Taxonomy—Dependent Seed Tocochromanol Composition in the Rutaceae Family: Application of Sustainable Approach for Their Extraction

Several members of the Rutaceae (citrus) family are widely cultivated and processed. Tocopherol (T) synthesis and composition are well-documented, while tocotrienols (T3) in most plant families remain underreported. To amend this, mass screening of Rutaceae species' seed tocochromanols were analysed. Of the 53 analysed species, seed tocochromanols were tocotrienol-dominated in 22 species, including a majority of species Zanthoxyloideae (<i>Choisya</i>, <i>Dictamnus</i>, <i>Melicope</i>, <i>Ptelea</i>, <i>Skimmia</i>, <i>Tetradium</i>, <i>Zanthoxylum</i>) and the Cneoroideae (<i>Cneorum</i>) subfamily. Total tocochromanol content ranged from 0.20-25.98 mg 100 g^-1 dry weight (dw) seeds. The highest tocochromanol content was observed in <i>Murraya paniculata</i>, <i>Ruta graveolens</i> seeds, the highest tocotrienol (T3) content was observed in <i>Skimmia anquetilia</i> and <i>Dictamnus albus</i>-19.80 and 19.70 mg 100 g^-1 dw, respectively. The major tocochromanols in the seeds were γ-T and γ-T3, while others were present in low concentration or absent. Linear discriminant analysis (LDA), principal component analysis (PCA) and non-hierarchal cluster analysis (N-HCA) identified similar tocochromanol content trends in the Rutoideae subfamily species and the <i>Bergera</i> and <i>Murraya</i> genus, while the Zanthoxyloideae subfamily species' seed tocochromanol composition was highly variable. The efficient extractability of tocochromanols using sustainable solvent-ethanol is demonstrating suitability of this approach for daily samples screening and bioactive extraction.