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To comprehend the biosynthesis processes of conifers, it is essential to investigate the disparity between the cell wall shape and the interior chemical structures of polymers throughout the development of Chinese pine. In this study, branches of mature Chinese pine were separated according to their growth time (2, 4, 6, 8 and 10 years). The variation of cell wall morphology and lignin distribution was comprehensively monitored by scanning electron microscopy (SEM) and confocal Raman microscopy (CRM), respectively. Moreover, the chemical structures of lignin and alkali-extracted hemicelluloses were extensively characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The thickness of latewood cell walls increased steadily from 1.29 μm to 3.38 μm, and the structure of the cell wall components became more complicated as the growth time increased. Based on the structural analysis, it was found that the content of β-O-4 (39.88-45.44/100 Ar), β-β (3.20-10.02/100 Ar) and β-5 (8.09-15.35/100 Ar) linkages as well as the degree of polymerization of lignin increased with the growth time. The complication propensity increased significantly over 6 years before slowing to a trickle over 8 and 10 years. Furthermore, alkali-extracted hemicelluloses of Chinese pine mainly consist of galactoglucomannans and arabinoglucuronxylan, in which the relative content of galactoglucomannans increased with the growth of the pine, especially from 6 to 10 years., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

As a green sustainable material, lignin-derived porous carbon (LPC) exhibits great application potential when used as the anode material in lithium-ion batteries (LIBs), but the applications are limited by the heterogeneity of the lignin precursor. Therefore, it is crucial to reveal the relationship among lignin properties, porous carbon structure and the kinetics of lithium-ion storage. Herein, LPCs from fractionated lignin have been prepared by an eco-friendly and recyclable activator. The structure of the LPCs was regulated by adjusting the molecular weight, linkage abundance and glass transition temperature (T g ) of lignin macromolecules. As the anode material of LIBs, the prepared 3D flower-like LPC E70 could achieve a reversible capacity of 528 mAh g -1 at a current density of 0.2 A g -1 after 200 cycles, 63 % higher than that of commercial graphite. Furthermore, kinetic calculations of lithium-ion storage behavior of LPCs were firstly used to confirm the contribution ratio of diffusion-controlled behavior and capacitive effect. Lignin with a high linkage abundance could yield LPC E70 with the largest interlayer spacing and specific surface area to maximize lithium-ion storage from both diffusion-controlled and capacitive contributions of specific capacities. This work provides a green, facile and effective pathway for value-added utilization of lignin in LIBs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Complex and heterogeneous structures of lignin impede its further conversion and valorization. Herein, three technical lignins (from softwood, hardwood, and grass) were fractionated with acetone solvent to reduce their structural heterogeneity, which were then blended with poly-(butylene adipate-co-terephthalate) (PBAT) to fabricate biodegradable bio-composites. Macromolecular structures of lignins and their effects on the properties of lignin/PBAT composites were thoroughly investigated. Results showed that all fractionated lignin composites displayed better properties. Particularly, the raw and fractionated softwood lignin-based composites exhibited superior performance compared with others. Benefiting from the lower molecular weight, hydroxyl groups, and condensation, acetone fractionated softwood lignin presented the lowest T g (115.7 °C), achieving ideal melt miscibility and interfacial interaction between lignin and PBAT. The decreased T g of lignin facilitated the lignin dispersion in the matrix and increase the mechanical strength of the composites. Overall, the fractionated technical lignin possessed desirable physical and chemical structure features, conferring composites good miscibility and mechanical properties., (Copyright © 2022 Elsevier B.V. All rights reserved.)

To maximize the utilization of Abaca lignin in the current biorefinery, structural characteristics of native lignin from Abaca were firstly comprehensively investigated. Parallelly, effective delignification of Abaca was achieved by alkaline hydrogen peroxide (AHP) process, which facilitated the production of specialty paper in industry. The structural changes of lignin macromolecules during the AHP delignification were illustrated by comparing the structural differences of the released lignin fraction and corresponding native lignin, which were analyzed via the advanced analytical methods, such as 2D-HSQC NMR, 31 P NMR, pyrolysis-GC/MS, and GPC techniques. It was found that Abaca lignin is a HGS-type lignin, which is overwhelmingly composed of β-O-4 linkages and abundant hydroxycinnamic acids (mainly p-coumaric acid). In addition, partial cleavage of β-O-4 linkages and p-coumarate in lignin occurred during the AHP delignification process. Meanwhile, AHP process also led to the elevation of H-type lignin units in AHPL. Considering that β-O-4 bond is vulnerable in the catalytic degradation process of lignin, the lignin with abundant β-O-4 linkages is beneficial to the downstream conversion of lignin into aromatic chemicals., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2018. Published by Elsevier B.V.)

The alcoholic depolymerization and Mannich reaction were conducted to improve the chemical activity of biorefinery technical lignins and introduce amino groups into lignins, respectively. To understand the chemical structural transformations and examine the reaction mechanism, GPC and solution-state NMR techniques were performed. Element analysis was also used to quantify the amount of amine groups. The NMR characterization the depolymerized lignins indicated of the depolymerization, demethoxylation, and bond cleavage of linkages occurred during the depolymerization process. Results showed that the depolymerization temperature instead of the addition of capping reagents was the main factor for improving the reactivity of lignin under the given conditions. The Mannich reaction was very selective, primarily occurred at H 3,5 and G 5 positions, and the H units present a higher chemical reactivity. It is believed that the understanding of the fundamental chemistry of lignin during depolymerization and Mannich reaction process will contribute to the extension of high value-added applications of biorefinery lignin., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Fibroblast growth factor (FGF) 1 is known to be released in response to cellular stress conditions through formation of a multi-protein complex with synaptotagmin 1 and S100A13. In this study, we characterized the denaturant-induced unfolding of synaptotagmin 1, C2A domain in a residue-specific manner by NMR spectroscopy. The amide protons of 30 residues distributed throughout the 3D structure of the whole protein could be followed in a series of (1)H-(15)N HSQC spectra recorded from 0 to 8 M urea under equilibrium conditions. The midpoint for the urea-induced unfolding obtained from NMR coincides with those obtained from steady state fluorescence and CD spectroscopy, revealing that the protein unfolds via a two-state mechanism without accumulating stable intermediates. The thermodynamic parameter obtained from the denaturation curve illustrates the cooperative unfolding of the C2A domain. The implications of C2A domain folding in relation to the release of FGF-1 from the multi-protein complex were discussed.