Dihydroisocoumarins and Phenylglycosides from Scorzonera longiana, Their Antimicrobial Activities and Molecular Docking Studies

Abstract

Five new phenyl dihydroisocoumarin glycosides (1 -5) and two known compounds (6 -7) were identified from the butanol fraction of Scorzonera longiana. The structures of 1-7 were elucidated based on spectroscopic methods. Antimicrobial, antitubercular, and antifungal evaluation of compounds 1-7 were carried out using the microdilution method against nine microorganisms. Compound 1 was active only against Mycobacterium smegmatis (Ms) with a MIC value of 14.84 μg/mL. All tested compounds (1 -7) were active against Ms but only compounds 3-7 were active against fungi (C. albicans, S. cerevisiae) with MIC values of 25.0 -125 μg/mL. In addition, molecular docking studies were conducted against Ms DprE1 (PDB ID: 4F4Q), Mycobacterium tuberculosis (Mbt) DprE1 (PDB ID: 6HEZ), and arabinosyltransferase C (EmbC, PDB ID: 7BVE) enzymes. Compounds 2, 5, and 7 are the most effective Ms 4F4Q inhibitors. Compound 4 was the most promising inhibitory activity on Mbt DprE with the lowest binding energy of À 9,9 kcal/mol.