Comparison of Phenolic Compounds and Evaluation of Antioxidant Properties of Porophyllum ruderale (Jacq.) Cass (Asteraceae) from Different Geographical Areas of Queretaro (Mexico)

Abstract

Porophyllum ruderale (P. ruderale) is a well-known Mexican plant from the group of "Quelites", widely consumed plant species used for several food and medicinal purposes. As the production is very heterogeneous and the diverse agroclimatic conditions significantly impact the plant's phytochemical composition, this research aimed to compare the phenolic compound composition and the antioxidant capacity of the P. ruderale plant from three different collection sites (Queretaro, Landa de Matamoros, and Arroyo Seco) in the State of Queretaro (Mexico). Plants collected from Queretaro displayed the lowest total phenolic compounds, flavonoids, and condensed tannins, reflected in a lower antioxidant capacity (DPPH, FRAP, ABTS), compared to the other collection places. Flavones (epicatechin and epigallocatechin gallate) were the most abundant (36.1-195.2 μg equivalents/g) phenolics quantified by HPLC-DAD, while 31 compounds were identified by UHPLC-DAD-QToF/MS-ESI. Most compounds were linked to biological mechanisms related to the antioxidant properties of the leaves. A PCA analysis clustered Landa de Matamoros and Arroyo Seco into two groups based on flavones, hydroxybenzoic acids, the antioxidant capacity (ABTS and DPPH), and total phenolic compounds, the main contributors to its variation. The results indicated contrasting differences in the polyphenolic composition of collected P. ruderale in Queretaro, suggesting the need to standardize and select plants with favorable agroclimatic conditions to obtain desirable polyphenolic compositions while displaying potential health benefits.

Keywords: Porophyllum ruderale; antioxidant capacity; bioactive compounds; phenolic compounds.

Figure 1

Normalized HPLC composition (A) and enrichment metabolic analysis (B) of identified and quantified phenolic compounds in P. ruderale samples from Landa de Matamoros and Arroyo Seco collecting sites. Benz: benzenoids. HPLC composition was normalized using a min-max normalization. For the exact HPLC-DAD values, please refer to Supplementary Table S1.

Figure 2

Bioinformatics analysis of pathways linked to the polyphenolic composition of P. ruderale samples. The figure was generated in the PathwayMap module from https://playmolecule.org (accessed on 21 July 2023). The red and purple lines are an sample indication of matching between a predicted metabolic pathway and its relative association.

Figure 3

Principal components analysis (PCA) of the polyphenolic composition (HPLD-DAD) and the antioxidant capacity of P. ruderale samples from Arroyo Seco and Landa de Matamoros. (A) Participation of each principal component (PC) in the total variation. (B) Scatter and loading plots of the first and the second principal components for all the assessed samples. ABTS: 2,2-azino-bis(e-ethylbenzotiazoline-6-sulfonic acid); CA: caffeic acid; CAT: (+)-catechin; CHA: chlorogenic acid; COU: p-coumaric acid; CT: condensed tannins; DPPH: 2,2-diphenyl-1-picrylhydrazil; EPIC: epicatechin; EPICG: epigallocatechin gallate; FA: ferulic acid; FRAP: ferric reducing antioxidant power; GA: gallic acid; HBA: hydroxybenzoic acid; HPA: hydroxyphenylacetic acid; RUT: rutin; QUE: quercetin; SA: sinapic acid; TF: total flavonoids; TPC: total phenolic compounds.

Figure 4

(1) Climatology and (2) use of soil land and vegetation of the sampled areas from the state of Queretaro (Mexico). A 10 km scale was used to visualize pictures taken from the Mexican National Institute of Statistics and Geography (Spanish acronym: INEGI) [12].