Extraction Investigation Chemical Modifications and Antimicrobial Activity of Important Terpenoidal Constituents into Its Bioactive Products Along With Seasonal Variation of Eucalyptus Globulus

Abstract

Eucalyptus globulus, commonly known as blue gum and belonging to the family Myrtaceae, is renowned for its ethnomedicinal and therapeutic significance. This study aimed to investigate the variation in oil content, characterize the essential oil, perform chemical modifications, and evaluate the antimicrobial properties of Eucalyptus globulus grown in the Saharanpur region (Uttar Pradesh) from July 2021 to June 2022. Hydro-distillation methods were employed for the extraction of leaf oil from the Eucalyptus globulus tree. The oil content of Eucalyptus globulus leaves significantly ranged from 0.6% to 1.04% v/w. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis revealed the presence of twenty compounds in the essential oil, with the major components identified as Eucalyptol, and#945;-Terpineol, gammaTerpinene, Alloaromadendrene, Epiglobulol, (-)-Globulol, (-)-Isolongifolene, and Nerolidol. Chemical modifications of the Eucalyptus globulus oil were carried out using acetylation reactions, and the chemically modified terpenoids were characterized using Gas Chromatography-Mass Spectrometry (GC-MS). The essential oil contained significant amounts of Eucalyptol (28.09%), (-)- Globulol (10.66%), and and#945;-terpineol (6.81%) with respective retention times (Rt) of 9.415 min, 13.966 min, and 10.990 min. The chemically modified terpenoids confirmed the presence of monoterpene and sesquiterpene hydrocarbons, including 3-Cyclohexen-1-ol, 1-methyl-4-(1-methylethyl); vii Trans-5-Isopropyl-6,7-epoxy-8-hydroxy-8-met; Gama-eudesmol; and 9HCycloisolongifolene, 8-oxo-, with retention times of 10.451, 13.492, 14.211, and 15.142, respectively. Antibacterial and antifungal activity of the essential oils and chemically modified oil were evaluated against various microbial strains using the paper disc diffusion method. The results demonstrated antimicrobial activity, particularly against Pseudomonas aeruginosa (MTCC 2642) with a zone of inhibition of 11.50mm (20 and#956;L of oil/disc) and Candida albicans with a zone of inhibition of 20 mm (20 and#956;L of oi