Effect of drying method on the anticancer activity and metabolite profile of Mango (Mangifera indica) leaf extracts as revealed using LC‐MS/MS metabolomics

Mangifera indica is a widely‐distributed crop with known pharmacological properties. Knowing that sample preparation techniques could affect the chemical composition of natural products, we studied the effect of three common sample preparation methods ‐ airdrying, oven‐drying, and grinding in liquid‐nitrogen– on the compositions and bioactivities of n‐hexane, ethyl‐acetate, and methanol extracts of M. indica. By leveraging the Feature‐Based Molecular Networking (FBMN) of GNPS coupled with feature‐detection of MS‐DIAL, as well as simple orthogonal analyses using TLC and PLS‐DA, we were able to show the variation of several compound superclasses as affected by sample preparation. In general, the addition of thermal energy or long exposure to ambient conditions, significantly reduced the amount of heat‐ and environment‐sensitive compounds such as polyketides and phenylpropanoids, and organoheterocyclic compounds in the ethyl‐acetate and methanol extracts. By utilizing FBMN, we were also able identify structurally‐related compounds in the n‐hexane, ethyl‐acetate, and methanol extracts, providing insights into the chemodiversity of these extracts. In terms of bioactivity, we found that the oven‐ and air‐dried samples exhibited the best percent cytotoxicity against lung cancer cells (A549). This is the first report that utilized FBMN to analyze the effects of sample preparation on a plant extract's metabolomic and bioactivity profiles.