Phytochemical and Nutritional Characterization of <i>Porophyllum linaria</i> : Novel Cyclopropane‐Containing Waxes and Comparative Analysis With <i>P. macrocephalum</i>

(1:1) extract of P. linaria afforded two undescribed long-chain cyclopropyl alcohol waxes, identified as cis-8,9-methylenuntriacontan-5-ol and cis-7,8-methylenuntriacontan-5-ol, whose structures were established by extensive spectroscopic analysis (1D and 2D NMR, HRESIMS) and chemical derivatization. Volatile constituents of both species were characterized, revealing interspecific differences. P. linaria essential oil was dominated by β-myrcene, d-limonene, nonanal, decanal, and (E)-2-dodecenal, whereas P. macrocephalum showed a limonene-rich profile with lower aldehyde content. LC-ESI-MS analysis of infusion extracts demonstrated distinct flavonoid patterns, with avicularin as the major marker of P. linaria and quercetin derivatives predominant in P. macrocephalum. Two validated UHPLC-MS methods were developed for the quantification of avicularin and quercetin in the respective species. Aqueous extracts exhibited antihyperglycemic and radical-scavenging activities. Nutrient analysis revealed their high fiber and mineral content. This study expands the chemical diversity of the genus Porophyllum, reports new cyclopropane-derived wax constituents, and provides analytical markers to support species differentiation and quality control. Chemical diversity of plant wax constituents contributes novel structural motifs to the genus Porophyllum.