Lignins are currently considered promising biomaterials for pharmaceutical industry [1,2]. The main advantages they offer, relate to natural origin, biocompatibility and biodegradability. This is connected to their potential use as both enterosorbents and efficient drug careers. Besides, lignins alone possess antioxidant, antimicrobial, antiviral activities and low cytotoxicity. From the structural point of view, lignins represent oxygenated hetoropolymers with a highly heterogeneous tridimensional cross-linked network of aromatic monomers. This is the main reason of their recalcitrance and low solubility in most solvents. In order to dissolve lignin, the polymeric network must be disassembled, that is usually achieved by harsh chemical action. As a result, the target biopolymer integrity is severely affected and its practical use limited. We present in the current communication our results on the isolation of natural lignins from the wastes of agricultural and forestry production, including common spruce (Picea аbies) bark and de-fated grape (Vítis vinífera) seeds, and their following ozonolytic cleavage leading to new analogues with improved properties. The selected extractive agent and ozonolysis media was a nontoxic deep eutectic solvent (DES) composed of choline chloride and 1,2-propyleneglycol. DESs are considered green solvents and are especially suitable for lignin dissolution due to their high boiling points that makes possible extractions to be efficiently run at elevated temperatures. The lipophilic and low-molecular weight polyphenolic compounds have been extracted with suitable solvents prior to lignin recovery. The pretreated materials have been suspended in the DES and kept at 160oC for 4 hours on continuous stirring. The obtained lignin solution was filtered while hot through a steel course filter in order to separate insoluble polysaccharides and tar. The homogenous solution was used either for unmodified lignin sedimentation or ozonolytic treatment. It was performed on ozone bubbling at 0–5oC for 60 minutes. The resulting polymeric fractions have been investigated by spectral methods (IR and NMR). In particular, heteronuclear HSQC and DOSY experiments allowed to draw important conclusions on structural changes of native lignin after ozonolysis. The partial degradation of polymeric structures has been demonstrated.