Efficient solar-driven tandem catalysis for biomass valorization: selective CC bond cleavage to synthesize xylitol.

The Liquid-Sunshine presents a transformative approach for converting biomass into high-value platform chemicals (HPCs). However, conventional photorefineries suffer from low efficiency and excessive byproduct formation due to the inherent incompatibility between biomass and photocatalysts. Herein, we introduce an innovative tandem oxygen-reforming-photocatalysis (TORP) strategy, which first selectively reforms biomass functional groups before driving photocatalytic CC bond cleavage to produce HPCs.

Conformational gating in CYP154C2: Gln230-mediated substrate recognition and catalytic switching revealed by structural dynamics.

Previously, we reported that CYP154C2 from Streptomyces avermitilis is capable of catalyzing the 2α-hydroxylation of the two model substrates, testosterone (TES) and androstenedione (ASD), and resolved the closed structures of both the substrate-free form and the TES-bound form. In this study, we extend these findings by determining the open-conformation structures of the substrate-free and ASD-bound forms-a rare achievement among bacterial P450s. Structural analyses revealed coordinated conformational shifts in the FG helices, HI helices, and BC loop during open-to-closed transitions.

Engineering Asymmetric Bimetallic CoM (M = Ni, Fe, Mn, Cu) Nanoparticles Encapsulated in Freestanding Wood-Derived Carbon Electrodes for Enhanced ORR Kinetics in Zinc-Air Batteries.

The electrochemical reduction of oxygen is pivotal for advancing emerging energy technologies. Precise control over morphology and electronic structure is essential for enhancing catalytic activity and stability in the oxygen reduction reaction (ORR). In this study, a freestanding carbon electrode is developed by in-situ growth of carbon nanotube (CNT)-encapsulated bimetallic CoM (M = Ni, Fe, Mn, Cu) nanoparticles (NPs) within a hierarchical carbonized wood matrix (CoM@NWCC).

Photocatalytic Upcycling of Plastic Waste into Syngas by ZnS/GaO Z-Scheme Heterojunction.

The photocatalytic conversion of plastic waste into value-added products using solar energy presents a promising approach for promoting environmental sustainability. Nonetheless, the emission of CO during the conventional photocatalytic degradation process remains a major hurdle that impedes its further development. In this study, we propose an efficient photocatalytic conversion of polyethylene plastic into syngas (CO+H mixtures) by using a ZnS/GaO Z-scheme heterojunction photocatalyst.

Tuning the electronic metal-carbon interactions in Lignin-based carbon-supported ruthenium-based electrocatalysts for enhanced hydrogen evolution reactions.

Ruthenium (Ru) nanoparticles dispersed on carbon support are promising electrocatalysts for hydrogen evolution reaction (HER) due to strong electronic metal-carbon interactions (EMCIs). Defects engineering in carbon supports is an effective strategy to adjust EMCIs. We prepared nitrogen/sulfur co-doped carbon supported Ru nanoparticles (Ru@N/S-LC) using sodium lignosulfonate and urea as feedstocks.

Improved 2α-Hydroxylation Efficiency of Steroids by CYP154C2 Using Structure-Guided Rational Design.

Cytochrome P450 enzymes are promising biocatalysts for industrial use because they catalyze site-selective C-H oxidation and have diverse catalytic reactions and a broad substrate range. In this study, the 2α-hydroxylation activity of CYP154C2 from Streptomyces avermitilis MA-4680T toward androstenedione (ASD) was identified by an conversion assay. The testosterone (TES)-bound structure of CYP154C2 was solved at 1.

Regulating the coordination capacity of ATMP using melamine: facile synthesis of cobalt phosphides as bifunctional electrocatalysts for the ORR and HER.

Due to the complexity of the synthetic process of cobalt phosphides (CoP), ongoing efforts concentrate on simplifying the preparation process of CoP. In this work, amino tris(methylene phosphonic acid) (ATMP, L1) and melamine (MA, L2) are assembled into two-dimensional (2D) organic nanostructures by hydrogen bonding and ionic interactions a supramolecular assembly, which greatly weakens the coordination ability of L1 with Co. As the introduced L2 is rich in carbon and nitrogen, it allows the cobalt-organophosphate complex to be placed under a strongly reducing atmosphere during the high-temperature calcination process to achieve an phosphating purpose.

The 16α-Hydroxylation of Progesterone by Cytochrome P450 107X1 from Streptomyces avermitilis.

Cytochrome P450 enzymes (CYPs or P450s) are ubiquitous heme-dependent enzymes that catalyze the monooxygenation of non-activated C-H bonds to modify the structure of the substrate. In this study, we heterologously expressed CYP107X1 from Streptomyces avermitilis and conducted in vitro substrate screening using the alternative redox partners putidaredoxin and putidaredoxin reductase. CYP107X1 catalyzed the 16α-hydroxylation of progesterone with regio- and stereoselectivity.

Multi-tailoring of a modified MOF-derived CuO electrochemical transducer for enhanced hydrogen peroxide sensing.

Reasonable control of the redox states within the catalytic units together with the interconnection degrees of the substrate is of great significance in the modulation of a well-performing transducer. Herein, a novel carbon black (CB)-modified copper metal-organic framework nanomaterial (CB@Cu-MOF) prepared at room temperature was utilized as a precursor to synthesize mixed-valent copper-oxide composite catalysts (NC/CuO-). By tuning the carbonization process of the precursor at different temperatures ( = 100 °C, 200 °C, 300 °C and 400 °C), the different ratio configurations of the redox-alternated CuO portions were successfully controlled with the simultaneous effective tailoring of the defect abundance in the N-doped carbon substrate.

Hydroxylation, Epoxidation, and Dehydrogenation of Capsaicin by a Microbial Promiscuous Cytochrome P450 105D7.

Cytochrome P450 enzymes (P450s) are versatile biocatalysts, which insert a molecular oxygen into inactivated C-H bonds under mild conditions. CYP105D7 from Streptomyces avermitilis has been reported as a bacterial substrate-promiscuous P450 which catalyzes the hydroxylation of 1-deoxypentalenic acid, diclofenac, naringenin, compactin and steroids. In this study, CYP105D7 catalyzes hydroxylation, epoxidation and dehydrogenation of capsaicin, a pharmaceutical agent, revealing its functional diversity.

Chemical and Biological Study of Novel Aplysiatoxin Derivatives from the Marine Cyanobacterium sp.

Since 1970s, aplysiatoxins (ATXs), a class of biologically active dermatoxins, were identified from the marine mollusk , whilst further research indicated that ATXs were originally metabolized by cyanobacteria. So far, there have been 45 aplysiatoxin derivatives discovered from marine cyanobacteria with various geographies. Recently, we isolated two neo-debromoaplysiatoxins, neo-debromoaplysiatoxin G () and neo-debromoaplysiatoxin H () from the cyanobacterium sp.

Regio- and stereoselective hydroxylation of testosterone by a novel cytochrome P450 154C2 from Streptomyces avermitilis.

Cytochrome P450 enzymes (P450 or CYP) are some of the most versatile biocatalysts, and offer advantages for oxidizing unreactive C-H bonds in mild conditions. In this study, we identified a novel cytochrome P450 154C2 from Streptomyces avermitilis and characterized its function in 2α-hydroxylation of testosterone with regio- and stereoselectivity. To investigate the efficiency of electron transfer, we conducted biotransformation using two different P450 redox partners-RhFRED (RhF reductase domain) from Rhodococcus sp.

Hydroxylation of Steroids by a Microbial Substrate-Promiscuous P450 Cytochrome (CYP105D7): Key Arginine Residues for Rational Design.

Our previous study showed that CYP105D7, a substrate-promiscuous P450, catalyzes the hydroxylation of 1-deoxypentalenic acid, diclofenac, naringenin, and compactin. In this study, 14 steroid compounds were screened using recombinant cells harboring genes encoding CYP105D7 and redox partners (Pdx/Pdr, RhFRED, and FdxH/FprD), and the screening identified steroid A-ring 2β- and D-ring 16β-hydroxylation activity. Wild-type CYP105D7 was able to catalyze the hydroxylation of five steroids (testosterone, progesterone, 4-androstene-3,17-dione, adrenosterone, and cortisone) with low (<10%) conversion rates.

Comparative Genomic Insights into Secondary Metabolism Biosynthetic Gene Cluster Distributions of Marine .

Bacterial secondary metabolites have huge application potential in multiple industries. Biosynthesis of bacterial secondary metabolites are commonly encoded in a set of genes that are organized in the secondary metabolism biosynthetic gene clusters (SMBGCs). The development of genome sequencing technology facilitates mining bacterial SMBGCs.

ATMP-induced three-dimensional conductive polymer hydrogel scaffold for a novel enhanced solid-state electrochemiluminescence biosensor.

Reliable and sensitive detection of xanthine has important medical and biological significance. In this work, a novel three-dimensional (3D) conductive polymer hydrogel of polyaniline (PAni) was feasibly prepared using aniline (Ani), amino trimethylene phosphonic acid (ATMP) and ammonium persulfate ((NH)SO) as monomer, gelatinizing agent and oxidizing agent, respectively. Protonation of aniline can be achieved by ATMP, inducing good conductivity of the obtained hydrogel.

Rational and semi-rational engineering of cytochrome P450s for biotechnological applications.

The cytochrome P450 enzymes are ubiquitous heme-thiolate proteins performing regioselective and stereoselective oxygenation reactions in cellular metabolism. Due to their broad substrate scope and catalytic versatility, P450 enzymes are also attractive candidates for many industrial and biopharmaceutical applications. For particular uses, enzyme properties of P450s can be further optimized through directed evolution, rational, and semi-rational engineering approaches, all of which introduce mutations within the P450 structures.

Hydroxylation of Compactin (ML-236B) by CYP105D7 (SAV_7469) from .

Compactin and pravastatin are competitive cholesterol biosynthesis inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase and belong to the statin drugs; however, the latter shows superior pharmacokinetic characteristics. Previously, we reported that the bacterial P450, CYP105D7, from can catalyze the hydroxylation of 1-deoxypentalenic acid, diclofenac, and naringenin. Here, we demonstrate that CYP105D7 could also catalyze compactin hydroxylation in vitro.

Structural basis for the 4'-hydroxylation of diclofenac by a microbial cytochrome P450 monooxygenase.

Diclofenac is a nonsteroidal anti-inflammatory drug. It undergoes hydroxylation by mammalian cytochrome P450 enzymes at 4'- and/or 5'-positions. A bacterial P450 enzyme, CYP105D7 from Streptomyces avermitilis, has been shown to catalyze hydroxylation of 1-deoxypentalenic acid and an isoflavone daidzein.

Pentalenic acid is a shunt metabolite in the biosynthesis of the pentalenolactone family of metabolites: hydroxylation of 1-deoxypentalenic acid mediated by CYP105D7 (SAV_7469) of Streptomyces avermitilis.

Pentalenic acid (1) has been isolated from many Streptomyces sp. as a co-metabolite of the sesquiterpenoid antibiotic pentalenolactone and related natural products. We have previously reported the identification of a 13.

Regio- and stereospecificity of filipin hydroxylation sites revealed by crystal structures of cytochrome P450 105P1 and 105D6 from Streptomyces avermitilis.

The polyene macrolide antibiotic filipin is widely used as a probe for cholesterol and a diagnostic tool for type C Niemann-Pick disease. Two position-specific P450 enzymes are involved in the post-polyketide modification of filipin during its biosynthesis, thereby providing molecular diversity to the "filipin complex." CYP105P1 and CYP105D6 from Streptomyces avermitilis, despite their high sequence similarities, catalyze filipin hydroxylation at different positions, C26 and C1', respectively.

Crystal structures of cytochrome P450 105P1 from Streptomyces avermitilis: conformational flexibility and histidine ligation state.

The polyene macrolide antibiotic filipin is widely used as a probe for cholesterol in biological membranes. The filipin biosynthetic pathway of Streptomyces avermitilis contains two position-specific hydroxylases, C26-specific CYP105P1 and C1'-specific CYP105D6. In this study, we describe the three X-ray crystal structures of CYP105P1: the ligand-free wild-type (WT-free), 4-phenylimidazole-bound wild-type (WT-4PI), and ligand-free H72A mutant (H72A-free) forms.