Phenolic Compounds and Capsaicinoids in Three Capsicum annuum Varieties: From Analytical Characterization to In Silico Hypotheses on Biological Activity

The affinity of specific phenolic compounds (PCs) and capsaicinoids (CAPs) present in three Capsicum annuumvarieties (Friariello, Cayenne and Dzuljunska Sipka) to the transient receptorpotential vanilloid member 1 (TRPV1) was investigated by integrating an analytic approach for thesimultaneous extraction and analysis through high-performance liquid chromatography coupledwith ion trap mass spectrometry (HPLC/ITMS) and UV detection (HPLC-UV) of PCs and CAPs andstructural bioinformatics based on the protein modelling and molecular simulations of protein-liganddocking. Overall, a total of 35 compounds were identified in the different samples and CAPs werequantified. The highest content of total polyphenols was recorded in the pungent Dzuljunska Sipkavariety (8.91 +/- 0.05 gGAE/Kg DW) while the lowest was found in the non-pungent variety Friariello(3.58 +/- 0.02 gGAE/Kg DW). Protein modelling generated for the first time a complete model ofthe homotetrameric human TRPV1, and it was used for docking simulations with the compoundsdetected via the analytic approach, as well as with other compounds, as an inhibitor reference. Thesimulations indicate that different capsaicinoids can interact with the receptor, providing details onthe molecular interaction, with similar predicted binding energy values. These results offer newinsights into the interaction of capsaicinoids with TRPV1 and their possible actions.

Automated summary

This study investigated the affinity of specific phenolic compounds and capsaicinoids in three Capsicum annuum varieties with TRPV1. The results showed that different varieties contained different compounds and capsaicinoids could interact with the receptor, providing insights into the molecular interactions.