Antimicrobial Properties of Distichochlamys citrea M.F. Newman Rhizome n-Hexane Extract against Streptococcus pyogenes: Experimental Evidences and Computational Screening

摘要

Distichochlamys citrea, an endemic plant species found only in Vietnam, traditionally known effective for internal inflammation and infection, thus considered as a promising natural antibiotic source. A variety of experimental-computational methodologies were utilised. Gas chromatography-mass spectrometry reveals twenty-one bioactive components (C1-C21) is found in the n-hexan extract. Bioassays indicate its total antibiotic activity of high significance against Streptococcus pyogenes (IZD 14±2.0 mm; MIC value of 156.25 μg.mL~(-1)). Docking simulation predicts C17 (DS -12.9 kcal.mol~(-1); RMSD 1.34A)>C14 (DS -12.3 kcal.mol~(-1); RMSD 1.58A)>C16 (DS -12.0 kcal.mol~(-1); RMSD 1.30 A) as the most effective inhibitors towards S-ribosylhomocysteine lyase structure (UniProtKB: P0C0C7). Quantitative structure-activity relationships suggest all the compounds are predicted with high biocompatibility in reference for oral drug development, and specifiy C1-C21 especially safe for use in vertebrates. The results preliminarily confirm the significant antibiotic activity of Distichochlamys citrea and encourage further in-depth experiments in order to harness its pharmacological potentiality.