Adv Healthc Mater
September 2024
J-aggregate is a promising strategy to enhance second near-infrared window (NIR-II) emission, while the controlled synthesis of J-aggregated NIR-II dyes is a huge challenge because of the lack of molecular design principle. Herein, bulk spiro[fluorene-9,9'-xanthene] functionalized benzobisthiadiazole-based NIR-II dyes (named BSFX-BBT and OSFX-BBT) are synthesized with different alkyl chains. The weak repulsion interaction between the donor and acceptor units and the S…N secondary interactions make the dyes to adopt a co-planar molecular conformation and display a peak absorption >880 nm in solution.
View Article and Find Full Text PDFSecond near-infrared (NIR-II) fluorescence imaging shows huge application prospects in clinical disease diagnosis and surgical navigation, while it is still a big challenge to exploit high performance NIR-II dyes with long-wavelength absorption and high fluorescence quantum yield. Herein, based on planar π-conjugated donor-acceptor-donor systems, three NIR-II dyes (TP-DBBT, TP-TQ1, and TP-TQ2) were synthesized with bulk steric hindrance, and the influence of acceptor engineering on absorption/emission wavelengths, fluorescence efficiency and photothermal properties was systematically investigated. Compared with TP-DBBT and TP-TQ2, the TP-TQ1 based on 6,7-diphenyl-[1,2,5]thiadiazoloquinoxaline can well balance absorption/emission wavelengths, NIR-II fluorescence brightness and photothermal effects.
View Article and Find Full Text PDFAn aqueous N-acylation reaction for preparing cinnamic acid amides was realized by using a variant of acyltransferase from Mycobacterium smegmatis (MsAcT-L12A), whereas the wild-type MsAcT showed no activity. MsAcT-L12A exhibited broad substrate adaptability, and preferred the substrates with electron-donating group. When the vinyl cinnamate (1a, 40 mM) and p-methoxyaniline (2a, 4 mM) were involved in the reaction, the excellent yield reached to 86.
View Article and Find Full Text PDFEnantio-pure α-hydroxy amides are valuable intermediates for the synthesis of chiral pharmaceuticals. The asymmetric reduction of α-keto amides to generate chiral α-hydroxy amides is a difficult and challenging task in biocatalysis. In this study, iolS, an aldo-keto reductase from Bacillus subtilis 168 was exhibited as a potential biocatalyst, which could catalyze the reduction of diaryl α-keto amide such as 2-oxo-N, 2-diphenyl-acetamide (ONDPA) with moderate S-selectivity (76.
View Article and Find Full Text PDFFluorescence imaging in the second window (NIR-II, 1000-1700 nm) provides deeper penetration depth and higher resolution, but there is still a dilemma for designing NIR-II dyes for simultaneously enhancing fluorescence efficiency and prolonging excitation wavelength. Herein, a molecular conformation planarization strategy has been revisited to guide the synthesis of two donor-acceptor-donor dyes (named T-BBT and BT-BBT). On the one hand, conformational planarization can extend the absorption peaks of T-BBT and BT-BBT to the NIR region with high molar extinction coefficients of 30.
View Article and Find Full Text PDFHere the metal-organic framework material MIL-88A is used to purify and immobilize an acyltransferase from Mycobacterium smegmatis (MsAcT) simultaneously from the broken bacterial liquid. Regarding the possibility that the MsAcT@MIL-88A may display weak stability in its application, a silica layer is further introduced around it as a "shield" to protect the enzyme from degradation. The obtained MsAcT@MIL-88A@silica can exhibit high activity recovery, excellent thermal, pH, and storage stabilities compared with those of MsAcT@MIL-88A.
View Article and Find Full Text PDFCardiovasc Drugs Ther
August 2023
Purpose: Diabetic cardiomyopathy (DM) is the cause of late cardiac dysfunction in diabetic patients. Myocardial fibrosis is the main pathological mechanism, and it is associated with transforming growth factor-β1(TGF-β1) expression up-regulation. 2-Arachidonoylglycerol (2-AG) is an endogenous cannabinoid that can effectively improve myocardial cell energy metabolism and cardiac function.
View Article and Find Full Text PDFAn efficacious method in which BINOL-type chiral imidodiphosphoric acid catalyzed the asymmetric [5 + 1] annulation reaction of 2-pyrrolylphenol with 1-methylindoline-2,3-dione was established. The strategy tolerated a broad substrate scope, and 30 examples were obtained. A range of enantioenriched spiro[3,2'-morpholine-oxindole] derivatives which incorporate a tertiary stereocenter, with moderate to excellent yields (up to 96%) and enantioselectivities (up to 99%) under mild conditions, was delivered.
View Article and Find Full Text PDFObjective: The transmuscular quadratus lumborum (TQL) block and the oblique subcostal transversus abdominis plane (OSTAP) block both contribute to multimodal analgesia after laparoscopic surgery. The objective of this study was to compare the analgesic effects of the TQL block versus OSTAP block after laparoscopic hysterectomy.
Design: Prospective single-centre randomised single-blind trial.
Background: A larger volume of local anesthetic provides a wider range of blocked sensory but carries a greater risk. The purpose of this trial was to compare the effect of different volumes of ropivacaine injected to deep serratus anterior plane in patients undergoing breast surgery.
Methods: In this randomized double-blind trial, 60 patients undergoing breast surgery were randomly allocated to R10, R20 and R30 groups (n=20), and received deep serratus anterior plane block with 10, 20 and 30 mL of 0.
Purpose: Serratus anterior plane (SAP) block is effective for analgesia after breast surgery. Whether a higher local anesthetic concentration prolongs sensory block duration and improves postoperative analgesia remains unclear. The aim of this study was to compare the analgesic effects of SAP block with different concentrations of ropivacaine.
View Article and Find Full Text PDFA rational enhancement of kinetic resolution process for producing (S)-N-(2-ethyl-6-methylphenyl) alanine from racemic methyl ester using lipase B from Candida antarctica (CalB) was investigated. With the benefit results that lipase CalB-catalyzed reactions can be effectively regulated using amino acids (such as histidine and lysine) as additives, CalBs modified (mCalBs) by n-histidines at the N terminal and n-lysines at the C terminal were constructed and expressed. The results show that both soluble and precipitated mCalBs can effectively catalyze the hydrolysis reaction without adding any extra additives.
View Article and Find Full Text PDFIn our previous study, we could achieve high soluble expression of Candida antarctica lipase B (CalB) in E. coli by fusion poly‑amino acid tags on CalB (pCalB). Herein, we are surprised to find that pCalB can be easily and directly covalent binding on a simply oxidized aspen powder (OAP) by the aid of poly‑lysine tags.
View Article and Find Full Text PDFIn this study, functionalized poplar powder (FPP) was used as a support material for the immobilization of enoate reductase (ER) and glucose-6-phosphate dehydrogenase (GDH) by covalent binding. Under optimal conditions, the immobilization efficiency of ER-FPP and GDH-FPP was 95.1% and 84.
View Article and Find Full Text PDFHerein, three aldo/ketoreductases (AKRs) were obtained and used to prepare N- ethyl-methyl-carbamic acid-3-[(1S)-hydroxy-ethyl]-phenyl ester ((S)-NEMCA-HEPE), which is a key intermediate of (S)-Rivastigmine. To avoid the usage of extra cofactors, the recombinant whole-cells containing AKRs and glucose dehydrogenase (GDH) were constructed and applied in the reduction reaction. The excellent conversion of 83.
View Article and Find Full Text PDFEnzyme Microb Technol
February 2018
Herein we established co-immobilized methods for enoate reductases (ERs) and glucose dehydrogenase (GDH), forming a cofactor regeneration system. In cross-linked enzyme aggregates (CLEAs), ammonium sulfate and oxidized dextran were selected as a precipitant and a cross-linker, respectively. In biomimetic immobilization (BI), ER-GDH-silica particles (ER-GDH-SPs) were rapidly formed through a one-step approach by using a silicic acid precursor.
View Article and Find Full Text PDFPolyamine tags fused in Candida antarctica lipase B (CalB) can help achieve high soluble expression of CalB in E. coli and can directly mediate silicification, which leads to rapid formation of a CalB-silica particle complex through a one-step approach. After optimization experiments, the fused lipase CalB tagged with 6-histidine at the N terminal and 10-lysine at the C terminal (6His-CalB-10Lys) is effectively expressed with high solubility (0.
View Article and Find Full Text PDFEnzyme Microb Technol
March 2016
The first Novozym 435 lipase-catalyzed Morita-Baylis-Hillman (MBH) reaction with amides as co-catalyst was realized. Results showed that neither Novozym 435 nor amide can independently catalyze the reaction. This co-catalytic system that used a catalytic amount of Novozym 435 with a corresponding amount of amide was established and optimized.
View Article and Find Full Text PDFJ Microbiol Biotechnol
January 2016
The enzyme-catalyzed Henry reaction was realized using deep eutectic solvents (DESs) as a reaction medium. The lipase from Aspergillus niger (lipase AS) showed excellent catalytic activity toward the substrates aromatic aldehydes and nitromethane in choline chloride:glycerol at a molar ratio of 1:2. Addition of 30 vol% water to DES further improved the lipase activity and inhibited DES-catalyzed transformation.
View Article and Find Full Text PDFIn this study, a new method was developed to prepare enantiopure caffeic acid amides by enzyme-catalyzed asymmetric aminolysis reaction. Methoxymethyl chloride (MOMCl) was first introduced as a protective and esterified reagent to obtain the MOM-protected caffeic acid MOM ester 1d. Aminolysis reaction occurred between 1d and (R, S)-α-phenylethylamine in the presence of an immobilized lipase (Novozym 435) from Candida antarctica.
View Article and Find Full Text PDFAcetyl-coenzyme A carboxylase (ACCase) has been identified as one of the most important targets of herbicide Aryloxyphenoxypropionates (APPs). ACCase shows different enantioselectivity toward APPs, and only (R)-enantiomers of APPs have the herbicidal activity. In order to deeply understand the enantioselective recognition mechanism of ACCase, (R)-haloxyfop, which is a typical commercial herbicide from APPs, is selected and the relative binding free energy between ACCase and (R)-haloxyfop is investigated and compared with that between ACCase and (S)-haloxyfop by homology modeling and molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) method.
View Article and Find Full Text PDFBiochem Biophys Res Commun
August 2008
Lipases were adsorbed in siliceous mesocellular foams containing different amounts of residual template in the nanopores. It is found that the hydrolytic activities of the adsorbed lipases are increased with increasing the contents of template in the mesopores. The triacetin hydrolytic activity of the lipase adsorbed in the foam containing 46% of template can be 13 times higher than that of the lipase adsorbed in the foam without template in the nanopores, and its specific activity is about three times higher than that of the free lipase, showing the hyperactivation effect on lipase resulting from the interaction between the lipase and the surfactant in the nanopores.
View Article and Find Full Text PDF