The poster presents research on the essential oil of Artemisia nilagirica leaves. The leaves were subjected to hydrodistillation to extract the essential oil. Testing showed the oil had antibacterial activity against methicillin-resistant Staphylococcus aureus. Chemical analysis identified several compounds in the oil including 3-thujanone, isothujol, and thujone. In silico docking found that β-eudesmol, terpinen-4-ol, and thujone showed affinity for the β-lactamase enzyme, suggesting these compounds contribute to the oil's anti-β-lactamase activity and effectiveness against MRSA.

1. Mode of Presentation:- Poster
Essentialoil of Artemisia nilagirica (Clarke)Pamp leaves: In silico anti- -
lactamase activity
Suraj S.V1 ,Sanjay B.M.1, Drisya K1., Mahesh D.M1., Adarsh Krishna T. P1, Sunil A. R1,
Suresh N Nair1, Ranjith D1., Juliet S1 and Ravindran R.2
1Centre for Ethnopharmacology and Department of Veterinary Pharmacology and Toxicology,
College of Veterinary and Animal Sciences, Kerala Veterinary and Animal Sciences
University, Pookode, Wayanad, Kerala- 673 576.
2 Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Kerala
Veterinary and Animal Sciences University, Pookode, Wayanad, Kerala- 673 576
Artemisia nilagirica (Clarke) Pamp is an aromatic herbaceous perennial plant belonging to
Asteraceae family. In this study the fresh leaves of A. nilagirica were subjected to hydro
distillation for 5 hours (at 60-70OC) using a Clevenger type apparatus and the essential oils
were separated by using a separating funnel. The antibacterial effect of the essential oil was
tested against Methicillin resistant strain of Staphylococcus aureus (MRSA) by using agar disc
diffusion method. The HPTLC profiling of the A. nilagirica (leaves) essential oil was
performed by Camag HPTLC Instrument using TLC plate (60 F254) with Toluene: Ethyl
acetate (93:7 v/v) solvent system and the developed bands were analysed under different wave
lengths, 264nm, 366nm and visible light. Identification of the phytochemicals was done with
single quadruple GCMS and the obtained spectrum was matched for similarity using NIST-11
and Wiley 08 software. The identified compounds were docked with -lactamase (PDB id:
3CG5) and the binding energy, hydrogen bonding and hydrophobic interactions were evaluated
using AutoDock Tools 1.5.6. and ligPlus. The A. nilagirica (leaves) essential oil elicited
antibacterial activity. The predominant compounds identified were 3-thujanone (48.41%),
isothujol (17.7%), thujone (8.88%), germacrene-D (6.41%), α-zingiberene (3.36%), β-
caryophyllene (3.19%) and β-sesquiphellandrene (1.19%), α-pinene (0.84%), terpinen-4-ol
(0.64%) β–eudesmol (0.83%), (R)-lavandulyl acetate (0.96%), β-curcumene (0.58%), and (+)-
4-carene (0.51%). Among these compounds only β -eudesmol, terpinen-4-ol and thujone showed
good affinity for the β lactamase enzyme though the binding energies were little bit high. Many
of the above mentioned compounds are already established to have antibacterial activity. Hence
it can be concluded that the effectiveness of essential oil against MRSA is attributed by the
compounds with anti - lactamase activity.