Department of Chemistry, Federal University of Paraná, P.O. Box 19032, Curitiba, PR 81531-980, Brazil.
Department of Biochemistry and Molecular Biology, Federal University of Paraná, P.O. Box 19046, Curitiba, PR 81531-980, Brazil.
Int J Biol Macromol. 2024 Feb;257(Pt 1):128612. doi: 10.1016/j.ijbiomac.2023.128612. Epub 2023 Dec 7.
Eucalypt kraft lignin isolated in a LignoBoost™ pilot plant was characterized by GC-MS, ICP-OES, DSC, HPSEC, P NMR, and HSQC 2D-NMR to be used without any further processing to produce lignin nanoparticles (LNPs) by nanoprecipitation. Tetrahydrofuran (THF) was used as a solvent, and water as a non-solvent. Microscopic analysis (TEM) showed that LNPs were regularly spherical with some hollow particles dispersed in-between, and sizes were tunable by changing the solvent dripping rate onto the non-solvent. LNP particle sizes had a bimodal distribution, with the largest population having an average apparent hydrodynamic diameter ranging from 105.6 to 75.6 nm. Colloidal dispersions of LNPs in water presented good stability in different dilutions without significant size changes upon storage at pH close to neutral for as long as 45 days. Zeta potentials around -40 mV were obtained for LNP suspensions at pH ranging from 7 to 9. The high carbohydrate content (circa 10 % on a dry basis, mostly xylans) of the lignin precursor did not interfere in LNP formation, whose antioxidant activity was expressive as demonstrated by the ABTS assay at pH 7.4, with an EC of 4.04 μg mL. Also, the Trolox® equivalent antioxidant capacity (TEAC) of LNPs reached 1.90 after 40 min reaction time.
在 LignoBoost™ 中提取的桉木硫酸盐木质素，采用 GC-MS、ICP-OES、DSC、HPSEC、P NMR 和 HSQC 2D-NMR 进行了表征，无需进一步处理即可用于通过纳米沉淀生产木质素纳米颗粒（LNP）。四氢呋喃（THF）用作溶剂，水用作非溶剂。微观分析（TEM）表明，LNP 呈规则的球形，有些中空颗粒分散在其中，通过改变溶剂滴入非溶剂的速率可以调节 LNP 的尺寸。LNP 的粒径呈双峰分布，最大粒径的平均表观水动力直径范围为 105.6 至 75.6nm。在接近中性 pH 值的条件下，LNPs 在水中的胶体分散体在不同稀释度下表现出良好的稳定性，在 45 天的储存过程中没有明显的粒径变化。在 pH 值为 7 至 9 的范围内，LNP 悬浮液的 Zeta 电位约为-40mV。木质素前体的高碳水化合物含量（干重约 10%，主要为木聚糖）不会干扰 LNP 的形成，其抗氧化活性在 pH7.4 的 ABTS 测定中表现出色，EC 为 4.04μg·mL。此外，在 40min 的反应时间后，LNPs 的 Trolox®当量抗氧化能力（TEAC）达到 1.90。
