Sustainable production of pharmaceutical building blocks from lignocellulosic biomass.

This review provides a unified and critical perspective on the sustainable production of pharmaceutical building blocks from lignocellulosic biomass, bridging advances across hemicellulose and lignin valorization pathways. The classification of lignocellulosic residues and methods for their processing are outlined, and the composition and potential of different types of feedstocks are discussed. Methods for obtaining key building blocks from hemicellulose are examined, with an emphasis on effective technological approaches such as the use of heterogeneous catalysts. The emerging role of lignin as an underutilized aromatic resource is also discussed. Recent progress in the valorization of H-, G-, and S-derived phenolic building blocks is highlighted, demonstrating their potential in the synthesis of active pharmaceutical ingredients, lead compounds, and nanoscale drug delivery systems. Importantly, this review moves beyond conventional summaries by critically comparing biomass-derived and petrochemical routes using green chemistry metrics and by identifying key limitations in current assessment approaches for complex processing chains. Strategies for wastewater treatment are also discussed as an integral component of sustainable pharmaceutical production. By integrating catalytic, synthetic, and sustainability perspectives, this work defines key challenges and opportunities, positioning lignocellulosic biomass as a viable platform for next-generation pharmaceutical manufacturing.