7.

Chemical Composition and Bioactivity of the Essential Oil of Chromolaena odorata from Nigeria

Moses S. Owolabi, Akintayo Ogundajo,  Kamil O. Yusuf, Labunmi Lajide, Heather E. Villanueva, Jessika A. Tuten, and William N. Setzer

Department of Chemistry, Lagos State University, P.M.B. 001, Ojo, Lagos, Nigeria

Department of Chemistry, Federal University of Technology, Akure, Ondo State, Nigeria

Department of Chemistry, University of Alabama in Huntsville, Huntsville, AL 35899, USA

Department of Biological Sciences, University of Alabama in Huntsville, Huntsville, AL 35899, USA

Abstract: The essential oil from the dried leaves of Chromolaena odorata (L.) R.M. King & H. Rob. was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS).  The major components were α-pinene (42.2%), β-pinene (10.6%), germacrene D (9.7%), β-copaen-4α-ol (9.4%), (E)-caryophyllene (5.4%), and geijerene/prejeigerene (7.5%).  The oil was screened for antimicrobial activity and showed antibacterial activity against Bacillus cereus (MIC = 39 μg/mL) and antifungal activity against Aspergillus niger (MIC = 78 μg/mL). DFT (B3LYP/6-31G*) and post-HF (MP2/6-311+G**) indicate that pregeigerene is less stable (0.45 and 3.99 kcal/mol, respectively) than its Cope rearrangement product geigerene.

Keywords: Chromolaena odorata; Eupatorium odoratum; Asteraceae; essential oil; pinene; germacrene D; β-copaen-4α-ol; geijerene; pregeijerene; Cope rearrangement