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1.
J Oleo Sci ; 72(11): 1037-1048, 2023.
Article in English | MEDLINE | ID: mdl-37914265

ABSTRACT

Six optically active (Z)-7-decen-4-olide derivatives (1a-1f) were synthesized in 99% enantiomeric excess using diastereomeric resolution. The odour properties of the racemic and optically active 1a-1f were evaluated in terms of their orthonasal aromas. All of the stereoisomers had different odour characteristics and thresholds. Decen-4-olides (1a-1c) had a strong fruity note, whereas undecen-4-olide (1d and 1e) and dodecen-4-olide (1f) had a strong green note. For 7-alken-4-olides (1a, 1d, and 1f), the (R)-enantiomer had a lower odour threshold than the (S)-enantiomer. In contrast, no difference in the odour threshold was observed for the enantiomers of the 8-alken-4-olides (1b and 1e). Furthermore, the antimicrobial activity against Escherichia coli (E. coli; ATCC 25922) and Staphylococcus aureus (S. aureus; ATCC 29213) were investigated. Although the no differences in the antimicrobial activity of the stereoisomers was observed, 1d and 1e showed slight antimicrobial activity against E. coli, whereas only 1f showed antimicrobial activity against S. aureus. No antimicrobial activity was exhibited by (R)-1f, whereas (S)-1f exhibited strong antimicrobial activity.


Subject(s)
Odorants , Staphylococcus aureus , Escherichia coli
2.
Polymers (Basel) ; 11(11)2019 Oct 23.
Article in English | MEDLINE | ID: mdl-31652850

ABSTRACT

In this study, the effect of glass fiber powder on the properties of waterborne coatings with thermochromic ink was investigated, using Chinese fir board as the base material and temperature-sensitive thermochromic waterborne coatings with thermochromic ink as the paint base. The concentration of glass fiber powder was determined when the microstructure, optical properties, mechanical properties, liquid resistance, and heat preservation effect were the best. The results showed that the paint film with glass fiber powder concentration of 1.0% to 7.0% had better discoloration performance. With an increase of the glass fiber powder concentration, the gloss of the paint film decreased gradually, and when the concentration of glass fiber powder was 0% to 5.0%, the gloss of the paint film was better. The concentration of glass fiber powder had no effect on the adhesion, impact resistance, and liquid resistance. In the first 2.5 min, the temperature value of the waterborne coating with 3.0% glass fiber powder was higher than that without glass fiber powder, which has a certain heat preservation effect. When the glass fiber powder content was 3.0%, the microstructure of paint film was the best. The composition of paint film with different glass fiber powder concentrations was not different and the discoloration performance of paint film with heat preservation effect was not affected by time. The analysis showed that the waterborne coating with 3.0% glass fiber powder had the best comprehensive performance. This work provides a technical reference for the industrialization of heat preservation and thermochromic coating on wood.

3.
Environ Pollut ; 245: 810-819, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30502710

ABSTRACT

Volatile organic compounds (VOCs) are an important factor affecting ambient air quality, and furniture production is one of the important sources of VOC pollution. High VOC concentrations have adverse effects on the environment and worker welfare in furniture factories. In order to control VOC emissions in a furniture workshop, the VOC species and concentration distributions were examined. Qualitative analysis of VOC species was carried out by headspace gas chromatography/mass spectrometry. The results showed that VOCs from a furniture workshop were mainly 12 substances including acetate, toluene, and xylene compounds. The heights and representative positions of VOCs released during the coating process were determined, and the results showed that VOC concentrations depended on environmental and height factors. The concentration of VOCs decreased with increasing altitude and reached a maximum concentration at 0.4 m above the ground. Because the concentration of VOCs varied with temperature, humidity, air pressure, and amount of spray paint, this paper established functional relationships between VOC concentrations and temperature, humidity, air pressure, and amount of spray paint. These results provide a theoretical basis for furniture workshops to automatically monitor and control VOCs. MAIN FINDING OF THIS WORK: VOCs from the furniture workshop were mainly composed of 10 substances including acetate, toluene, and xylene compounds.


Subject(s)
Air Pollutants/analysis , Environmental Monitoring , Interior Design and Furnishings , Volatile Organic Compounds/analysis , Air Pollution/analysis , Gas Chromatography-Mass Spectrometry , Humidity , Paint , Temperature , Toluene/analysis
4.
Asian J Psychiatr ; 37: 167-171, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30293050

ABSTRACT

OBJECTIVES: Structural brain magnetic resonance imaging studies of individuals at ultra-high risk (UHR) for psychosis have shown subtle but widespread reductions in baseline gray matter volume (GMV) in the frontal, temporal, and limbic regions compared with healthy controls (HC). These regions coincide with regions of reduced GMV in patients with established psychosis and have led to the consideration of structural changes in UHR as a potential biomarker for future transition to psychosis. However, most studies have been from Europe, North America, and Australia, with few reports from other regions, and two recent studies from Asian countries have failed to detect regional GMV reduction in UHR, suggesting the need for further analysis of an Asian sample. In this study, we investigated GMV reduction in Japanese UHR subjects. RESULTS: The study used voxel-based morphometry to compare magnetic resonance imaging brain scans between 45 UHR individuals recruited by a specialist and 33 HCs. This showed no significant GMV reduction in the UHR group compared with the healthy control group. This negative result may be attributable to characteristics of Asian samples, such as a low prevalence of illicit drug use, or to the heterogeneous nature of UHR subjects.


Subject(s)
Gray Matter/pathology , Psychotic Disorders/pathology , Adolescent , Adult , Female , Gray Matter/diagnostic imaging , Humans , Japan , Magnetic Resonance Imaging , Male , Psychotic Disorders/diagnostic imaging , Risk , Young Adult
5.
Talanta ; 189: 315-323, 2018 Nov 01.
Article in English | MEDLINE | ID: mdl-30086925

ABSTRACT

A new approach based on online pyrolysis-comprehensive gas chromatography/mass spectrometry (Py-GCxGC/MS) is introduced for analysis of lacquer saps with potential applications to analysis of Asian lacquers. The bidimensional GCxGC separation demonstrated its benefits for characterization of the markers of lacquer saps, alkylhydrocarbons, alkylbenzenes, alkylphenols, and alkylcatechols, in a visual way not attainable in monodimensional Py-GC/MS analysis. Moreover, the potentiality offered by GCxGC allows the separation of regioisomers difficult to obtain with a monodimensional separation. Under these circumstances, urushiol (Japanese, Chinese), laccol (Vietnamese), and thitsiol (Myanmar) lacquer sap films were differentiated by their marker fingerprints with a limit of detection in the low µg range. Additionally, thermally assisted pyrolysis with tetramethylammonium hydroxyde (TMAH) clearly differentiated the alkylcatechol markers of the four lacquer samples investigated, with a net separation of stereoisomers particularly well exemplified in the case of the Myanmar lacquer sample. The proposed Py-GCxGC/MS approach greatly facilitates the analysis of Asian lacquer saps, and is very promising for sensitive detection of lacquers in archaeological artifacts.

6.
Polymers (Basel) ; 10(12)2018 Nov 24.
Article in English | MEDLINE | ID: mdl-30961227

ABSTRACT

In this study, Fraxinus mandshurica veneer was dyed with reactive brilliant red X-3B, black KN-B and blue K-3R dyes. The dye concentration, bath ratio and dyeing time were selected for an orthogonal experiment. Analysis of variance showed that the dye concentration had the greatest effect on the dye uptake of F. mandshurica veneer. In the independent experiments, dye uptake increased at first and then decreased with increasing dye concentration; the chromatic aberration increased with the dye concentration and then remained steady. The infrared spectra were used to examine the dyeing behaviors before and after dyeing and the binding form between reactive dyes and F. mandshurica veneer was analyzed. Based on the optimization of process parameters, the optimal dyeing condition was considered to be 75 °C, the dye concentration to be 0.5⁻1.0%, the dyeing time to be 60 min and the bath ratio to be 20:1. The dye uptakes of reactive brilliant red X-3B, black KN-B and blue K-3R dyes were 75.0⁻75.4%, 50.0⁻64.6% and 32.0⁻66.0%, respectively. The chromatic aberration of F. mandshurica veneer dyed with reactive brilliant red X-3B, black KN-B and blue K-3R dyes was 53.0⁻59.0, which was a significant increase. After dyeing, the hardness and impact strength of the waterborne coating on the dyed F. mandshurica increased but adhesion was reduced. The coating films produced a matte glossiness.

7.
Anal Sci ; 33(11): 1253-1257, 2017.
Article in English | MEDLINE | ID: mdl-29129864

ABSTRACT

The chemical structure of fresh lacquer sap collected from a lacquer tree growing in Nago City of Okinawa, Japan, was analyzed by gas chromatography/mass-spectrometry (GC/MS) and nuclear magnetic resonance (NMR). The results showed that Nago lacquer is laccol lacquer and its major components are 3-(heptadeca-10Z,13E,15E-trienyl)catechol, 3-(heptadeca-10Z,13E-dienyl)catechol, 3-(heptadeca-14Z-enyl)catechol, and 3-(heptadeca-12Z-enyl)catechol, which are similar to the components of Vietnamese lacquer. It showed higher laccase activity at pH 5 - 8 and better low temperature adaptability than Vietnamese lacquer. The Nago lacquer reached a dust free dry (DF) condition after 6 h, but Vietnamese lacquer did not. However, both were able to achieve harden dry (HD) in 24 h at 25°C, 80% relative humidity. In order to identify the lacquer provenance, the strontium isotope ratio was analyzed. The strontium isotope ratio (87Sr/86Sr) of Nago lacquer was 0.7110, which is different from the 0.7450 of Vietnamese lacquer.


Subject(s)
Toxicodendron/chemistry , Trees/chemistry , Desiccation , Laccase/metabolism , Toxicodendron/enzymology , Trees/enzymology , Xylem/chemistry
9.
PLoS One ; 11(2): e0149875, 2016.
Article in English | MEDLINE | ID: mdl-26918629

ABSTRACT

Expressed emotion (EE), especially criticism, is an important predictor of outcomes for the patient for a wide range of mental health problems. To understand complex links between EE and various relevant variables in early phase psychosis, this study examined criticism, distress of caregivers, other patients', and caregivers' variables, and links between criticism and these variables in those with at-risk mental state (ARMS) for psychosis and first-episode psychosis (FEP). The participants were 56 patients (mean age 18.8 ± 4.2 years) with ARMS and their caregivers (49.4 ± 5.8 years) and 43 patients (21.7 ± 5.2 years) with FEP and their caregivers (49.3 ± 7.4 years). We investigated criticisms made by caregivers using the Japanese version of the Family Attitude Scale and caregiver depressive symptoms via the self-report Beck Depression Inventory. We also assessed psychiatric symptoms and functioning of the patients. Approximately one-third of caregivers of patients with ARMS or FEP had depressive symptoms, predominately with mild-to-moderate symptom levels, whereas only a small portion exhibited high criticism. The level of criticism and depression were comparable between ARMS and FEP caregivers. The link between criticism, caregivers' depression, and patients' symptoms were observed in FEP but not in ARMS caregivers. These findings imply that the interaction between criticism and caregivers' and patients' mental states may develop during or after the onset of established psychosis and interventions for the caregivers should be tailored to the patient's specific stage of illness. Interventions for FEP caregivers should target their emotional distress and include education about patient's general symptoms.


Subject(s)
Adaptation, Psychological , Caregivers/psychology , Depression/psychology , Expressed Emotion , Psychotic Disorders/psychology , Adolescent , Adult , Attitude , Family/psychology , Female , Humans , Japan , Male , Middle Aged , Psychiatric Status Rating Scales , Risk , Self Report , Young Adult
10.
J Oleo Sci ; 64(11): 1213-26, 2015.
Article in English | MEDLINE | ID: mdl-26468231

ABSTRACT

A combination of Novozym 435-catalyzed methanolysis and amidation using racemic N-methyl-5-acetoxytridecan- and tetradecanamides as a substrate proceeded in good enantioselectivity to afford the corresponding (R)-N-methyl-5-acetoxyalkanamides, (S)-N-methyl-5-hydroxyalkanamides, and (S)-N-cyclohexyl-5-hydroxyalkanamides. Both enantiomers of δ-tri- and δ-tetradecalactones were synthesized in over 90% enantiomeric excesses from the corresponding (R)- or (S)-alkanamides. Addition of cyclohexylamine to Novozym 435-catalyzed methanolysis shortened 24-hour reaction time to reach about 50% conversion. Enantiomers of optically active δ-tri- and δ-tetradecalactones had different odors and thresholds.


Subject(s)
Lactones/chemical synthesis , Lipase/chemistry , Pyrones/chemical synthesis , Catalysis , Cyclohexylamines/chemistry , Enzymes, Immobilized , Fungal Proteins , Odorants , Organic Chemistry Phenomena , Stereoisomerism , Time Factors
11.
J Oleo Sci ; 64(5): 561-75, 2015.
Article in English | MEDLINE | ID: mdl-25948138

ABSTRACT

A new enzymatic method for synthesis of enantiomerically enriched δ-hexadecalactone (3) based on the enzymatic kinetic resolution of N-methyl-5-acetoxyhexadecanamide (1) is described. A combination of lipase-catalyzed hydrolysis and amidation improved enantioselectivity. Lipase-catalyzed amidation was also investigated. Detailed screening of solvents and additive amines was performed. The addition of cyclohexylamine to lipase-catalyzed hydrolysis afforded the best results to give both enantiomers of 3 with more than 90% enantiomeric excess.


Subject(s)
Amides/chemistry , Lactones/chemical synthesis , Lipase/chemistry , Pyrones/chemical synthesis , Amines , Catalysis , Cyclohexylamines/chemistry , Enzymes, Immobilized , Fungal Proteins , Hydrolysis , Solvents , Stereoisomerism
12.
J Oleo Sci ; 64(1): 75-90, 2015.
Article in English | MEDLINE | ID: mdl-25742924

ABSTRACT

Synthesis of optically pure δ-lactones by diastereomeric resolution was investigated. Amino acid derivatives, which can be obtained at a relatively low cost, were used as resolving agents. Six optically pure δ-lactones were efficiently synthesized using Cbz-L-alanine without other expensive resolving agents. Both enantiomers of δ-lactone obtained had over 98% enantiomeric excesses. This diastereomeric resolution is very efficient for the preparation of optically pure δ-lactones.


Subject(s)
Amino Acids/chemistry , Lactones/chemical synthesis , Alanine/analogs & derivatives , Alanine/chemistry , Stereoisomerism
13.
Schizophr Res ; 158(1-3): 32-8, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25034763

ABSTRACT

OBJECTIVE: The notion of at-risk mental state (ARMS) is valuable for identifying individuals in a putative prodromal state of psychosis and for reducing conversion risk by pharmacological and psychological interventions. However, further systematic study is required because 1) diagnostic reliability in various clinical settings is not yet established; 2) predictive ability is insufficient; 3) optimal interventions in diversified populations are elusive; and 4) little evidence from non-Western regions exists. METHODS: A naturalistic longitudinal study was conducted at a specialized clinic for early psychosis at a university hospital in Sendai, Japan. Individuals with ARMS (n=106) were recruited and followed up with case-by-case treatment. RESULTS: Two-thirds of the participants were psychiatrist referrals, and 83 were followed up for at-least 1 year (mean follow-up=2.4 years). Fourteen developed psychosis and the estimated (by Kaplan-Meier) cumulative transition rate was 11.1% at 12, 15.4% at 24, and 17.5% at 30 months. At the end-point, about 30% of the 83 followed-up participants including 11 converters received antipsychotic medication. Compared to non-converters, converters showed more severe attenuated psychotic symptoms, including ego-boundary disturbance, formal thought disorder, and emotional disturbance. CONCLUSIONS: The present study replicated previous major Western longitudinal studies, in terms of clinical characteristics, psychosis transition rate, and antipsychotic prescription rate. Our results emphasize the importance of phenomenological assessment of ARMS and intensive care in a clinical setting.


Subject(s)
Psychotic Disorders/epidemiology , Disease Progression , Female , Follow-Up Studies , Humans , Japan/epidemiology , Kaplan-Meier Estimate , Longitudinal Studies , Male , Prodromal Symptoms , Psychotic Disorders/drug therapy , Psychotic Disorders/psychology , Risk , Young Adult
14.
Carbohydr Res ; 388: 138-46, 2014 Mar 31.
Article in English | MEDLINE | ID: mdl-24642363

ABSTRACT

Various hydroxycinnamoyl ß-d-xylopyranosides were efficiently prepared from 2,3,4-tri-O-acetyl-α-d-xylopyranosyl bromide (TAXB) with amine by amine-promoted glycosylation. The resulted acetylated hydroxycinnamoyl ß-d-xylopyranosides with acetoxy groups at C-2, C-3, and C-4 were regioselectively deacetylated at C-4 position with Novozym 435. Antioxidant activities of free hydroxycinnamic acids and the respective ß-d-xylopyranosides were evaluated by DPPH radical scavenging activity as well as their inhibitory effect on autoxidation of bulk methyl linoleate. The radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) decreased in the order ferulic acid>caffeic acid≈caffeoyl ß-d-xylopyranosides≈sinapinic acid>sinapoyl ß-d-xylopyranosides≈feruloyl ß-d-xylopyranosides>p-coumaric acid>p-coumaroyl ß-d-xylopyranosides. In bulk methyl linoleate, the antioxidant activity order against autoxidation was almost consistent with the scavenging activity order. The results showed that caffeoyl ß-d-xylopyranosides and sinapoyl ß-d-xylopyranosides were as effective as free caffeic acid, sinapinic acid, and ferulic acid.


Subject(s)
Coumaric Acids/chemical synthesis , Free Radical Scavengers/chemical synthesis , Glycosides/chemical synthesis , Xylose/chemical synthesis , Acetylation , Biphenyl Compounds/antagonists & inhibitors , Caffeic Acids/chemistry , Coumaric Acids/chemistry , Enzymes, Immobilized , Free Radical Scavengers/chemistry , Fungal Proteins , Glycosides/chemistry , Glycosylation , Linoleic Acids/chemistry , Lipase/chemistry , Oxidation-Reduction , Picrates/antagonists & inhibitors , Stereoisomerism , Xylose/analogs & derivatives , Xylose/chemistry
15.
Psychiatry Res ; 217(1-2): 20-4, 2014 Jun 30.
Article in English | MEDLINE | ID: mdl-24656897

ABSTRACT

Cognitive insight, defined as the ability to evaluate and correct one׳s own distorted beliefs and misinterpretations, is hypothesized to contribute to the development of psychotic symptoms. We investigated cognitive insight in individuals with at-risk mental state (ARMS), which is associated with a clinically high risk of psychosis. Sixty individuals with ARMS were compared with 200 healthy controls in terms of cognitive insight measured using the Beck Cognitive Insight Scale. We also investigated the relationship between cognitive insight and attenuated delusional symptoms. In addition, we examined differences in the cognitive insight of individuals with ARMS with or without near-threshold delusional symptoms and differences in the cognitive insight of individuals with ARMS with or without later transition to psychosis. The results showed that individuals with ARMS exhibited higher self-certainty than healthy controls, indicating impairments in cognitive insight in the former. More importantly, our results revealed that self-certainty was correlated with attenuated delusional symptoms and that individuals with ARMS who had near threshold delusional symptoms had higher self-certainty. These findings indicate that overconfidence in one׳s own beliefs or judgments might be related to the formation and maintenance of attenuated delusions in individuals with ARMS.


Subject(s)
Cognition , Delusions/psychology , Psychotic Disorders/psychology , Adolescent , Adult , Case-Control Studies , Culture , Female , Humans , Male , Psychiatric Status Rating Scales , Schizophrenic Psychology , Young Adult
16.
Psychiatry Clin Neurosci ; 67(7): 526-31, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24147562

ABSTRACT

AIMS: The recognition of emotion is often impaired in patients with schizophrenia. The relationship of this deficit with symptoms of psychosis remains unclear. In the current study, we investigated the relationship between emotional processing and positive psychotic symptoms in schizophrenia. METHODS: Twenty-eight patients with schizophrenia and 37 healthy participants were included in the study. They were instructed to listen to a set of sentences and judge whether the emotional valence expressed verbally and that expressed by affective prosody were congruous or incongruous. RESULTS: Overall, the patients with schizophrenia had more inaccurate responses than the healthy participants and the poor performance was prominent when the patients processed affectively negative scenarios. The percentage of accurate responses negatively correlated with the severity of positive symptoms when the scenarios and/or the affective prosody had a negative valence. CONCLUSION: Patients with schizophrenia appear to have impaired function in the processing of negative verbal information. Impaired processing of negative verbal and prosodic information seems to be associated with positive symptoms in schizophrenia.


Subject(s)
Emotions/physiology , Language , Schizophrenic Psychology , Social Perception , Speech/physiology , Adult , Female , Humans , Male , Neuropsychological Tests , Schizophrenia/physiopathology
17.
Carbohydr Res ; 359: 11-7, 2012 Oct 01.
Article in English | MEDLINE | ID: mdl-22925758

ABSTRACT

Various glycosyl ferulates were efficiently synthesized from 2,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (TAGB) with amine by amine-promoted glycosylation without using heavy metal. The resulted acetylated glycosyl ferulates with acetoxyl groups at C-2, C-3 and C-4 were regioselectively deacetylated at C-4 and C-6 positions with Novozym 435. Antioxidant abilities of free ferulic acids and its synthetic glycosyl ferulates were evaluated by inhibitory effect on autoxidation of bulk methyl linoleate as well as their radical scavenging activity. The radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH·) decreased in the order ferulic acid>sinapinic acid ≈ glycosyl sinapinates ≈ glycosyl ferulates>p-coumaric acid>glycosyl p-coumarates. In bulk methyl linoleate, the antioxidant activity order against autoxidation was very consistent with the scavenging activity order. The results showed that glycosyl ferulates and sinapinates were effective as well as free carboxylic acid forms.


Subject(s)
Amines/chemistry , Biocatalysis , Coumaric Acids/chemistry , Coumaric Acids/chemical synthesis , Free Radical Scavengers/chemistry , Free Radical Scavengers/chemical synthesis , Lipase/metabolism , Acetylation , Biphenyl Compounds/chemistry , Candida/enzymology , Chemistry Techniques, Synthetic , Enzymes, Immobilized , Fungal Proteins , Glycosylation , Hydrolysis , Linoleic Acids/chemistry , Oxidation-Reduction , Picrates/chemistry , Stereoisomerism , Substrate Specificity
18.
J Mass Spectrom ; 47(4): 539-46, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22689631

ABSTRACT

The competition between benzylic cleavage (simple bond fission [SBF]) and retro-ene rearrangement (RER) from ionised ortho, meta and para RC(6) H(4) OH and RC(6) H(4) OCH(3) (R = n-C(3) H(7) , n-C(4) H(9) , n-C(5) H(11) , n-C(7) H(15) , n-C(9) H(19) , n-C(15) H(31) ) is examined. It is observed that the SBF/RER ratio is significantly influenced by the position of the substituent on the aromatic ring. As a rule, phenols and anisoles substituted by an alkyl group in meta position lead to more abundant methylene-2,4-cyclohexadiene cations (RER fragmentation) than their ortho and para homologues. This 'meta effect' is explained on the basis of energetic and kinetic of the two reaction channels. Quantum chemistry computations have been used to provide estimate of the thermochemistry associated with these two fragmentation routes. G3B3 calculation shows that a hydroxy or a methoxy group in the meta position destabilises the SBF and stabilises the RER product ions. Modelling of the SBF/RER intensities ratio has been performed assuming two single reaction rates for both fragmentation processes and computing them within the statistical RRKM formalism in the case of ortho, meta and para butyl phenols. It is clearly demonstrated that, combining thermochemistry and kinetics, the inequality (SBF/RER)(meta) < (SBF/RER)(ortho) < (SBF/RER)(para) holds for the butyl phenols series. It is expected that the 'meta effect' described in this study enables unequivocal identification of meta isomers from ortho and para isomers not only of alkyl phenols and alkyl anisoles but also in other alkyl benzene series.

19.
Enzyme Res ; 2012: 375309, 2012.
Article in English | MEDLINE | ID: mdl-22545205

ABSTRACT

Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera) from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110 kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined. In addition, the behaviors on catalytic oxidation of phenols also were conducted.

20.
Int J Biol Macromol ; 50(3): 530-3, 2012 Apr 01.
Article in English | MEDLINE | ID: mdl-22289862

ABSTRACT

Several important monolignols such as coniferyl alcohol were catalyzed using Rhus laccase (RL) from Rhus vernicifera in a water/acetone solution. The enzymatic mechanism is discussed in detail. Sites 6, ß, and phenolic oxygen were the main active sites of phenylpropanoid compounds, which were first oxidized by the enzyme and then radicalized. RL was also responsible for lignin biosynthesis, especially in the early stage.


Subject(s)
Laccase/metabolism , Phenols/metabolism , Rhus/enzymology , Water/chemistry , Biotransformation , Lignin/metabolism , Solutions
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