Toshihiro Ona

Investigation of relationships between cell and pulp properties in Eucalyptus by examination of within-tree property variations

Abstract Relationships between cell and pulp properties were investigated by examining the within-tree property variations in Eucalyptus camaldulensis and Eucalyptus globulus. Properties investigated included proportions of ray and axial parenchyma, thickness of cell walls and cell wall percentages. The characteristics of the ray and axial parenchyma (their proportions and wall thickness) were found to have a significant influence on all measured pulp properties, including paper strength properties. Multiple regression of pulp properties in relation to cell properties revealed that nearly all measured pulp properties were explained by cell properties at the 1% significance level. It was concluded, therefore, that all cell types are important for predicting pulp properties, and it is strongly recommended that tree breeding programs for Eucalyptus include the measurement of all cell types.

Characterization of within-tree variation of lignin components in Eucalyptus camaldulensis by pyrolysis–gas chromatography

Pyrolysis–gas chromatography (Py-GC) using a vertical microfurnace pyrolyzer was applied to the precise determination of the ‘within-tree variation’ of the ratio of syringyl and guaiacyl units (S/G ratio) for lignin in Eucalyptus camaldulensis. On the pyrogram of the Eucalyptus obtained at 450 °C, many characteristic peaks derived from syringyl and guaiacyl units of lignin were reproducibly observed, together with those from cellulose and hemicellulose. On the basis of the relative intensities of those characteristic peaks relating to the syringyl and guaiacyl units, the ‘within-tree variation’ of the S/G ratio was determined precisely in about 1 h using only about 0.1 mg of the powdered wood sample with a 2% relative standard deviation. The results obtained were also compared with those obtained by the thioacidolysis method.

Non-destructive determination of wood constituents by fourier transform Raman spectroscopy

Abstract The feasibility of using FT-Raman spectroscopy for rapid determination of various wood constituents non-destructively was examined using five Eucalyptus species, including samples of various ages and colors of samples, which are of importance as a plantation source. Wood constituents which relate to pulp properties (holocellulose, α -cellulose, hemicellulose, lignin, extractives, alkali-extractives, total-extractives, and extractives-free (EF) wood constituents for holocellulose, α -cellulose, hemicellulose and lignin) were measured. The application of 2nd derivatives transformation of Raman spectroscopic data revealed highly significant correlations between wet chemical and Raman predicted values for all traits except EF-hemicellulose, with standard error of prediction (SEP) < 0.8 points in the calibration (for known samples) and SEP < 3.4 points in the prediction (for unknown samples), respectively. Consequently, this non-destructive method has proved its validity for analyzing various Eucalypt...

Relationship of lignin content, lignin monomeric composition and hemicellulose composition in the same trunk sought by their within-tree variations in Eucalyptus camaldulensis and E. globulus.

The relationship of extractives-free (EF) lignin content, lignin monomeric composition as syringyl/guaiacyl (S/G) ratio by thioacidolysis, and neutral sugars constituting hemicellulose by hydrolysis with trifluoroacetic acid was examined. This was performed in the same trunk by their within-tree variations, which mean the investigation with the same genes, in Eucalyptus camaldulensis and E. globulus. As results, each species had a high negative correlation between EF-lignin content and lignin S/G ratio although the difference between species and/or individuals was observed in the trend of within-tree variations of the wood properties. The relationship between EF-lignin content and lignin S/G ratio is considered to be caused from the difference in the fiber morphology from the relationship between lignin and EF-basic density which may relate to the fiber morphology. Furthermore, the relationship between the lignin monomeric composition derived from b-O-4 bonds and the hemicellulose composition is concluded to exist since common trend was observed between two species as higher lignin S/G ratio with the increase in xylan and or with decrease in arabinogalactan (galactan). We also discuss and suggest that the hemicellulose composition can influence on the lignin monomeric composition.

Discriminative analysis of Eucalyptus camaldulensis grown from seeds of various origins based on lignin components measured by pyrolysis-gas chromatography

Abstract Pyrolysis-gas chromatography (Py-GC) using a vertical microfurnace pyrolyzer combined with the principal component analysis (PCA) was applied to the discriminative analysis of Eucalyptus camaldulensis trees grown at the same field from the seeds of different origins. On the pyrograms of the Eucalyptus samples obtained at 450°C, many characteristic peaks derived from syringyl (S) and guaiacyl (G) units of lignin were reproducibly observed along with those derived from cellulose and hemicellulose. First, the discriminative analysis among the Eucalyptus trees was attempted on the basis of the S/G ratio calculated from the relative peak intensities of the pyrolyzates characteristic to lignin. However, it was difficult to make unequivocal specification for the origins of the seeds by the observed S/G ratio alone. Then, the PCA was applied to discriminate Eucalyptus tree samples based on the molar yields of the peaks specifically derived from lignin observed by Py-GC. As a result, the origin of Eucalyptus trees was successfully discriminated even grown at the same field.

Histochemical study on heterogeneity of lignin in Eucalyptus species II. The distribution of lignins and polyphenols in the walls of various cell types

We examined the effects of polyphenols on the analysis of lignin by histochemical methods, namely, the Maule color reaction coupled with microspectrophotometry and ultraviolet microspectrophotometry, in wood of Eucalyptus camaldulensis and E. globulus. Thin sections and wood meals were extracted with solutions of alkali at different concentrations. The amounts of alkali-soluble extractives increased with increasing concentrations of NaOH. By contrast, there was no clear correlation between amounts of Klason lignin and the concentration of NaOH. The visible-light absorption spectra of cell walls of all woody tissues from both species changed after alkali extraction. In particular, the spectra of cell walls of vessel elements changed considerably, even when only a dilute solution of alkali was used. Ultraviolet absorption spectra did not show clear changes after extraction with alkali. These results indicate that polyphenols in cell walls affect the results of histochemical analysis. Therefore, a preliminary extraction with alkali, namely, extraction with a 1% solution of NaOH, is needed to assess the precise distribution of lignins in the cell walls of Eucalyptus wood by histochemical methods. The cell walls of wood fibers of Eucalyptus camaldulensis contained both guaiacyl and syringyl units and those of vessel walls contained mostly guaiacyl units. However, the cell walls of wood fibers in Eucalyptus globulus contained mainly syringyl units, while those of vessel elements contained both guaiacyl and syringyl units. Syringyl-type polyphenols, which have spectra similar to those of syringyl-type lignins, were found in the cell walls of wood fibers and vessel elements and in cell corners among wood fibers in both species of Eucalyptus.

Non-destructive determination of lignin syringyl/guaiacyl monomeric composition in native wood by Fourier transform Raman spectroscopy

Abstract The feasibility of using FT-Raman spectroscopy for rapid non-destructive determination of lignin syringyl/guaiacyl (S/G) monomeric composition was examined using Eucalyptus camaldulensis and E. globulus, including samples of various ages and colors, which are of importance as a plantation source. The application of 2nd derivatives transformation of Raman spectroscopic data revealed highly significant correlations between wet chemical and Raman predicted values with correlation coefficient (r) = 0.998 and standard error of prediction (SEP) < 0.07 points in the calibration (for known samples), and r = 0.935 and SEP < 0.32 points in the prediction (for unknown samples), respectively. Consequently, this nondestructive method has proved its validity for analyzing Eucalyptus native wood meal samples, regardless of their age and color to determine lignin S/G monomeric composition. Using FT-Raman spectroscopy, elite tree selection based on quality aspects for pulp and paper production can be performed.

Advanced dynamic monitoring of cellular status using label-free and non-invasive cell-based sensing technology for the prediction of anticancer drug efficacy

Quantitative evaluation of anticancer drug efficacy using in vitro cell-based assays is useful for cancer patients, particularly those who show unconventional cancer development. Nevertheless, conventional chemosensitivity testing often requires widely used labeling agents and time-consuming laboratory procedures that provide low reliability. Label-free non-invasive cell-based assays are desired for dynamic monitoring of cellular status. This critical review first describes conventional chemosensitivity testing and then advanced label-free cell-based technology used to screen anticancer drugs through dynamic monitoring of cellular status, focusing on dosage and the use of drug-resistant cancer cells. Results from label-free cell-based approaches are compared with those of conventional chemosensitivity testing. The cellular statuses, addressed in terms of respective mechanisms and disadvantages, are extracellular fluxes of proton (H+), O2, and anticancer drugs, cell morphology changes, cell–environment interaction, and mitochondrial membrane potential. Finally, a cell-based systems outlook is presented. This paper represents a step toward efficient and accurate initial screening of anticancer drugs and development of compounds and their combined use to achieve pharmacodynamic and pharmacokinetic interactions, and chemotherapy evaluation of particular anticancer drugs for individual patients.

Non-Destructive Determination of Hemicellulosic Neutral Sugar Composition in Native Wood by Fourier Transform Raman Spectroscopy

Abstract The feasibility of using FT-Raman spectroscopy for rapid non-destructive determination of hemicellulosic neutral sugar composition, important factors for pulp properties, in native wood was examined using two Eucalyptus species, including samples of various ages and colors, which are important sources of plantation pulpwood. The sugars, glucose, xylose, galactose, rhamnose, arabinose and mannose were utilized. The application of 2nd derivatives transformation of Raman spectroscopic data revealed highly significant correlations between wet chemical and Raman predicted values in the calibration (known samples) with correlation coefficients > 0.99, and in the prediction (unknown samples) with correlation coefficients > 0.80 with the exception of rhamnose and mannose. Consequently, this non-destructive method will be valid for analyzing Eucalyptus native wood meal samples, regardless of their age and color to determine hemicellulosic neutral sugar composition except rhamnose and mannose. Elite tree s...

Effect of the lateral growth rate on wood properties in fast-growing hardwood species

We investigated the feasibility of using several fast-growing tropical or subtropical hardwood species for timber production by measuring key wood qualities in relationship to the high rates of lateral growth. The trees tested were sampled from even-aged plantations of Acacia mangium, A. auriculiformis, hybrid Acacia (A. mangium × A. auriculiformis), Eucalyptus grandis, E. globulus, and Paraserianthes falcataria (Solomon and Java origin) that had already reached commercial harvesting age. The released strain of the surface growth stress (RS), xylem density (XD), microfibril angle (MFA), and fiber length (FL) were measured at the outermost part of the xylem at breast height in each tree. Results were then compared to the lateral growth rate (radius/age) at breast height, which provides a relative indicator of the amount of tree growth per year. Our findings indicated that RS was constant, regardless of lateral growth rate in each species. Similar results were observed for XD, MFA, and FL, with a few exceptions, suggesting that high growth rates do not intrinsically affect the wood properties of fast-growing tropical or subtropical species that have reached harvesting age. However, special attention must be paid to patterns of xylem maturation when developing plantations of such species.