Learn More
Some prominent cultured plant cell lines, such as the BY-2 cell line of tobacco (Nicotiana tabacum cv. ‘Bright Yellow 2’) and the T87 cell line of Arabidopsis (Arabidopsis thaliana L. Heynh., ecotype Columbia) are used as model plant cells. These suspension cell culture systems are highly applicable for investigating various aspects of plant cell biology.(More)
Several kinds of natural woods and isolated lignins with various syringyl to guaiacyl (S/G) ratios were subjected to thioacidolysis followed by Raney nickel desulfuration to elucidate the relationships between the S/G ratio and the interunit linkage types of lignin. Furthermore, enzymatic dehydrogenation polymers (DHP) were produced by the Zutropf (gradual(More)
We describe the synthesis and NMR spectroscopic analysis of three artificial lignin polymers containing only the beta-O-4 substructure: syringyl-type homopolymer, p-hydroxyphenyl-type homopolymer and guaiacyl/syringyl-type heteropolymer. Using gel permeation chromatography, the weight-average degree of polymerization (DP(w)) of the three polymers was(More)
Lignin in plant cell walls is a complex, irregular polymer built from phenylpropanoid C6-C3 units that are connected via various C-C and C-O linkages. A recent study using time-of-flight secondary ion mass spectrometry (ToF-SIMS) with Ga primary ion bombardment showed that lignin polymers can be characterized by specific positive ions possessing a(More)
The beta-O-4 structure is the most abundant substructure in lignin. Lignin related polymers composed of only the beta-O-4 structure were prepared using simple aromatic compounds as starting materials. Acetophenone derivatives were brominated, polymerized in the presence of K2CO3 and reduced with NaBH4 to give the lignin related polymers. These are linear(More)
An artificial lignin polymer containing only the beta-O-4 substructure was synthesized. The procedure consists of two key steps: 1) polycondensation of a brominated monomer by aromatic Williamson reaction; and 2) subsequent reduction of the carbonyl polymer. 13C-NMR and HMQC spectra of the polymer were consistent with beta-O-4 substructures in milled wood(More)
An ionic liquid, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), was used to dissolve Japanese fir (Abies sachallnensis MAST) wood. Milled woods prepared by planetary ball-milling for 8 h dissolved completely in [Bmim]Cl at 100 °C in 2 h. The dissolved woods were then subjected to in situ acetylation, and the fully acetylated woods were regenerated from(More)
Human immunodeficiency virus type 1 (HIV-1) is a cytopathic retrovirus and the primary etiological agent of acquired immunodeficiency syndrome (AIDS) and related disorders. In cells chronically infected with HIV-1, nuclear factor-kappaB (NF-kappaB) activation by external stimuli such as tumor necrosis factor alpha (TNFalpha) augments replication of HIV-1.(More)
Exosite 2 of human thrombin contributes to two opposing pathways, the anticoagulant pathway and the platelet aggregation pathway. We reasoned that an exosite 2 directed allosteric thrombin inhibitor should simultaneously induce anticoagulant and antiplatelet effects. To assess this, we synthesized SbO4L based on the sulfated tyrosine-containing sequence of(More)
Several lignin model polymers and their derivatives comprised exclusively of β-O-4 or 8-O-4' interunitary linkages were synthesized to better understand the relation between the thermal mobility of lignin, in particular, thermal fusibility and its chemical structure; an area of critical importance with respect to the biorefining of woody biomass and the(More)