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Chemistry Central Journal Dec 2017A simple solvent-free protocol for the preparation of flunixin, a potent non-narcotic, non-steroidal anti-inflammatory drugs is reported using boric acid as catalyst....
A simple solvent-free protocol for the preparation of flunixin, a potent non-narcotic, non-steroidal anti-inflammatory drugs is reported using boric acid as catalyst. Its salt, flunixin meglumine are then prepared under reflux in EtOH. This sustainable method are then extended for the synthesis of a series of 2-(arylamino) nicotinic acid derivatives. The present protocol combines non-hazardous neat conditions with associated benefits like excellent yield, straightforward workup, and use of readily available and safe catalyst in the absence of any solvent, which are important factors in the pharmaceutical industry. The pathway for catalytic activation of 2-chloronicotic acid with boric acid was also investigated using Gaussian 03 program package.
PubMed: 29196901
DOI: 10.1186/s13065-017-0355-4 -
Ulusal Travma Ve Acil Cerrahi Dergisi =... May 2021In this experimental rat model, we aimed to investigate boric acid's possible protective effect against the formation of post-operative abdominal adhesions through its...
BACKGROUND
In this experimental rat model, we aimed to investigate boric acid's possible protective effect against the formation of post-operative abdominal adhesions through its anti-inflammatory and antioxidant properties.
METHODS
Forty healthy male albino rats were randomly and evenly allocated to vehicle, hyaluronic acid-based (HA-b) material, boric acid 50 (BA50), boric acid 100 (BA100), and sham groups. Intra-abdominal adhesions were induced by mechanical cecal abrasion. Macroscopic and pathologic assessments of the adhesions were done and tissue tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) levels were measured.
RESULTS
Total abdominal adhesion scores were 129.7, 91.07, 53.77, 90.07, and 140.5 for the vehicle, HA-b, BA50, BA100, and sham groups, respectively, with the highest score indicating more severe adhesions. A significant difference in fibrosis scores was noted between both BA50 and BA100, and the sham group (p=0.018). When objective parameters were analyzed, TNF-α levels were significantly lower in the BA50 group than the sham, BA100, and vehicle groups (p=0.01, 0.019, and 0.03, respectively). TGF-β1 levels were also significantly lower in BA50 group than the sham, BA100, and the vehicle groups (p=0.013, 0.016, and 0.05, respectively). No difference was observed for any parameter between BA50 group and HA-b group.
CONCLUSION
Topical boric acid at a dose of 50 mg/kg is found safe and as effective as the hyaluronic acid-based agent in preventing postoperative abdominal adhesions in our rat model.
Topics: Abdomen; Animals; Boric Acids; Hyaluronic Acid; Male; Postoperative Complications; Rats; Tissue Adhesions
PubMed: 33884596
DOI: 10.14744/tjtes.2020.23460 -
Life (Basel, Switzerland) Feb 2023Osteosarcoma (OS) is the most common primary malignancy of the bone and is notoriously resistant to radiation therapy. High-dose cytotoxic chemotherapy and surgical...
BACKGROUND
Osteosarcoma (OS) is the most common primary malignancy of the bone and is notoriously resistant to radiation therapy. High-dose cytotoxic chemotherapy and surgical resection have improved the survival rate and prognosis of patients with OS. Nonetheless, treatment challenges remain when the tumor cannot be removed by surgery. Boron neutron capture therapy (BNCT) provides high linear energy transfer (LET) radiation, and its internal targeted characteristics make BNCT a novel therapy for removing OS and reducing radiation damage to adjacent healthy tissues.
METHODS
In this study, a UMR-106-grafted OS rat model was developed, and boric acid (BA) was used as the boron drug for BNCT. The pharmacokinetics of BA, following intravenous injection, were evaluated to determine the optimal time window for neutron irradiation. OS-bearing rats were irradiated by an epithermal neutron beam at Tsing Hua Open-Pool Reactor (THOR). The therapeutic efficacy of and tissue response after BNCT were evaluated by radiographic and histopathological observations.
RESULTS
OS-bearing rats were irradiated by neutrons in the first hour following the intravenous injection of BA. The prescription-absorbed doses in the tumor regions were 5.8 and 11.0 Gy. BNCT reduced the body weight of the tumor-bearing rats, but they recovered after a few days. The BA-mediated BNCT effectively controlled the orthotopic OS tumor, reduced osteolysis, and induced bone healing. Autoradiography and histological analysis confirmed that the BA retention region is consistent with the calcification region in OS tissue.
CONCLUSION
BA is specifically retained in OS, and the BA-mediated BNCT can significantly reduce the tumor burden and osteolysis in OS-bearing rats.
PubMed: 36836871
DOI: 10.3390/life13020514 -
California State Journal of Medicine Sep 1904
PubMed: 18733192
DOI: No ID Found -
Polymers Nov 2022Biologically compatible chitosan-based scaffolds have been considered a promising platform for tissue regeneration, tumor treatment, and targeted drug delivery....
Biologically compatible chitosan-based scaffolds have been considered a promising platform for tissue regeneration, tumor treatment, and targeted drug delivery. Chitosan-based scaffolds can be utilized as pH-sensitive drug carriers with targeted drug delivery resulting in less invasive tumor treatments. Further improvement with bioactive ions, such as borate ions, can result in the dual functionality of chitosan carriers provided by simultaneous antitumor efficacy and tissue regeneration. Here, boric acid-containing crosslinked chitosan scaffolds were prepared as delivery systems of doxorubicin, a chemotherapy drug used in the treatment of osteosarcoma. The encapsulation of boric acid was indicated by FTIR spectroscopy, while the ICP-MS analysis indicated the rapid release of boron in phosphate buffer (pH 6.0) and phosphate-buffered saline solution (pH 7.4). The obtained chitosan-boric acid scaffolds exhibit a highly porous and interconnected structure responsible for high swelling capacity, while enzymatic degradation indicated good scaffolds stability during four weeks of incubation at pH 6.0 and 7.4. Furthermore, the release of doxorubicin investigated in phosphate buffers indicated lower doxorubicin concentrations at pH 7.4 with respect to pH 6.0. Finally, the cytotoxicity of prepared doxorubicin-encapsulated scaffolds was evaluated on human sarcoma cells indicating the scaffolds' potential as cytostatic agents.
PubMed: 36365746
DOI: 10.3390/polym14214753 -
Bioengineering (Basel, Switzerland) Dec 2020The REACH regulation stands for "Registration, Evaluation, Authorization and Restriction of Chemicals" and defines certain substances as harmful to human health and the...
The REACH regulation stands for "Registration, Evaluation, Authorization and Restriction of Chemicals" and defines certain substances as harmful to human health and the environment. This urges manufacturers to adapt production processes. Boric acid and cobalt dichloride represent such harmful ingredients, but are commonly used in yeast cultivation media. The yeast () is an important host for heterologous protein production and compliance with the REACH regulation is desirable. Boric acid and cobalt dichloride are used as boron and cobalt sources, respectively. Boron and cobalt support growth and productivity and a number of cobalt-containing enzymes exist. Therefore, depletion of boric acid and cobalt dichloride could have various negative effects, but knowledge is currently scarce. Herein, we provide an insight into the impact of boric acid and cobalt depletion on recombinant protein production with and additionally show how different vessel materials affect cultivation media compositions through leaking elements. We found that boric acid could be substituted through boron leakiness from borosilicate glassware. Furthermore, depletion of boric acid and cobalt dichloride neither affected high cell density cultivation nor cell morphology and viability on methanol. However, final protein quality of three different industrially relevant enzymes was affected in various ways.
PubMed: 33322107
DOI: 10.3390/bioengineering7040161 -
Polymers Nov 2023In the present paper, a scalable, economically feasible, and continuous process for making cellulose-based carbon fibers (CFs) is described encompassing precursor...
In the present paper, a scalable, economically feasible, and continuous process for making cellulose-based carbon fibers (CFs) is described encompassing precursor spinning, precursor additivation, thermal stabilization, and carbonization. By the use of boric acid (BA) as an additive, the main drawback of cellulose-based CFs, i.e., the low carbon yield, is overcome while maintaining a high level of mechanical properties. This is demonstrated by a systematic comparison between CFs obtained from a BA-doped and an un-doped cellulose precursor within a temperature range for carbonization between 1000 and 2000 °C. The changes in chemical composition (via elemental analysis) and physical structure (via X-ray scattering) as well as the mechanical and electrical properties of the resulting CFs were investigated. It turned out that, in contrast to current opinion, the catalytic effect of boron in the formation of graphite-like structures sets in already at 1000 °C. It becomes more and more effective with increasing temperature. The catalytic effect of boron significantly affects crystallite sizes (, ), lattice plane spacings (), and orientation of the crystallites. Using BA, the carbon yield increased by 71%, Young's modulus by 27%, and conductivity by 168%, reaching 135,000 S/m. At the same time, a moderate decrease in tensile strength by 25% and an increase in density of 14% are observed.
PubMed: 37959990
DOI: 10.3390/polym15214310 -
Molecules (Basel, Switzerland) Jun 2023To investigate the synergistic catalytic effects of boric acid and α-hydroxycarboxylic acids (HCAs), we analyzed and measured the effects of the complexation reactions...
To investigate the synergistic catalytic effects of boric acid and α-hydroxycarboxylic acids (HCAs), we analyzed and measured the effects of the complexation reactions between boric acid and HCAs on the ionization equilibrium of the HCAs. Eight HCAs, glycolic acid, D-(-)-lactic acid, (R)-(-)-mandelic acid, D-gluconic acid, L-(-)-malic acid, L-(+)-tartaric acid, D-(-)-tartaric acid, and citric acid, were selected to measure the pH changes in aqueous HCA solutions after adding boric acid. The results showed that the pH values of the aqueous HCA solutions gradually decreased with an increase in the boric acid molar ratio, and the acidity coefficients when boric acid formed double-ligand complexes with HCAs were smaller than those of the single-ligand complexes. The more hydroxyl groups the HCA contained, the more types of complexes could be formed, and the greater the rate of change in the pH. The total rates of change in the pH of the HCA solutions were in the following order: citric acid > L-(-)-tartaric acid = D-(-)-tartaric acid > D-gluconic acid > (R)-(-)-mandelic acid > L-(-)-malic acid > D-(-)-lactic acid > glycolic acid. The composite catalyst of boric acid and tartaric acid had a high catalytic activity-the yield of methyl palmitate was 98%. After the reaction, the catalyst and methanol could be separated by standing stratification.
PubMed: 37375278
DOI: 10.3390/molecules28124723 -
[Determination of boric acid and silicic acid in mineral water by nonsuppressed ion chromatography].Se Pu = Chinese Journal of... Dec 2023Boron and silicon are widely distributed in nature; in water, these compounds typically present in the forms of boric acid and silicic acid, respectively. The maximum...
Boron and silicon are widely distributed in nature; in water, these compounds typically present in the forms of boric acid and silicic acid, respectively. The maximum allowable levels of silicic acid and boric acid in water are stipulated in relevant national and industry standards, such as GB 8538-2022. Quality changes in water, which are of great significance in water-quality evaluations, can be understood in terms of its silicic acid and boric acid contents. Boric acid content is usually determined by ion exclusion chromatography, whereas silicic acid content is usually determined by postcolumn derivatization. Therefore, traditional methods cannot achieve the simultaneous determination of silicic acid and boric acid contents in water. Modern ion chromatography has been widely used in the detection of ionic compounds, such as anions, cations, organic acids, organic amines, amino acids, and sugars. Boric (p=9.24) and silicic (p=9.77) acids are weak acids that dissociate into ionic states under alkaline conditions. Although these compounds cannot be tested using suppressed ion chromatography, they can be retained on ion chromatography columns. In this study, a method based on nonsuppressed conductance detection was established for the simultaneous determination of boric acid and silicic acid in water. The contents of boric acid and silicic acid were detected by nonsuppressed ion chromatography using a Dionex IonPac AS20 analytical column. The chromatographic conditions were as follows: flow rate, 1.0 mL/min; column temperature, 30 ℃; eluent, 6 mmol/L sodium hydroxide solution and 60 mmol/L mannitol; and sample injection volume, 50 μL. The effective separation of silicic acid and boric acid was achieved within 8 min. SiO and boric acid demonstrated good linear relationships in the concentration ranges of 0.25-100 and 0.5-100 mg/L (correlation coefficients, 0.9999), respectively. The method detection (MDL) and quantification (MQL) limits were 0.078 and 0.26 mg/L for SiO, and the MDL and MQL limits were 0.18 and 0.60 mg/L for boric acid. The average recoveries of boric acid and SiO (=6) were 97.3%-105.3%. Moreover, the relative standard deviations were less than 0.9% for boric acid at four spiked levels and less than 0.30% for SiO at three spiked levels. Thus, the method meets detection requirements. The pretreatment method is very simple, and the sample can be directly injected through a 0.22 μm water filtration membrane and into the column. The boric acid and silicic acid contents in nine mineral drinking water samples were determined under the optimized analytical conditions. Boric acid was not detected in these nine samples, but silicic acid was detected in six samples. The silicic acid contents detected were between 18.70 and 62.08 mg/L, which was consistent with the concentration ranges marked on the manufacturers' packaging. The proposed method can be used for the determination of boric acid and silicic acid in mineral drinking water and laboratory water, and provides a reference for the simultaneous detection of boric acid and silicic acid in ultrapure water used in the semiconductor industry.
PubMed: 38093542
DOI: 10.3724/SP.J.1123.2023.09025 -
Biomacromolecules Aug 2019We report on a controlled process allowing for the gelation of a diol-rich chitosan-derivative named CTL (lactose-modified chitosan) in the presence of boric acid as the...
We report on a controlled process allowing for the gelation of a diol-rich chitosan-derivative named CTL (lactose-modified chitosan) in the presence of boric acid as the cross-linker. A two-step approach is described, namely (i) the mixing of CTL and boric acid at pH = 5, a condition where the inorganic component is mildly reactive; (ii) the addition of sodium bicarbonate (NaHCO) as a trigger, allowing for the gradual and slow pH increase. The goal was to convert gradually the almost inert neutral boric acid into the much more reactive borate anion, the latter promoting the formation of borate esters with CTL diols. Gelling kinetics as well as mechanical behavior at small and large deformations was investigated by rheometry. CTL-boric acid gels behaved essentially as transient networks, hence continuously assembling and dissociating in a highly dynamic fashion. The present gelling mechanism preserves the strain-hardening behavior in the nonlinear region of stress-strain response, corroborating the already suggested potential applications of such gels as mimics of biological soft tissues.
Topics: Biocompatible Materials; Boric Acids; Chitosan; Gels; Hydrogen-Ion Concentration; Lactose
PubMed: 31268693
DOI: 10.1021/acs.biomac.9b00636