scholarly journals Difference in enzymatic dehydrogenative polymerization of dilignols using horseradish peroxidase and crude enzyme obtained from Japanese cypress (Chamaecyparis obtusa)

2019 ◽  
Vol 65 (1) ◽  
Author(s):  
Yasuyuki Matsushita ◽  
Daisuke Baba ◽  
Dan Aoki ◽  
Kazuhiko Fukushima
1999 ◽  
Vol 39 (12) ◽  
pp. 99-107 ◽  
Author(s):  
Takao Kunimatsu ◽  
Miki Sudo ◽  
Takeshi Kawachi

In the last ten years, the number of golf courses has been increasing in some countries as the game gains popularity. This indicates, a need to estimate the nutrient loading from golf courses in order to prevent the eutrophication of water bodies. Nutrient concentrations and flow rates of a brook were measured once a week from 1989 to 1990 at two sites: Site A of a brook flowing out from D-golf course (53 ha) and Site B of the same brook discharging into the golf course from an upper forested basin (23 ha) covered mainly with planted Japanese cypress (Chamaecyparis obtusa SIEB. et ZUCC). The bedrock of the area was granite. The annual values of precipitation and mean temperature were 1947 mm and 13.5°C in 1989, respectively. The arithmetic average values of discharge from the forested basin and the golf course were 0.392 and 1.26 mg/l total nitrogen (TN), 0.0072 and 0.145 mg/l total phosphorus (TP), 0.82 and 3.53 mg/l potassium ion (K+, 5.92 and 8.24 mg/l sodium ion (Na+), 2.1 and 9.9 mg/l suspending solid (0.001–2.0 mm, SS), 0.087 and 0.147 mS/cm electric conductivity (EC), and 0.031 and 0.037 m3/km2•s specific discharge, respectively. The loading rates of the forested basin and the golf course were 5.42 and 13.5 TN, 0.133 and 3.04 TP, 8.84 and 33.9 K+, 55.0 and 73.0 Na+, and 54.3 and 118 SS in kg/ha•y. The leaching and runoff rate of nitrogen in the chemical fertilizers applied on the golf course was calculated as 32%. These results indicated the importance of controlling the phosphorus loading for the management of golf courses.


2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Yuko Tsunetsugu ◽  
Masaki Sugiyama

AbstractThis study investigates the physiological responses and subjective perceptions of touching wood. In particular, it focuses on their respective relationships with the amount of heat transfer across the hand–material interface during contact. The study participants included 55 university students (20 females and 35 males) who gave written informed consent. The participants’ blood pressure, pulse rate, and cerebral blood hemoglobin concentrations were measured continuously for 90 s while they gently held vertical bar-shaped specimens of Japanese cypress (Chamaecyparis obtusa), Japanese oak (Quercus crispula), polyethylene, and aluminum. The specimens also included wood with a surface coating. We measured subjective warmth and comfort as well as the heat flux between the palm and the surface of the material. The wooden materials were rated as significantly warmer compared to aluminum and polyethylene, regardless of the wood species (cypress or oak) or its coating; this result corresponds with smaller heat transfers in the wooden materials. Additionally, the wooden materials were more comfortable to hold as compared to the aluminum bar. Based on the changes in blood pressure, touching Japanese cypress and uncoated Japanese oak were interpreted to induce less physiological stress. Therefore, we can conclude that wood, with lower thermal conductivity, feels warm, and it causes relatively smaller physiological changes compared to other materials with higher thermal conductivity. Thus, they may present less physiological burdens when touched.


2019 ◽  
Vol 50 (6) ◽  
pp. 416-422
Author(s):  
Tomoka NAKAMURA ◽  
Yuma MONOBE ◽  
Hitoshi IWAMOTO ◽  
Noboru KISHIMOTO ◽  
Masamitsu DOI

Holzforschung ◽  
2006 ◽  
Vol 60 (5) ◽  
pp. 513-518 ◽  
Author(s):  
Yuki Tobimatsu ◽  
Toshiyuki Takano ◽  
Hiroshi Kamitakahara ◽  
Fumiaki Nakatsubo

Abstract Dehydrogenative polymerization of isoconiferin (IC; coniferyl alcohol γ-O-β-D-glucopyranoside) catalyzed by horseradish peroxidase (HRP) was carried out. The polymerization of IC proceeded in a homogeneous system, resulting in a water-soluble dehydrogenation polymer (IC-DHP). The degree of polymerization (DP) of IC-DHP was significantly higher than that of a standard dehydrogenative polymer (CA-DHP) obtained from coniferyl alcohol (CA) in a heterogeneous system. Under optimum conditions, the DP of IC-DHP was 44 (M n=1.5×104), whereas that for CA-DHP was only 11 (M n=3.0×103, as acetate). Spectroscopic analyses confirmed that IC-DHP has a lignin-like structure containing D-glucose moieties attached to the lignin side-chains. The D-glucose unit introduced into γ-O position of CA essentially influenced the water solubility and molecular mass of the resulting DHP.


2008 ◽  
Vol 21 (6) ◽  
pp. 414-422 ◽  
Author(s):  
Kenji TSURUTA ◽  
Tomonori KUME ◽  
Hikaru KOMATSU ◽  
Naoko HIGASHI ◽  
Tomo'omi KUMAGAI ◽  
...  

2008 ◽  
Vol 56 (7) ◽  
pp. 1030-1034 ◽  
Author(s):  
Hui Yuan Gao ◽  
Li Jun Wu ◽  
Norio Muto ◽  
Hiroyuki Fuchino ◽  
Takahisa Nakane ◽  
...  

Holzforschung ◽  
2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Yuki Tobimatsu ◽  
Toshiyuki Takano ◽  
Hiroshi Kamitakahara ◽  
Fumiaki Nakatsubo

Abstract Horseradish peroxidase (HRP)-catalyzed dehydrogenative polymerization of guaiacyl (G) and syringyl (S)-type monolignol γ-O-glucosides, isoconiferin (iso-G) and isosyringin (iso-S), which contain a hydrophilic glucosyl unit on γ-position of coniferyl alcohol and sinapyl alcohol, respectively, was monitored by gel permeation chromatography coupled with photodiode array detection (GPC-PDA). Contrary to the conventional dehydrogenative polymerization of monolignols, the polymerization of the glycosides produces water-soluble synthetic lignins (DHPs) in a homogeneous aqueous phase. Taking advantage of this unique reaction system, the method was developed to follow the changes of molecular weights in the course of DHP formations. Moreover, PDA detection permits determination of oligomeric S-type quinone methide intermediates (QMs) formed as stable transient compounds during polymerization of iso-S. A detailed comparison of the polymerization profiles revealed entirely different behaviors of G- and S-type monomers. The data strongly support the view that the low reactivity of oligomeric S-type QMs impedes the formation of DHPs from S-type monomers. In copolymerization of G- and S-type monomers, it is conceivable that G-type phenolic hydroxyl groups serve as good nucleophilic reactants to scavenge S-type QMs resulting in efficient production of DHPs. As a consequence, the present approach can be a powerful tool to study the in vitro dehydrogenative polymerization providing further mechanistic insights into lignin polymerization in vivo.


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