• 임산에너지
• /
• 제20권1호
• /
• pp.35-41
• /
• 2001

리그닌 모델화합물 Ⅰ-Ⅳ의 시료를 315℃에서 열분해 시킨 결과, 리그닌 모델호합물 Ⅰ, Ⅱ의 열분해에서는 guaiacol이 0.47mol, DMP가 0.57mol로, DMAP는 0.12와 0.23mol로 각각 생성되었으며, 리그닌 모델화합물 Ⅲ, Ⅳ의 열분해에서는 guaiacol의 생성이 0.26mol, DMP가 0.30mol로 TMAP는 0.09mol 과 0.15mol이 각각 생성되었다. 리그닌 모델화합물 열분해 메커니즘으로서는 우선 탈수되고, 이어서 β-O-4 결합이 개열되어 guaiacol, DMP, DMAP와 TMAP가 생성되는 것을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
• /
• 제45권2호
• /
• pp.168-181
• /
• 2017

Whole cell of Phanerochaete chrysosporium with reducing agent was applied to verify the degradation mechanism of aromatic compounds derived from lignin precisely. Unlike the free-reducing agent experiment, various degraded products of aromatic compounds were detected under the fungal treatment. Our results suggested that demethoxylation, $C_{\alpha}$ oxidation and ring cleavage of aromatic compounds occurred under the catabolic system of P. chrysosporium. After that, degraded products stimulated the primary metabolism of fungus, so succinic acid was ultimately main degradation product of lignin derived-aromatic compounds. Especially, hydroquinone was detected as final intermediate in the degradation of aromatics and production of succinic acid. In conclusions, P. chrysosporium has an unique catabolic metabolism related to the production of succinic acid from lignin derived-aromatic compounds, which was meaningful in terms of lignin valorization.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제5권6호
• /
• pp.422-430
• /
• 2000

Mechanism of lignin biodegradation caused by basidiomycetes and the history of lignin biodegradation studies were briefly reviewed. The important roles of fungal extracellular ligninolytic enzymes such as lignin and manganese peroxidases (LiP and MnP) were also summarized. These enzymes were unique in their catalytic mechanisms and substrate specificities. Either LiP or MnP system is capable of oxidizing a variety of aromatic substrates via a one-electron oxidation. Extracellular fungal system for aromatic degradation is non-specific, which recently attracts many people working a bioremediation field. On the other hand, an intracellular degradation system for aromatic compounds is rather specific in the fungal cell. Structurally similar compounds were prepared and metabolized, indicating that an intracellular degradation strategy consisted of the cellular systems for substrate recognition and metabolic response. It was assumed that lignin-degrading fungi might be needed to develop multiple metabolic pathways for a variety of aromatic compounds caused by the action of non-specific ligninolytic enzymes on lignin. Our recent results on chemical stress responsible factors analyzed using mRNA differential display techniques were also mentioned.

• 임산에너지
• /
• 제18권1호
• /
• pp.17-24
• /
• 1999

액화목재는 목재 및 목질계 자원으로부터 신소재 개발을 위한 새로운 유효이용법의 하나이다. 이 액화목재의 주요 성분변화를 조사하기 위한 실험으로서 액화 전후의 리그닌의 구조적 변화를 알기 위하여 잣나무 KP리그닌과 리그닌설포산을 액화시켜서 유기용매로 분리하고, IR, 1H(13C)-NMR, GC-MS분석기기로 분석하였다. 액화리그닌 중에는 다수의 페놀성 물질들 즉, diguaiacol, acetic acid phenyl ester, phenol, 1-phenyl ethanone 등이 분석되었다.

• 펄프종이기술
• /
• 제35권3호
• /
• pp.74-78
• /
• 2003

The structural property of phenolic and non-phenolic lignin has an effect on the reaction rate of lignin by oxygen and chlorine dioxide respectively. Moreover, the undesirable degradation of cellulose followed by lignin degradation is influenced by chemical charge and reaction time. In this paper, several lignin model compounds were used to illuminate the interaction of oxygen and chlorine dioxide by varying the position of O and D(OD, DO, ODO and DOD), and gas chromatography method was used to investigate the degradation of lignin by determining the content of methoxyl groups in lignin. It was shown that structural properties of lignin models were more influential on the degradation and demethylation of lignin than the above combination. Combination of oxygen and chlorine dioxide, however, was more effective in degradation of lignin than only one stage, and three stages than two stages.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
• /
• pp.251.2-251.2
• /
• 2010

Plant biomass has been proposed to be an alternative source for petroleum-based chemical compounds. Especially, phenolic chemical compounds can be obtained from lignin by chemical depolymerization processes because lignin consists of complex aromatic polymer such as trans-p-coumaryl, coniferyl and sinapyl alcohols, etc. Phenolic chemical compounds from lignin were usually produced in super critical water. However, we applied Near-critical water (NCW) system because NCW is known as a good solvent for lignin depolymerization. Organic matter like lignin can be solved in NCW system and the system has a unique acid-base property without conventional non-eco-friendly chemicals such as sulfuric acid and sodium hydroxide. In this work, we tried to optimize the NCW depolymerization system by adjusting the processing variables such as reaction time, temperature and pressure. Moreover, the amount of additional phenol was optimized by changing the molar ratio between water and phenol. Phenol was used as capping agent to prevent re-polymerization of active fragment such as formaldehyde. Alkali-lignin was used as a starting material and characterized by a Solid State 13C-NMR, FT-IR and EA (Elemental Analysis). GC-MS analysis confirmed that o-cresol, p-cresol, anisole and 4-hydroxyphathalic acid were the main product and they were quantitatively analyzed by HPLC.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2002년도 생물공학의 동향 (X)
• /
• pp.473-476
• /
• 2002

A lignin degradation bacteria, symbiotic bacteria was isolated from the gut of Sympetrum depressiusculum and tested for its lignin degrading activity using lignin model compounds and related aromatic compounds. The strain was identified as Serratia marcescens HY-5 based on the 165 rDNA, cellular fatty acid composition, biochemical and physiological characteristics. S. marcescens showed 40-50% lignin degrading activity in the media that contained vaillin, guaiacol and dealkaline lignin. S. marcescens showed three ligninase activities [Jaccase, lignin peroxidase(LiP) and Manganase peroxidase(MnP)]. Addition of dealkaline lignin to the basal media increased about 6fold of laccase activity. Vanillic acid or vanillin increase 1.3fold of MnP activity and p-coumaric acid increased 12fold of LiP activity which added to the basal medium.

• BMB Reports
• /
• 제45권5호
• /
• pp.265-274
• /
• 2012

Lignin hydrolysates contain many different chemical species, including ferulic acid, coumaric acid, vanillic acid, vanillin, syringaldehyde and furfural. From the perspective of biofuels, these compounds are problematic and can cause downstream loss of product if not removed prior to beginning the fermentative process. In contrast, a search for these compounds within the literature turns up many papers where the same compounds have beneficial properties pertaining to human health, including as antioxidants and in cancer prevention, or are involved in bacterial cell-to-cell signaling. Consequently, this article reviews the dual nature of these and other compounds found in lignin hydrolysates, highlighting both their detrimental and beneficial activities.

• Journal of Forest and Environmental Science
• /
• 제12권1호
• /
• pp.37-44
• /
• 1996

Veratrylglycerol-${\beta}$-vanillylalcohol ether 결합 (${\beta}$-O-4 linkage)을 갖는 이양체(二量體) 리그닌 모델화합물(化合物)의 합성(合成)하여 각종 리그닌 반응(反應)의 시료(試料)로서 활용(活用)하고자 3,5-dimethoxyacetophenone을 출발물질(出發物質)로 하여 ${\beta}$-ring에 측소(側銷)를 갖는 이양체(二量體) 리그닌 모델화합물(化合物)(I-IV)을 합성(合成)하였고, 융점측정, $^1H(^{13}C)$-NMR 및 Mass 스펙트라에 의하여 그 화학구조(化學構造)를 동정(同定)하였다. 이 합성화합물(合成化合物)중에서 1-(3,4-dimethoxyphenyl)-2-(2'-methoxy-4'-hydroxymethylphenoxy)ropanediol-1,3[IV]는 매우 중요한 리그닌 이양체(二量體) 화합물(化合物)이다. 이러한 리그닌 합성연구(合成硏究)는 기초적(基礎的)인 연구(硏究)의 중요성(重要性) 뿐만아니라 응용면(應用面)에서도 그 활용도(活用度)가 높을 것이다.

• Journal of the Korean Wood Science and Technology
• /
• 제18권4호
• /
• pp.79-85
• /
• 1990

Many kinds of acetosolv lignin including ricestraw and spruce lignin were pyrolyzed. and liquefied in the autoclave reactor using 50% tetralin and m-cresol solution respectively as soluble solvent and Co-Mo as catalyst. In order to promote deoxyhydrogenolysis reaction $H_2$ gas was supplied into the reactor. The ratio between lignin and the soluble solvent are lg and 10cc. The reaction conditions are $200^{\circ}-700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure and 100-500rpm of the reactor stirrer. By the deoxyhydrogenolysis liquefaction reaction, the main chemical structures of lignin which are aryl-alkyl-${\beta}$-0-4 ether, phenylcoumaran and biphenyl etc. are easily destroyed into liqufied aromatic compounds and aliphatic compunds linked with aromatic compounds. The percent yield of monomeric phenols on the weight bvase of lignin reacted reached to 12-14% by the chemical analytic GC-MS etc.