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The stability and chemical reactions of lignans during alkaline cooking is not yet fully clarified although their degradation products may have a considerable effect on the pulp and its bleaching, such as spotting and color contamination. To fill this gap, a phenolic lignan (pinoresinol) and four non-phenolic furofuran lignans (gmelinol, paulownin, eudesmin and sesamin) were submitted to alkaline cooking at various conditions. The effect of cooking duration shows that non-phenolic lignans are more stable during a 3-h reaction time than pinoresinol. After a 24-h reaction, most of the lignans were decomposed or polymerized. The effect of cooking temperature shows that pinoresinol, eudesmin and sesamin are more susceptible to degradation with increasing temperature. The concentration of the alkaline liquors only affect significantly to pinoresinol because of its acidity. It was also observed that pinoresinol, gmelinol and eudesmin give rise to small amounts of vanillin and acetovanillone, while paulownin and sesamin were mainly polymerized or degraded. To confirm the reaction mechanism of the occurrence of acetovanillone in the reaction, 13C-labeled pinoresinol was also submitted to alkaline cooking. It was revealed that the cleavage at β-β′ position occurred during alkaline reaction. The stability of these compounds during alkaline cooking are not affected by the hydroxyl group in the C-β′ position. [ABSTRACT FROM AUTHOR]

An occluding substance (gum) was observed in the vessels of Phellodendron amurense Rupr. and analysed by spectroscopic and chemical methods. Following safranin-alcian blue staining, the gum in sapwood (sW) turned to blue and in heartwood (hW) to red. The gum was studied in situ by UV and Raman microscopies, time-offlight secondary ion mass spectrometry (TOF-SIMS). The gum was isolated by laser microdissection (LMD) and it was alkali hydrolysed and the degradation products were analysed by GC-MS. The staining experiments, and the UV and Raman microscopies indicated that the major component of the sW gum is constituted of polysaccharides, while in the hW gum the aromatic character is dominating. TOF-SIMS measurements were interpreted as showing the aromatic substances in the hW gum did not contain lignin. The GC-MS analysis revealed the presence of vanillic acid in the degradation products of hW gum. [ABSTRACT FROM AUTHOR]

To elucidate the effect of soil conditions on the in planta distribution of inorganic elements, an aluminium (Al)-tolerant plant, Hydrangea macrophylla, was cultivated with the addition of Al ion to soils. Freeze-dried stems from the plants were analysed by time-of-flight secondary ion mass spectrometry (dry-TOF-SIMS). Freezefixed stems of the plants were analysed by cryo-TOF-SIMS. The inorganic metal content was quantified by inductively coupled plasma atomic absorption spectrometry (ICP-AES). The dry- and cryo-TOF-SIMS mapping analyses showed that in the native sample, inorganic elements are mainly localised in the cortex and pith. Al-treatment [i.e. Al2(SO4)3 administration to the soil] altered the distribution and content of inorganic metals. The actual amount of inorganic elements quantified by ICP-AES showed that Al-treatment on the soil increased the amounts of Na, Mg, Al and Ca and decreased that of K in the stem. The secondary ion counts of inorganic elements in freeze-dried and -fixed samples, determined by dry-/cryo-TOF-SIMS measurements, showed similar variations as that observed with ICP-AES measurements. These results are interpreted as that Al-treatment altered the distribution and amount of inorganic elements in the stems of Al-tolerant H. macrophylla plants. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the extractives of Gmelina arborea stem from the sapwood (sW) to heartwood (hW) including the transition zone (tZ) between them by means of quantitative GC-MS, while the spatial distribution of four typical compounds was analysed by TOF-SIMS. The focus was on gmelinol, paulownin, 7'-O-ethyl arboreol, and β-sitosterol, which were isolated and purified from hW. The four compounds revealed a characteristic distribution pattern corresponding to their key role in biosynthesis and depending on their susceptibility to secondary reactions in the hW. [ABSTRACT FROM AUTHOR]