Chemical composition of essential oils from the leaves, fruits and roots of Piper sarmentosum Roxb. (Piperaceae) growing wild in Andaman Islands, India was investigated by gas chromatography (GC), gas chromatography mass spectrometry (GC-MS) and 13C-nuclear magnetic resonance spectroscopy (13C-NMR). The phenyl propanoid myristicin was identified as the major compound comprising 83.4% in the leaf oil, 84.2% in the fruit oil and 81.2% in the root oil. The sesquiterpenoid Î²-caryophyllene was present in all the oils, 4.2% in the leaves, 5.7% in the fruits and 4.0% in the roots oil. The major constituent myristicin was isolated and structure was further confirmed by 13C-NMR analysis. The antimicrobial efficacy of myristicin was evaluated by both in vitro and in silico FtsZ inhibition studies. The in vitro assay showed 13.0% FtsZ inhibition by 200-Î¼Î myristicin and the molecular docking simulation supported the activity of myristicin.