Most of biorefinery technologies are focused on the utilization of plant polysaccharides into chemicals, whereas lignin, the second most abundant natural polymer, is commonly used as a resource to generate power. This is the first report on flavones-bound lignin obtained by wheat straw (WS) pretreatment under low-frequency ultrasound (US) and hydrodynamic cavitation (HC) in sugar production processing. US and HC procedures carried out in aqueous 0.2–0.4% NaOH solutions and various liquid/biomass ratios strongly decreased the lignin content in the solid fraction by 30–45% and 25%, respectively, compared to non-treated WS. Moreover, НС pretreatment increased (approximately tenfold) the portion of ordered cellulose in residual biomass that could hinder the further enzymatic hydrolysis of WS. By means of sequential HC and US pretreatment the ordered cellulose content in solid fraction significantly decreased, compared to the HC alone. Furthermore, it was demonstrated that, after US pretreatment, hemicelluloses and oligomeric fragments of lignin and ligno-carbohydrate complexes were transferred into the liquid phase. In particular, tricin derivatives were detected in liquid fractions with a concentration of 30–35% on o.v.d. ash free sample, and more than 50 compounds associated with low-molecular-weight lignin fragments. These compounds were tentatively identified using high-resolution mass spectrometry (HR-MS) based fragmentation (sequencing) and a self-made database, showing that 16 out of 50 identified compounds belonged to the fragments of model lignin structural units. Tricin and low molecular weight lignin derivatives may find applications as strong antioxidants (i.e. lipidic systems). These findings proved that waste lignin streams obtained after cavitational processes could be a source of value-added products from WS conversion.

大多数生物精炼技术专注于将植物多糖用于化学物质，而木质素是第二大天然聚合物，通常被用作发电的资源。这是有关在制糖过程中通过低频超声（US）和水力空化（HC）预处理麦草（WS）进行黄酮结合的木质素的首次报道。与未经处理的WS相比，US和HC在0.2-0.4％NaOH水溶液中进行的程序和各种液体/生物质比率分别将固体部分中的木质素含量分别降低了30-45％和25％。此外，НС预处理增加了（约十倍）残余生物量中有序纤维素的比例，这可能会阻碍WS的进一步酶促水解。与单独的HC相比，通过顺序的HC和US预处理，固体部分中的有序纤维素含量显着降低。此外，已经证明，在美国预处理之后，木质素和木质素-碳水化合物复合物的半纤维素和寡聚片段被转移到液相中。尤其是，在不含ovd灰分的样品中，在液体馏分中检测到的Tricin衍生物的浓度为30–35％，还有50多种与低分子量木质素片段相关的化合物。尝试使用基于高分辨率质谱（HR-MS）的片段化（测序）和自制数据库对这些化合物进行了初步鉴定，结果表明，在50种鉴定出的化合物中，有16种属于模型木质素结构单元的片段。Tricin和低分子量木质素衍生物可能会用作强抗氧化剂（即脂质系统）。这些发现证明，空化过程后获得的废木质素流可能是WS转化产生的增值产品的来源。