Phenolic Compound Content of Leaf Extracts from Different Roselle (Hibiscus sabdariffa) Accessions

The leaves of roselle (Hibiscus sabdariffa L.) have been used as a traditional folk medicine that has diuretic and mild laxative effects. Roselle is cultivated in many countries for medicines and food. However, studies on the variation of functional compounds in different accessions are relatively limited. In this study, we investigated the phenolic compound content of leaf extracts from 49 different roselle accessions from a worldwide collection by ultra-high performance liquid chromatography mass spectrometry. The aim was to chemically classify and assess the pharmacological properties of the phenolic compounds in the leaves. The phenolic compounds were identified as neochlorogenic acid, cryptochlorogenic acid, rutin, rutin isomer, isoquercitin, kaempferol-3-O-rutinoside, kaempferol-3-O-glucoside, quercetin, quercetin isomer, and kaempferol. These compounds were present at significantly different levels among the accessions. The most abundant phenolic compound was rutin, which was found in 45 accessions where the total phenolic compound content was 18.75-46.51 mg/g (average 31.52 mg/g). The phenolic compounds were classified into four groups. The two accessions with the highest total phenolic compound content were from Ghana (PI286316) and Senegal (PI275413). The hierarchical cluster analysis of the 49 roselle accessions showed that they formed five groups according to their phenolic compound content. Our results will be useful for the selection of roselle genotypes with improved functional compounds.