Isolation and Structural Elucidation of Flavan-3-ols and PhenylacIsolation and Structural Elucidation of Flavan-3-ols and Phenylacrylaldehydes from the Leavrylaldehydes from the Leaves of Tapinanthus globiferus (Loranthaceae) a Host Plant on Vitex Doniana

Abstract

Tapinanthus globiferus is a medicinal plant used in traditional medicine in the treatment of inflammation, diabetes, and infections. The secondary metabolites responsible for its effect have not been thoroughly characterized, despite its ethnomedicinal uses. This study aimed to isolate and characterize secondary metabolites from the leaves of T. globiferus on Vitex Doniana. The leaves were extracted with 70% aqueous methanol which was then partitioned with n-hexane, chloroform, ethyl acetate, and n-butanol in the order of increasing polarity to give the respective fractions. The isolation of the bioactive compounds from the ethyl acetate and chloroform fractions was done using chromatographic techniques (TLC, column chromatography, and gel filtration). Structural elucidation of the compounds was achieved through spectroscopic analysis such 1D NMR (1H, 13C, DEPT) and 2D NMR (COSY, HSQC, HMBC). column chromatography of the ethyl acetate fraction led to the isolation of catechin (Y12) and catechin-3-gallate (Y13). The isolation of 4-methoxyphenylacrylaldehyde (Y17) and 3-hydroxy-4-methoxyphenylacrylaldehyde (Y18) from the chloroform fraction, was done using column chromatography. The identification of the compounds was done by comparing spectral data with literature. The isolation of these compounds for the first time from this plant species is reported herein. Notably, Y17 and Y18 are of significant pharmacological interest, often associated with antimicrobial and anti-diabetic activities. The isolation of catechin and its derivatives scientifically justifies the established anti-inflammatory, bacteriostatic, and antioxidant properties and its traditional use. These findings significantly contribute to the phytochemical profile of the plant and identify key markers for future standardization and pharmacological investigation.