Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115029
Chaitra N. Mallannavar , S. Sujith , Shrinidhi D. Patil , Sanjeev P. Maradur , Ganapati V. Shanbhag
The bimetallic oxide dispersed on silanol rich SBA-15-OH was designed for the synthesis of cyclic carbonates from epoxides and CO2. The SBA-15-OH was synthesized via desilication and active metals were loaded by sol-gel method. Pure Sn-Ni oxide with a low surface area and lesser activity was modified by dispersing it on a high surface area SBA-15-OH. The different characterization techniques such as XRD, N2-sorption, CO2 and NH3-TPD, H2-TPR, SEM-EDX, TEM and XPS confirmed that the surface silanol group acts as anchoring site for the enhanced metal oxide-support interaction. Supported Sn-Ni oxide exhibited 16-fold better activity than pure Sn-Ni oxide, due to improved dispersion, which enhances the accessibility of reactants to the catalytic sites. Under the optimized reaction conditions 10Sn5Ni/SBA-15-OH gave 92.9 % styrene oxide conversion and 84.3 % selectivity for styrene carbonate. The catalyst is recyclable and the flexibility of the catalyst is tested for different epoxides with CO2.
{"title":"Bimetallic oxide catalysis meets silanol-enhanced synergy: A winning combination for efficient CO2 fixation by cycloaddition with styrene oxide","authors":"Chaitra N. Mallannavar , S. Sujith , Shrinidhi D. Patil , Sanjeev P. Maradur , Ganapati V. Shanbhag","doi":"10.1016/j.mcat.2025.115029","DOIUrl":"10.1016/j.mcat.2025.115029","url":null,"abstract":"<div><div>The bimetallic oxide dispersed on silanol rich SBA-15-OH was designed for the synthesis of cyclic carbonates from epoxides and CO<sub>2</sub>. The SBA-15-OH was synthesized via desilication and active metals were loaded by sol-gel method. Pure Sn-Ni oxide with a low surface area and lesser activity was modified by dispersing it on a high surface area SBA-15-OH. The different characterization techniques such as XRD, N<sub>2</sub>-sorption, CO<sub>2</sub> and NH<sub>3</sub>-TPD, H<sub>2</sub>-TPR, SEM-EDX, TEM and XPS confirmed that the surface silanol group acts as anchoring site for the enhanced metal oxide-support interaction. Supported Sn-Ni oxide exhibited 16-fold better activity than pure Sn-Ni oxide, due to improved dispersion, which enhances the accessibility of reactants to the catalytic sites. Under the optimized reaction conditions 10Sn5Ni/SBA-15-OH gave 92.9 % styrene oxide conversion and 84.3 % selectivity for styrene carbonate. The catalyst is recyclable and the flexibility of the catalyst is tested for different epoxides with CO<sub>2.</sub></div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115029"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115019
Violetta A. Ionova , Artem N. Fakhrutdinov , Daniil I. Gusev , Anton S. Abel , Alexei D. Averin , Irina P. Beletskaya
A new series of polytopic ligands based on 1,10-phenanthroline and polyoxadiamines has been synthesized through SNAr amination between 2-chloro-1,10-phenanthroline and diamines of various structures. The obtained podands were investigated as polytopic ligands for potassium and zinc ions in the industrially important reaction of cyclic carbonates synthesis from CO2 and epoxides under mild conditions (p(CO2) = 1 atm., T = 60–80 °C). The advantage of 1,11-diamino-3,6,9-trioxaundecane functionalized by 1,10-phenanthroline units compared to the diamine itself is demonstrated. It is revealed that heteroarylated 1,11-diamino-3,6,9-trioxaundecane can be used as a catalyst in the presence of KI (2 mol.%) with a low loading of the ligand (0.2 mol.%) instead of the usually employed 5–10 mol.% for unfunctionalized podands. Under these reaction conditions mono-substituted cyclic carbonates of various structures have been synthesized in excellent preparative yields ranging from 87 to 99%. Coordination of two Zn(II) ions to both 1,10-phenanthroline moieties has been shown to provide additional enhancement of catalytic activity. The catalysts demonstrate excellent stability and can be reused at least in 6 cycles.
{"title":"Bifunctional catalysts based on 2-amino-1,10-phenanthroline-containing podands for cyclic carbonates synthesis from CO2 and epoxides under mild conditions","authors":"Violetta A. Ionova , Artem N. Fakhrutdinov , Daniil I. Gusev , Anton S. Abel , Alexei D. Averin , Irina P. Beletskaya","doi":"10.1016/j.mcat.2025.115019","DOIUrl":"10.1016/j.mcat.2025.115019","url":null,"abstract":"<div><div>A new series of polytopic ligands based on 1,10-phenanthroline and polyoxadiamines has been synthesized through S<sub>N</sub>Ar amination between 2-chloro-1,10-phenanthroline and diamines of various structures. The obtained podands were investigated as polytopic ligands for potassium and zinc ions in the industrially important reaction of cyclic carbonates synthesis from CO<sub>2</sub> and epoxides under mild conditions (p(CO<sub>2</sub>) = 1 atm., T = 60–80 °C). The advantage of 1,11-diamino-3,6,9-trioxaundecane functionalized by 1,10-phenanthroline units compared to the diamine itself is demonstrated. It is revealed that heteroarylated 1,11-diamino-3,6,9-trioxaundecane can be used as a catalyst in the presence of KI (2 mol.%) with a low loading of the ligand (0.2 mol.%) instead of the usually employed 5–10 mol.% for unfunctionalized podands. Under these reaction conditions mono-substituted cyclic carbonates of various structures have been synthesized in excellent preparative yields ranging from 87 to 99%. Coordination of two Zn(II) ions to both 1,10-phenanthroline moieties has been shown to provide additional enhancement of catalytic activity. The catalysts demonstrate excellent stability and can be reused at least in 6 cycles.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115019"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115052
Boxuan Zhang , Jinxing Cui , Zhifang Li , Changlong Yang , Weiwei Dong , Ke Li
The key to generating hydrogen by electrolysis of water is to design the low-cost and high-catalytic activity catalyst. In this paper, FeNi-Layered Double Hydroxide@L-NCP/nickel foam (FeNi-LDH@L-NCP/NF) is prepared using leaf-like zeolitic imidazolate framework (L-Co-ZIF) as the precursor, phosphating to produce NiCoP (denoted as L-NCP) and then growing FeNi layered double hydroxide (FeNi-LDH) through a hydrothermal crystallization method. FeNi-LDH@L-NCP/NF is an exceptional catalyst for hydrogen evolution reaction (HER) as well as oxygen evolution reaction (OER). It shows the low overpotential of FeNi-LDH@L-NCP/NF and the values are 106 and 220 mV at 10 mA·cm-2 in 1 M KOH for HER and OER, respectively. This is because the more ordered L-NCP is formed due to the role of the ZIF templates, which favors rapid charge transfer between the electrolyte and the electrode, thereby promoting its catalytic performance. The synergistic effect of FeNi-LDH and L-NCP also contributes to activity.
{"title":"Fabrication of excellent bifunctional electrocatalyst FeNi-LDH@L-NiCoP using ZIF as a sacrifice template for alkaline electrolysis of water","authors":"Boxuan Zhang , Jinxing Cui , Zhifang Li , Changlong Yang , Weiwei Dong , Ke Li","doi":"10.1016/j.mcat.2025.115052","DOIUrl":"10.1016/j.mcat.2025.115052","url":null,"abstract":"<div><div>The key to generating hydrogen by electrolysis of water is to design the low-cost and high-catalytic activity catalyst. In this paper, FeNi-Layered Double Hydroxide@L-NCP/nickel foam (FeNi-LDH@L-NCP/NF) is prepared using leaf-like zeolitic imidazolate framework (L-Co-ZIF) as the precursor, phosphating to produce NiCoP (denoted as L-NCP) and then growing FeNi layered double hydroxide (FeNi-LDH) through a hydrothermal crystallization method. FeNi-LDH@L-NCP/NF is an exceptional catalyst for hydrogen evolution reaction (HER) as well as oxygen evolution reaction (OER). It shows the low overpotential of FeNi-LDH@L-NCP/NF and the values are 106 and 220 mV at 10 mA·cm<sup>-2</sup> in 1 M KOH for HER and OER, respectively. This is because the more ordered L-NCP is formed due to the role of the ZIF templates, which favors rapid charge transfer between the electrolyte and the electrode, thereby promoting its catalytic performance. The synergistic effect of FeNi-LDH and L-NCP also contributes to activity.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115052"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115020
Jian Lu , Zhentao Jiang , Xiubing Xie , Zhiwen Xi , Wenchi Zhang , Rongzhen Zhang
Pro-Xylane (boseine), a key cosmetic ingredient renowned for its anti-wrinkle effects and bioaffinity, has drawn considerable attention for its efficient biosynthesis. In this study, a NADP(H)-dependent carbonyl reductase from Canariomyces notabilis (CnCR) was identified through in silico screening. Using alanine scanning and semi-saturation mutagenesis, the double mutant Y98K/N208Q was obtained, exhibiting a 15.8-fold increase in specific activity (60.11 U mg⁻¹) and an 11.5-fold improvement in catalytic efficiency (kcat/Km = 0.25 mM⁻¹ s⁻¹) compared to the wild-type enzyme. Mechanistic insights into the improved performance of Y98K/N208Q were revealed through molecular docking. In the enzyme-β-acetone xyloside complex, Y98K/N208Q showed enhanced hydrogen bonding and a refined active site, which improving substrate binding and anchoring. The shorter distance to NADPH and stronger interactions with the substrate boosted the mutant's catalytic efficiency compared to the wild-type. To enable efficient cofactor regeneration, glucose dehydrogenase from Bacillus amyloliquefaciens was integrated into the Y98K/N208Q-mediated Pro-Xylane biosynthetic pathway. Under optimized conditions (30 °C, pH 7.5, 40 g L⁻¹ cells, and a co-substrate-to-substrate ratio of 1.5 : 1), the coupled system produced Pro-Xylane at a titer of 160 g L⁻¹ within 10 h, achieving a conversion rate and diastereomeric excess (S-enantiomer) of ≥99 %. To our knowledge, this is the highest reported Pro-Xylane production to date. This study highlights the discovery and semi-rational engineering of a novel enzyme for efficient Pro-Xylane biosynthesis, offering a robust platform for industrial-scale production of this valuable compound.
{"title":"Efficient biosynthesis of Pro-Xylane through semi-rational engineering of carbonyl reductase from Canariomyces notabilis","authors":"Jian Lu , Zhentao Jiang , Xiubing Xie , Zhiwen Xi , Wenchi Zhang , Rongzhen Zhang","doi":"10.1016/j.mcat.2025.115020","DOIUrl":"10.1016/j.mcat.2025.115020","url":null,"abstract":"<div><div>Pro-Xylane (boseine), a key cosmetic ingredient renowned for its anti-wrinkle effects and bioaffinity, has drawn considerable attention for its efficient biosynthesis. In this study, a NADP(H)-dependent carbonyl reductase from <em>Canariomyces notabilis</em> (<em>Cn</em>CR) was identified through <em>in silico</em> screening. Using alanine scanning and semi-saturation mutagenesis, the double mutant Y98K/N208Q was obtained, exhibiting a 15.8-fold increase in specific activity (60.11 U mg⁻¹) and an 11.5-fold improvement in catalytic efficiency (<em>k</em><sub>cat</sub>/<em>K</em><sub>m</sub> = 0.25 mM⁻¹ s⁻¹) compared to the wild-type enzyme. Mechanistic insights into the improved performance of Y98K/N208Q were revealed through molecular docking. In the enzyme-β-acetone xyloside complex, Y98K/N208Q showed enhanced hydrogen bonding and a refined active site, which improving substrate binding and anchoring. The shorter distance to NADPH and stronger interactions with the substrate boosted the mutant's catalytic efficiency compared to the wild-type. To enable efficient cofactor regeneration, glucose dehydrogenase from <em>Bacillus amyloliquefaciens</em> was integrated into the Y98K/N208Q-mediated Pro-Xylane biosynthetic pathway. Under optimized conditions (30 °C, pH 7.5, 40 g L⁻¹ cells, and a co-substrate-to-substrate ratio of 1.5 : 1), the coupled system produced Pro-Xylane at a titer of 160 g L⁻¹ within 10 h, achieving a conversion rate and diastereomeric excess (<em>S</em>-enantiomer) of ≥99 %. To our knowledge, this is the highest reported Pro-Xylane production to date. This study highlights the discovery and semi-rational engineering of a novel enzyme for efficient Pro-Xylane biosynthesis, offering a robust platform for industrial-scale production of this valuable compound.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115020"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115045
Majed S. AlFayi , Farag M.A. Altalbawy , Viralkumar Mandaliya , Suhas Ballal , Jameel M.A. Sulaiman , Deepak Bhanot , Girish Chandra Sharma , Subhash Chandra , Iskandar Shernazarov , Fadhel F. Sead
This study reports the synthesis and characterization of novel halogen-functionalized UiO-67 MOFs for CO₂ capture and conversion. Three mixed-linker Zr-UiO-67 MOFs, [Zr₆O₄(OH)₄(L₁L₂)₁₂], were synthesized, incorporating 2,2′-bipyridine-5,5′-dicarboxylic acid (L₁) and halogen-substituted 4,4′-biphenyl dicarboxylic acids (L₂) with chlorine (MOF-1), bromine (MOF-2), or iodine (MOF-3). Comprehensive characterization confirmed successful MOF synthesis and halogen incorporation. Gas adsorption studies showed selective CO₂ adsorption over N₂ and CH₄. Critically, these MOFs exhibited exceptional catalytic activity for solvent-free CO₂ conversion to cyclic carbonates at ambient temperature and pressure. The Lewis acidic Zr centers facilitated heterogeneous catalysis of CO₂ fixation with epoxides, yielding cyclic carbonates with TBAB as a cocatalyst. High conversion (91–99 %) of epichlorohydrin to 4-(chloromethyl)-1,3-dioxolan-2-one was achieved within 12 h at room temperature and 1 bar CO₂ pressure. A structure-activity relationship was established, revealing a direct correlation between halogen electronegativity and catalytic performance. CO₂ uptake and epoxide conversion rates increased across the halogen series from chlorine to iodine, attributed to the synergistic effect of the Lewis acidic Zr centers and the increasing polarizability of the halogen substituents. Moreover, the MOFs demonstrated robust recyclability, retaining substantial catalytic activity for at least five cycles. These findings underscore the potential of halogen-functionalized UiO-67 MOFs as promising candidates for sustainable CO₂ capture and utilization strategies.
{"title":"Green and efficient epoxide fixation and CO2 separation using halogen-decorated Zr-based UiO-67 MOFs","authors":"Majed S. AlFayi , Farag M.A. Altalbawy , Viralkumar Mandaliya , Suhas Ballal , Jameel M.A. Sulaiman , Deepak Bhanot , Girish Chandra Sharma , Subhash Chandra , Iskandar Shernazarov , Fadhel F. Sead","doi":"10.1016/j.mcat.2025.115045","DOIUrl":"10.1016/j.mcat.2025.115045","url":null,"abstract":"<div><div>This study reports the synthesis and characterization of novel halogen-functionalized UiO-67 MOFs for CO₂ capture and conversion. Three mixed-linker Zr-UiO-67 MOFs, [Zr₆O₄(OH)₄(L₁L₂)₁₂], were synthesized, incorporating 2,2′-bipyridine-5,5′-dicarboxylic acid (L₁) and halogen-substituted 4,4′-biphenyl dicarboxylic acids (L₂) with chlorine (<strong>MOF-1</strong>), bromine (<strong>MOF-2</strong>), or iodine (<strong>MOF-3</strong>). Comprehensive characterization confirmed successful MOF synthesis and halogen incorporation. Gas adsorption studies showed selective CO₂ adsorption over N₂ and CH₄. Critically, these MOFs exhibited exceptional catalytic activity for solvent-free CO₂ conversion to cyclic carbonates at ambient temperature and pressure. The Lewis acidic Zr centers facilitated heterogeneous catalysis of CO₂ fixation with epoxides, yielding cyclic carbonates with TBAB as a cocatalyst. High conversion (91–99 %) of epichlorohydrin to 4-(chloromethyl)-1,3-dioxolan-2-one was achieved within 12 h at room temperature and 1 bar CO₂ pressure. A structure-activity relationship was established, revealing a direct correlation between halogen electronegativity and catalytic performance. CO₂ uptake and epoxide conversion rates increased across the halogen series from chlorine to iodine, attributed to the synergistic effect of the Lewis acidic Zr centers and the increasing polarizability of the halogen substituents. Moreover, the MOFs demonstrated robust recyclability, retaining substantial catalytic activity for at least five cycles. These findings underscore the potential of halogen-functionalized UiO-67 MOFs as promising candidates for sustainable CO₂ capture and utilization strategies.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115045"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115028
M Manod , Archana Vijayakumar , TS Abhinav , R Bharath Krishna , Chithra Mohan
The development of green and streamlined methods for alkenylation reactions has long been a longstanding challenge in organic synthesis. Recently, visible light-mediated alkenylation has emerged as a potent strategy for the efficient and sustainable synthesis of diverse carbon-carbon double bonds. This approach offers a more effective and environmentally friendly alternative to traditional synthetic approaches. This review highlights the latest advancements in visible light-mediated alkenylation reactions, with a focus on novel photocatalytic systems, alkene sources, and applications in complex molecule synthesis. Mechanistic insights into the role of visible light in facilitating efficient and selective alkenylation are also provided.
{"title":"Harnessing visible light for alkenylation reactions: A promising strategy in organic synthesis","authors":"M Manod , Archana Vijayakumar , TS Abhinav , R Bharath Krishna , Chithra Mohan","doi":"10.1016/j.mcat.2025.115028","DOIUrl":"10.1016/j.mcat.2025.115028","url":null,"abstract":"<div><div>The development of green and streamlined methods for alkenylation reactions has long been a longstanding challenge in organic synthesis. Recently, visible light-mediated alkenylation has emerged as a potent strategy for the efficient and sustainable synthesis of diverse carbon-carbon double bonds. This approach offers a more effective and environmentally friendly alternative to traditional synthetic approaches. This review highlights the latest advancements in visible light-mediated alkenylation reactions, with a focus on novel photocatalytic systems, alkene sources, and applications in complex molecule synthesis. Mechanistic insights into the role of visible light in facilitating efficient and selective alkenylation are also provided.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115028"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115051
Kangping Huang , Wei Song , Wanqing Wei , Guipeng Hu , Xiaomin Li , Cong Gao , Jing Wu
Salvianic acid A (SAA), a bioactive compound from Salvia miltiorrhiza, has attracted significant attention for its therapeutic properties, including antitumor and antioxidant activities. However, its large-scale application is limited by the conventional production methods, which rely primarily on physical extraction and chemical synthesis. In this study, we constructed a de novo biosynthetic pathway for SAA by integrating two key modules: the HPPA hydroxylation module HpaBC (4-hydroxyphenylacetate 3-monooxygenase from Escherichia coli) and the DHPPA reductase module RgMDH (D-mandelic acid dehydrogenase from Rhodotorula graminis) into a high-yield tyrosine-producing strain, Tyr0, generating the engineered strain Dps01. Metabolic analysis identified the low catalytic efficiency of RgMDH as the critical bottleneck. To address this, structure-guided protein engineering of RgMDH was performed. Molecular dynamics (MD) simulations revealed that the optimal mutant RgMDHM4 (T312A/F316S/T255I/A59H) exhibited a 10.3-fold increase in catalytic conformation occupancy compared to the wild-type (4.74% vs 0.46%), indicating enhanced substrate channel dynamics. This mutant exhibited a 295% increase in activity toward DHPPA, with enhanced substrate affinity and a 5.76-fold improvement in catalytic efficiency (kcat/Km). When integrated into strain Dps02, the engineered system achieved a maximum SAA production of 6.82 g/L within 34 hours, with a productivity of 0.21 g/L·h⁻¹ in a 5 L fed-batch fermentation. These results represent a significant advancement in the biosynthesis of SAA.
{"title":"Engineering mandelate dehydrogenase for the efficient biosynthesis of salvianic acid A","authors":"Kangping Huang , Wei Song , Wanqing Wei , Guipeng Hu , Xiaomin Li , Cong Gao , Jing Wu","doi":"10.1016/j.mcat.2025.115051","DOIUrl":"10.1016/j.mcat.2025.115051","url":null,"abstract":"<div><div>Salvianic acid A (SAA), a bioactive compound from <em>Salvia miltiorrhiza</em>, has attracted significant attention for its therapeutic properties, including antitumor and antioxidant activities. However, its large-scale application is limited by the conventional production methods, which rely primarily on physical extraction and chemical synthesis. In this study, we constructed a de novo biosynthetic pathway for SAA by integrating two key modules: the HPPA hydroxylation module HpaBC (4-hydroxyphenylacetate 3-monooxygenase from <em>Escherichia coli</em>) and the DHPPA reductase module <em>Rg</em>MDH (D-mandelic acid dehydrogenase from <em>Rhodotorula graminis</em>) into a high-yield tyrosine-producing strain, <em>Tyr0</em>, generating the engineered strain Dps01. Metabolic analysis identified the low catalytic efficiency of <em>Rg</em>MDH as the critical bottleneck. To address this, structure-guided protein engineering of <em>Rg</em>MDH was performed. Molecular dynamics (MD) simulations revealed that the optimal mutant <em>Rg</em>MDH<sup>M4</sup> (T312A/F316S/T255I/A59H) exhibited a 10.3-fold increase in catalytic conformation occupancy compared to the wild-type (4.74% vs 0.46%), indicating enhanced substrate channel dynamics. This mutant exhibited a 295% increase in activity toward DHPPA, with enhanced substrate affinity and a 5.76-fold improvement in catalytic efficiency (<em>k<sub>cat</sub></em>/<em>K</em><sub>m</sub>). When integrated into strain Dps02, the engineered system achieved a maximum SAA production of 6.82 g/L within 34 hours, with a productivity of 0.21 g/L·h⁻¹ in a 5 L fed-batch fermentation. These results represent a significant advancement in the biosynthesis of SAA.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115051"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115023
Meng Lan, Xiaoli Dong, Nan Zheng, Yujun Liu
The continuous increase of heavy metal pollution has seriously affected the ecological environment and human health, and photocatalysis technology is considered to be one of the most effective and environmentally friendly treatment methods. Herein, BiOI/Bi2S3 Z-scheme heterostructure photocatalyst with abundant oxygen vacancies was fabricated and applied for the removal of hexavalent chromium (Cr(VI)). The tightly contact interface of in situ heterostructure and abundant oxygen vacancies can accelerate charge transport and improve the photogenerated carrier separation efficiency. The unique charge transmission path of the Z-scheme heterostructure endows the material with superior redox ability. BiOI/Bi2S3 with optimized ratio can achieve effective reduction of Cr(VI) with the efficiency of 95.6 % under 10 min visible light illumination This work offers a promising photocatalyst for promoting the disposal of chromium-containing wastewater.
{"title":"In-situ controlled synthesis of BiOI/Bi2S3 Z-scheme heterostructure with enriched oxygen vacancies for efficient photocatalytic removal of hexavalent chromium","authors":"Meng Lan, Xiaoli Dong, Nan Zheng, Yujun Liu","doi":"10.1016/j.mcat.2025.115023","DOIUrl":"10.1016/j.mcat.2025.115023","url":null,"abstract":"<div><div>The continuous increase of heavy metal pollution has seriously affected the ecological environment and human health, and photocatalysis technology is considered to be one of the most effective and environmentally friendly treatment methods. Herein, BiOI/Bi<sub>2</sub>S<sub>3</sub> Z-scheme heterostructure photocatalyst with abundant oxygen vacancies was fabricated and applied for the removal of hexavalent chromium (Cr(VI)). The tightly contact interface of in situ heterostructure and abundant oxygen vacancies can accelerate charge transport and improve the photogenerated carrier separation efficiency. The unique charge transmission path of the Z-scheme heterostructure endows the material with superior redox ability. BiOI/Bi<sub>2</sub>S<sub>3</sub> with optimized ratio can achieve effective reduction of Cr(VI) with the efficiency of 95.6 % under 10 min visible light illumination This work offers a promising photocatalyst for promoting the disposal of chromium-containing wastewater.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115023"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115047
Wenbo Li , Xin Yan , Wenli Xia , Linguo Zhao , Jianjun Pei
Enzymes are highly efficient and specific biocatalysts. However, they are unstable and prone to deactivation, which limits their practical applications. To address these challenges, immobilization technology has been developed. Traditional immobilization methods typically require purified enzymes, but enzyme purification is often time-consuming and labor-intensive. Therefore, this study aims to develop a one-step method that directly purifies, adsorbs, and immobilizes enzymes from crude extracts, while simultaneously enhancing their activity. In this work, we examined the importance of the location of anchoring peptide (LCI) in fused enzyme functionality and binding affinity across various materials. LCI was fused with Aspergillus fumigatiaffinis prenyltransferase (AfPT) at the N-terminus to obtain the fusion enzyme LCI-AfPT, which displayed maximum load (38.9 mg/g) and highest activity recovery (92.7%) on polystyrene (PS). The free enzyme LCI-AfPT exhibited highest activity at pH 8.0 and 40°C. The highest activity of LCI-AfPT@PS was achieved at pH 7.5 and 55°C, with over 70% residual activity after 4 hours of incubation at 55°C. The tolerance of LCI-AfPT@PS to ethanol and methanol was significantly higher than that of LCI-AfPT. Immobilization significantly improved substrate affinity (Km reduced from 0.273 mM to 0.09 mM) and organic solvent tolerance, with no activity loss in ≤10% ethanol/methanol, highlighting its potential for industrial biocatalysis of hydrophobic flavonoids. The Kcat/Km value of LCI-AfPT@PS reached 0.072 s-1· mM-1, which was higher than that of LCI-AfPT and AfPT. LCI-AfPT was directly immobilized on PS from crude enzymes without purification, with a high adsorption selectivity of 80.5%, which was about 8-fold higher than that of AfPT. LCI-AfPT@PS retained 70% of its original activity after 10 cycles of reuse, resulting in a total of 4.4 mM of 3’-C-prenylnaringenin. This study represents the first investigation on the one-step purification and immobilization of prenyltransferase using an anchoring peptide, and its application in the efficient production of prenylated flavonoids.
{"title":"One-step direct immobilization of engineered prenyltransferase on polystyrene for prenylated flavonoid production","authors":"Wenbo Li , Xin Yan , Wenli Xia , Linguo Zhao , Jianjun Pei","doi":"10.1016/j.mcat.2025.115047","DOIUrl":"10.1016/j.mcat.2025.115047","url":null,"abstract":"<div><div>Enzymes are highly efficient and specific biocatalysts. However, they are unstable and prone to deactivation, which limits their practical applications. To address these challenges, immobilization technology has been developed. Traditional immobilization methods typically require purified enzymes, but enzyme purification is often time-consuming and labor-intensive. Therefore, this study aims to develop a one-step method that directly purifies, adsorbs, and immobilizes enzymes from crude extracts, while simultaneously enhancing their activity. In this work, we examined the importance of the location of anchoring peptide (LCI) in fused enzyme functionality and binding affinity across various materials. LCI was fused with <em>Aspergillus fumigatiaffinis</em> prenyltransferase (AfPT) at the N-terminus to obtain the fusion enzyme LCI-AfPT, which displayed maximum load (38.9 mg/g) and highest activity recovery (92.7%) on polystyrene (PS). The free enzyme LCI-AfPT exhibited highest activity at pH 8.0 and 40°C. The highest activity of LCI-AfPT@PS was achieved at pH 7.5 and 55°C, with over 70% residual activity after 4 hours of incubation at 55°C. The tolerance of LCI-AfPT@PS to ethanol and methanol was significantly higher than that of LCI-AfPT. Immobilization significantly improved substrate affinity (<em>Km</em> reduced from 0.273 mM to 0.09 mM) and organic solvent tolerance, with no activity loss in ≤10% ethanol/methanol, highlighting its potential for industrial biocatalysis of hydrophobic flavonoids. The <em>Kcat/Km</em> value of LCI-AfPT@PS reached 0.072 s<sup>-1</sup>· mM<sup>-1</sup>, which was higher than that of LCI-AfPT and AfPT. LCI-AfPT was directly immobilized on PS from crude enzymes without purification, with a high adsorption selectivity of 80.5%, which was about 8-fold higher than that of AfPT. LCI-AfPT@PS retained 70% of its original activity after 10 cycles of reuse, resulting in a total of 4.4 mM of 3’-C-prenylnaringenin. This study represents the first investigation on the one-step purification and immobilization of prenyltransferase using an anchoring peptide, and its application in the efficient production of prenylated flavonoids.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115047"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mcat.2025.115050
Shuang Li , Xiaowei Xu , Ziqiang Li , Lijuan Ding , Ying Peng , Xiaohui Kang , Yi Luo
Organic catalytic ring-opening polymerization (ROP) of cyclic esters and carbonates is an effective strategy for obtaining biodegradable and biocompatible aliphatic polyesters and polycarbonates. The challenge is to develop highly active and green organocatalysts in this domain. Herein, the zwitterionic carboxybetaine catalyzed the ROP mechanism of trimethylene carbonate (TMC) cyclic ester and lactide (LA) was investigated by density functional theory (DFT). By comparing the ROP of TMC catalyzed by natural trimethyl glycine (TMG) and unnatural tetramethylammonium acetate (TMAA), we found the proton-accepting ability of the anion part in zwitterionic carboxybetaine is the main influencing factor of polymerization activity. Based on this finding, it is proposed to enhance the proton-accepting ability of the anion part in TMG by extending carbon spacer lengths between CH3COO‒ and N(CH3)4+ of TMG. Among them zwitterionic carboxybetaine molecules ((CH3)3N+(CH2)nCOO‒ (n = 1–5)), the (CH3)3N+(CH2)4COO‒ shows the highest catalytic activity in the ROP of TMC. Moreover, the ROP of LA catalyzed by (CH3)3N+(CH2)4COO‒ showed very high catalytic activity compared to the TMG in both theoretical calculation and experiment. This work will inspire the future development of natural organocatalysts with high catalytic performance.
{"title":"The ring-opening polymerization of cyclic ester and carbonate catalyzed by trimethyl glycine and catalyst design: A DFT study","authors":"Shuang Li , Xiaowei Xu , Ziqiang Li , Lijuan Ding , Ying Peng , Xiaohui Kang , Yi Luo","doi":"10.1016/j.mcat.2025.115050","DOIUrl":"10.1016/j.mcat.2025.115050","url":null,"abstract":"<div><div>Organic catalytic ring-opening polymerization (ROP) of cyclic esters and carbonates is an effective strategy for obtaining biodegradable and biocompatible aliphatic polyesters and polycarbonates. The challenge is to develop highly active and green organocatalysts in this domain. Herein, the zwitterionic carboxybetaine catalyzed the ROP mechanism of trimethylene carbonate (TMC) cyclic ester and lactide (LA) was investigated by density functional theory (DFT). By comparing the ROP of TMC catalyzed by natural trimethyl glycine (TMG) and unnatural tetramethylammonium acetate (TMAA), we found the proton-accepting ability of the anion part in zwitterionic carboxybetaine is the main influencing factor of polymerization activity. Based on this finding, it is proposed to enhance the proton-accepting ability of the anion part in TMG by extending carbon spacer lengths between CH<sub>3</sub>COO<sup>‒</sup> and N(CH<sub>3</sub>)<sub>4</sub><sup>+</sup> of TMG. Among them zwitterionic carboxybetaine molecules ((CH<sub>3</sub>)<sub>3</sub>N<sup>+</sup>(CH<sub>2</sub>)<sub>n</sub>COO<sup>‒</sup> (n = 1–5)), the (CH<sub>3</sub>)<sub>3</sub>N<sup>+</sup>(CH<sub>2</sub>)<sub>4</sub>COO<sup>‒</sup> shows the highest catalytic activity in the ROP of TMC. Moreover, the ROP of LA catalyzed by (CH<sub>3</sub>)<sub>3</sub>N<sup>+</sup>(CH<sub>2</sub>)<sub>4</sub>COO<sup>‒</sup> showed very high catalytic activity compared to the TMG in both theoretical calculation and experiment. This work will inspire the future development of natural organocatalysts with high catalytic performance.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"579 ","pages":"Article 115050"},"PeriodicalIF":3.9,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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