DNP-enhanced ssNMR has been successfully applied to non-isotope enriched (unlabelled) organic materials and crystalline biological materials to yield informative 2D spectra. It has also enabled 1 H- C heteronuclear correlation (HETCOR) experiments on heterogeneous biomaterials such as bone and maize stems . Here, we obtained 2D spectra of human cartilage samples and gained insight into the structural change in collagen proteins upon pigmentation in AKU.