Abstract

Stumps and knotwood of Norway spruce (Picea abies) are valuable sources of wood extractives. Although lignans from knotwood have already been utilized in value-added products, the behavior and valorization of stump-derived extractives are less studied. In this study, the composition of lipophilic and hydrophilic extractives, particularly lignans, from various spruce stump samples (stump bottom, stump heart, and crushed stump samples) stored outside were studied. Lipophilic and hydrophilic extracts were separated with an accelerated solvent extraction (ASE) apparatus using n-hexane and hot water, respectively. The detailed extractives content of samples was then determined by gas chromatography equipped with a flame ionization detector and a mass detector (GC-FID/MS) and high-performance liquid chromatography (HPLC). In stump bottom samples, an apparent decrease in total dissolved solids was observed in all the major extractives groups during storage: lignans, sugars, stilbene–glucosides, organic acids, resin acids, fatty acids, diterpenoids, and sterols. While a definitive decrease in extractives could not be demonstrated due to the moderately high variation of extractives among different samples, a good indication of the accessibility of important extractives in weathered stumps was obtained. Of the identified hydrophilic extractives, 79% were lignans, 53% of them being composed of 7-hydroxymatairesinol (HMR), 16% conidendric acid, and 12% todolactol. After 12 weeks of storage, the total amount of lignans was 15.3 mg/g of dry matter in stump bottom, 17.0 mg/g of dry matter in stump heart samples, and 10.2 mg/g of dry matter in crushed stump samples.

摘要

挪威云杉 ( Picea abies ) 的树桩和节材是木材提取物的宝贵来源。尽管来自结节木的木脂素已被用于增值产品，但对树桩提取物的行为和价值研究较少。在这项研究中，研究了来自室外储存的各种云杉树桩样品（树桩底部、树桩心和压碎的树桩样品）的亲脂性和亲水性提取物的组成，特别是木脂素。使用n的加速溶剂萃取 (ASE) 装置分离亲脂性和亲水性提取物-分别为己烷和热水。然后通过配备火焰离子化检测器和质谱检测器的气相色谱 (GC-FID/MS) 和高效液相色谱 (HPLC) 测定样品的详细提取物含量。在树桩底部样品中，在储存期间观察到所有主要提取物组的总溶解固体明显减少：木脂素、糖、茋-葡萄糖苷、有机酸、树脂酸、脂肪酸、二萜类化合物和甾醇。虽然由于不同样品中提取物的中等高度差异，无法证明提取物的明确减少，但获得了风化树桩中重要提取物可及性的良好指示。在已鉴定的亲水性提取物中，79% 是木脂素，其中 53% 由 7-羟基马塔伊酚 (HMR) 组成，16% conidendric 酸和 12% todolactol。储存 12 周后，木脂素总量在树桩底部为 15.3 mg/g 干物质，在树桩心脏样本中为 17.0 mg/g 干物质，在压碎的树桩样本中为 10.2 mg/g 干物质。