Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru...Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru/C and a base,which afforded high yields of phenolic monomers from the lignin component and a solid carbohydrate pulp,is reported.The introduction of Cs_(2)CO_(3) led to the generation of C2 side‐chained phenols through the cleavage of C_(β)–O and C_(β)–C_(γ) bonds inβ–O–4 units in addition to C3 side‐chained phenols;the relationship between C2 and C3 was dependent on the base dosage.The reaction conditions,including base species,temperature,time,and H_(2) pressure,were optimized in terms of phenolic product distribution,delignification degree,and carbohydrate retention.The carbohydrate pulps generated from reductive catalytic fractionation in the presence of Cs_(2)CO_(3) were more amenable to enzymatic hydrolysis,indicating that this treatment of biomass constituted the fractionation of biomass components together with the breakdown of biomass recalcitrance.展开更多
A chemical investigation of the aerial parts ofArtemisia vestita Wall. led to the isolation of 12 known sesquiterpenes, including 2 furan-containing sesquiterpenoids and 10 eudesmane sesquiterpene lactones. Their stru...A chemical investigation of the aerial parts ofArtemisia vestita Wall. led to the isolation of 12 known sesquiterpenes, including 2 furan-containing sesquiterpenoids and 10 eudesmane sesquiterpene lactones. Their structures were identified as negunfurol （1）, schensianol A （2）, artemine （3）, erivanin （4）, 1,5-diepi-artemin （5）, acetylartemin （6）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy） decahydro-9a-hydroxy-3,Sa-dimethyl-9-methylene-（3S,3aS,5aS,6S,9aS, ghS） （7）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy）- 3a,4,5,5a,6,7,8,9b-octahydro-8-hydroxy-3,Sa,9-trimethyl- （3S,3aS, SaR,6S, SS,9bS） （8）, isoerivanin （9）, harrelierin （10）, （11S）-1- oxoeudesm-4（14）-eno-13,6a-lactone （11）, 1-epi-dehydroisoeranin （12）, respectively. All of these compounds were isolated from Artemisia vestita for the first time, and compounds 1 and 2 were isolated from the genus Artemisia for the first time.展开更多
文摘Lignin,which is the most recalcitrant component of lignocellulosic biomass,is also the most abundant renewable aromatic resource.Herein,reductive treatment of triploid poplar sawdust by the integration of catalytic Ru/C and a base,which afforded high yields of phenolic monomers from the lignin component and a solid carbohydrate pulp,is reported.The introduction of Cs_(2)CO_(3) led to the generation of C2 side‐chained phenols through the cleavage of C_(β)–O and C_(β)–C_(γ) bonds inβ–O–4 units in addition to C3 side‐chained phenols;the relationship between C2 and C3 was dependent on the base dosage.The reaction conditions,including base species,temperature,time,and H_(2) pressure,were optimized in terms of phenolic product distribution,delignification degree,and carbohydrate retention.The carbohydrate pulps generated from reductive catalytic fractionation in the presence of Cs_(2)CO_(3) were more amenable to enzymatic hydrolysis,indicating that this treatment of biomass constituted the fractionation of biomass components together with the breakdown of biomass recalcitrance.
基金National Natural Science Foundation of China(Grant No.30973629)National Key Technology R&D Program "New Drug Innovation" of China(Grant No.2012ZX09301002-002-002,2012ZX09304-005)
文摘A chemical investigation of the aerial parts ofArtemisia vestita Wall. led to the isolation of 12 known sesquiterpenes, including 2 furan-containing sesquiterpenoids and 10 eudesmane sesquiterpene lactones. Their structures were identified as negunfurol （1）, schensianol A （2）, artemine （3）, erivanin （4）, 1,5-diepi-artemin （5）, acetylartemin （6）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy） decahydro-9a-hydroxy-3,Sa-dimethyl-9-methylene-（3S,3aS,5aS,6S,9aS, ghS） （7）, naphtho[1,2-b]furan-2（3H）-one, 6-（acetyloxy）- 3a,4,5,5a,6,7,8,9b-octahydro-8-hydroxy-3,Sa,9-trimethyl- （3S,3aS, SaR,6S, SS,9bS） （8）, isoerivanin （9）, harrelierin （10）, （11S）-1- oxoeudesm-4（14）-eno-13,6a-lactone （11）, 1-epi-dehydroisoeranin （12）, respectively. All of these compounds were isolated from Artemisia vestita for the first time, and compounds 1 and 2 were isolated from the genus Artemisia for the first time.
