Significance: Fungus-cultivating termites are icons of ecologically successful herbivores in (sub)tropical ecosystems, cultivating Termitomyces fungi for overcoming the rigid lignin barrier of wood resources. To date, research on these ectosymbiotic fungi has only identified laccases, rather than the typical ligninolytic peroxidases. Using 2D gel-state NMR, we chemically tracked the fate of lignin from the original poplar wood throughout the complex food-processing system in a farming termite. We found young worker termites rapidly depolymerize and degrade even the most recalcitrant wood lignin structures, facilitating polysaccharide cleavage by symbiotic fungi. These results suggest that the natural systems for lignin degradation/pretreatment are far beyond the systems currently recognized and are potential sources of novel ligninolytic agents, enabling more efficient plant cell wall utilization.

Hemin-catalyzed competing routes of [1,2]-Stevens and Sommelet–Hauser rearrangements of benzyl sulfonium ylides through an iron porphyrin carbenoid were established. These rearrangements can be controlled by the electronic property of the substituents on the benzyl group together with solvent effects. Electron-donating or weak electron-withdrawing groups lead to the [1,2]-Stevens rearrangement, whereas strong electron-withdrawing groups at the para-position favor the latter pathway under aqueous conditions.

Natural deep eutectic solvents (NaDESs) are recently developed green solvent alternatives to conventional fossil solvents. The present work systematically screened 22 different NaDESs for the ultrasonic-assisted extraction of bioactive components from Salvia miltiorrhiza (SM), a widely used traditional Chinese medical plant. The suitable solvent and extraction condition were optimized in a two-round screening. In comparison with fossil solvents, NaDESs, especially L-proline-lactic acid (L-Pro-Lac) showed significant advantages in the extraction of salvianolic acid B (SAB), tanshinone IIA (TIIA) and cryptotanshinone (CYT). The optimized yields of the three targeting compounds were 42.05, 1.485 and 0.839 mg/g, respectively. The present method was also applied to the pretreatment of SM samples from different geographic origins. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of NaDES extracts were determined in the study to prove the feasibility of NaDES in bioactive component extraction. The application of NaDESs in the extraction of both hydrophilic and hydrophobic small molecules from SM is proved to be a green and efficient method for pretreatment of herbal materials.