Taiki Nishimoto, Kyoka Takagi, Dan Aoki, Kazuhiko Fukushima, Yasuyuki Matsushita
A lignin model oligomer with only β-O-4 linkages and a selectively deuterium-labelled methoxy group at the phenolic terminal units was synthesised to clarify the behaviour of the phenolic end of oligolignols. First, t-butoxycarbonylmethyl vanillin was synthesised and oligomerised by nucleophilic addition, a known method. The terminal of the oligomers was then subjected to nucleophilic addition to [3-OCD3]benzyl vanillin to achieve selective labelling of the terminal units. A deuterium-labelled lignin model oligomer (D-LM) was obtained through debenzylation and subsequent reduction. The results of thioacidolysis after methylation revealed that the degree of polymerisation was about five, and the deuterium-labelled phenylpropane unit was located only at the phenolic terminal moiety.
{"title":"Synthesis of β-O-4 linked model oligolignol with a selectively deuterium-labelled methoxy group at the phenolic terminal unit","authors":"Taiki Nishimoto, Kyoka Takagi, Dan Aoki, Kazuhiko Fukushima, Yasuyuki Matsushita","doi":"10.1515/hf-2023-0095","DOIUrl":"https://doi.org/10.1515/hf-2023-0095","url":null,"abstract":"A lignin model oligomer with only β-<jats:italic>O</jats:italic>-4 linkages and a selectively deuterium-labelled methoxy group at the phenolic terminal units was synthesised to clarify the behaviour of the phenolic end of oligolignols. First, <jats:italic>t-</jats:italic>butoxycarbonylmethyl vanillin was synthesised and oligomerised by nucleophilic addition, a known method. The terminal of the oligomers was then subjected to nucleophilic addition to [3-OCD<jats:sub>3</jats:sub>]benzyl vanillin to achieve selective labelling of the terminal units. A deuterium-labelled lignin model oligomer (D-LM) was obtained through debenzylation and subsequent reduction. The results of thioacidolysis after methylation revealed that the degree of polymerisation was about five, and the deuterium-labelled phenylpropane unit was located only at the phenolic terminal moiety.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"3 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139469989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lignin is an abundant polymer found in wood and grasses, but due to its heterogeneity and complex macromolecular structure it has been less utilized than cellulose. While the building blocks are known, the way they are linked is less understood. Here, Molecular Dynamics simulations were used to systematically characterize seven linkages found in native lignin. Their influence on lignin and water structure, and their interactions were analyzed. The study is limited to guaiacyl (G-G) dimers connected by the following common softwood linkages; 5-5′, 4-O-5′, α-O-4′, β-1′, β-5′, β-O-4′ and β-β′. The simulations show that the linkage has a significant effect on conformational preference and lignin-water interaction. Especially, the behavior of the β-O-4′ shows unique properties, both in terms of conformational freedom and interaction with water. Within the β-O-4′ dimer, π–π stacking between the aromatic rings is possible. The molecule has two distinct common conformations, one compressed and one extended. These preferences also lead to a different effect of β-O-4′ dimer on the surrounding water, where water is found close to the linkage itself but expelled from the aromatic rings to a larger extent than the other linkages. These findings are important for lignin solubility as well as its depolymerization mechanisms.
{"title":"Structure, flexibility and hydration properties of lignin dimers studied with Molecular Dynamics simulations","authors":"Klara Hackenstrass, Merima Hasani, Malin Wohlert","doi":"10.1515/hf-2023-0054","DOIUrl":"https://doi.org/10.1515/hf-2023-0054","url":null,"abstract":"Lignin is an abundant polymer found in wood and grasses, but due to its heterogeneity and complex macromolecular structure it has been less utilized than cellulose. While the building blocks are known, the way they are linked is less understood. Here, Molecular Dynamics simulations were used to systematically characterize seven linkages found in native lignin. Their influence on lignin and water structure, and their interactions were analyzed. The study is limited to guaiacyl (G-G) dimers connected by the following common softwood linkages; 5-5′, 4-O-5′, <jats:italic>α</jats:italic>-O-4′, <jats:italic>β</jats:italic>-1′, <jats:italic>β</jats:italic>-5′, <jats:italic>β</jats:italic>-O-4′ and <jats:italic>β</jats:italic>-<jats:italic>β</jats:italic>′. The simulations show that the linkage has a significant effect on conformational preference and lignin-water interaction. Especially, the behavior of the <jats:italic>β</jats:italic>-O-4′ shows unique properties, both in terms of conformational freedom and interaction with water. Within the <jats:italic>β</jats:italic>-O-4′ dimer, <jats:italic>π</jats:italic>–<jats:italic>π</jats:italic> stacking between the aromatic rings is possible. The molecule has two distinct common conformations, one compressed and one extended. These preferences also lead to a different effect of <jats:italic>β</jats:italic>-O-4′ dimer on the surrounding water, where water is found close to the linkage itself but expelled from the aromatic rings to a larger extent than the other linkages. These findings are important for lignin solubility as well as its depolymerization mechanisms.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"23 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139103167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafif Pujasmara, Tomy Listyanto, Sri Nugroho Marsoem
The establishment of fast-growing teak plantations in Indonesia provides opportunities for shorter harvesting periods. However, it also poses challenges on wood utilization due to juvenility and growth stress-related defects. This study investigated growth stress levels and some wood properties of 10-year-old fast-growing teak grown in Gunungkidul Regency, Yogyakarta. The strain gauge method was used to measure longitudinal surface released-strains (LRS), tangential surface released-strains (TRS), and longitudinal internal residual strains (IRS). Wood specimens were also collected near each strain measurement point for the analysis of wood properties. The results showed LRS values ranging from −1243 to 320 με, TRS values ranging from −779 to 382 με, and IRS values ranging from −589 to 786 με. Meanwhile, radial variations in fiber length, modulus of elasticity, and lignin content were observed. Significant correlations were found between IRS values and microfibril angle, fiber length, modulus of elasticity, lignin content, and hemicellulose content, while no significant correlations were observed between LRS and TRS values and wood properties. These findings suggest a moderate level of growth stress. Additionally, the results also indicate that this 10-year-old fast-growing teak is still in the juvenile stage. Therefore, its utilization should be performed with caution.
{"title":"Growth stress and wood properties of 10-year-old fast-growing teak grown in Gunungkidul, Yogyakarta","authors":"Rafif Pujasmara, Tomy Listyanto, Sri Nugroho Marsoem","doi":"10.1515/hf-2023-0078","DOIUrl":"https://doi.org/10.1515/hf-2023-0078","url":null,"abstract":"The establishment of fast-growing teak plantations in Indonesia provides opportunities for shorter harvesting periods. However, it also poses challenges on wood utilization due to juvenility and growth stress-related defects. This study investigated growth stress levels and some wood properties of 10-year-old fast-growing teak grown in Gunungkidul Regency, Yogyakarta. The strain gauge method was used to measure longitudinal surface released-strains (LRS), tangential surface released-strains (TRS), and longitudinal internal residual strains (IRS). Wood specimens were also collected near each strain measurement point for the analysis of wood properties. The results showed LRS values ranging from −1243 to 320 με, TRS values ranging from −779 to 382 με, and IRS values ranging from −589 to 786 με. Meanwhile, radial variations in fiber length, modulus of elasticity, and lignin content were observed. Significant correlations were found between IRS values and microfibril angle, fiber length, modulus of elasticity, lignin content, and hemicellulose content, while no significant correlations were observed between LRS and TRS values and wood properties. These findings suggest a moderate level of growth stress. Additionally, the results also indicate that this 10-year-old fast-growing teak is still in the juvenile stage. Therefore, its utilization should be performed with caution.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"23 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139103096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lignin dimeric units are characterized by various inter-unit linkage types such as β-O-4, β-5, β-β, and β-1. Spirodienones are the native form of the β-1 structures, but the content in lignin has not been clarified. In this study, the ring-1-13C labeled coniferin was synthesized and administered to Ginkgo biloba shoots, obtaining ring-1 selectively labeled xylem samples. Enzymatically saccharified lignin (EL) samples were prepared from the xylem sample (400–600 µm distant region from the cambial zone), and solution-state quantitative 13C NMR and solid-state CP/MAS NMR measurements were conducted. Acetylated EL (ELAc) was also prepared from the xylem sample (600–800 µm distant region from the cambial zone), and solution-state quantitative 13C NMR and 1H–13C 2D NMR measurements were conducted. Difference spectra obtained by subtracting the unlabeled spectra from the ring-1 labeled spectra showed that the ring-1 was responsible for broad signals at 134 ppm and signals of the spirodienone structure at 56.11 ppm (in solid-state), 54.70 ppm (EL in solution-state), and 54.72 ppm (ELAc in solution-state). The ratio of spirodienone structure was evaluated as 0.68 % (EL) and 0.72 % (ELAc) by the solution-state quantitative 13C difference spectra, and 2.3 % (ELAc) by HSQC volume ratio of Cα′-H to G2-H.
{"title":"Quantitative analysis of the β-1 structure in lignin by administration of [ring-1-13C]coniferin","authors":"Shori Imamura, Masaki Hosokawa, Yasuyuki Matsushita, Dan Aoki, Kazuhiko Fukushima, Masato Katahira","doi":"10.1515/hf-2023-0100","DOIUrl":"https://doi.org/10.1515/hf-2023-0100","url":null,"abstract":"Lignin dimeric units are characterized by various inter-unit linkage types such as β-O-4, β-5, β-β, and β-1. Spirodienones are the native form of the β-1 structures, but the content in lignin has not been clarified. In this study, the ring-1-<jats:sup>13</jats:sup>C labeled coniferin was synthesized and administered to <jats:italic>Ginkgo biloba</jats:italic> shoots, obtaining ring-1 selectively labeled xylem samples. Enzymatically saccharified lignin (EL) samples were prepared from the xylem sample (400–600 µm distant region from the cambial zone), and solution-state quantitative <jats:sup>13</jats:sup>C NMR and solid-state CP/MAS NMR measurements were conducted. Acetylated EL (ELAc) was also prepared from the xylem sample (600–800 µm distant region from the cambial zone), and solution-state quantitative <jats:sup>13</jats:sup>C NMR and <jats:sup>1</jats:sup>H–<jats:sup>13</jats:sup>C 2D NMR measurements were conducted. Difference spectra obtained by subtracting the unlabeled spectra from the ring-1 labeled spectra showed that the ring-1 was responsible for broad signals at 134 ppm and signals of the spirodienone structure at 56.11 ppm (in solid-state), 54.70 ppm (EL in solution-state), and 54.72 ppm (ELAc in solution-state). The ratio of spirodienone structure was evaluated as 0.68 % (EL) and 0.72 % (ELAc) by the solution-state quantitative <jats:sup>13</jats:sup>C difference spectra, and 2.3 % (ELAc) by HSQC volume ratio of Cα′-H to G2-H.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"19 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139092140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wood wettability, the process of liquid interaction with wood surfaces, is influenced by wood surface chemistry, structure, ambient conditions, and temperature. Understanding how temperature impacts wood wettability is crucial for high-temperature manufacturing processes. In this study, the sessile drop method was employed to explore the dynamic wettability of Chinese fir wood using three different liquids (water, glycerol and polyvinyl acetate (PVAc)) across a range of temperatures (25, 40, 60 and 80 °C). By considering spreading, penetration and evaporation, we revealed that the dynamic wettability of Chinese fir was strongly dependent on temperature and the type of liquid. Temperature elevation enhances wettability, leading to reduced contact angles and increased penetration ratios. Water exhibited the highest wettability, followed by glycerol, with PVAc being the least wetting agent. Notably, after 180 s of wetting at 80 °C, the measured contact angles were 0° for water, 45° for glycerol, and 120° for PVAc. When accounting for evaporation, the penetration of water decreased from 57 % to 47 % (25 °C) and 100 % to 62 % (80 °C). The activation energies for the penetration of water and PVAc into Chinese fir exhibited variations, with values of 35.3 and 158.3 kJ/mol, respectively. These comprehensive wetting results, covering spreading, penetration and evaporation, provide valuable insights into wood–water and wood–adhesive interactions, particularly when exposed to high-temperature conditions.
{"title":"Effect of temperature on the dynamic wettability of Chinese fir wood: integrative consideration of surface spreading, penetration and evaporation","authors":"Xianfu Xiao, Kaiwen Chen, Hui Peng, Jianxiong Lyu, Tianyi Zhan","doi":"10.1515/hf-2023-0096","DOIUrl":"https://doi.org/10.1515/hf-2023-0096","url":null,"abstract":"Wood wettability, the process of liquid interaction with wood surfaces, is influenced by wood surface chemistry, structure, ambient conditions, and temperature. Understanding how temperature impacts wood wettability is crucial for high-temperature manufacturing processes. In this study, the sessile drop method was employed to explore the dynamic wettability of Chinese fir wood using three different liquids (water, glycerol and polyvinyl acetate (PVAc)) across a range of temperatures (25, 40, 60 and 80 °C). By considering spreading, penetration and evaporation, we revealed that the dynamic wettability of Chinese fir was strongly dependent on temperature and the type of liquid. Temperature elevation enhances wettability, leading to reduced contact angles and increased penetration ratios. Water exhibited the highest wettability, followed by glycerol, with PVAc being the least wetting agent. Notably, after 180 s of wetting at 80 °C, the measured contact angles were 0° for water, 45° for glycerol, and 120° for PVAc. When accounting for evaporation, the penetration of water decreased from 57 % to 47 % (25 °C) and 100 % to 62 % (80 °C). The activation energies for the penetration of water and PVAc into Chinese fir exhibited variations, with values of 35.3 and 158.3 kJ/mol, respectively. These comprehensive wetting results, covering spreading, penetration and evaporation, provide valuable insights into wood–water and wood–adhesive interactions, particularly when exposed to high-temperature conditions.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"26 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139066646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuxin Zhao, Luxi He, Jiayi Kang, Jingjing Gao, Guochen Huo, Kai Xu, Tinghuan Wang, Zhengbin He, Zhenyu Wang, Songlin Yi
Thermal treatment is an effective method for improving the dimensional stability of wood; however, it typically requires high temperatures. To achieve low-temperature heat treatment, this study employed wood samples impregnated with 10 % tannin acid (TA) and examined their changes in dimensional stability and chemical components after heat treatment at various initial moisture content levels. The results revealed that the TA-10 %-HT group exhibited enhanced dimensional stability. Specifically, both the tangential and radial moisture swelling decreased by 21.7 % and 11.8 %, respectively. FTIR and XRD analysis indicated that the presence of tannin acid catalytically facilitated the degradation of hemicellulose. Moreover, an increase in moisture content resulted in the ionization of TA, amplifying acidity and further affecting cellulose degradation. TGA demonstrated that TA impacted the thermal stability of heat-treated materials by lowering the initial decomposition temperature of wood components and increasing the residual weight of wood. Overall, pretreatment with TA impregnation and moisture content significantly improved the dimensional stability of Chinese fir wood and altered its chemical composition. This approach holds considerable potential for enhancing wood properties through a low-energy consumption method during the heat treatment process, expanding the practical application of wood.
热处理是提高木材尺寸稳定性的有效方法，但通常需要较高的温度。为了实现低温热处理，本研究采用了浸渍了 10 % 单宁酸（TA）的木材样本，并在不同初始含水率水平下考察了热处理后木材尺寸稳定性和化学成分的变化。结果显示，TA-10 %-HT 组的尺寸稳定性更强。具体来说，切向和径向湿膨胀分别降低了 21.7% 和 11.8%。傅立叶变换红外光谱和 XRD 分析表明，单宁酸的存在催化了半纤维素的降解。此外，水分含量的增加导致 TA 离子化，酸性增强，进一步影响纤维素降解。热重分析表明，TA 通过降低木材成分的初始分解温度和增加木材残重，影响了热处理材料的热稳定性。总之，使用 TA 浸渍和含水率进行预处理可显著提高杉木的尺寸稳定性，并改变其化学成分。这种方法具有相当大的潜力，可在热处理过程中通过低能耗方法提高木材性能，扩大木材的实际应用范围。
{"title":"Effects of tannin acid impregnated pretreatment on dimensional stability and chemical composition of heat-treated Chinese fir","authors":"Yuxin Zhao, Luxi He, Jiayi Kang, Jingjing Gao, Guochen Huo, Kai Xu, Tinghuan Wang, Zhengbin He, Zhenyu Wang, Songlin Yi","doi":"10.1515/hf-2023-0081","DOIUrl":"https://doi.org/10.1515/hf-2023-0081","url":null,"abstract":"Thermal treatment is an effective method for improving the dimensional stability of wood; however, it typically requires high temperatures. To achieve low-temperature heat treatment, this study employed wood samples impregnated with 10 % tannin acid (TA) and examined their changes in dimensional stability and chemical components after heat treatment at various initial moisture content levels. The results revealed that the TA-10 %-HT group exhibited enhanced dimensional stability. Specifically, both the tangential and radial moisture swelling decreased by 21.7 % and 11.8 %, respectively. FTIR and XRD analysis indicated that the presence of tannin acid catalytically facilitated the degradation of hemicellulose. Moreover, an increase in moisture content resulted in the ionization of TA, amplifying acidity and further affecting cellulose degradation. TGA demonstrated that TA impacted the thermal stability of heat-treated materials by lowering the initial decomposition temperature of wood components and increasing the residual weight of wood. Overall, pretreatment with TA impregnation and moisture content significantly improved the dimensional stability of Chinese fir wood and altered its chemical composition. This approach holds considerable potential for enhancing wood properties through a low-energy consumption method during the heat treatment process, expanding the practical application of wood.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"14 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139072146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bamboo culm is a natural material characterized by a graded structure of vascular bundles in the radial direction and a regular distribution of bamboo nodes in the axial direction. To investigate the adaptation of bamboo culm structure to its natural environment, the bamboo culm structure was analyzed using a vascular bundle identification model, complemented by mechanical simulations. The results showed a certain pattern in the macroscopic dimensional characteristics of bamboo from the base to the top: the outer diameter decreased linearly; the internode length initially increased before decreasing; the length-to-diameter ratio gradually increased; and the wall-to-cavity ratio initially decreased before increasing. In response to external forces, bamboo exhibited strong stability, which was attributed to the thin and hollow wall as well as parabolic distribution of bamboo nodes. Along the axial direction, vascular bundle numbers linearly decreased, while the ratio of fiber sheath tissue and the distribution frequency of vascular bundles increased from the base to the top. In the radial direction, the length and area of vascular bundles tended to increase before decreasing, while the width tended to increase, leading to a decreasing length-to-width ratio. Overall, the radial variation pattern of vascular bundles showed nonsignificant variations at different heights.
{"title":"Analyzing the structure of bamboo culms using computer vision and mechanical simulation","authors":"Fukuan Dai, Yuxuan Chen, Wenfu Zhang, Tuhua Zhong, Genlin Tian, Hankun Wang","doi":"10.1515/hf-2023-0093","DOIUrl":"https://doi.org/10.1515/hf-2023-0093","url":null,"abstract":"Bamboo culm is a natural material characterized by a graded structure of vascular bundles in the radial direction and a regular distribution of bamboo nodes in the axial direction. To investigate the adaptation of bamboo culm structure to its natural environment, the bamboo culm structure was analyzed using a vascular bundle identification model, complemented by mechanical simulations. The results showed a certain pattern in the macroscopic dimensional characteristics of bamboo from the base to the top: the outer diameter decreased linearly; the internode length initially increased before decreasing; the length-to-diameter ratio gradually increased; and the wall-to-cavity ratio initially decreased before increasing. In response to external forces, bamboo exhibited strong stability, which was attributed to the thin and hollow wall as well as parabolic distribution of bamboo nodes. Along the axial direction, vascular bundle numbers linearly decreased, while the ratio of fiber sheath tissue and the distribution frequency of vascular bundles increased from the base to the top. In the radial direction, the length and area of vascular bundles tended to increase before decreasing, while the width tended to increase, leading to a decreasing length-to-width ratio. Overall, the radial variation pattern of vascular bundles showed nonsignificant variations at different heights.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"18 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139055530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laise de Jesus dos Santos, Elesandra da Silva Araujo, Mário Sérgio Lorenço, Bianca Bueno Rosário, Sabrina Benmuyal Vieira, Agust Sales, Marco Antonio Siviero, Luiz Eduardo de Lima Melo, Graciene da Silva Mota, Gabriela Aguiar Campolina, Fabio Akira Mori
The bark anatomy was analysed, as was the overall chemical composition (extractives, lignin, suberin, ash and polysaccharides), and a quantitative elemental analysis was performed of the bark and two tannin extracts (extracted with water only and with a mixture of water and Na2SO3). The phenolic composition and antioxidant activity of the bark extracts were quantified. The results indicated that the bark is composed of conductive phloem, nonconductive phloem, rhytidome, crystals and secretory cells. The average chemical composition was 15.9 % extractives, 35.3 % total lignin, 1.9 % suberin, 15.4 % ash and 31.5 % polysaccharides. The condensed tannin yield in the extract obtained with water alone was 5.1 %, and that in the treatment with water and Na2SO3 was 8.1 %. The ethanol-water extract had a high phenolic content (112.6 mg GAE g−1 extract). The bark extract showed strong antioxidant activity, reaching 83.5 % inhibition of DPPH free radicals, which was higher than the value of 75.0 % for the commercial antioxidant BHT at the same concentration. These results demonstrate that Protium tenuifolium is a potential natural Amazonian source of phenolic compounds and antioxidants and can be used for medicinal purposes and the production of various sustainable products, such as cosmetics.
{"title":"Characterization of the bark of Protium tenuifolium Engl. from the Amazonian biome as a source of natural antioxidants","authors":"Laise de Jesus dos Santos, Elesandra da Silva Araujo, Mário Sérgio Lorenço, Bianca Bueno Rosário, Sabrina Benmuyal Vieira, Agust Sales, Marco Antonio Siviero, Luiz Eduardo de Lima Melo, Graciene da Silva Mota, Gabriela Aguiar Campolina, Fabio Akira Mori","doi":"10.1515/hf-2023-0039","DOIUrl":"https://doi.org/10.1515/hf-2023-0039","url":null,"abstract":"The bark anatomy was analysed, as was the overall chemical composition (extractives, lignin, suberin, ash and polysaccharides), and a quantitative elemental analysis was performed of the bark and two tannin extracts (extracted with water only and with a mixture of water and Na<jats:sub>2</jats:sub>SO<jats:sub>3</jats:sub>). The phenolic composition and antioxidant activity of the bark extracts were quantified. The results indicated that the bark is composed of conductive phloem, nonconductive phloem, rhytidome, crystals and secretory cells. The average chemical composition was 15.9 % extractives, 35.3 % total lignin, 1.9 % suberin, 15.4 % ash and 31.5 % polysaccharides. The condensed tannin yield in the extract obtained with water alone was 5.1 %, and that in the treatment with water and Na<jats:sub>2</jats:sub>SO<jats:sub>3</jats:sub> was 8.1 %. The ethanol-water extract had a high phenolic content (112.6 mg GAE g<jats:sup>−1</jats:sup> extract). The bark extract showed strong antioxidant activity, reaching 83.5 % inhibition of DPPH free radicals, which was higher than the value of 75.0 % for the commercial antioxidant BHT at the same concentration. These results demonstrate that <jats:italic>Protium tenuifolium</jats:italic> is a potential natural Amazonian source of phenolic compounds and antioxidants and can be used for medicinal purposes and the production of various sustainable products, such as cosmetics.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"8 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139051083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jaco-Pierre van der Merwe, Martin Bacher, Sechaba Madiope, Thandekile Ncongwane, Robert Ngomane, Olwethu Spogter, Hilton Kuisis, Jaco Potgieter, Oscar Tait, Charlie Clarke, Julie Cool, Stavros Avramidis, Simon Ellis, Shawn D. Mansfield
South Africa is a water scarce country with minimal natural forests. Plantation forest species such as the Mexican tropical hard pine, Pinus patula Schiede & Deppe ex Schltdl. & Cham., was introduced into the country to satisfy local fibre demand. Today, the majority of pine plantations in South Africa are found in the Mpumalanga province. The province has diverse growing conditions in relation to climate and soil properties. Sample plots were established in even-aged P. patula plantations and stratified according to soil parent material and altitude. Growing conditions of each sample plot were characterised according to climate and soil properties. A total of 540 sample trees were measured for height, diameter, density, and latewood content. The sample trees were harvested to produce 2690 logs. The logs were milled, and the resultant lumber was graded according to density, dynamic modulus of elasticity, and modulus of rupture. Annual maximum temperature had the most significant impact on tree growth, while rainfall correlated with wood density and latewood content of standing trees. However, annual maximum temperature and tree height had a negative relationship with the recovered lumber properties and dimensional stability. Spring rainfall appeared to be the most important factor influencing lumber twist and this was possibly due to the associated larger juvenile core present in the trees.
南非是一个缺水国家，天然森林极少。为了满足当地的纤维需求，该国引进了墨西哥热带硬松（Pinus patula Schiede & Deppe ex Schltdl.如今，南非大部分的松树种植园都位于姆普马兰加省。该省的气候和土壤条件各不相同。我们在树龄均匀的 P. patula 人工林中建立了样地，并根据土壤母质和海拔高度进行了分层。根据气候和土壤特性对每个样地的生长条件进行了描述。共测量了 540 棵样树的高度、直径、密度和晚材含量。样本树被采伐后产生了 2690 根原木。原木经过碾磨后，根据密度、动态弹性模量和断裂模数对木材进行分级。年最高气温对树木生长的影响最大，而降雨量则与立木的木材密度和晚材含量相关。然而，年最高气温和树高与木材的恢复特性和尺寸稳定性呈负相关。春季降雨似乎是影响木材捻度的最重要因素，这可能是由于树木中存在较大的幼核。
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