Comparative Phytochemical Analysis of the Aerial Parts of Pelargonium radula and Geranium macrorrhizum Cultivated in Bulgaria Using GC-MS and HPLC

<b>Background</b>: <i>Geraniaceae</i> species are widely used in traditional medicine. <i>Pelargonium radula</i> and <i>Geranium macrorrhizum</i> are aromatic medicinal plants traditionally used in Bulgaria for their antimicrobial, anti-inflammatory, and wound-healing properties. Comparative phytochemical data on <i>Pelargonium radula</i> and <i>Geranium macrorrhizum</i> cultivated in Bulgaria, however, remain limited. The present work aimed to characterize and compare the chemical composition of essential oils and main phenols, in support of future pharmacological evaluation. <b>Methods</b>: Essential oils from aerial parts of both species were obtained by hydrodistillation and analyzed by GC-MS. Through HPLC-UV, ethanol extracts were evaluated to quantify the major phenolic acids and flavonoids. <b>Results</b>: The yield of essential oils was 0.10% for <i>P. radula</i> and 0.03% for <i>G. macrorrhizum</i>, dominated by oxidized monoterpenes, mainly citronellol and geraniol-type compounds. HPLC analysis revealed marked differences in their phenolic profiles. <i>P. radula</i> showed a composition with six phenolic acids-primary protocatechuic and ferulic acids, and very low levels of flavonoids, with rutin being the only quantifiable glycoside. In contrast, <i>G. macrorrhizum</i> contained nine phenolic acids and four flavonoids, with remarkably high levels of salicylic, rosmarinic, and <i>p</i>-coumaric acids, as well as catechins, absent in <i>P. radula</i>. <b>Conclusions</b>: The two species showed different phytochemical characteristics in both their volatile and non-volatile fractions. <i>P. radula</i> is characterized by a citronellol/geraniol-rich essential oil and a moderate phenolic profile, while <i>G. macrorrhizum</i> exhibits significantly higher phenolic diversity and abundance. These findings expand the current phytochemical knowledge of both taxa and provide a solid basis for future chemotaxonomic and pharmacological studies. The obtained results suggest that <i>Geranium macrorrhizum</i> may be more promising for antioxidant and anti-inflammatory applications, while <i>Pelargonium radula</i> may be preferentially explored for ant-microbial purposes.