, limiting their usefulness for algorithmic analysis. This paper presents a possible extension to the IUPAC RInChI standard via an auxiliary layer, termed ProcAuxInfo, which is a standardised, extensible form in which to report certain key reaction parameters such as declaration of all products and reactants as well as auxiliaries known in the reaction, reaction stoichiometry, amounts of substances used, conversion, yield and operating conditions. The standard is demonstrated via creation of the RInChI including the ProcAuxInfo layer based on three published reactions and demonstrates accurate data recoverability via reverse translation of the created strings. Implementation of this or another method of reporting process data by the publishing community would ensure that databases, such as Reaxys, would be able to abstract crucial data for big data analysis of their contents.

The cytotoxic activity of phenylboroxine acid was evaluated in vitro on mouse mammary adenocarcinoma 4T1, mouse squamous cell carcinoma SCCVII, hamster lung fibroblast V79 and mouse dermal fibroblasts L929 cell lines. The cytotoxic effects were dose dependent for all tested tumour and non-tumour cell lines. Under in vivo conditions, three application routes of phenylboronic acid were studied: intra-peritoneal (i.p.), intra-tumour (i.t.) and per-oral. After tumour transplantation in syngeneic mice, phenylboronic acid was shown to slow the growth of both tumour cell lines (4T1 and SCCVII) compared with the control. The inhibitory effects were pronounced during the application of phenylboronic acid. For both tested tumour cell lines, the most prominent antitumour effect was obtained by intraperitoneal administration, followed significantly by oral administration.

ChunYan Li,1 ZhiGang Huang,2 ZheShuo Liu,1 LiQian Ci,3 ZhePeng Liu,3 Yu Liu,2 XueYing Yan,1 WeiYue Lu2 1School of Pharmacy, Heilongjiang University of Chinese Medicine, Harbin, 2Department of Pharmaceutics, School of Pharmacy, Key Laboratory of Smart Drug Delivery, Ministry of Education, Fudan University, 3School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, People’s Republic of China Abstract: Effective interaction between mucoadhesive drug delivery systems and mucin is the basis of effective local placement of drugs to play its therapeutic role after mucosal administration including vaginal use, which especially requires prolonged drug presence for the treatment of gynecological infectious diseases. Our previous report on phenylboronic acid-rich nanoparticles (PBNPs) demonstrated their strong interaction with mucin and mucin-sensitive release profiles of the model protein therapeutics interferon (IFN) in vitro, but their poor stability and obvious tendency to aggregate over time severely limited future application. In this study, sulfonate-modified PBNPs (PBNP-S) were designed as a stable mucoadhesive drug delivery system where the negative charges conferred by sulfonate groups prevented aggregation of nanoparticles and the phenylboronic acid groups ensured effective interaction with mucin over a wide pH range. Results suggested that PBNP-S were of spherical morphology with narrow size distribution (123.5 nm, polydispersity index 0.050), good stability over a wide pH range and 3-month storage and considerable in vitro mucoadhesion capability at vaginal pH as shown by mucin adsorption determination. IFN could be loaded to PBNP-S by physical adsorption with high encapsulation efficiency and released in a mucin-dependent manner in vitro. In vivo near-infrared fluorescent whole animal imaging and quantitative vaginal lavage followed by enzyme-linked immunosorbent assay (ELISA) assay of IFN demonstrated that PBNP-S could stay in the vagina and maintain intravaginal IFN level for much longer time than IFN solution (24 hours vs several hours) without obvious histological irritation to vaginal mucosa after vaginal administration to mice. In summary, good stability, easy loading and controllable release of protein therapeutics, in vitro and in vivo mucoadhesive properties and local safety of PBNP-S suggested it as a promising nanoscale mucoadhesive drug delivery system for vaginal administration of protein therapeutics. Keywords: mucoadhesion, phenylboronic acid, stability, controlled-release, protein therapeutics, nanoparticles

Herein, a very simple colorimetric chemosensor array is reported for saccharides (D-glucose, D-fructose, D-xylose, D-galactose, D-mannose, L-rhamnose, and N-acetyl-D-gluosamine). While various types of chemosensors for saccharides have been investigated extensively to-this-date, tremendous additional efforts are still required on a regular basis for the syntheses of new chemosensors. Complicated syntheses would be a bottleneck, given that artificial receptor-based chemosensing systems are not so popular in comparison to biomaterial-based (e.g., enzyme-based) sensing systems. Toward this end, chemosensor array systems using molecular self-assembled materials can avoid the abovementioned synthetic efforts and achieve simultaneous qualitative and quantitative detection of a number of guest saccharides. Using a practical approach, we focus on an indicator displacement assay (IDA) to fabricate a chemosensor array for colorimetric saccharide sensing. On this basis, 3-nitrophenylboronic acid (3-NPBA) spontaneously reacts with catechol dyes such as alizarin red S (ARS), bromopyrogallol red (BPR), pyrogallol red (PR), and pyrocatechol violet (PV), and yields boronate ester derivatives with color changes. The addition of saccharides into the aqueous solution of the boronate esters induces color recovery owing to the higher binding affinity of 3-NPBA for saccharides, thus resulting in the release of dyes. By employing this system, we have succeeded in discriminating saccharides qualitatively and quantitatively with a classification success rate of 100%. Most importantly, our chemosensor array has been fabricated by only mixing low cost commercially available reagents in situ, which means that complicated synthetic processes are avoided for saccharide sensing. We believe this simple colorimetric assay that uses only commercially available reagents can create new, user-friendly supramolecular sensing pathways for saccharides.

A fluorescent sensing system based on a conjugated polyelectrolyte was constructed to detect dopamine (DA) in complex samples. The conjugated polymer PFPE-PBA with poly[fluorenyl- alt - p -phenyleneethynylene] (PFPE) as the backbone and carrying four pendant phenylboronic acid (PBA) groups in each repeat unit was synthesized. PFPE-PBA was found to have good solubility in polar solvents. After optimization, glycine-NaOH at pH 10 was selected as the buffer, and the solvent composition of the system was set to methanol/water (9/1 by volume). Titration experiments showed that DA could effectively quench the fluorescence of the polymer solution with a response time within 60 s and a limit of detection of 23 nM. Polyols, cations, and other possible interfering substances do not significantly affect the fluorescence of the polymer, thereby allowing for the highly selective detection of DA. Furthermore, quantitative determination of DA in spiked serum and artificial urine samples was successfully demonstrated, with recoveries ranging from 96.7 to 104%. Preliminary mechanism studies suggest that the pedant PBAs capture DA via reaction with the catechol group, and the fluorescence quenching is most likely due to the photoinduced electron transfer between the aromatic part of DA and the conjugated backbone. This study provides a general strategy for the future design of conjugated polyelectrolyte-based sensing systems.

Nucleoside drugs, which are analogues of natural nucleosides, have been widely applied in the clinical treatment of viral infections and cancers. The development of nucleoside drugs, repurposing of existing drugs, and combined use of multiple drug types have made the rapid sensing of nucleoside drugs urgently needed. Nanopores are emerging single-molecule sensors that have high resolution to resolve even minor structural differences between chemical compounds. Here, an engineered Mycobacterium smegmatis porin A hetero-octamer was used to perform general nucleoside drug analysis. Ten nucleoside drugs were simultaneously detected and fully discriminated. An accuracy of >99.9% was consequently reported. This sensing capacity was further demonstrated in direct nanopore analysis of ribavirin buccal tablets, confirming its sensing reliability against complex samples and environments. No sample separation is needed, however, significantly minimizing the complexity of the measurement. This technique may inspire nanopore applications in pharmaceutical production and pharmacokinetics measurements.

It is known that phenylboronic acid (PBA) can target tumor tissues by binding to sialic acid, a substrate overexpressed by cancer cells. This capability has previously been explored in the design of targeting diagnostic probes such as Gd- and 68Ga-DOTA-EN-PBA, two contrast agents for magnetic resonance imaging (MRI) and positron emission tomography (PET), respectively, whose potential has already been demonstrated through in vivo experiments. In addition to its high resolution, the intrinsic low sensitivity of MRI stimulates the search for more effective contrast agents, which, in the case of small-molecular probes, basically narrows down to either increased tumbling time of the entire molecule or elevated local concentration of the paramagnetic ions, both strategies resulting in enhanced relaxivity, and consequently, a higher MRI contrast. The latter strategy can be achieved by the design of multimeric GdIII complexes. Based on the monomeric PBA-containing probes described recently, herein, we report the synthesis and characterization of the dimeric analogues (GdIII-DOTA-EN)2-PBA and (GdIII-DOTA-EN)2F2PBA. The presence of two Gd ions in one molecule clearly contributes to the improved biological performance, as demonstrated by the relaxometric study and cell-binding investigations.

Triphenylborane was unexpectedly formed from phenylboronic acid in the presence of an inorganic base and a polar solvent. When K2CO3 was used as the base and DMF was used as the solvent, 0.22 mmol of triphenylborane was obtained from 1.5 mmol of phenylboronic acid after 1 h at 130 °C. The in‐situ formed triphenylborane reacted with chorobenzene over a supported Pd catalyst to afford biphenyl as the cross coupling product. [ABSTRACT FROM AUTHOR]

Locoregional chemotherapy, especially using implantable hydrogel depots to sustainably deliver chemotherapeutics at tumor site, has shown great potential for improving antitumor efficacy and reducing systemic toxicity. However, the hydrogel applications are limited by some intrinsic constraints, especially the contradiction between increasing drug penetration and accumulation in tumor and decreasing random drug diffusion into surrounding normal tissues. Herein, we report a unique "Jekyll and Hyde" nanoparticle-hydrogel (NP-gel) hybrid platform, which can keep dormant in adjacent normal tissues but be activated by mildly acidic and hyaluronidase-rich microenvironment in malignant tumor tissues to unidirectionally release tumor-targeting and penetrative doxorubicin (DOX)-loaded NPs. Apart from tumor-specific recognition, penetration, internalization and release, NP-gel features: shear-thinning behavior for injection, tissue-adhesiveness for continuous on-site activation, and full biodegradability for safe use. Precise delivery was clearly demonstrated in both tumor-grafted and tumor-resected mice. A single peritumoral injection of DOX-loaded NP-gel exhibited a significantly higher drug accumulation in tumor for 3 weeks than in nontarget organs and thus long-term tumor remission. More importantly, significant inhibition in tumor recurrence without detectable toxicity to healthy organs was demonstrated when applied after tumor resection. The designed system displayed long-acting and precise anticancer efficacy, paving the way toward effective tumor locoregional treatment. Injectable hydrogels, allowing sustained drug delivery directly at tumor site, has shown great potential for locoregional chemotherapy. However, how to achieve tumor-specific drug accumulation but meanwhile impede the random drug diffusion into surrounding normal tissues remains an insurmountable challenge, especially considering high drug concentration gradient, higher interstitial fluid pressure and denser extracellular matrix in tumor than adjacent normal tissue. Herein, a 'Jekyll and Hyde' nanoparticle-hydrogel hybrid formulation was designed to keep dormant in adjacent normal tissues but be activated by mildly acidic and hyaluronidase-rich microenvironment in malignant tumor tissues to unidirectionally release tumor-targeting and penetrative DOX-loaded nanoparticles, leading to a significant tumor inhibition and antirecurrence efficiency without detectable toxicity to healthy organs, thus presenting great potential for precise locoregional chemotherapy. [ABSTRACT FROM AUTHOR]

There are many patients with diabetes in the world and the treatment of diabetes is still a hectic problem, which has a nagative impact on the life of diabetic patients. A lot of research has been done on this, among which the phenylboronic acid-based smart drug delivery system mimics the working mode of human islets. When it is injected into the human body, it automatically releases the corresponding amount of insulin according to the blood glucose level of the human body. Such drug delivery systems can be divided into gels, micelles, capsules and vesicles, etc. according to the microstructure. This paper mainly highlights the recent progress in this field. Unlabelled Image [ABSTRACT FROM AUTHOR]

[Display omitted] • Mesoporous silica-supported Rh complex with tertiary amine is prepared and characterized by spectroscopic techniques. • The catalyst affords excellent yield and selectivity, wide substrate scope, and the highest TON of 8500 for 1,4-addition. • Co-immobilization of tertiary amine enhances catalytic activity cooperatively. • The use of the mesoporous support is more effective compared to the nonporous silica support. Mesoporous silica-supported Rh complex catalysts were prepared by simple silane-coupling, followed by complexation, and characterized by FT-IR, SEM, Rh K-edge XAFS, and elemental analysis. Local structures of the Rh complexes in each sample were almost similar to those of a nonporous silica-supported diaminorhodium complex. Co-immobilization of a tertiary amine on the same silica surface induced slight changes to the Rh complex structure in the case of the support with smaller pores. The prepared catalysts showed high activity for the 1,4-addition reaction of phenylboronic acids. Co-immobilization of the tertiary amine increased the reaction rate by more than 7-fold, with turnover number of nearly 8500. The catalytic performance achieved with this novel system is with much higher than that reported previously with a nonporous silica-supported catalyst. The mesoporous silica-supported Rh complex-tertiary amine showed a wide substrate scope, including unsaturated ketones and nitriles. This co-immobilized tertiary amine may activate phenylboronic acid to enhance its reactivity in the transmetalation step with Rh-OH species. [ABSTRACT FROM AUTHOR]

We reported on the fabrication of sugar-responsive nanogels covalently incorporated with 3-acrylamidophenylboronic acid (AAPBA) as glucose-recognizing moiety, 2-(acrylamido)glucopyranose (AGA) as biocompatible moiety, and boron dipyrromethene (BODIPYMA) as fluorescence donor molecule. The p(AAPBA-AGA-BODIPYMA) nanogels were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization in the mixture solvents of H2O/ethanol. Nanogels could respond to glucose and size of nanogels increased after treating with 3 mg/mL glucose medium. The fluorescent intensity of nanogels varied dependent on different glucose concentrations. Besides, insulin, a model drug, can be encapsulated into nanogels with the loading amount up to 8.2%. The drug release was dependent on the content of AAPBA moieties in nanogels and glucose concentrations in release medium. The investigation on the cytotoxicity of nanogels revealed that nanogels had good compatibility. Such glucose-responsive nanogels have potential in detection and treatment of diabetes. [ABSTRACT FROM AUTHOR]

This review focuses on sugar-responsive materials based on phenylboronic acid (PBA) as a sugar-sensing motif and cyclodextrins (CyDs) as a basic skeleton of smart materials. PBA modified α-CyD (PBA-α-CyD) forms a supramolecular polymer through intermolecular interactions between PBA part and CyD cavity. Similarly, PBA-β-CyD forms a head-to-head dimer. Meanwhile, combining PBA-γ-CyD and polyethylene glycol (PEG) produces a molecular necklace. Additionally, combining PBA-modified PEG and native α-CyD or γ-CyD results in another type of molecular necklace. These supramolecular structures are obtained as powders, and their solubility increases in the presence of sugar. Besides the powder type, a unique gel is formed through crosslinking polyvinyl alcohol with PBA-triazole-γ-CyD (PBA-Tri-γ-CyD). This gel can contain model drug, and it shows sugar-responsive drug release. The sugar response of all of these smart materials can be explained by the concept of equilibrium. The smart materials are constructed with CyD-guest interactions. The CyD-guest equilibrium moves by a reaction between sugar and PBA moiety attached to the smart material. In these smart materials, sugar induces a dissociation in the CyD-guest interaction, and this dissociation results in sugar-induced disintegration of CyD-guest supramolecular structures. [ABSTRACT FROM AUTHOR]

Here, new series of the 2‐hydroxyethyl‐substituted (NHC)PdI2(pyridine) (Pd‐PEPPSI) complexes have been synthesized. These complexes have been prepared from the 2‐hydroxyethyl‐substituted N‐heterocyclic carbene (NHC) precursors, palladium chloride and pyridine. The synthesized Pd‐PEPPSI complexes have been characterized by using 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. The catalytic activity of the 2‐hydroxyethyl‐substituted Pd‐PEPPSI complexes has been examined in the Sonogashira cross‐coupling reaction by using phenylacetylene and aryl bromide. The Pd‐PEPPSI complexes have demonstrated great activity in the Sonogashira cross‐coupling reaction. The molecular and crystal structures of the three of the Pd‐PEPPSI complexes were determined by single‐crystal X‐ray diffraction method. X‐ray studies show that all the molecular structures adopt slightly distorted square‐planar geometry around the palladium (II) center. [ABSTRACT FROM AUTHOR]

For type 1 and advanced type 2 diabetic patients, insulin replacement therapy with simulating on-demand prandial and basal insulin secretion is the best option for optimal glycemic control. However, there is no insulin delivery system yet could mimic both controlled basal insulin release and rapid prandial insulin release in response to real-time blood glucose changes. Here we reported an artificial insulin delivery system, mimicking physiological basal and prandial insulin secretion, to achieve real-time glycemic control and reduce risk of hypoglycemia. A phenylboronic acid (PBA)/galactosyl-based glucose-responsive insulin delivery system was prepared with insulin-loaded micelles embedded in hydrogel matrix. At the hyperglycemic state, both the hydrogel and micelles could swell and achieve rapid glucose-responsive release of insulin, mimicking prandial insulin secretion. When the glucose level returned to the normal state, only the micelles partially responded to glucose and still released insulin gradually. The hydrogel with increased crosslinking density could slow down the diffusion speed of insulin inside, resulting in controlled release of insulin and simulating physiological basal insulin secretion. This hydrogel-micelle composite insulin delivery system could quickly reduce the blood glucose level in a mouse model of type 1 diabetes, and maintain normal blood glucose level without hypoglycemia for about 24 h. This kind of glucose-responsive hydrogel-micelle composite may be a promising candidate for delivery of insulin in the treatment of diabetes. [ABSTRACT FROM AUTHOR]

Abstract Series of novel N -(fluorophenyl)piperazine derivatives of phenylboronic compounds including benzoxaboroles, phenylboronic acids and phenylboronic methyl monoester have been obtained by facile synthetic methods starting from 2-formylphenylboronic acid. Molecular and crystal structures of those novel derivatives have been investigated by single crystal X-ray diffraction method. The Bond Valence Vector Model was used to describe strains in the boron coordination sphere. Microbiological activity of novel benzoxaboroles as well as their corresponding acid analogues against: A. niger, A. terreus, P. ochrochloron, C. tenuis and F. dimerum has been evaluated. The presence of heterocyclic benzoxaborole ring has been shown to be crucial for the studied activity. Graphical abstract Image 1 Highlights • Novel boronic derivatives of fluorophenylpiperazines obtained. • Structural elucidation as well as antifungal activity of novel benzoxaboroles. • Comparison of benzoxaborole, phenylboronic acid and its methyl monoester. [ABSTRACT FROM AUTHOR]

Recently, chemists studying with organometallic compounds are increasingly interested in Pd-PEPPSI complexes. This study contains the synthesis of the 2-morpholinoethyl-substituted Pd-PEPPSI complexes and their catalytic activity in the Suzuki-Miyaura reaction. Synthesized the Pd-PEPPSI complexes have been prepared from the 2-morpholinoethyl-substituted N-heterocyclic carbene (NHC) precursors, palladium chloride and 3-chloropyridine. These complexes have been characterized by using 1H NMR, 13C NMR, FTIR spectroscopy and elementel analysis techniques. Also, synthesized the Pd-PEPPSI complexes have been examined as catalysts in the Suzuki-Miyaura cross-coupling reaction with arylboronic acid derivatives and have shown to exhibit well activity in this reaction. [ABSTRACT FROM AUTHOR]