INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Jingjing Zhai,Fen You,Suting Xu,Ao Zhu,Xiaohui Kang,Yat-Ming So,Xiaochao Shi
A PNP-pincer ligand provides a versatile ligation framework, which is highly useful in organometallic chemistry and catalytic chemistry. In this work, by a de novo strategy, a simple and efficient synthetic pathway, has been developed to prepare the new iminodibenzyl-based PNP pincer proligand imin-RPNP(Li or H) (R = isopropyl, phenyl). By employing salt metathesis or direct alkyl elimination, we successfully synthesized a series of iminodibenzyl-PNP rare-earth-metal (Ln = Sc, Y, Dy, Ho, Er, Tm, Lu) complexes and characterized them by NMR and X-ray diffraction analyses. Upon addition of a borate and triisobutylaluminum (TIBA), the rare-earth-metal complexes 2-Y, 2-Dy, 2-Ho, 2-Er, and 2-Tm bearing the imin-PhPNP ligand exhibited unexpectedly high 3,4-selectivity (up to 95%) for the polymerization of 1,3-dienes (isoprene and myrcene); in particular, the chosen yttrium complex 2-Y promoted the 1,3-diene polymerization in a living manner. A computational study suggested that the sterically congested configuration around the metal center imposed by the imin-RPNP ligand might be the main reason for this unusual selectivity.
研究领域:
有机金属化学
·
催化化学
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Food Bioscience
·
2026
·
IF 6.2
Mengrui Wang,Yaokang Wu,Xueqin Lv,Jianghua Li,Long Liu,Guocheng Du,Jian Chen,Yanfeng Liu
3-Hydroxy-3-methylbutyrate (HMB), a key L-leucine metabolite, alters protein metabolic balance during the growth of new muscle tissue and exhibits anti-catabolic effects, garnering widespread attention as a dietary supplement for sarcopenia treatment and sports training. Here, we identified an efficient 4-hydroxyphenylpyruvate dioxygenase from Allokutzneria albata ( Aa HPPD) via molecular docking and whole-cell reaction yield verification. By coupling this enzyme with an efficient L-amino acid deaminase derived from Proteus vulgaris ( Pv LAAD) for whole-cell biocatalysis, 8.66 mM HMB was produced from 25 mM L-leucine, achieving a molar conversion of 34.6%. To coordinate the expression of pathway enzymes, ribosome binding site combinations were optimized, increasing the molar conversion to 56.5%. Additionally, for the rate-limiting enzyme Aa HPPD, distal mutations enhancing thermostability were identified using the Protein Repair One Stop Shop server and Disulfide by Design 2. The co-expression of the double mutant Aa HPPD Q65L/E99D and Pv LAAD resulted in a 61.24% conversion rate. To further improve catalytic activity, four sites identified via alanine scanning were subjected to grouped saturation mutagenesis based on spatial location. The final strain, co-expressing Aa HPPD Q65L/E99D/L260I/V306I and Pv LAAD, achieved a molar conversion of 73.73% for HMB production using 25 mM L-Leu as substrates within 10 h under optimal whole-cell conditions. This study established an efficient method for HMB production via whole-cell catalysis and provided a feasible strategy for engineering the thermostability and activity of the rate-limiting enzyme, as well as synergistically optimizing the expression levels of cascade enzymes.
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CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yuanchu Qin,Mude Zhu,Yi Tang,Xueqin Chen,Fu Wang,Xiaoyun Fan
How to efficiently treat a type of new emerging organic pollutant, carbamazepine (CBZ), with the features of environmental persistence, toxicity, and bioaccumulation, is now posing a challenge to scientists. Piezocatalysis, through the harvesting of mechanical energy, has a high capacity to degrade organic pollutants and is gaining increasing attention. Herein, a novel piezo material Cd 4 BiO(BO 3 ) 3 (CBB) with a 3-chromophore asymmetric structure showing an excellent CBZ degradation activity has been synthesized. The removal efficiency can reach 96.2% in 60 min, which is 4.13 times that of tetragonal phase BaTiO 3 (BTO) under the same conditions. The superior catalytic performance can be attributed to the easily polarized 3-chromophore asymmetric structure units of CBB, d 10 Cd 2+ ion, stereochemically active lone pair of Bi 3+ , and π-delocalization of BO 3 , which can generate a very strong internal alternating piezoelectric field under the action of ultrasonic vibration. Driven by this internal electric field force, the excited free charges can be easily separated and transferred to the surface of the material to take part in the redox reactions. Besides, CBB also exhibits high stability and excellent removal efficiency for rhodamine B (Rh B) and tetracycline (TC). Hydroxylation and aldehyde oxidation are the main processes of CBZ degradation. The eco-toxicity of CBZ and its intermediates was evaluated using T.E.S.T. software. This study shows that the easily strongly polarized borate material has a potential application in the piezocatalytic degradation of organic pollutants.
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POLYMER COMPOSITES
·
2022
·Vol. 43
·期 11
·7871-7881
·
IF 3.531
Dongdong Zeng,Yuhang Su,Jiaqi Dong,Xiaojun Ma,Lili Yu,Youjun Lv
In this study, four typical biocomposites from lignin blended with poly-3-hydroxybutyrate-3-hydroxyhexanoate (PHBH) using inorganic nanoparticles (INPs) (SiO 2 , MMT, CaCO 3 , and BN) as fillers were evaluated, which enhanced the thermal, mechanical, and barrier properties of composites. The results revealed that the selection of suitable INPs doped into the lignin/PHBH (L/P) composites was an important approach to achieve available function. MMT/L/P nanocomposites were significantly higher than those of untreated L/P composites in thermal stability (T max exceed 10%) and barrier properties (water vapor and oxygen resistance increased by 48% and 46%), and BN particles increased the initial thermal decomposition temperature by 8%. The elongation at break of CaCO 3 /L/P and BN/L/P composites were increased by 344% and 319%, while SiO 2 /L/P composites had the best tensile strength (18.8 MPa). Besides, the INPs/L/P nanocomposites in this paper exhibited excellent ultraviolet (UV) resistance and might become potential anti-UV packaging materials for grease foods.
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TENSIDE SURFACTANTS DETERGENTS
·
2021
·Vol. 58
·期 6
·468-474
·
IF 1.049
Zhonghua Zuo,Ming Zhou,Mao Liao,Pengao Peng,Jingfeng Zhang
Surfactants are very often used in tertiary oil production. However, the conventional surfactants cannot be used in high salinity reservoirs of tertiary oil production because the high salinity leads to the deactivation of the surfactants. Gemini sulpho-betaine surfactants have been developed to meet the requirements of tertiary oil production in such reservoirs. In this study, the Gemini sulphobetaine surfactant (bis{[(N-methyl-N-(3-alkoxy-2-hydroxy)propyl-N-(3-sulfonate)propyl]methylene}) was prepared by etherification, ring opening reaction and sulfonation reaction with decyl alcohol, epichlorohydrin, N,N’-dimethyl ethylene diamine and 1,3-propanesultone. The experimental conditions obtained are: the ratio of 1,3-propanesulfonic acid lactone to tertiary amine intermediate = 2.3 : 1, reaction temperature = 70°C and reaction time = 11 h. The analysis of the infrared spectrum showed that the structure of the synthesised substance corresponds to that of a Gemini sulphobetaine surfactant. The chemical shifts of the groups were determined by 1 HNMR structural characterisation of the products. The surface tension, emulsifying properties, foaming properties and wetting properties were investigated. The results showed that the surfactant has good foaming properties and good compatibility in a high salt environment.
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JOURNAL OF MEDICINAL CHEMISTRY
·
2020
·
IF 6.205
Mei-Xin Li,Yiqing Yang,Qiuye Zhao,Yue Wu,Lei Song,Haiyan Yang,Ming He,Hongying Gao,Bao-Liang Song,Jie Luo,Yu Rao
3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) is an eight-pass transmembrane protein in the endoplasmic reticulum (ER) and a classical drug target to treat dyslipidemia. Statins including the well-known atorvastatin (Lipitor; Pfizer) have been widely used for the prevention and treatment of cardiovascular disease for decades. However, statins can elicit a compensatory upregulation of HMGCR protein and cause adverse effects including skeletal muscle damage. They are ineffective for patients with statin intolerance. Inspired by the recently emerging proteolysis-targeting chimeras (PROTACs), we set out to eliminate HMGCR protein using PROTAC-mediated degradation. One PROTAC designated as P22A was found to reduce HMGCR protein level and block cholesterol biosynthesis potently with less compensatory upregulation of HMGCR. To the best of our knowledge, HMGCR is the first ER-localized, polytopic transmembrane protein successfully degraded by the PROTAC technique. This finding may provide a new strategy to lower cholesterol levels and treat the associated diseases.
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PubMed
高影响因子
Current Pharmaceutical Analysis
·
2023
·Vol. 19
·期 6
·511-520
·
IF 0.6
Zhang Mengmeng,Zou Qiaogen
Background: Atopic dermatitis (AD) is an allergic skin disease that can be inherited. Crisaborole is a specific drug developed to deal with this disease. The compounds of 4-(4- Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4-bromo-3-formylphenoxy)-3- formylphenoxy) benzonitrile
are the representative impurities in the synthesis of Crisaborole active pharmaceutical in gradient (API). Owing to the genotoxic impurities that could lead to cancer and gene mutations, it is necessary to develop a simple, efficient, sensitive, and accurate method to detect these impurities.
In this study, the 4-(4-Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4- bromo-3-formylphenoxy)-3-formylphenoxy)benzo- nitrile present in Crisaborole API were detected using UPLC-MS/MS. Methods: The separation was made on a ZORBAX Eclipse XDB-Pheny column (4.6 mm ×75mm, 3.5
μm) with the mobile phase of acetonitrile solution containing 0.1% trifluoroacetic acid (A) and water containing 0.1% formic acid (B) in gradient elution mode. Quantification was performed using positive ion electrospray ionization (ESI), and the contents of two compounds were determined
using the multiple reaction monitoring (MRM) modes. Results: The quantitative analytical method was fully validated with respect to linearity (r > 0.9998), sensitivity, precision, accuracy (the average recovery of two impurities was 84.1% to 90.7%), and robustness. Conclusion:
Three batches of samples were detected by UPLC-MS/MS, indicating that the proposed approach was applicable for the quality evaluation of Crisaborole.
研究领域:
药物分析
·
皮肤病学
·
毒理学
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SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Danyang Ji,Yahui Du,Hongmin Meng,Lin Zhang,Zhongming Huang,Yalei Hu,Jianjun Li,Fei Yu,Zhaohui Li
In this work, cobalt oxyhydroxide nanoflakes (CoOOH nanoflakes) were reported to possess a high oxidizability toward TMB for the first time and based on which we have developed a new strategy for qualitative and quantitative detection of ascorbic acid (AA). In our design, CoOOH nanoflakes can directly oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) to oxTMB with an obvious blue color emerging, and AA can selectively inhibit the oxidation of TMB to oxTMB by resolving CoOOH nanoflakes to Co 2+ , resulting in a decrease in the absorbance of oxTMB and bleaching of blue color. As such, the concentration of AA could be identified very easily by UV–vis spectroscopy and bare eyes. Under optimal conditions, this sensing platform showed a highly sensitive response to AA with a detection limit of 142 nM and a short assay time of 5 min. This assay was also successfully used to quantify AA in human serum samples and practical food samples. Importantly, using this fabricated sensing strategy, we have further developed a paper-based strip sensor for AA detection with satisfactory results, showing its great potential for point of care applications.
研究领域:
分析化学
·
医学诊断
·
食品科学
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高影响因子
INORGANIC CHEMISTRY
·
2026
·Vol. 65
·期 31
·18475-18483
·
IF 4.6
Zhang Quan-Wei,Tian Zi-Han,Wu Ming-Xing,Ma Chen-Yuan,Bi Xing-Yu,Fang Zhi,Duan Mei-Hong
Exploring high-performance birefringent crystals holds
paramount
significance in modern optics, yet traditional candidates generally
struggle to reconcile substantial birefringence with broad spectral
transparency. To circumvent this long-standing bottleneck, a synergistic
multifunctional-group assembly strategy has been devised to guide
the rational design of birefringent crystals. Correspondingly, driven
by lanthanide coordination and hydrogen bonding, two kinds of π-conjugated
units were successfully incorporated into a new birefringent crystal,
Ce(2,2 ′ -bipyridyl) 3 (SCN) 3 . Synthesized
via a facile solution evaporation method, Ce(2,2 ′ -bipyridyl) 3 (SCN) 3 was characterized by a large birefringence
of 0.18@546 nm, broad transmission windows (nearly spanning 0.445–25
μm), and moderate thermal stability (up to 270 ° C), making
it favorable for practical applications.
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INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Mingyang Liu,Zhongwen Ouyang,Xiaochen Liu,Jiaojiao Cao,Tongtong Xiao,Zhengcai Xia,Zhenxing Wang
Isolated large-spin Heisenberg antiferromagnetic uniform chain is quite rare. Here, we have successfully synthesized an ideal one-dimensional (1D) S = 5/2 linear-chain antiferromagnet [C2NH8]3[Fe(SO4)3], which crystallizes in a trigonal lattice with the space group R3c. A broad maximum at Tmax = 18 K is observed in the magnetic susceptibility curve. Notably, no long-range magnetic ordering is observed down to 2 K even if the material has a large Curie–Weiss temperature of θCW = −25.5 K. High-field magnetization at 2 K shows a linear increase until saturation at 30 T, and a high-field electron spin resonance (ESR) reveals the absence of a zero-field spin gap. The intrachain interaction J and interchain interaction J′ are determined. Quite a small ratio of J′/J < 2.5 × 10–3 suggests that [C2NH8]3[Fe(SO4)3] behaves as an ideal 1D uniform linear-chain antiferromagnet, in which the magnetic ordering is prevented by the extremely small interchain interaction and quantum fluctuation even for a classical spin of S = 5/2.
研究领域:
物理学
·
材料科学
·
磁学
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JOURNAL OF ORGANIC CHEMISTRY
·
2023
·
IF 3.6
Yuhang Xue,Chengjun Wu,Haiwen Li,Cunde Wang
Acetic acid-catalyzed (3 + 2) cyclization reaction of substituted 2-aroyl-3-aryl-1,1-dicyanocyclopropanes with arylhydrazines was investigated for the efficient synthesis of 4-dicyanomethyl-1,3,5-triaryl-4,5-dihydropyrazoles in good yields, in which 4,5-double substituents are predominantly trans selective. This approach included the consecutive condensation, ring opening, and double nucleophilic cyclization reaction.
研究领域:
有机化学
·
合成方法学
·
杂环化学
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Shuyang Shi,Baozhong Ma,Shuang Shao,Yongqiang Chen,Chengyan Wang
An original technology named HNO3 pressure leaching has been proposed by our team to leach Al from coal gangue and fly ash. Although the preliminary separation of Al and Fe had been achieved during leaching, a small amount of Fe impurity was still unavoidably dissolved into the leach liquor. To obtain pure Al2O3 during subsequent pyrolysis, it is imperative to synchronously remove Fe3+ during the crystallization of Al(NO3)3·9H2O. Herein, the phase equilibria of the Al(NO3)3–Fe(NO3)3–H2O(−HNO3) system at 25–40 °C and 0–8.12 mol kg–1 of HNO3 molality were investigated. The results indicated that the ternary system was a simple cosaturated type consisting of an immutable point, two univariate curves, and two crystallization regions. Notably, the solubility and crystallization region of Al(NO3)3·9H2O were barely impacted by acidity, while the opposite was true for Fe(NO3)3·9H2O. This finding was instructive for the crystallization of Fe(NO3)3·9H2O from the liquor with high Fe and low Al. Moreover, a high crystallization yield could be obtained at low temperatures. Finally, an appropriate crystallization procedure was provided. This study is expected to provide basic data and theoretical support for the crystallization and separation of mixed nitrates containing Al and Fe.
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