In order to expand the variety of sources of plant fodder protein, the study focused on antinutritional substances in feedstuffs from rape and wild cabbage, especially goitrin (5-vinyloxazolidin-2-thione) with pronounced goitrogenic properties. A simpler and more effective method for isolating goitrin was developed: chromatographic separation of glucosinolate hydrolysis products from defatted rape seed flour using an activated silica gel column with diethyl ether as eluent. The structure of goitrin (C₅H₇ONS, mp 50°C) was confirmed by PMR spectroscopy and the PANIC program, with its chemical shifts and spin-spin coupling constants determined. For the covalent immobilization of heparin on a collagen film, p-aminophenethylheparin with additional amino groups was prepared via Finlay et al.'s method. Heparin and modified heparin were immobilized using three methods (carbodiimide, azide, and cyanuryl chloride). Results showed amino group modification significantly enhanced heparin immobilization, and the carbodiimide method yielded the best outcomes.