Chemical Composition and Antibacterial Potential of Terminalia arjuna (Roxb. ex DC.) Wight Arn. Leaves Essential Oil Against Phytopathogenic Bacteria of Rice and Potato

Abstract

This study aimed to investigate the chemical composition and antibacterial potential of Terminalia arjuna (Roxb. ex DC.) Wight Arn. commonly called Arjun leaves essential oil and its major compound i.e., α-terpineol against phytopathogenic bacteria of rice and potato i.e., Xanthomonas oryzae pv. oryzae, Dickeya zeae and Streptomyces scabies. The essential oil was extracted from the leaves by hydro-distillation method using Clevenger apparatus. The essential oil was characterized by Gas Chromatography-Mass Spectrometry analysis which revealed the presence of 34 compounds having α-terpineol as a major compound. It was isolated from the essential oil by column chromatography and its purity was confirmed by ¹H-NMR and IR studies. Both the essential oil and α-terpineol were tested for antibacterial activity against X. oryzae pv. oryzae, D. zeae and S. scabies using agar disc diffusion method. Arjun leaves essential oil was found ineffective against D. zeae but exhibited minimum inhibitory concentrations (MIC) of 38.5 and 40.0 ppm against X. oryzae pv. oryzae and S. scabies respectively. The major compound i.e., α-terpineol was found more effective than the essential oil against all the three tested bacteria with MIC values of 31.5, 29.5 and 27.0 ppm against X. oryzae pv. oryzae, D. zeae and S. scabies respectively. Hence it can be concluded that α-terpineol, a major compound in Arjun leaves essential oil may be used as a natural eco-friendly antibacterial agent against the above said phytopathogenic bacteria

Keywords:

• Arjun leaves
• Terminalia arjuna
• Essential oil
• α-Terpineol
• Antibacterial activity