Valorization of Pimenta racemosa Essential Oils and Extracts: GC-MS and LC-MS Phytochemical Profiling and Evaluation of Helicobacter pylori Inhibitory Activity

Abstract

<i>Pimenta racemosa</i> is a commonly known spice used in traditional medicine to treat several ailments. In this study, comprehensive phytochemical profiling of the essential oils and methanol extracts of <i>P. racemosa</i> leaves and stems was performed, alongside assessing their potential <i>Helicobacter pylori</i> inhibitory activity in vitro and in silico. The essential oils were chemically profiled via GC-MS. Moreover, the methanol extracts were profiled using HPLC-PDA-ESI-MS/MS. The antibacterial activity of the essential oils and methanol extracts against <i>H. pylori</i> was determined by adopting the micro-well dilution method. GC-MS analysis unveiled the presence of 21 constituents, where eugenol represented the major component (57.84%) and (59.76%) in both leaves and stems of essential oils, respectively. A total of 61 compounds were annotated in both leaves and stems of <i>P. racemosa</i> methanolic extracts displaying richness in phenolic compounds identified as (<i>epi</i>)catechin and (<i>epi</i>)gallocatechin monomers and proanthocyanidins, hydrolyzable tannin derivatives (gallotannins), flavonoids, and phenolic acids. The stem essential oil showed the most promising inhibitory effects on <i>H. pylori,</i> exhibiting an MIC value of 3.9 µg/mL, comparable to clarithromycin with an MIC value of 1.95 µg/mL. Additionally, in silico molecular modeling studies revealed that decanal, eugenol, terpineol, delta-cadinene, and amyl vinyl showed potential inhibitory activity on <i>H. pylori</i> urease as demonstrated by high-fitting scores indicating good binding to the active sites. These findings indicate that <i>P. racemosa</i> comprises valuable phytochemical constituents with promising therapeutic effects, particularly the stem, an economic agro-industrial waste.