Differentiation of Ficus deltoidea varieties and chemical marker determination by UHPLC-TOFMS metabolomics for establishing quality control criteria of this popular Malaysian medicinal herb

Abstract

Background: Ficus deltoidea Jack (Moraceae) is a plant used in Malaysia for various diseases including as a supplement in diabetes management. Morphology distinction of the 7 main varieties (var. angustifolia, var. bilobata, var. deltoidea, var. intermedia, var. kunstleri, var. motleyana and var. trengganuensis) is challenging due to the extreme leaf heterophylly and unclear varietal boundaries, making it difficult for quality control of F. deltoidea products.

Objective: We aimed to compare the phytochemical composition of 7 varieties growing in different conditions at various geographical locations. We also aimed to establish the quality control markers for the authentication of these varieties.

Methods: We applied untargeted UHPLC-TOFMS metabolomics to discriminate 100 leaf samples of F. deltoidea collected from 6 locations in Malaysia. A genetic analysis on 21 leaf samples was also performed to validate the chemotaxonomy differentiation.

Results: The PCA and HCA analysis revealed the existence of 3 chemotypes based on the differentiation in the flavonoid content. The PLS-DA analysis identified 15 glycosylated flavone markers together with 1 furanocoumarin. These markers were always consistent for the respective varieties, regardless of the geographical locations and growing conditions. The chemotaxonomy differentiation was in agreement with the DNA sequencing. In particular, var. bilobata accession which showed divergent morphology was also differentiated by the chemical fingerprints and genotype.

Conclusion: Chemotype differentiation based on the flavonoid fingerprints along with the proposed markers provide a powerful identification tool to complement morphology and genetic analyses for the quality control of raw materials and products from F. deltoidea.

Keywords: Chemical marker; Chemotaxonomy; DNA; Ficus deltoidea; MS metabolomics; Phylogenetic; Quality control.