Chemical Composition and Structural Traits of Leaf Biomass in Selected Asparagaceae Species

This study presents an integrated chemical and anatomical characterization of leaves from seven Asparagaceae species (Agave convallis Trel., A. salmiana Otto ex Salm.-Dyck, A. striata Zucc., Dasylirion acrotrichum Zucc., Nolina excelsa García-Mend. & E. Solano, Yucca filifera Chabaud, and Y. periculosa Baker). Leaf biomass was subjected to successive Soxhlet extractions to quantify extractives, followed by isolation of lignocellulosic fractions. Lignin and cellulose were analyzed by Fourier-transform infrared (FTIR) spectroscopy to determine the syringyl/guaiacyl (S/G) ratio and total crystallinity index. Leaf anatomy was examined using fluorescence microscopy. Total extractives ranged from 13.4 to 24.0%, with A. salmiana and D. acrotrichum showing the highest values. Lignin content varied markedly among genera, reaching up to 45.1% in Yucca species, whereas cellulose content ranged from 31.3 to 42.2%. Crystalline cellulose accounted for 42.1–56.9% of total cellulose, with the highest crystallinity observed in A. convallis. FTIR analysis revealed a predominance of guaiacyl-type lignin in all species except Y. periculosa (S/G = 1.2). Multivariate analyses discriminated between genera primarily based on lignin, hemicellulose, and cellulose contents. These findings highlight genus-level differences in leaf lignocellulosic composition and support the potential use of Asparagaceae leaves as feedstocks for bioenergy and biomaterial applications.