Identifying anti-HSV compounds from unrelated plants using NMR and LC-MS metabolomic analysis

Plants have been used to treat various ailments and diseases, including viral infections. Often activity is reported after screening plants traditionally used, without identifying the active principles.

This study investigated the use of metabolomics to identify common compound groups or compounds from unrelated plants, but with similar reported biological activity. Plants with anti-viral activities against Herpes Simplex Virus (HSV), Cytomegalovirus (CMV) and Human Immunodeficiency Virus (HIV) were collected and analysed. A few non-active plants, with no reported anti-viral activity were included as control samples.

1H-NMR and LC-MS metabolomic analysis were conducted, to determine the chemical similarity between plants with similar activity using SIMCA and XCMS online.

Plants with anti-HSV, anti-HIV and anti-CMV activity, presented specific clusters, with the non-active samples separating from the active samples. The anti-HSV group presented a clear contribution plot and chlorogenic acid was identified by NMR. LC-MS metabolomic analysis confirmed the NMR results and furthermore identified several chlorogenic acid isomers including the main substructures of chlorogenic acids.

Metabolomic analysis on unrelated plants with similar activity can be used to identify the active compound groups or compounds, thereby eliminating the need for screening of plants to determine biological activity, additionally providing information on possible active principles. The two analytical methods identified chlorogenic acids and its building blocks as common and important compounds within plants with anti-HSV activity. Intensified research on plants containing chlorogenic acids should be the focus of future research for development of accessible anti-HSV treatments.